Merge branch 'master' into fix/scanner-size-change-detection-4798

.gitignore

@@ -41,3 +41,6 @@ openspec/
 go.work*
 .worktrees/
 .playwright-mcp/
+
+# Temp benchmark files
+zz_*_test.go

adapters/deezer/deezer.go

@@ -70,16 +70,27 @@ func (s *deezerAgent) GetArtistImages(ctx context.Context, _, name, _ string) ([
 		{artist.PictureSmall, deezerApiPictureSmallSize},
 	}
 	for _, imgData := range possibleImages {
-		if imgData.URL != "" {
+		if imgData.URL != "" && !isPlaceholderPicture(imgData.URL) {
 			res = append(res, agents.ExternalImage{
 				URL:  imgData.URL,
 				Size: imgData.Size,
 			})
 		}
 	}
+	if len(res) == 0 {
+		return nil, agents.ErrNotFound
+	}
 	return res, nil
 }
 
+// deezerEmptyPicturePath is Deezer's empty-image-id path shape for artists with no picture
+// (…/images/artist//1000x1000-…), which serves a generic silhouette on any CDN host.
+const deezerEmptyPicturePath = "/images/artist//"
+
+func isPlaceholderPicture(url string) bool {
+	return strings.Contains(url, deezerEmptyPicturePath)
+}
+
 func (s *deezerAgent) searchArtist(ctx context.Context, name string) (*Artist, error) {
 	artists, err := s.client.searchArtists(ctx, name, deezerArtistSearchLimit)
 	if errors.Is(err, ErrNotFound) || len(artists) == 0 {

adapters/deezer/deezer_test.go

@@ -94,6 +94,54 @@ var _ = Describe("deezerAgent", func() {
 		})
 	})
 
+	Describe("GetArtistImages", func() {
+		var agent *deezerAgent
+		var httpClient *fakeHttpClient
+
+		BeforeEach(func() {
+			httpClient = &fakeHttpClient{}
+			agent = &deezerAgent{
+				dataStore: &tests.MockDataStore{},
+				client:    newClient(httpClient),
+			}
+		})
+
+		It("returns the real images when the artist has a picture", func() {
+			httpClient.mock("https://api.deezer.com/search/artist", http.Response{
+				StatusCode: 200,
+				Body: io.NopCloser(bytes.NewBufferString(`{"data":[
+					{"id":412,"name":"Queen","nb_fan":12744378,
+					 "picture_xl":"https://cdn-images.dzcdn.net/images/artist/abc/1000x1000-000000-80-0-0.jpg",
+					 "picture_big":"https://cdn-images.dzcdn.net/images/artist/abc/500x500-000000-80-0-0.jpg"}
+				],"total":1}`)),
+			})
+
+			images, err := agent.GetArtistImages(ctx, "", "Queen", "")
+
+			Expect(err).ToNot(HaveOccurred())
+			Expect(images).To(HaveLen(2))
+			Expect(images[0].URL).To(ContainSubstring("1000x1000"))
+		})
+
+		It("returns ErrNotFound when the artist only has empty-id placeholder pictures", func() {
+			httpClient.mock("https://api.deezer.com/search/artist", http.Response{
+				StatusCode: 200,
+				Body: io.NopCloser(bytes.NewBufferString(`{"data":[
+					{"id":412,"name":"Queen","nb_fan":12744378,
+					 "picture_xl":"https://cdn-images.dzcdn.net/images/artist//1000x1000-000000-80-0-0.jpg",
+					 "picture_big":"https://cdn-images.dzcdn.net/images/artist//500x500-000000-80-0-0.jpg",
+					 "picture_medium":"https://cdn-images.dzcdn.net/images/artist//250x250-000000-80-0-0.jpg",
+					 "picture_small":"https://cdn-images.dzcdn.net/images/artist//56x56-000000-80-0-0.jpg"}
+				],"total":1}`)),
+			})
+
+			images, err := agent.GetArtistImages(ctx, "", "Queen", "")
+
+			Expect(err).To(MatchError(agents.ErrNotFound))
+			Expect(images).To(BeEmpty())
+		})
+	})
+
 	Describe("GetArtistBiography - Language Fallback", func() {
 		var agent *deezerAgent
 		var httpClient *langAwareHttpClient

adapters/lastfm/agent.go

@@ -93,7 +93,7 @@ func (l *lastfmAgent) GetAlbumInfo(ctx context.Context, name, artist, mbid strin
 	var resp agents.AlbumInfo
 	for _, lang := range l.languages {
 		var err error
-		a, err = l.callAlbumGetInfo(ctx, name, artist, mbid, lang)
+		a, err = l.callAlbumGetInfo(ctx, name, artist, lang)
 		if err != nil {
 			return nil, err
 		}
@@ -114,7 +114,7 @@ func (l *lastfmAgent) GetAlbumInfo(ctx context.Context, name, artist, mbid strin
 }
 
 func (l *lastfmAgent) GetAlbumImages(ctx context.Context, name, artist, mbid string) ([]agents.ExternalImage, error) {
-	a, err := l.callAlbumGetInfo(ctx, name, artist, mbid, l.languages[0])
+	a, err := l.callAlbumGetInfo(ctx, name, artist, l.languages[0])
 	if err != nil {
 		return nil, err
 	}
@@ -286,22 +286,18 @@ func (l *lastfmAgent) GetArtistImages(ctx context.Context, _, name, mbid string)
 	return res, nil
 }
 
-func (l *lastfmAgent) callAlbumGetInfo(ctx context.Context, name, artist, mbid string, lang string) (*Album, error) {
-	a, err := l.client.albumGetInfo(ctx, name, artist, mbid, lang)
-	var lfErr *lastFMError
-	isLastFMError := errors.As(err, &lfErr)
-
-	if mbid != "" && (isLastFMError && lfErr.Code == 6) {
-		log.Debug(ctx, "LastFM/album.getInfo could not find album by mbid, trying again", "album", name, "mbid", mbid)
-		return l.callAlbumGetInfo(ctx, name, artist, "", lang)
-	}
-
+// callAlbumGetInfo matches on name+artist only. Last.fm's album.getInfo by MBID is unreliable —
+// a correct MBID can return a different album (or none) — so the MBID is deliberately not passed.
+func (l *lastfmAgent) callAlbumGetInfo(ctx context.Context, name, artist, lang string) (*Album, error) {
+	a, err := l.client.albumGetInfo(ctx, name, artist, "", lang)
 	if err != nil {
-		if isLastFMError && lfErr.Code == 6 {
-			log.Debug(ctx, "Album not found", "album", name, "mbid", mbid, err)
-		} else {
-			log.Error(ctx, "Error calling LastFM/album.getInfo", "album", name, "mbid", mbid, err)
+		if lfErr, ok := errors.AsType[*lastFMError](err); ok && lfErr.Code == 6 {
+			// A not-found is a definitive absence, not a fault: return the shared sentinel so the
+			// artwork worker's breaker/transient checks don't retry it, and log it at Debug.
+			log.Debug(ctx, "Album not found in Last.fm", "album", name, "artist", artist)
+			return nil, agents.ErrNotFound
 		}
+		log.Error(ctx, "Error calling LastFM/album.getInfo", "album", name, "artist", artist, err)
 		return nil, err
 	}
 	return a, nil
@@ -313,6 +309,12 @@ func (l *lastfmAgent) callArtistGetInfo(ctx context.Context, name string, lang s
 
 	a, err := l.client.artistGetInfo(ctx, name, lang)
 	if err != nil {
+		if lfErr, ok := errors.AsType[*lastFMError](err); ok && lfErr.Code == 6 {
+			// A not-found is a definitive absence, not a fault: return the shared sentinel so it
+			// doesn't trip the artwork worker's breaker, and log at Debug instead of Error.
+			log.Debug(ctx, "Artist not found in Last.fm", "artist", name)
+			return nil, agents.ErrNotFound
+		}
 		log.Error(ctx, "Error calling LastFM/artist.getInfo", "artist", name, err)
 		return nil, err
 	}

adapters/lastfm/agent_test.go

@@ -539,7 +539,10 @@ var _ = Describe("lastfmAgent", func() {
 				URL:         "https://www.last.fm/music/Cher/Believe",
 			}))
 			Expect(httpClient.RequestCount).To(Equal(1))
-			Expect(httpClient.SavedRequest.URL.Query().Get("mbid")).To(Equal("03c91c40-49a6-44a7-90e7-a700edf97a62"))
+			// MBID is deliberately not sent — album.getInfo matches on name+artist only.
+			Expect(httpClient.SavedRequest.URL.Query().Get("mbid")).To(BeEmpty())
+			Expect(httpClient.SavedRequest.URL.Query().Get("album")).To(Equal("Believe"))
+			Expect(httpClient.SavedRequest.URL.Query().Get("artist")).To(Equal("Cher"))
 		})
 
 		It("returns empty images if no images are available", func() {
@@ -558,7 +561,7 @@ var _ = Describe("lastfmAgent", func() {
 			_, err := agent.GetAlbumInfo(ctx, "123", "U2", "mbid-1234")
 			Expect(err).To(HaveOccurred())
 			Expect(httpClient.RequestCount).To(Equal(1))
-			Expect(httpClient.SavedRequest.URL.Query().Get("mbid")).To(Equal("mbid-1234"))
+			Expect(httpClient.SavedRequest.URL.Query().Get("mbid")).To(BeEmpty())
 		})
 
 		It("returns an error if Last.fm call returns an error", func() {
@@ -566,23 +569,17 @@ var _ = Describe("lastfmAgent", func() {
 			_, err := agent.GetAlbumInfo(ctx, "123", "U2", "mbid-1234")
 			Expect(err).To(HaveOccurred())
 			Expect(httpClient.RequestCount).To(Equal(1))
-			Expect(httpClient.SavedRequest.URL.Query().Get("mbid")).To(Equal("mbid-1234"))
+			Expect(httpClient.SavedRequest.URL.Query().Get("mbid")).To(BeEmpty())
 		})
 
-		It("returns an error if Last.fm call returns an error 6 and mbid is empty", func() {
+		It("returns an error when Last.fm returns an error 6 (album not found)", func() {
 			httpClient.Res = http.Response{Body: io.NopCloser(bytes.NewBufferString(lastfmError6)), StatusCode: 200}
-			_, err := agent.GetAlbumInfo(ctx, "123", "U2", "")
+			_, err := agent.GetAlbumInfo(ctx, "123", "U2", "mbid-1234")
 			Expect(err).To(HaveOccurred())
+			// A definitive not-found must satisfy the sentinel, or the artwork worker retries it.
+			Expect(errors.Is(err, agents.ErrNotFound)).To(BeTrue())
 			Expect(httpClient.RequestCount).To(Equal(1))
-		})
-
-		Context("MBID non existent in Last.fm", func() {
-			It("calls again when last.fm returns an error 6", func() {
-				httpClient.Res = http.Response{Body: io.NopCloser(bytes.NewBufferString(lastfmError6)), StatusCode: 200}
-				_, _ = agent.GetAlbumInfo(ctx, "123", "U2", "mbid-1234")
-				Expect(httpClient.RequestCount).To(Equal(2))
-				Expect(httpClient.SavedRequest.URL.Query().Get("mbid")).To(BeEmpty())
-			})
+			Expect(httpClient.SavedRequest.URL.Query().Get("mbid")).To(BeEmpty())
 		})
 	})
 
@@ -613,6 +610,13 @@ var _ = Describe("lastfmAgent", func() {
 			Expect(images[0].URL).To(Equal("https://lastfm.freetls.fastly.net/i/u/ar0/818148bf682d429dc21b59a73ef6f68e.png"))
 		})
 
+		It("maps a Last.fm error 6 (artist not found) to the shared not-found sentinel", func() {
+			apiClient.Res = http.Response{Body: io.NopCloser(bytes.NewBufferString(lastfmError6)), StatusCode: 200}
+			_, err := agent.GetArtistImages(ctx, "123", "Nonexistent Artist", "")
+			// Not a fault: runs of missing artists must not trip the worker's circuit breaker.
+			Expect(errors.Is(err, agents.ErrNotFound)).To(BeTrue())
+		})
+
 		It("returns empty list if image is the ignored default image", func() {
 			fApi, _ := os.Open("tests/fixtures/lastfm.artist.getinfo.json")
 			apiClient.Res = http.Response{Body: fApi, StatusCode: 200}

cmd/pls.go

@@ -12,7 +12,7 @@ import (
 	"strings"
 
 	"github.com/Masterminds/squirrel"
-	"github.com/navidrome/navidrome/core"
+	"github.com/navidrome/navidrome/core/artwork"
 	"github.com/navidrome/navidrome/core/playlists"
 	"github.com/navidrome/navidrome/log"
 	"github.com/navidrome/navidrome/model"
@@ -260,7 +260,7 @@ func runImport(ctx context.Context, files []string) {
 		ctx = request.WithUser(ctx, *user)
 	}
 
-	pls := playlists.NewPlaylists(ds, core.NewImageUploadService())
+	pls := playlists.NewPlaylists(ds, artwork.NewUploader(ds))
 
 	for _, file := range files {
 		absPath, err := filepath.Abs(file)

cmd/root.go

@@ -11,6 +11,7 @@ import (
 	"github.com/go-chi/chi/v5/middleware"
 	"github.com/navidrome/navidrome/conf"
 	"github.com/navidrome/navidrome/consts"
+	"github.com/navidrome/navidrome/core/artwork"
 	"github.com/navidrome/navidrome/db"
 	"github.com/navidrome/navidrome/log"
 	"github.com/navidrome/navidrome/model"
@@ -88,6 +89,9 @@ func runNavidrome(ctx context.Context) {
 	g.Go(startInsightsCollector(ctx))
 	g.Go(scheduleDBAnalyzer(ctx))
 	g.Go(startPluginManager(ctx))
+	artworkWorker := CreateArtworkWorker()
+	g.Go(startArtworkWorker(ctx, artworkWorker))
+	g.Go(scheduleArtworkHousekeeping(ctx, artworkWorker))
 	g.Go(runInitialScan(ctx))
 	if conf.Server.Scanner.Enabled {
 		g.Go(startScanWatcher(ctx))
@@ -344,6 +348,68 @@ func startPlaybackServer(ctx context.Context) func() error {
 	}
 }
 
+// startArtworkWorker starts the background artwork acquisition worker. It always
+// runs; the queue is simply empty until something enqueues work into it.
+func startArtworkWorker(ctx context.Context, worker *artwork.Worker) func() error {
+	return func() error {
+		log.Info(ctx, "Starting artwork worker")
+		return worker.Run(ctx)
+	}
+}
+
+// scheduleArtworkHousekeeping runs the startup fingerprint backfill and registers the
+// recurring stale-absent recheck and prune jobs.
+func scheduleArtworkHousekeeping(ctx context.Context, worker *artwork.Worker) func() error {
+	return func() error {
+		schedulerInstance := scheduler.GetInstance()
+
+		if _, err := schedulerInstance.Add(consts.ArtworkStaleAbsentRecheckSchedule, func() {
+			if err := worker.EnqueueStaleAbsentAll(ctx); err != nil {
+				log.Error(ctx, "Error enqueueing stale artwork rechecks", err)
+			}
+			if err := worker.EnqueueMissingAll(ctx); err != nil {
+				log.Error(ctx, "Error enqueueing missing artwork rechecks", err)
+			}
+		}); err != nil {
+			log.Error(ctx, "Error scheduling artwork stale-absent recheck", err)
+		}
+
+		if _, err := schedulerInstance.Add(consts.ArtworkPruneSchedule, func() {
+			if err := worker.RunPrune(ctx); err != nil {
+				log.Error(ctx, "Error running artwork prune", err)
+			}
+		}); err != nil {
+			log.Error(ctx, "Error scheduling artwork prune", err)
+		}
+
+		// Also run the missing-row recheck once at startup so a never-scanned entity is picked up
+		// immediately, not only on the next hourly tick (e.g. after enabling the feature).
+		if err := worker.EnqueueMissingAll(ctx); err != nil {
+			log.Error(ctx, "Error enqueueing missing artwork rechecks", err)
+		}
+
+		backfilled, err := worker.Backfill(ctx)
+		if err != nil {
+			log.Error(ctx, "Error running artwork backfill", err)
+			return nil
+		}
+		if !backfilled {
+			return nil
+		}
+		log.Info(ctx, "Artwork backfill enqueued, scheduling a follow-up prune")
+		timer := time.NewTimer(consts.ArtworkPostBackfillPruneDelay)
+		defer timer.Stop()
+		select {
+		case <-timer.C:
+			if err := worker.RunPrune(ctx); err != nil {
+				log.Error(ctx, "Error running post-backfill artwork prune", err)
+			}
+		case <-ctx.Done():
+		}
+		return nil
+	}
+}
+
 // startPluginManager starts the plugin manager, if configured.
 func startPluginManager(ctx context.Context) func() error {
 	return func() error {

cmd/scan.go

@@ -9,7 +9,7 @@ import (
 	"os"
 	"strings"
 
-	"github.com/navidrome/navidrome/core"
+	"github.com/navidrome/navidrome/core/artwork"
 	"github.com/navidrome/navidrome/core/playlists"
 	"github.com/navidrome/navidrome/db"
 	"github.com/navidrome/navidrome/log"
@@ -82,7 +82,7 @@ func runScanner(ctx context.Context) {
 	sqlDB := db.Db()
 	defer db.Db().Close()
 	ds := persistence.New(sqlDB)
-	pls := playlists.NewPlaylists(ds, core.NewImageUploadService())
+	pls := playlists.NewPlaylists(ds, artwork.NewUploader(ds))
 
 	// Parse targets from command line or file
 	var scanTargets []model.ScanTarget

cmd/wire_gen.go

@@ -65,25 +65,18 @@ func CreateNativeAPIRouter(ctx context.Context) *nativeapi.Router {
 	sqlDB := db.Db()
 	dataStore := persistence.New(sqlDB)
 	share := core.NewShare(dataStore)
-	imageUploadService := core.NewImageUploadService()
-	playlistsPlaylists := playlists.NewPlaylists(dataStore, imageUploadService)
+	uploader := artwork.NewUploader(dataStore)
+	playlistsPlaylists := playlists.NewPlaylists(dataStore, uploader)
 	insights := metrics.GetInstance(dataStore)
-	fileCache := artwork.GetImageCache()
-	fFmpeg := ffmpeg.New()
 	broker := events.GetBroker()
 	metricsMetrics := metrics.GetPrometheusInstance(dataStore)
-	manager := plugins.GetManager(dataStore, broker, metricsMetrics)
-	agentsAgents := agents.GetAgents(dataStore, manager)
-	matcherMatcher := matcher.New(dataStore)
-	provider := external.NewProvider(dataStore, agentsAgents, matcherMatcher)
-	artworkArtwork := artwork.NewArtwork(dataStore, fileCache, fFmpeg, provider)
-	cacheWarmer := artwork.NewCacheWarmer(artworkArtwork, fileCache)
-	modelScanner := scanner.New(ctx, dataStore, cacheWarmer, broker, playlistsPlaylists, metricsMetrics)
+	modelScanner := scanner.New(ctx, dataStore, broker, playlistsPlaylists, metricsMetrics)
 	watcher := scanner.GetWatcher(dataStore, modelScanner)
+	manager := plugins.GetManager(dataStore, broker, metricsMetrics)
 	library := core.NewLibrary(dataStore, modelScanner, watcher, broker, manager)
 	user := core.NewUser(dataStore, manager)
 	maintenance := core.NewMaintenance(dataStore)
-	router := nativeapi.New(dataStore, share, playlistsPlaylists, insights, library, user, maintenance, manager, imageUploadService)
+	router := nativeapi.New(dataStore, share, playlistsPlaylists, insights, library, user, maintenance, manager, uploader)
 	return router
 }
 
@@ -91,23 +84,23 @@ func CreateSubsonicAPIRouter(ctx context.Context) *subsonic.Router {
 	sqlDB := db.Db()
 	dataStore := persistence.New(sqlDB)
 	fileCache := artwork.GetImageCache()
+	imageStore := artwork.GetImageStore()
 	fFmpeg := ffmpeg.New()
+	artworkArtwork := artwork.NewArtwork(dataStore, fileCache, imageStore, fFmpeg)
+	transcodingCache := stream.GetTranscodingCache()
+	mediaStreamer := stream.NewMediaStreamer(dataStore, fFmpeg, transcodingCache)
+	share := core.NewShare(dataStore)
+	archiver := core.NewArchiver(mediaStreamer, dataStore, share)
+	players := core.NewPlayers(dataStore)
 	broker := events.GetBroker()
 	metricsMetrics := metrics.GetPrometheusInstance(dataStore)
 	manager := plugins.GetManager(dataStore, broker, metricsMetrics)
 	agentsAgents := agents.GetAgents(dataStore, manager)
 	matcherMatcher := matcher.New(dataStore)
 	provider := external.NewProvider(dataStore, agentsAgents, matcherMatcher)
-	artworkArtwork := artwork.NewArtwork(dataStore, fileCache, fFmpeg, provider)
-	transcodingCache := stream.GetTranscodingCache()
-	mediaStreamer := stream.NewMediaStreamer(dataStore, fFmpeg, transcodingCache)
-	share := core.NewShare(dataStore)
-	archiver := core.NewArchiver(mediaStreamer, dataStore, share)
-	players := core.NewPlayers(dataStore)
-	cacheWarmer := artwork.NewCacheWarmer(artworkArtwork, fileCache)
-	imageUploadService := core.NewImageUploadService()
-	playlistsPlaylists := playlists.NewPlaylists(dataStore, imageUploadService)
-	modelScanner := scanner.New(ctx, dataStore, cacheWarmer, broker, playlistsPlaylists, metricsMetrics)
+	uploader := artwork.NewUploader(dataStore)
+	playlistsPlaylists := playlists.NewPlaylists(dataStore, uploader)
+	modelScanner := scanner.New(ctx, dataStore, broker, playlistsPlaylists, metricsMetrics)
 	playTracker := scrobbler.GetPlayTracker(dataStore, broker, manager)
 	playbackServer := playback.GetInstance(dataStore)
 	lyricsLyrics := lyrics.NewLyrics(dataStore, manager)
@@ -121,21 +114,22 @@ func CreateJellyfinAPIRouter(ctx context.Context) *jellyfin.Router {
 	sqlDB := db.Db()
 	dataStore := persistence.New(sqlDB)
 	fileCache := artwork.GetImageCache()
+	imageStore := artwork.GetImageStore()
 	fFmpeg := ffmpeg.New()
-	broker := events.GetBroker()
-	metricsMetrics := metrics.GetPrometheusInstance(dataStore)
-	manager := plugins.GetManager(dataStore, broker, metricsMetrics)
-	agentsAgents := agents.GetAgents(dataStore, manager)
-	matcherMatcher := matcher.New(dataStore)
-	provider := external.NewProvider(dataStore, agentsAgents, matcherMatcher)
-	artworkArtwork := artwork.NewArtwork(dataStore, fileCache, fFmpeg, provider)
+	artworkArtwork := artwork.NewArtwork(dataStore, fileCache, imageStore, fFmpeg)
 	transcodingCache := stream.GetTranscodingCache()
 	mediaStreamer := stream.NewMediaStreamer(dataStore, fFmpeg, transcodingCache)
 	transcodeDecider := stream.NewTranscodeDecider(dataStore, fFmpeg)
 	players := core.NewPlayers(dataStore)
+	broker := events.GetBroker()
+	metricsMetrics := metrics.GetPrometheusInstance(dataStore)
+	manager := plugins.GetManager(dataStore, broker, metricsMetrics)
 	playTracker := scrobbler.GetPlayTracker(dataStore, broker, manager)
-	imageUploadService := core.NewImageUploadService()
-	playlistsPlaylists := playlists.NewPlaylists(dataStore, imageUploadService)
+	uploader := artwork.NewUploader(dataStore)
+	playlistsPlaylists := playlists.NewPlaylists(dataStore, uploader)
+	agentsAgents := agents.GetAgents(dataStore, manager)
+	matcherMatcher := matcher.New(dataStore)
+	provider := external.NewProvider(dataStore, agentsAgents, matcherMatcher)
 	sonicSonic := sonic.New(dataStore, manager, matcherMatcher)
 	lyricsLyrics := lyrics.NewLyrics(dataStore, manager)
 	router := jellyfin.New(dataStore, artworkArtwork, mediaStreamer, transcodeDecider, players, playTracker, playlistsPlaylists, provider, sonicSonic, lyricsLyrics, broker)
@@ -146,14 +140,9 @@ func CreatePublicRouter() *public.Router {
 	sqlDB := db.Db()
 	dataStore := persistence.New(sqlDB)
 	fileCache := artwork.GetImageCache()
+	imageStore := artwork.GetImageStore()
 	fFmpeg := ffmpeg.New()
-	broker := events.GetBroker()
-	metricsMetrics := metrics.GetPrometheusInstance(dataStore)
-	manager := plugins.GetManager(dataStore, broker, metricsMetrics)
-	agentsAgents := agents.GetAgents(dataStore, manager)
-	matcherMatcher := matcher.New(dataStore)
-	provider := external.NewProvider(dataStore, agentsAgents, matcherMatcher)
-	artworkArtwork := artwork.NewArtwork(dataStore, fileCache, fFmpeg, provider)
+	artworkArtwork := artwork.NewArtwork(dataStore, fileCache, imageStore, fFmpeg)
 	transcodingCache := stream.GetTranscodingCache()
 	mediaStreamer := stream.NewMediaStreamer(dataStore, fFmpeg, transcodingCache)
 	share := core.NewShare(dataStore)
@@ -193,38 +182,22 @@ func CreatePrometheus() metrics.Metrics {
 func CreateScanner(ctx context.Context) model.Scanner {
 	sqlDB := db.Db()
 	dataStore := persistence.New(sqlDB)
-	fileCache := artwork.GetImageCache()
-	fFmpeg := ffmpeg.New()
 	broker := events.GetBroker()
+	uploader := artwork.NewUploader(dataStore)
+	playlistsPlaylists := playlists.NewPlaylists(dataStore, uploader)
 	metricsMetrics := metrics.GetPrometheusInstance(dataStore)
-	manager := plugins.GetManager(dataStore, broker, metricsMetrics)
-	agentsAgents := agents.GetAgents(dataStore, manager)
-	matcherMatcher := matcher.New(dataStore)
-	provider := external.NewProvider(dataStore, agentsAgents, matcherMatcher)
-	artworkArtwork := artwork.NewArtwork(dataStore, fileCache, fFmpeg, provider)
-	cacheWarmer := artwork.NewCacheWarmer(artworkArtwork, fileCache)
-	imageUploadService := core.NewImageUploadService()
-	playlistsPlaylists := playlists.NewPlaylists(dataStore, imageUploadService)
-	modelScanner := scanner.New(ctx, dataStore, cacheWarmer, broker, playlistsPlaylists, metricsMetrics)
+	modelScanner := scanner.New(ctx, dataStore, broker, playlistsPlaylists, metricsMetrics)
 	return modelScanner
 }
 
 func CreateScanWatcher(ctx context.Context) scanner.Watcher {
 	sqlDB := db.Db()
 	dataStore := persistence.New(sqlDB)
-	fileCache := artwork.GetImageCache()
-	fFmpeg := ffmpeg.New()
 	broker := events.GetBroker()
+	uploader := artwork.NewUploader(dataStore)
+	playlistsPlaylists := playlists.NewPlaylists(dataStore, uploader)
 	metricsMetrics := metrics.GetPrometheusInstance(dataStore)
-	manager := plugins.GetManager(dataStore, broker, metricsMetrics)
-	agentsAgents := agents.GetAgents(dataStore, manager)
-	matcherMatcher := matcher.New(dataStore)
-	provider := external.NewProvider(dataStore, agentsAgents, matcherMatcher)
-	artworkArtwork := artwork.NewArtwork(dataStore, fileCache, fFmpeg, provider)
-	cacheWarmer := artwork.NewCacheWarmer(artworkArtwork, fileCache)
-	imageUploadService := core.NewImageUploadService()
-	playlistsPlaylists := playlists.NewPlaylists(dataStore, imageUploadService)
-	modelScanner := scanner.New(ctx, dataStore, cacheWarmer, broker, playlistsPlaylists, metricsMetrics)
+	modelScanner := scanner.New(ctx, dataStore, broker, playlistsPlaylists, metricsMetrics)
 	watcher := scanner.GetWatcher(dataStore, modelScanner)
 	return watcher
 }
@@ -236,6 +209,20 @@ func GetPlaybackServer() playback.PlaybackServer {
 	return playbackServer
 }
 
+func CreateArtworkWorker() *artwork.Worker {
+	sqlDB := db.Db()
+	dataStore := persistence.New(sqlDB)
+	imageStore := artwork.GetImageStore()
+	broker := events.GetBroker()
+	metricsMetrics := metrics.GetPrometheusInstance(dataStore)
+	manager := plugins.GetManager(dataStore, broker, metricsMetrics)
+	agentsAgents := agents.GetAgents(dataStore, manager)
+	fFmpeg := ffmpeg.New()
+	fileCache := artwork.GetImageCache()
+	worker := artwork.NewWorker(dataStore, imageStore, agentsAgents, fFmpeg, broker, fileCache)
+	return worker
+}
+
 func getPluginManager() *plugins.Manager {
 	sqlDB := db.Db()
 	dataStore := persistence.New(sqlDB)
@@ -247,7 +234,7 @@ func getPluginManager() *plugins.Manager {
 
 // wire_injectors.go:
 
-var allProviders = wire.NewSet(core.Set, artwork.Set, server.New, subsonic.New, jellyfin.New, nativeapi.New, public.New, persistence.New, lastfm.NewRouter, listenbrainz.NewRouter, events.GetBroker, scanner.New, scanner.GetWatcher, metrics.GetPrometheusInstance, db.Db, plugins.GetManager, sonic.New, wire.Bind(new(agents.PluginLoader), new(*plugins.Manager)), wire.Bind(new(scrobbler.PluginLoader), new(*plugins.Manager)), wire.Bind(new(lyrics.PluginLoader), new(*plugins.Manager)), wire.Bind(new(sonic.PluginLoader), new(*plugins.Manager)), wire.Bind(new(sonic.Engine), new(*sonic.Sonic)), wire.Bind(new(nativeapi.PluginManager), new(*plugins.Manager)), wire.Bind(new(core.PluginUnloader), new(*plugins.Manager)), wire.Bind(new(plugins.PluginMetricsRecorder), new(metrics.Metrics)), wire.Bind(new(core.Watcher), new(scanner.Watcher)))
+var allProviders = wire.NewSet(core.Set, artwork.Set, server.New, subsonic.New, jellyfin.New, nativeapi.New, public.New, persistence.New, lastfm.NewRouter, listenbrainz.NewRouter, events.GetBroker, scanner.New, scanner.GetWatcher, metrics.GetPrometheusInstance, db.Db, plugins.GetManager, sonic.New, wire.Bind(new(agents.PluginLoader), new(*plugins.Manager)), wire.Bind(new(scrobbler.PluginLoader), new(*plugins.Manager)), wire.Bind(new(lyrics.PluginLoader), new(*plugins.Manager)), wire.Bind(new(sonic.PluginLoader), new(*plugins.Manager)), wire.Bind(new(sonic.Engine), new(*sonic.Sonic)), wire.Bind(new(nativeapi.PluginManager), new(*plugins.Manager)), wire.Bind(new(core.PluginUnloader), new(*plugins.Manager)), wire.Bind(new(plugins.PluginMetricsRecorder), new(metrics.Metrics)), wire.Bind(new(core.Watcher), new(scanner.Watcher)), wire.Bind(new(playlists.ImageUploadService), new(artwork.Uploader)))
 
 func GetPluginManager(ctx context.Context) *plugins.Manager {
 	manager := getPluginManager()

cmd/wire_injectors.go

@@ -14,6 +14,7 @@ import (
 	"github.com/navidrome/navidrome/core/lyrics"
 	"github.com/navidrome/navidrome/core/metrics"
 	"github.com/navidrome/navidrome/core/playback"
+	"github.com/navidrome/navidrome/core/playlists"
 	"github.com/navidrome/navidrome/core/scrobbler"
 	"github.com/navidrome/navidrome/core/sonic"
 	"github.com/navidrome/navidrome/db"
@@ -56,6 +57,7 @@ var allProviders = wire.NewSet(
 	wire.Bind(new(core.PluginUnloader), new(*plugins.Manager)),
 	wire.Bind(new(plugins.PluginMetricsRecorder), new(metrics.Metrics)),
 	wire.Bind(new(core.Watcher), new(scanner.Watcher)),
+	wire.Bind(new(playlists.ImageUploadService), new(artwork.Uploader)),
 )
 
 func CreateDataStore() model.DataStore {
@@ -136,6 +138,12 @@ func GetPlaybackServer() playback.PlaybackServer {
 	))
 }
 
+func CreateArtworkWorker() *artwork.Worker {
+	panic(wire.Build(
+		allProviders,
+	))
+}
+
 func getPluginManager() *plugins.Manager {
 	panic(wire.Build(
 		allProviders,

conf/configuration.go

@@ -144,6 +144,8 @@ type configOptions struct {
 	DevArtworkThrottleBacklogLimit    int
 	DevArtworkThrottleBacklogTimeout  time.Duration
 	DevArtworkThrottleBuffered        bool
+	DevArtworkWorkerConcurrency       int
+	DevArtworkExternalMaxRPS          int
 	DevArtistInfoTimeToLive           time.Duration
 	DevAlbumInfoTimeToLive            time.Duration
 	DevExternalScanner                bool
@@ -1071,6 +1073,12 @@ func setViperDefaults() {
 	viper.SetDefault("devartworkthrottlebackloglimit", consts.RequestThrottleBacklogLimit)
 	viper.SetDefault("devartworkthrottlebacklogtimeout", consts.RequestThrottleBacklogTimeout)
 	viper.SetDefault("devartworkthrottlebuffered", true)
+	// Half the CPU count (min 2), so local resolution scales with the host but stays under the
+	// SQLite pool (MaxOpenConns) — leaving connections for the scanner, scrobbles and the UI.
+	viper.SetDefault("devartworkworkerconcurrency", max(2, runtime.NumCPU()/2))
+	// External RPS gates outbound calls to third-party services (per service); it is bounded by
+	// their tolerance, not the host, so it stays a small constant regardless of CPU count.
+	viper.SetDefault("devartworkexternalmaxrps", 2)
 	viper.SetDefault("devartistinfotimetolive", consts.ArtistInfoTimeToLive)
 	viper.SetDefault("devalbuminfotimetolive", consts.AlbumInfoTimeToLive)
 	viper.SetDefault("devexternalscanner", true)

consts/consts.go

@@ -24,6 +24,9 @@ const (
 	LastDBAnalyzeAttemptAtKey     = "LastDBAnalyzeAttemptAt"
 	DBAnalyzePendingKey           = "DBAnalyzePending"
 	DBAnalyzeFailureCountKey      = "DBAnalyzeFailureCount"
+	// ArtConfFingerprintPropertyKey is the model.PropertyRepository key Backfill compares against
+	// to detect artwork-affecting config changes across restarts.
+	ArtConfFingerprintPropertyKey = "ArtConfFingerprint"
 
 	UIAuthorizationHeader  = "X-ND-Authorization"
 	UIClientUniqueIDHeader = "X-ND-Client-Unique-Id"
@@ -36,6 +39,10 @@ const (
 	DBAnalyzeCheckSchedule = "@every 30m"
 	DBAnalyzeMaxAge        = 24 * time.Hour
 
+	ArtworkStaleAbsentRecheckSchedule = "@every 1h"
+	ArtworkPruneSchedule              = "@daily"
+	ArtworkPostBackfillPruneDelay     = 10 * time.Minute
+
 	// DefaultEncryptionKey This is the encryption key used if none is specified in the `PasswordEncryptionKey` option
 	// Never ever change this! Or it will break all Navidrome installations that don't set the config option
 	DefaultEncryptionKey  = "just for obfuscation"
@@ -80,6 +87,9 @@ const (
 	I18nFolder     = "i18n"
 	ScanIgnoreFile = ".ndignore"
 	ArtworkFolder  = "artwork"
+	// HashedArtworkFolder is a subtree of ArtworkFolder, kept apart from the name-addressed
+	// upload folders beside it so Prune's sweep never reaches them.
+	HashedArtworkFolder = "hashed"
 
 	PlaceholderArtistArt            = "artist-placeholder.webp"
 	PlaceholderAlbumArt             = "album-placeholder.webp"

core/agents/agents.go

@@ -124,6 +124,42 @@ func (a *Agents) AgentName() string {
 	return "agents"
 }
 
+// ArtistImageAgent pairs an enabled agent's name with its ArtistImageRetriever capability.
+type ArtistImageAgent struct {
+	Name      string
+	Retriever ArtistImageRetriever
+}
+
+// AlbumImageAgent pairs an enabled agent's name with its AlbumImageRetriever capability.
+type AlbumImageAgent struct {
+	Name      string
+	Retriever AlbumImageRetriever
+}
+
+// ArtistImageAgents returns the enabled agents implementing ArtistImageRetriever,
+// in conf.Server.Agents order (same order the aggregate dispatch uses).
+func (a *Agents) ArtistImageAgents() []ArtistImageAgent {
+	var result []ArtistImageAgent
+	for _, ea := range a.getEnabledAgentNames() {
+		if retriever, ok := a.getAgent(ea).(ArtistImageRetriever); ok {
+			result = append(result, ArtistImageAgent{Name: ea.name, Retriever: retriever})
+		}
+	}
+	return result
+}
+
+// AlbumImageAgents returns the enabled agents implementing AlbumImageRetriever,
+// in conf.Server.Agents order (same order the aggregate dispatch uses).
+func (a *Agents) AlbumImageAgents() []AlbumImageAgent {
+	var result []AlbumImageAgent
+	for _, ea := range a.getEnabledAgentNames() {
+		if retriever, ok := a.getAgent(ea).(AlbumImageRetriever); ok {
+			result = append(result, AlbumImageAgent{Name: ea.name, Retriever: retriever})
+		}
+	}
+	return result
+}
+
 func (a *Agents) GetArtistMBID(ctx context.Context, id string, name string) (string, error) {
 	switch id {
 	case consts.UnknownArtistID:

core/agents/agents_test.go

@@ -362,6 +362,64 @@ var _ = Describe("Agents", func() {
 			})
 		})
 	})
+
+	Describe("Image retriever enumeration", func() {
+		var ag *Agents
+		var artistImg, artistImg2 *testImageAgent
+		var albumImg, albumImg2 *testAlbumImageAgent
+
+		BeforeEach(func() {
+			artistImg = &testImageAgent{Name: "artistImg"}
+			artistImg2 = &testImageAgent{Name: "artistImg2"}
+			albumImg = &testAlbumImageAgent{name: "albumImg"}
+			albumImg2 = &testAlbumImageAgent{name: "albumImg2"}
+			Register("artistImg", func(model.DataStore) Interface { return artistImg })
+			Register("artistImg2", func(model.DataStore) Interface { return artistImg2 })
+			Register("albumImg", func(model.DataStore) Interface { return albumImg })
+			Register("albumImg2", func(model.DataStore) Interface { return albumImg2 })
+			Register("noImages", func(model.DataStore) Interface { return &emptyAgent{} })
+		})
+
+		Describe("ArtistImageAgents", func() {
+			It("returns only ArtistImageRetriever agents, named, in configured order", func() {
+				conf.Server.Agents = "artistImg,noImages,artistImg2"
+				ag = createAgents(ds, nil)
+
+				result := ag.ArtistImageAgents()
+				Expect(result).To(HaveLen(2))
+				Expect(result[0].Name).To(Equal("artistImg"))
+				Expect(result[0].Retriever).To(BeIdenticalTo(artistImg))
+				Expect(result[1].Name).To(Equal("artistImg2"))
+				Expect(result[1].Retriever).To(BeIdenticalTo(artistImg2))
+			})
+
+			It("is empty when external services are disabled", func() {
+				conf.Server.Agents = "" // what disableExternalServices() sets when EnableExternalServices=false
+				ag = createAgents(ds, nil)
+				Expect(ag.ArtistImageAgents()).To(BeEmpty())
+			})
+		})
+
+		Describe("AlbumImageAgents", func() {
+			It("returns only AlbumImageRetriever agents, named, in configured order", func() {
+				conf.Server.Agents = "albumImg,noImages,albumImg2"
+				ag = createAgents(ds, nil)
+
+				result := ag.AlbumImageAgents()
+				Expect(result).To(HaveLen(2))
+				Expect(result[0].Name).To(Equal("albumImg"))
+				Expect(result[0].Retriever).To(BeIdenticalTo(albumImg))
+				Expect(result[1].Name).To(Equal("albumImg2"))
+				Expect(result[1].Retriever).To(BeIdenticalTo(albumImg2))
+			})
+
+			It("is empty when external services are disabled", func() {
+				conf.Server.Agents = "" // what disableExternalServices() sets when EnableExternalServices=false
+				ag = createAgents(ds, nil)
+				Expect(ag.AlbumImageAgents()).To(BeEmpty())
+			})
+		})
+	})
 })
 
 type mockAgent struct {
@@ -497,3 +555,17 @@ func (t *testImageAgent) GetArtistImages(_ context.Context, id, name, mbid strin
 	t.Args = []any{id, name, mbid}
 	return t.Images, t.Err
 }
+
+type testAlbumImageAgent struct {
+	name   string
+	Images []ExternalImage
+	Err    error
+	Args   []any
+}
+
+func (t *testAlbumImageAgent) AgentName() string { return t.name }
+
+func (t *testAlbumImageAgent) GetAlbumImages(_ context.Context, name, artist, mbid string) ([]ExternalImage, error) {
+	t.Args = []any{name, artist, mbid}
+	return t.Images, t.Err
+}

core/artwork/agent_images.go

@@ -0,0 +1,100 @@
+package artwork
+
+import (
+	"context"
+	"io"
+	"net/url"
+
+	"github.com/navidrome/navidrome/conf"
+	"github.com/navidrome/navidrome/consts"
+	"github.com/navidrome/navidrome/core/agents"
+	"github.com/navidrome/navidrome/log"
+	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/utils/str"
+)
+
+// externalName mirrors the normalization the aggregate provider applies, so agent searches match.
+func externalName(name string) string {
+	if conf.Server.DevPreserveUnicodeInExternalCalls {
+		return name
+	}
+	return str.Clear(name)
+}
+
+// bestImageURL returns the largest fetchable image URL. Only one is returned and its failure ends
+// the agent's turn, so an unfetchable candidate must never win: url.Parse alone accepts anything.
+func bestImageURL(imgs []agents.ExternalImage) *url.URL {
+	var best *url.URL
+	var bestSize int
+	for i := range imgs {
+		if imgs[i].URL == "" {
+			continue
+		}
+		u, err := url.Parse(imgs[i].URL)
+		if err != nil || !u.IsAbs() || (u.Scheme != "http" && u.Scheme != "https") || u.Host == "" {
+			continue
+		}
+		if best == nil || imgs[i].Size > bestSize {
+			best, bestSize = u, imgs[i].Size
+		}
+	}
+	return best
+}
+
+// fetchArtistImage tries each enabled artist-image agent in order. extErr is true only when no
+// agent succeeded and at least one failed transiently.
+func fetchArtistImage(ctx context.Context, ag *agents.Agents, gate gateFunc, ar model.Artist) (r io.ReadCloser, agentName string, extErr bool) {
+	// Synthetic artists would otherwise get an unrelated agent result assigned to them.
+	switch ar.ID {
+	case consts.UnknownArtistID, consts.VariousArtistsID:
+		return nil, "", false
+	}
+	name := externalName(ar.Name)
+	for _, a := range ag.ArtistImageAgents() {
+		reader, _, err := gate(a.Name, func() (io.ReadCloser, string, error) {
+			imgs, err := a.Retriever.GetArtistImages(ctx, ar.ID, name, ar.MbzArtistID)
+			if err != nil {
+				return nil, "", err
+			}
+			u := bestImageURL(imgs)
+			if u == nil {
+				return nil, "", agents.ErrNotFound
+			}
+			return fromURL(ctx, u)
+		})
+		if reader != nil {
+			return reader, a.Name, false
+		}
+		if isTransientExternal(err) {
+			extErr = true
+			log.Debug(ctx, "Artwork: External artist-image lookup failed", "agent", a.Name, "artist", ar.Name, err)
+		}
+	}
+	return nil, "", extErr
+}
+
+// fetchAlbumImage is the album counterpart of fetchArtistImage.
+func fetchAlbumImage(ctx context.Context, ag *agents.Agents, gate gateFunc, al model.Album) (r io.ReadCloser, agentName string, extErr bool) {
+	name, artist := externalName(al.Name), externalName(al.AlbumArtist)
+	for _, a := range ag.AlbumImageAgents() {
+		reader, _, err := gate(a.Name, func() (io.ReadCloser, string, error) {
+			imgs, err := a.Retriever.GetAlbumImages(ctx, name, artist, al.MbzAlbumID)
+			if err != nil {
+				return nil, "", err
+			}
+			u := bestImageURL(imgs)
+			if u == nil {
+				return nil, "", agents.ErrNotFound
+			}
+			return fromURL(ctx, u)
+		})
+		if reader != nil {
+			return reader, a.Name, false
+		}
+		if isTransientExternal(err) {
+			extErr = true
+			log.Debug(ctx, "Artwork: External album-image lookup failed", "agent", a.Name, "album", al.Name, err)
+		}
+	}
+	return nil, "", extErr
+}

core/artwork/agent_images_test.go

@@ -0,0 +1,262 @@
+package artwork
+
+import (
+	"context"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"sync"
+
+	"github.com/navidrome/navidrome/conf"
+	"github.com/navidrome/navidrome/conf/configtest"
+	"github.com/navidrome/navidrome/consts"
+	"github.com/navidrome/navidrome/core/agents"
+	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/tests"
+	"github.com/navidrome/navidrome/utils/str"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+// fakeImageAgent is a built-in agent stub implementing both image retrievers; it
+// records call counts so per-agent ordering and short-circuiting can be asserted.
+type fakeImageAgent struct {
+	name          string
+	imgs          []agents.ExternalImage
+	err           error
+	artistCalls   int
+	albumCalls    int
+	gotArtistName string
+	gotAlbumName  string
+	// block, when set, holds every lookup until closed, standing in for a slow/rate-limited agent.
+	block chan struct{}
+	// mu guards the call counters: the worker resolves several items concurrently.
+	mu sync.Mutex
+}
+
+func (f *fakeImageAgent) AgentName() string { return f.name }
+
+func (f *fakeImageAgent) GetArtistImages(_ context.Context, _, name, _ string) ([]agents.ExternalImage, error) {
+	if f.block != nil {
+		<-f.block
+	}
+	f.mu.Lock()
+	f.artistCalls++
+	f.gotArtistName = name
+	f.mu.Unlock()
+	return f.imgs, f.err
+}
+
+func (f *fakeImageAgent) GetAlbumImages(_ context.Context, name, _, _ string) ([]agents.ExternalImage, error) {
+	f.albumCalls++
+	f.gotAlbumName = name
+	return f.imgs, f.err
+}
+
+// imageAgents registers the fakes as built-in agents and enables them in order. The fakes
+// ignore the DataStore, so reusing the process-wide GetAgents singleton across tests is safe.
+func imageAgents(fakes ...*fakeImageAgent) *agents.Agents {
+	names := make([]string, 0, len(fakes))
+	for _, f := range fakes {
+		fake := f
+		agents.Register(fake.name, func(model.DataStore) agents.Interface { return fake })
+		names = append(names, fake.name)
+	}
+	conf.Server.Agents = strings.Join(names, ",")
+	return agents.GetAgents(&tests.MockDataStore{}, nil)
+}
+
+var _ = Describe("agent images", func() {
+	var (
+		ctx context.Context
+		srv *httptest.Server
+	)
+
+	BeforeEach(func() {
+		DeferCleanup(configtest.SetupConfig())
+		ctx = context.Background()
+		srv = httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+			_, _ = w.Write([]byte("image-bytes"))
+		}))
+		DeferCleanup(srv.Close)
+	})
+
+	img := func(path string, size int) agents.ExternalImage {
+		return agents.ExternalImage{URL: srv.URL + path, Size: size}
+	}
+
+	Describe("bestImageURL", func() {
+		It("picks the largest-Size URL and skips empty ones", func() {
+			u := bestImageURL([]agents.ExternalImage{
+				{URL: "http://x/small", Size: 10},
+				{URL: "", Size: 9999},
+				{URL: "http://x/big", Size: 100},
+			})
+			Expect(u).ToNot(BeNil())
+			Expect(u.String()).To(Equal("http://x/big"))
+		})
+
+		It("skips a malformed largest URL and falls back to a valid smaller one", func() {
+			u := bestImageURL([]agents.ExternalImage{
+				{URL: "http://x/valid", Size: 10},
+				{URL: "http://x/%zz", Size: 100}, // invalid percent-escape, largest
+			})
+			Expect(u).ToNot(BeNil())
+			Expect(u.String()).To(Equal("http://x/valid"))
+		})
+
+		It("returns nil when there is no non-empty URL", func() {
+			Expect(bestImageURL(nil)).To(BeNil())
+			Expect(bestImageURL([]agents.ExternalImage{{URL: "", Size: 5}})).To(BeNil())
+		})
+
+		// Plugins hand these over as free-form strings, and url.Parse accepts them all. An
+		// unfetchable candidate that wins here ends the agent's turn before its valid images run.
+		DescribeTable("skips a candidate that cannot be fetched",
+			func(badURL string) {
+				u := bestImageURL([]agents.ExternalImage{
+					{URL: badURL, Size: 100}, // largest, and first
+					{URL: "https://cdn.example.com/ok.jpg", Size: 10},
+				})
+				Expect(u).ToNot(BeNil())
+				Expect(u.String()).To(Equal("https://cdn.example.com/ok.jpg"))
+			},
+			Entry("a relative path", "images/big.jpg"),
+			Entry("a root-relative path", "/images/big.jpg"),
+			Entry("a scheme we cannot fetch", "ftp://host/big.jpg"),
+			Entry("a scheme-relative URL", "//host/big.jpg"),
+			Entry("a URL with no host", "http:///big.jpg"),
+		)
+
+		// Size is often 0 for every candidate, and only a strictly larger one replaces the first,
+		// so an unfetchable entry in first position would otherwise stick.
+		It("skips an unfetchable first candidate when every Size is zero", func() {
+			u := bestImageURL([]agents.ExternalImage{
+				{URL: "images/rel.jpg"},
+				{URL: "https://cdn.example.com/ok.jpg"},
+			})
+			Expect(u).ToNot(BeNil())
+			Expect(u.String()).To(Equal("https://cdn.example.com/ok.jpg"))
+		})
+
+		It("returns nil when no candidate is fetchable", func() {
+			Expect(bestImageURL([]agents.ExternalImage{
+				{URL: "images/a.jpg", Size: 10},
+				{URL: "ftp://host/b.jpg", Size: 20},
+			})).To(BeNil())
+		})
+	})
+
+	Describe("fetchArtistImage", func() {
+		It("returns the first agent's image and its name", func() {
+			a := &fakeImageAgent{name: "agentA", imgs: []agents.ExternalImage{img("/a", 100)}}
+			ag := imageAgents(a)
+
+			r, name, extErr := fetchArtistImage(ctx, ag, passthroughGate, model.Artist{ID: "ar1", Name: "Artist"})
+			Expect(r).ToNot(BeNil())
+			defer r.Close()
+			Expect(name).To(Equal("agentA"))
+			Expect(extErr).To(BeFalse())
+		})
+
+		It("skips the external lookup for synthetic artists", func() {
+			a := &fakeImageAgent{name: "agentA", imgs: []agents.ExternalImage{img("/a", 100)}}
+			ag := imageAgents(a)
+
+			for _, id := range []string{consts.UnknownArtistID, consts.VariousArtistsID} {
+				r, name, extErr := fetchArtistImage(ctx, ag, passthroughGate, model.Artist{ID: id, Name: "Various Artists"})
+				Expect(r).To(BeNil())
+				Expect(name).To(BeEmpty())
+				Expect(extErr).To(BeFalse())
+			}
+			Expect(a.artistCalls).To(Equal(0), "synthetic artists never reach the agents")
+		})
+
+		It("clears typographic characters from the query name unless preserving unicode", func() {
+			conf.Server.DevPreserveUnicodeInExternalCalls = false
+			a := &fakeImageAgent{name: "agentA"}
+			ag := imageAgents(a)
+
+			_, _, _ = fetchArtistImage(ctx, ag, passthroughGate, model.Artist{ID: "ar1", Name: "AC’DC"})
+			Expect(a.gotArtistName).To(Equal(str.Clear("AC’DC")))
+		})
+
+		It("falls through to a later agent, and its success beats the earlier error", func() {
+			a := &fakeImageAgent{name: "agentA", err: errBreakerOpen}
+			b := &fakeImageAgent{name: "agentB", imgs: []agents.ExternalImage{img("/b", 50)}}
+			ag := imageAgents(a, b)
+
+			r, name, extErr := fetchArtistImage(ctx, ag, passthroughGate, model.Artist{ID: "ar1"})
+			Expect(r).ToNot(BeNil())
+			defer r.Close()
+			Expect(name).To(Equal("agentB"))
+			Expect(extErr).To(BeFalse(), "a later hit clears an earlier agent's error")
+			Expect(a.artistCalls).To(Equal(1))
+			Expect(b.artistCalls).To(Equal(1))
+		})
+
+		It("reports a clean miss when every agent finds nothing", func() {
+			a := &fakeImageAgent{name: "agentA"} // no images, no error -> not found
+			b := &fakeImageAgent{name: "agentB", err: agents.ErrNotFound}
+			ag := imageAgents(a, b)
+
+			r, name, extErr := fetchArtistImage(ctx, ag, passthroughGate, model.Artist{ID: "ar1"})
+			Expect(r).To(BeNil())
+			Expect(name).To(BeEmpty())
+			Expect(extErr).To(BeFalse(), "not-found is definitive, never a transient failure")
+		})
+
+		It("reports extErr when one agent fails transiently and the rest find nothing", func() {
+			a := &fakeImageAgent{name: "agentA", err: agents.ErrNotFound}
+			b := &fakeImageAgent{name: "agentB", err: context.DeadlineExceeded}
+			ag := imageAgents(a, b)
+
+			r, _, extErr := fetchArtistImage(ctx, ag, passthroughGate, model.Artist{ID: "ar1"})
+			Expect(r).To(BeNil())
+			Expect(extErr).To(BeTrue())
+		})
+	})
+
+	Describe("fetchAlbumImage", func() {
+		It("returns the winning agent's image and name", func() {
+			a := &fakeImageAgent{name: "agentA", imgs: []agents.ExternalImage{img("/a", 100)}}
+			ag := imageAgents(a)
+
+			r, name, extErr := fetchAlbumImage(ctx, ag, passthroughGate, model.Album{Name: "Album", AlbumArtist: "Artist"})
+			Expect(r).ToNot(BeNil())
+			defer r.Close()
+			Expect(name).To(Equal("agentA"))
+			Expect(extErr).To(BeFalse())
+			Expect(a.albumCalls).To(Equal(1))
+		})
+
+		It("reports extErr when the only agent fails transiently", func() {
+			a := &fakeImageAgent{name: "agentA", err: context.DeadlineExceeded}
+			ag := imageAgents(a)
+
+			r, _, extErr := fetchAlbumImage(ctx, ag, passthroughGate, model.Album{Name: "Album"})
+			Expect(r).To(BeNil())
+			Expect(extErr).To(BeTrue())
+		})
+	})
+
+	Describe("gate naming", func() {
+		It("invokes the gate once per agent, keyed by agent name", func() {
+			a := &fakeImageAgent{name: "agentA", err: context.DeadlineExceeded}
+			b := &fakeImageAgent{name: "agentB", imgs: []agents.ExternalImage{img("/b", 1)}}
+			ag := imageAgents(a, b)
+
+			var gatedNames []string
+			gate := func(name string, f func() (io.ReadCloser, string, error)) (io.ReadCloser, string, error) {
+				gatedNames = append(gatedNames, name)
+				return f()
+			}
+
+			r, _, _ := fetchArtistImage(ctx, ag, gate, model.Artist{ID: "ar1"})
+			Expect(r).ToNot(BeNil())
+			defer r.Close()
+			Expect(gatedNames).To(Equal([]string{"agentA", "agentB"}))
+		})
+	})
+})

core/artwork/artwork.go

@@ -1,134 +1,394 @@
 package artwork
 
 import (
+	"bytes"
 	"context"
 	"errors"
-	_ "image/gif"
+	"fmt"
 	"io"
+	"os"
 	"time"
 
+	"github.com/navidrome/navidrome/conf"
 	"github.com/navidrome/navidrome/consts"
-	"github.com/navidrome/navidrome/core/external"
 	"github.com/navidrome/navidrome/core/ffmpeg"
 	"github.com/navidrome/navidrome/log"
 	"github.com/navidrome/navidrome/model"
 	"github.com/navidrome/navidrome/resources"
 	"github.com/navidrome/navidrome/utils/cache"
-	_ "golang.org/x/image/webp"
 )
 
 var ErrUnavailable = errors.New("artwork unavailable")
 
+// errStaleSource means the backing file's mtime no longer matches RefMtime, so the stored hash may be stale.
+var errStaleSource = errors.New("artwork: source file changed since resolution")
+
+// Image is one servable artwork response.
+type Image struct {
+	io.ReadCloser
+	Hash        string // pixel identity; "" for placeholders
+	ETag        string // representation validator; "" means Hash applies (full-size original)
+	LastUpdated time.Time
+	Placeholder bool
+}
+
+// representationTag varies with dimensions and encode settings, so a config change invalidates
+// a revalidating client's cache even though the pixel hash is unchanged.
+func representationTag(hash string, size int, square bool) string {
+	return fmt.Sprintf("%s.%d.%v.%s", hash, size, square, formatQualityTag())
+}
+
 type Artwork interface {
-	Get(ctx context.Context, artID model.ArtworkID, size int, square bool) (io.ReadCloser, time.Time, error)
-	GetOrPlaceholder(ctx context.Context, id string, size int, square bool) (io.ReadCloser, time.Time, error)
+	// Get returns ErrUnavailable when there is nothing to serve and model.ErrNotFound when
+	// the id resolves to nothing, so the caller can pick placeholder vs 404.
+	Get(ctx context.Context, artID model.ArtworkID, size int, square bool) (*Image, error)
+	// GetOrPlaceholder accepts an artwork token or a raw entity id, falling back to the
+	// kind's placeholder image (never resized, Placeholder=true).
+	GetOrPlaceholder(ctx context.Context, id string, size int, square bool) (*Image, error)
 }
 
-func NewArtwork(ds model.DataStore, cache cache.FileCache, ffmpeg ffmpeg.FFmpeg, provider external.Provider) Artwork {
-	return &artwork{ds: ds, cache: cache, ffmpeg: ffmpeg, provider: provider}
+func NewArtwork(ds model.DataStore, cache cache.FileCache, store *ImageStore, ffm ffmpeg.FFmpeg) Artwork {
+	return &service{ds: ds, cache: cache, store: store, ffmpeg: ffm}
 }
 
-type artwork struct {
-	ds       model.DataStore
-	cache    cache.FileCache
-	ffmpeg   ffmpeg.FFmpeg
-	provider external.Provider
+// entityExists reports whether the entity an artwork id points at is still there: state rows
+// outlive a deleted entity until the next prune, so a servable row is not evidence of its owner.
+func entityExists(ctx context.Context, ds model.DataStore, artID model.ArtworkID) bool {
+	var found bool
+	var err error
+	switch artID.Kind {
+	case model.KindArtistArtwork:
+		found, err = ds.Artist(ctx).Exists(artID.ID)
+	case model.KindAlbumArtwork:
+		found, err = ds.Album(ctx).Exists(artID.ID)
+	case model.KindMediaFileArtwork:
+		found, err = ds.MediaFile(ctx).Exists(artID.ID)
+	case model.KindPlaylistArtwork:
+		found, err = ds.Playlist(ctx).Exists(artID.ID)
+	case model.KindRadioArtwork:
+		found, err = ds.Radio(ctx).Exists(artID.ID)
+	case model.KindDiscArtwork:
+		albumID, _, perr := model.ParseDiscArtworkID(artID.ID)
+		if perr != nil {
+			return false
+		}
+		found, err = ds.Album(ctx).Exists(albumID)
+	default:
+		return false
+	}
+	return err == nil && found
 }
 
-type artworkReader interface {
-	cache.Item
-	LastUpdated() time.Time
-	Reader(ctx context.Context) (io.ReadCloser, string, error)
+type service struct {
+	ds     model.DataStore
+	cache  cache.FileCache
+	store  *ImageStore
+	ffmpeg ffmpeg.FFmpeg
 }
 
-func (a *artwork) GetOrPlaceholder(ctx context.Context, id string, size int, square bool) (reader io.ReadCloser, lastUpdate time.Time, err error) {
-	artID, err := a.getArtworkId(ctx, id)
+func (s *service) GetOrPlaceholder(ctx context.Context, id string, size int, square bool) (*Image, error) {
+	artID, err := s.parseArtworkID(ctx, id)
+	var img *Image
 	if err == nil {
-		reader, lastUpdate, err = a.Get(ctx, artID, size, square)
+		img, err = s.Get(ctx, artID, size, square)
 	}
+	// Only a resolvable entity with no art gets a placeholder; an unknown id must stay
+	// ErrNotFound so callers can still answer 404 / Subsonic error 70.
 	if errors.Is(err, ErrUnavailable) {
-		if artID.Kind == model.KindArtistArtwork {
-			reader, _ = resources.FS().Open(consts.PlaceholderArtistArt)
-		} else {
-			reader, _ = resources.FS().Open(consts.PlaceholderAlbumArt)
-		}
-		return reader, consts.ServerStart, nil
+		return placeholderImage(artID.Kind), nil
 	}
-	return reader, lastUpdate, err
+	return img, err
 }
 
-func (a *artwork) Get(ctx context.Context, artID model.ArtworkID, size int, square bool) (reader io.ReadCloser, lastUpdate time.Time, err error) {
-	artReader, err := a.getArtworkReader(ctx, artID, size, square)
-	if err != nil {
-		return nil, time.Time{}, err
+func (s *service) Get(ctx context.Context, artID model.ArtworkID, size int, square bool) (*Image, error) {
+	if artID.ID == "" {
+		return nil, ErrUnavailable
 	}
-
-	r, err := a.cache.Get(ctx, artReader)
-	if err != nil {
-		if !errors.Is(err, context.Canceled) && !errors.Is(err, ErrUnavailable) {
-			log.Error(ctx, "Error accessing image cache", "id", artID, "size", size, err)
-		}
-		return nil, time.Time{}, err
+	if size < 0 {
+		size = 0 // a negative size means full-size, not a giant (OOM) resize rectangle
+	}
+	switch artID.Kind {
+	case model.KindDiscArtwork:
+		return s.serveDisc(ctx, artID, size, square)
+	case model.KindMediaFileArtwork:
+		return s.serveMediaFile(ctx, artID, size, square)
+	default:
+		return s.serveEntity(ctx, artID, size, square)
 	}
-	return r, artReader.LastUpdated(), nil
 }
 
-type coverArtGetter interface {
+// requestRecheckAge throttles view-triggered rechecks so reopening a genuinely-absent page can't
+// hammer external services; below staleAbsentAge to catch younger absences.
+const requestRecheckAge = time.Hour
+
+func (s *service) serveEntity(ctx context.Context, artID model.ArtworkID, size int, square bool) (*Image, error) {
+	ia, err := s.ds.Artwork(ctx).GetItemArtwork(artID.Kind, artID.ID, model.ImageTypePrimary)
+	switch {
+	case errors.Is(err, model.ErrNotFound):
+		return s.provisional(ctx, artID, size, square)
+	case err != nil:
+		return nil, err
+	case ia.Hash == "":
+		// Inserts an immediately-eligible recheck for a settled absent row.
+		if time.Since(ia.AttemptedAt) > requestRecheckAge {
+			s.enqueue(ctx, artID, model.ArtworkPriorityBump)
+		}
+		return nil, ErrUnavailable
+	default:
+		return s.serveHash(ctx, artID, ia, size, square)
+	}
+}
+
+// serveSource is the one place bytes become an Image. hash is the pixel identity ("" for disc art)
+// and doubles as the full-size validator, so an ETag is only needed when resized or hash is "".
+func (s *service) serveSource(ctx context.Context, key, hash string, lastUpdate time.Time,
+	size int, square bool, open func() (io.ReadCloser, error),
+) (*Image, error) {
+	if size == 0 && !square {
+		rc, err := open()
+		if err != nil {
+			return nil, err
+		}
+		if rc == nil {
+			return nil, ErrUnavailable
+		}
+		img := &Image{ReadCloser: rc, Hash: hash, LastUpdated: lastUpdate}
+		if hash == "" {
+			img.ETag = representationTag(key, size, square)
+		}
+		return img, nil
+	}
+	stream, err := s.cache.Get(ctx, &resizedItem{
+		hash: key, size: size, square: square, ffmpeg: s.ffmpeg, open: open,
+	})
+	if err != nil {
+		return nil, err
+	}
+	return &Image{ReadCloser: stream, Hash: hash, ETag: representationTag(key, size, square), LastUpdated: lastUpdate}, nil
+}
+
+// serveHash serves the bytes of a found state row. A mismatch/open error is dangling, but a
+// cancelled request is not: it must not enqueue a re-resolution.
+func (s *service) serveHash(ctx context.Context, artID model.ArtworkID, ia *model.ItemArtwork, size int, square bool) (*Image, error) {
+	// Only this path can hand back a deleted entity's bytes; the others load their entity anyway.
+	if !entityExists(ctx, s.ds, artID) {
+		return nil, ErrUnavailable
+	}
+	art, err := s.ds.Artwork(ctx).GetImage(ia.Hash)
+	if err != nil {
+		if errors.Is(err, model.ErrNotFound) {
+			return s.dangling(ctx, artID)
+		}
+		return nil, err
+	}
+	img, err := s.serveSource(ctx, ia.Hash, ia.Hash, ia.UpdatedAt, size, square,
+		func() (io.ReadCloser, error) { return openOriginal(ia, art.Mime, s.store) })
+	if err != nil {
+		if errors.Is(err, context.Canceled) {
+			return nil, err
+		}
+		log.Warn(ctx, "Artwork: Could not serve image", "artID", artID, "size", size, err)
+		return s.dangling(ctx, artID)
+	}
+	return img, nil
+}
+
+// openOriginal enforces the mtime invariant: bytes are never served under a hash they no longer match.
+func openOriginal(ia *model.ItemArtwork, mime string, store *ImageStore) (io.ReadCloser, error) {
+	if isFileBacked(ia.Source) {
+		f, err := os.Open(ia.SourcePath)
+		if err != nil {
+			return nil, err
+		}
+		info, err := f.Stat()
+		if err != nil {
+			f.Close()
+			return nil, err
+		}
+		if ia.RefMtime != 0 && info.ModTime().UnixNano() != ia.RefMtime {
+			f.Close()
+			log.Debug("Artwork: Backing file changed since resolution", "path", ia.SourcePath,
+				"hash", ia.Hash, "resolvedMtime", ia.RefMtime, "currentMtime", info.ModTime().UnixNano())
+			return nil, errStaleSource
+		}
+		return f, nil
+	}
+	// Store-backed bytes still carry the source's mtime, to detect edits to embedded art.
+	if ia.SourcePath != "" && ia.RefMtime != 0 {
+		info, err := os.Stat(ia.SourcePath)
+		if err != nil {
+			return nil, err
+		}
+		if info.ModTime().UnixNano() != ia.RefMtime {
+			log.Debug("Artwork: Source file changed since resolution", "path", ia.SourcePath,
+				"hash", ia.Hash, "resolvedMtime", ia.RefMtime, "currentMtime", info.ModTime().UnixNano())
+			return nil, errStaleSource
+		}
+	}
+	return store.Open(ia.Hash, mime)
+}
+
+// provisional serves local bytes for an entity with no state row, enqueuing the worker but
+// never writing a state row itself.
+func (s *service) provisional(ctx context.Context, artID model.ArtworkID, size int, square bool) (*Image, error) {
+	item := model.ArtworkQueueItem{ItemKind: artID.Kind.Prefix(), ItemID: artID.ID, ImageType: model.ImageTypePrimary}
+	res, err := newLocalResolver(s.ds, s.ffmpeg).resolve(ctx, item)
+	if err != nil {
+		return nil, err
+	}
+	s.enqueue(ctx, artID, model.ArtworkPriorityBump)
+	log.Debug(ctx, "Artwork: Provisional read-through, no state row yet", "artID", artID,
+		"source", res.source, "hit", res.reader != nil)
+	return s.serveResolution(ctx, res, size, square)
+}
+
+// serveResolution turns a local resolution's bytes into a servable Image (byte-hash only, no decode).
+func (s *service) serveResolution(ctx context.Context, res resolution, size int, square bool) (*Image, error) {
+	if res.reader == nil {
+		return nil, ErrUnavailable
+	}
+	defer res.reader.Close()
+	data, err := readCapped(res.reader)
+	if err != nil {
+		return nil, ErrUnavailable
+	}
+	hash, err := hashImage(bytes.NewReader(data))
+	if err != nil {
+		return nil, ErrUnavailable
+	}
+	// Keyed by the byte-hash, so the entry lines up with the worker's eventual store entry.
+	return s.serveSource(ctx, hash, hash, unixMtime(res.refMtime), size, square,
+		func() (io.ReadCloser, error) { return io.NopCloser(bytes.NewReader(data)), nil })
+}
+
+func (s *service) serveMediaFile(ctx context.Context, artID model.ArtworkID, size int, square bool) (*Image, error) {
+	// The setting is not in the config fingerprint, so honor it at serve time: a direct mf- URL
+	// must fall back to disc/album instead of serving stale persisted embedded art.
+	if !conf.Server.EnableMediaFileCoverArt {
+		mf, err := s.ds.MediaFile(ctx).Get(artID.ID)
+		if err != nil {
+			return nil, err
+		}
+		return s.Get(ctx, mf.DiscCoverArtID(), size, square)
+	}
+	ia, err := s.ds.Artwork(ctx).GetItemArtwork(model.KindMediaFileArtwork, artID.ID, model.ImageTypePrimary)
+	switch {
+	case err == nil && ia.Hash != "":
+		return s.serveHash(ctx, artID, ia, size, square)
+	case err == nil:
+		// absent row: fall through
+	case errors.Is(err, model.ErrNotFound):
+		// no row: fall through
+	default:
+		return nil, err
+	}
+	noRow := errors.Is(err, model.ErrNotFound)
+
+	mf, err := s.ds.MediaFile(ctx).Get(artID.ID)
+	if err != nil {
+		return nil, err
+	}
+	if noRow && conf.Server.EnableMediaFileCoverArt && mf.HasCoverArt {
+		return s.provisionalEmbedded(ctx, artID, *mf, size, square)
+	}
+	// Mirror MediaFile.CoverArtID: a track defers to its disc art, which falls back to the album.
+	return s.Get(ctx, mf.DiscCoverArtID(), size, square)
+}
+
+// provisionalEmbedded serves a track's embedded art immediately, leaving the state row to the worker.
+func (s *service) provisionalEmbedded(ctx context.Context, artID model.ArtworkID, mf model.MediaFile, size int, square bool) (*Image, error) {
+	lib, err := loadLibraryView(ctx, s.ds, mf.LibraryID)
+	if err != nil {
+		return nil, err
+	}
+	res, ok := resolveEmbedded(ctx, lib, s.ffmpeg, mf.Path)
+	s.enqueue(ctx, artID, model.ArtworkPriorityBump)
+	if !ok {
+		// Eligible but unextractable: fall back the way CoverArtID does, not to a placeholder.
+		return s.Get(ctx, mf.DiscCoverArtID(), size, square)
+	}
+	return s.serveResolution(ctx, res, size, square)
+}
+
+// serveDisc reads disc art through with no state row and no enqueue, falling back to the album cover.
+func (s *service) serveDisc(ctx context.Context, artID model.ArtworkID, size int, square bool) (*Image, error) {
+	dr, err := newDiscArtworkReader(ctx, s.ds, artID)
+	if err != nil {
+		return nil, err
+	}
+	// Single-disc albums run the chain too: a disc can carry art distinct from the album cover.
+	selectImage := func() (io.ReadCloser, string, error) {
+		funcs := dr.fromDiscArtPriority(ctx, s.ffmpeg, conf.Server.DiscArtPriority)
+		return selectImageReader(ctx, artID, funcs...)
+	}
+	albumArtID := model.ArtworkID{Kind: model.KindAlbumArtwork, ID: dr.album.ID}
+	// Disc art has no state row, hence no content hash: keying on id, album mtime and
+	// DiscArtPriority lets a warm cache answer without running the chain or touching the disk.
+	key := fmt.Sprintf("%s|%d|%s", artID.ID, dr.cacheTime().UnixNano(), conf.Server.DiscArtPriority)
+	img, err := s.serveSource(ctx, key, "", dr.cacheTime(), size, square,
+		func() (io.ReadCloser, error) { rc, _, err := selectImage(); return rc, err })
+	if err != nil {
+		if errors.Is(err, context.Canceled) {
+			return nil, err
+		}
+		return s.Get(ctx, albumArtID, size, square)
+	}
+	return img, nil
+}
+
+// dangling enqueues a re-resolution and reports unavailable, leaving the state row untouched.
+func (s *service) dangling(ctx context.Context, artID model.ArtworkID) (*Image, error) {
+	log.Debug(ctx, "Artwork: State row points at bytes we cannot serve, re-resolving", "artID", artID)
+	s.enqueue(ctx, artID, model.ArtworkPriorityScan)
+	return nil, ErrUnavailable
+}
+
+func (s *service) enqueue(ctx context.Context, artID model.ArtworkID, priority int) {
+	err := s.ds.ArtworkQueue(ctx).EnqueuePreservingBackoff(model.ArtworkQueueItem{
+		ItemKind:  artID.Kind.Prefix(),
+		ItemID:    artID.ID,
+		ImageType: model.ImageTypePrimary,
+		Priority:  priority,
+	})
+	if err != nil {
+		log.Warn(ctx, "Artwork: Could not enqueue re-resolution", "artID", artID, err)
+	}
+}
+
+func placeholderImage(kind model.Kind) *Image {
+	path := consts.PlaceholderAlbumArt
+	if kind == model.KindArtistArtwork {
+		path = consts.PlaceholderArtistArt
+	}
+	r, _ := resources.FS().Open(path)
+	return &Image{ReadCloser: r, Placeholder: true}
+}
+
+type coverArtIDGetter interface {
 	CoverArtID() model.ArtworkID
 }
 
-func (a *artwork) getArtworkId(ctx context.Context, id string) (model.ArtworkID, error) {
+// parseArtworkID accepts an artwork token or a raw entity id, resolving the latter to its CoverArtID.
+func (s *service) parseArtworkID(ctx context.Context, id string) (model.ArtworkID, error) {
 	if id == "" {
 		return model.ArtworkID{}, ErrUnavailable
 	}
-	artID, err := model.ParseArtworkID(id)
-	if err == nil {
+	if artID, err := model.ParseArtworkID(id); err == nil {
 		return artID, nil
 	}
-
-	log.Trace(ctx, "ArtworkID invalid. Trying to figure out kind based on the ID", "id", id)
-	entity, err := model.GetEntityByID(ctx, a.ds, id)
+	entity, err := model.GetEntityByID(ctx, s.ds, id)
 	if err != nil {
 		return model.ArtworkID{}, err
 	}
-	if e, ok := entity.(coverArtGetter); ok {
-		artID = e.CoverArtID()
+	if e, ok := entity.(coverArtIDGetter); ok {
+		return e.CoverArtID(), nil
 	}
-	switch e := entity.(type) {
-	case *model.Artist:
-		log.Trace(ctx, "ID is for an Artist", "id", id, "name", e.Name, "artist", e.Name)
-	case *model.Album:
-		log.Trace(ctx, "ID is for an Album", "id", id, "name", e.Name, "artist", e.AlbumArtist)
-	case *model.MediaFile:
-		log.Trace(ctx, "ID is for a MediaFile", "id", id, "title", e.Title, "album", e.Album)
-	case *model.Playlist:
-		log.Trace(ctx, "ID is for a Playlist", "id", id, "name", e.Name)
-	}
-	return artID, nil
+	return model.ArtworkID{}, model.ErrNotFound
 }
 
-func (a *artwork) getArtworkReader(ctx context.Context, artID model.ArtworkID, size int, square bool) (artworkReader, error) {
-	var artReader artworkReader
-	var err error
-	if size > 0 || square {
-		artReader, err = resizedFromOriginal(ctx, a, artID, size, square)
-	} else {
-		switch artID.Kind {
-		case model.KindArtistArtwork:
-			artReader, err = newArtistArtworkReader(ctx, a, artID, a.provider)
-		case model.KindAlbumArtwork:
-			artReader, err = newAlbumArtworkReader(ctx, a, artID, a.provider)
-		case model.KindMediaFileArtwork:
-			artReader, err = newMediafileArtworkReader(ctx, a, artID)
-		case model.KindPlaylistArtwork:
-			artReader, err = newPlaylistArtworkReader(ctx, a, artID)
-		case model.KindDiscArtwork:
-			artReader, err = newDiscArtworkReader(ctx, a, artID)
-		case model.KindRadioArtwork:
-			artReader, err = newRadioArtworkReader(ctx, a, artID)
-		default:
-			return nil, ErrUnavailable
-		}
+func unixMtime(mtime int64) time.Time {
+	if mtime <= 0 {
+		return time.Time{}
 	}
-	return artReader, err
+	return time.Unix(0, mtime) // RefMtime is unix-nanoseconds
 }

core/artwork/artwork_internal_test.go

@@ -1,629 +0,0 @@
-package artwork
-
-import (
-	"context"
-	"errors"
-	"image"
-	"image/jpeg"
-	"image/png"
-	"io"
-	"os"
-	"path/filepath"
-	"time"
-
-	_ "github.com/gen2brain/webp"
-	"github.com/navidrome/navidrome/conf"
-	"github.com/navidrome/navidrome/conf/configtest"
-	"github.com/navidrome/navidrome/log"
-	"github.com/navidrome/navidrome/model"
-	"github.com/navidrome/navidrome/tests"
-	. "github.com/onsi/ginkgo/v2"
-	. "github.com/onsi/gomega"
-)
-
-var _ = Describe("Artwork", func() {
-	var aw *artwork
-	var ds model.DataStore
-	var ffmpeg *tests.MockFFmpeg
-	var folderRepo *fakeFolderRepo
-	ctx := log.NewContext(context.TODO())
-	var alOnlyEmbed, alEmbedNotFound, alOnlyExternal, alExternalNotFound, alMultipleCovers, alSingleDisc model.Album
-	var arMultipleCovers model.Artist
-	var mfWithEmbed, mfAnotherWithEmbed, mfWithoutEmbed, mfCorruptedCover model.MediaFile
-
-	BeforeEach(func() {
-		DeferCleanup(configtest.SetupConfig())
-		conf.Server.ImageCacheSize = "0" // Disable cache
-		conf.Server.CoverArtPriority = "folder.*, cover.*, embedded , front.*"
-
-		folderRepo = &fakeFolderRepo{}
-		libRepo := &tests.MockLibraryRepo{}
-		repoRoot, _ := os.Getwd()
-		libRepo.SetData(model.Libraries{{ID: 0, Path: testFileLibPath(repoRoot)}})
-		ds = &tests.MockDataStore{
-			MockedTranscoding: &tests.MockTranscodingRepo{},
-			MockedFolder:      folderRepo,
-			MockedLibrary:     libRepo,
-		}
-		// Paths use forward slashes because the scanner stores fs.FS-relative paths in the DB.
-		alOnlyEmbed = model.Album{ID: "222", Name: "Only embed", EmbedArtPath: "tests/fixtures/artist/an-album/test.mp3", FolderIDs: []string{"f1"}}
-		alEmbedNotFound = model.Album{ID: "333", Name: "Embed not found", EmbedArtPath: "tests/fixtures/NON_EXISTENT.mp3", FolderIDs: []string{"f1"}}
-		alOnlyExternal = model.Album{ID: "444", Name: "Only external", FolderIDs: []string{"f1"}, Discs: model.Discs{1: "", 2: ""}}
-		alExternalNotFound = model.Album{ID: "555", Name: "External not found", FolderIDs: []string{"f2"}}
-		alSingleDisc = model.Album{ID: "888", Name: "Single disc", FolderIDs: []string{"f1"}, Discs: model.Discs{1: ""}}
-		arMultipleCovers = model.Artist{ID: "777", Name: "All options"}
-		alMultipleCovers = model.Album{
-			ID:            "666",
-			Name:          "All options",
-			EmbedArtPath:  "tests/fixtures/artist/an-album/test.mp3",
-			FolderIDs:     []string{"f1"},
-			AlbumArtistID: "777",
-		}
-		mfWithEmbed = model.MediaFile{ID: "22", Path: "tests/fixtures/test.mp3", HasCoverArt: true, AlbumID: "222"}
-		mfAnotherWithEmbed = model.MediaFile{ID: "23", Path: "tests/fixtures/artist/an-album/test.mp3", HasCoverArt: true, AlbumID: "666"}
-		mfWithoutEmbed = model.MediaFile{ID: "44", Path: "tests/fixtures/test.ogg", AlbumID: "444"}
-		mfCorruptedCover = model.MediaFile{ID: "45", Path: "tests/fixtures/test.ogg", HasCoverArt: true, AlbumID: "444"}
-
-		cache := GetImageCache()
-		ffmpeg = tests.NewMockFFmpeg("content from ffmpeg")
-		aw = NewArtwork(ds, cache, ffmpeg, nil).(*artwork)
-	})
-
-	Describe("albumArtworkReader", func() {
-		Context("ID not found", func() {
-			It("returns ErrNotFound if album is not in the DB", func() {
-				_, err := newAlbumArtworkReader(ctx, aw, model.MustParseArtworkID("al-NOT-FOUND"), nil)
-				Expect(err).To(MatchError(model.ErrNotFound))
-			})
-		})
-		Context("Embed images", func() {
-			BeforeEach(func() {
-				folderRepo.result = nil
-				ds.Album(ctx).(*tests.MockAlbumRepo).SetData(model.Albums{
-					alOnlyEmbed,
-					alEmbedNotFound,
-				})
-			})
-			It("returns embed cover", func() {
-				aw, err := newAlbumArtworkReader(ctx, aw, alOnlyEmbed.CoverArtID(), nil)
-				Expect(err).ToNot(HaveOccurred())
-				_, path, err := aw.Reader(ctx)
-				Expect(err).ToNot(HaveOccurred())
-				Expect(path).To(Equal("tests/fixtures/artist/an-album/test.mp3"))
-			})
-			It("returns ErrUnavailable if embed path is not available", func() {
-				ffmpeg.Error = errors.New("not available")
-				aw, err := newAlbumArtworkReader(ctx, aw, alEmbedNotFound.CoverArtID(), nil)
-				Expect(err).ToNot(HaveOccurred())
-				_, _, err = aw.Reader(ctx)
-				Expect(err).To(MatchError(ErrUnavailable))
-			})
-		})
-		Context("External images", func() {
-			BeforeEach(func() {
-				folderRepo.result = []model.Folder{}
-				ds.Album(ctx).(*tests.MockAlbumRepo).SetData(model.Albums{
-					alOnlyExternal,
-					alExternalNotFound,
-				})
-			})
-			It("returns external cover", func() {
-				folderRepo.result = []model.Folder{{
-					Path:       "tests/fixtures/artist/an-album",
-					ImageFiles: []string{"front.png"},
-				}}
-				aw, err := newAlbumArtworkReader(ctx, aw, alOnlyExternal.CoverArtID(), nil)
-				Expect(err).ToNot(HaveOccurred())
-				_, path, err := aw.Reader(ctx)
-				Expect(err).ToNot(HaveOccurred())
-				Expect(path).To(Equal("tests/fixtures/artist/an-album/front.png"))
-			})
-			It("returns ErrUnavailable if external file is not available", func() {
-				folderRepo.result = []model.Folder{}
-				aw, err := newAlbumArtworkReader(ctx, aw, alExternalNotFound.CoverArtID(), nil)
-				Expect(err).ToNot(HaveOccurred())
-				_, _, err = aw.Reader(ctx)
-				Expect(err).To(MatchError(ErrUnavailable))
-			})
-		})
-		Context("Multiple covers", func() {
-			BeforeEach(func() {
-				folderRepo.result = []model.Folder{{
-					Path:       "tests/fixtures/artist/an-album",
-					ImageFiles: []string{"cover.jpg", "front.png", "artist.png"},
-				}}
-				ds.Album(ctx).(*tests.MockAlbumRepo).SetData(model.Albums{
-					alMultipleCovers,
-				})
-			})
-			DescribeTable("CoverArtPriority",
-				func(priority string, expected string) {
-					conf.Server.CoverArtPriority = priority
-					aw, err := newAlbumArtworkReader(ctx, aw, alMultipleCovers.CoverArtID(), nil)
-					Expect(err).ToNot(HaveOccurred())
-					_, path, err := aw.Reader(ctx)
-					Expect(err).ToNot(HaveOccurred())
-					Expect(path).To(Equal(expected))
-				},
-				Entry(nil, " folder.* , cover.*,embedded,front.*", "tests/fixtures/artist/an-album/cover.jpg"),
-				Entry(nil, "front.* , cover.*, embedded ,folder.*", "tests/fixtures/artist/an-album/front.png"),
-				Entry(nil, " embedded , front.* , cover.*,folder.*", "tests/fixtures/artist/an-album/test.mp3"),
-			)
-		})
-		Context("LastUpdated", func() {
-			// Regression test for #5377: LastUpdated feeds the HTTP Last-Modified header.
-			// It must return max(album.UpdatedAt, ImagesUpdatedAt) so browsers revalidate
-			// cached cover art when only the image file changes.
-			now := time.Now().Truncate(time.Second)
-			DescribeTable("returns the max of album.UpdatedAt and ImagesUpdatedAt",
-				func(albumUpdatedAt, imagesUpdatedAt, expected time.Time) {
-					album := model.Album{ID: "al1", UpdatedAt: albumUpdatedAt}
-					folderRepo.result = []model.Folder{{ImagesUpdatedAt: imagesUpdatedAt}}
-					ds.Album(ctx).(*tests.MockAlbumRepo).SetData(model.Albums{album})
-
-					ar, err := newAlbumArtworkReader(ctx, aw, album.CoverArtID(), nil)
-					Expect(err).ToNot(HaveOccurred())
-					Expect(ar.LastUpdated()).To(Equal(expected))
-				},
-				Entry("album newer than images", now, now.Add(-1*time.Hour), now),
-				Entry("images newer than album", now.Add(-24*time.Hour), now.Add(-1*time.Hour), now.Add(-1*time.Hour)),
-				Entry("equal timestamps", now, now, now),
-			)
-		})
-	})
-	Describe("discArtworkReader", func() {
-		Context("LastUpdated", func() {
-			// Regression test for #5377: same bug as albumArtworkReader — disc covers
-			// must also revalidate when the image file changes, not only when media files do.
-			now := time.Now().Truncate(time.Second)
-			DescribeTable("returns the max of album.UpdatedAt and ImagesUpdatedAt",
-				func(albumUpdatedAt, imagesUpdatedAt, expected time.Time) {
-					album := model.Album{ID: "al1", UpdatedAt: albumUpdatedAt}
-					folderRepo.result = []model.Folder{{ImagesUpdatedAt: imagesUpdatedAt}}
-					ds.Album(ctx).(*tests.MockAlbumRepo).SetData(model.Albums{album})
-					ds.MediaFile(ctx).(*tests.MockMediaFileRepo).SetData(model.MediaFiles{
-						{ID: "mf1", AlbumID: "al1", DiscNumber: 1, Path: "tests/fixtures/test.mp3"},
-					})
-
-					artID := model.NewArtworkID(model.KindDiscArtwork, model.DiscArtworkID("al1", 1), nil)
-					dr, err := newDiscArtworkReader(ctx, aw, artID)
-					Expect(err).ToNot(HaveOccurred())
-					Expect(dr.LastUpdated()).To(Equal(expected))
-				},
-				Entry("album newer than images", now, now.Add(-1*time.Hour), now),
-				Entry("images newer than album", now.Add(-24*time.Hour), now.Add(-1*time.Hour), now.Add(-1*time.Hour)),
-				Entry("equal timestamps", now, now, now),
-			)
-		})
-	})
-	Describe("artistArtworkReader", func() {
-		Context("Multiple covers", func() {
-			BeforeEach(func() {
-				repoRoot, err := os.Getwd()
-				Expect(err).ToNot(HaveOccurred())
-				folderRepo.result = []model.Folder{{
-					ID:          "f1",
-					LibraryPath: testFileLibPath(repoRoot),
-					Path:        "tests/fixtures/artist/an-album",
-					ImageFiles:  []string{"artist.png"},
-				}}
-				ds.Artist(ctx).(*tests.MockArtistRepo).SetData(model.Artists{
-					arMultipleCovers,
-				})
-				ds.Album(ctx).(*tests.MockAlbumRepo).SetData(model.Albums{
-					alMultipleCovers,
-				})
-				ds.MediaFile(ctx).(*tests.MockMediaFileRepo).SetData(model.MediaFiles{
-					mfAnotherWithEmbed,
-				})
-			})
-			DescribeTable("ArtistArtPriority",
-				func(priority string, expected string) {
-					conf.Server.ArtistArtPriority = priority
-					aw, err := newArtistArtworkReader(ctx, aw, arMultipleCovers.CoverArtID(), nil)
-					Expect(err).ToNot(HaveOccurred())
-					_, path, err := aw.Reader(ctx)
-					Expect(err).ToNot(HaveOccurred())
-					Expect(filepath.ToSlash(path)).To(HaveSuffix(expected))
-				},
-				Entry(nil, " folder.* , artist.*,album/artist.*", "tests/fixtures/artist/artist.jpg"),
-				Entry(nil, "album/artist.*, folder.*,artist.*", "tests/fixtures/artist/an-album/artist.png"),
-			)
-		})
-	})
-	Describe("mediafileArtworkReader", func() {
-		Context("ID not found", func() {
-			It("returns ErrNotFound if mediafile is not in the DB", func() {
-				_, err := newMediafileArtworkReader(ctx, aw, model.MustParseArtworkID("mf-NOT-FOUND"))
-				Expect(err).To(MatchError(model.ErrNotFound))
-			})
-		})
-		Context("Embed images", func() {
-			BeforeEach(func() {
-				folderRepo.result = []model.Folder{{
-					Path:       "tests/fixtures/artist/an-album",
-					ImageFiles: []string{"front.png"},
-				}}
-				ds.Album(ctx).(*tests.MockAlbumRepo).SetData(model.Albums{
-					alOnlyEmbed,
-					alOnlyExternal,
-					alSingleDisc,
-				})
-				ds.MediaFile(ctx).(*tests.MockMediaFileRepo).SetData(model.MediaFiles{
-					mfWithEmbed,
-					mfWithoutEmbed,
-					mfCorruptedCover,
-				})
-			})
-			It("returns embed cover", func() {
-				aw, err := newMediafileArtworkReader(ctx, aw, mfWithEmbed.CoverArtID())
-				Expect(err).ToNot(HaveOccurred())
-				_, path, err := aw.Reader(ctx)
-				Expect(err).ToNot(HaveOccurred())
-				Expect(path).To(Equal("tests/fixtures/test.mp3"))
-			})
-			It("returns embed cover if successfully extracted by ffmpeg", func() {
-				aw, err := newMediafileArtworkReader(ctx, aw, mfCorruptedCover.CoverArtID())
-				Expect(err).ToNot(HaveOccurred())
-				r, path, err := aw.Reader(ctx)
-				Expect(err).ToNot(HaveOccurred())
-				data, _ := io.ReadAll(r)
-				Expect(data).ToNot(BeEmpty())
-				Expect(path).To(Equal("tests/fixtures/test.ogg"))
-			})
-			It("returns album cover if cannot read embed artwork", func() {
-				// Force fromTag to fail
-				mfCorruptedCover.Path = "tests/fixtures/DOES_NOT_EXIST.ogg"
-				Expect(ds.MediaFile(ctx).(*tests.MockMediaFileRepo).Put(&mfCorruptedCover)).To(Succeed())
-				// Simulate ffmpeg error
-				ffmpeg.Error = errors.New("not available")
-
-				aw, err := newMediafileArtworkReader(ctx, aw, mfCorruptedCover.CoverArtID())
-				Expect(err).ToNot(HaveOccurred())
-				_, path, err := aw.Reader(ctx)
-				Expect(err).ToNot(HaveOccurred())
-				Expect(path).To(Equal("al-444_0"))
-			})
-			It("returns album cover if media file has no cover art", func() {
-				aw, err := newMediafileArtworkReader(ctx, aw, model.MustParseArtworkID("mf-"+mfWithoutEmbed.ID))
-				Expect(err).ToNot(HaveOccurred())
-				_, path, err := aw.Reader(ctx)
-				Expect(err).ToNot(HaveOccurred())
-				Expect(path).To(Equal("al-444_0"))
-			})
-			It("falls back to disc cover art when media file has a disc number on a multi-disc album", func() {
-				mfWithDisc := model.MediaFile{ID: "46", Path: "tests/fixtures/test.ogg", AlbumID: "444", DiscNumber: 2}
-				Expect(ds.MediaFile(ctx).(*tests.MockMediaFileRepo).Put(&mfWithDisc)).To(Succeed())
-
-				aw, err := newMediafileArtworkReader(ctx, aw, model.MustParseArtworkID("mf-"+mfWithDisc.ID))
-				Expect(err).ToNot(HaveOccurred())
-				_, path, err := aw.Reader(ctx)
-				Expect(err).ToNot(HaveOccurred())
-				// Should fall back to disc art, which itself falls back to album art
-				Expect(path).To(Equal("dc-444:2_0"))
-			})
-			It("falls back to album cover art for single-disc albums even with a disc number", func() {
-				mfOnSingleDisc := model.MediaFile{ID: "47", Path: "tests/fixtures/test.ogg", AlbumID: "888", DiscNumber: 1}
-				Expect(ds.MediaFile(ctx).(*tests.MockMediaFileRepo).Put(&mfOnSingleDisc)).To(Succeed())
-
-				aw, err := newMediafileArtworkReader(ctx, aw, model.MustParseArtworkID("mf-"+mfOnSingleDisc.ID))
-				Expect(err).ToNot(HaveOccurred())
-				_, path, err := aw.Reader(ctx)
-				Expect(err).ToNot(HaveOccurred())
-				// Single-disc album should skip disc art and go straight to album art
-				Expect(path).To(Equal("al-888_0"))
-			})
-		})
-	})
-	Describe("playlistArtworkReader", func() {
-		Describe("findPlaylistSidecarPath", func() {
-			It("discovers sidecar image next to playlist file", func() {
-				tmpDir := GinkgoT().TempDir()
-				plsPath := filepath.Join(tmpDir, "MyPlaylist.m3u")
-				imgPath := filepath.Join(tmpDir, "MyPlaylist.jpg")
-				Expect(os.WriteFile(plsPath, []byte("#EXTM3U\n"), 0600)).To(Succeed())
-				Expect(os.WriteFile(imgPath, []byte("fake image"), 0600)).To(Succeed())
-
-				result := findPlaylistSidecarPath(GinkgoT().Context(), plsPath)
-				Expect(result).To(Equal(imgPath))
-			})
-
-			It("returns empty string when no sidecar image exists", func() {
-				tmpDir := GinkgoT().TempDir()
-				plsPath := filepath.Join(tmpDir, "MyPlaylist.m3u")
-				Expect(os.WriteFile(plsPath, []byte("#EXTM3U\n"), 0600)).To(Succeed())
-
-				result := findPlaylistSidecarPath(GinkgoT().Context(), plsPath)
-				Expect(result).To(BeEmpty())
-			})
-
-			It("returns empty string when playlist has no path", func() {
-				result := findPlaylistSidecarPath(GinkgoT().Context(), "")
-				Expect(result).To(BeEmpty())
-			})
-
-			It("finds sidecar with different case base name", func() {
-				tmpDir := GinkgoT().TempDir()
-				plsPath := filepath.Join(tmpDir, "myplaylist.m3u")
-				imgPath := filepath.Join(tmpDir, "MyPlaylist.jpg")
-				Expect(os.WriteFile(plsPath, []byte("#EXTM3U\n"), 0600)).To(Succeed())
-				Expect(os.WriteFile(imgPath, []byte("fake image"), 0600)).To(Succeed())
-
-				result := findPlaylistSidecarPath(GinkgoT().Context(), plsPath)
-				Expect(result).To(Equal(imgPath))
-			})
-		})
-
-		Describe("fromPlaylistExternalImage", func() {
-			It("opens local path from ExternalImageURL", func() {
-				tmpDir := GinkgoT().TempDir()
-				imgPath := filepath.Join(tmpDir, "cover.jpg")
-				Expect(os.WriteFile(imgPath, []byte("external image data"), 0600)).To(Succeed())
-
-				reader := &playlistArtworkReader{
-					pl: model.Playlist{ExternalImageURL: imgPath},
-				}
-				r, path, err := reader.fromPlaylistExternalImage(ctx)()
-				Expect(err).ToNot(HaveOccurred())
-				Expect(r).ToNot(BeNil())
-				Expect(path).To(Equal(imgPath))
-				data, _ := io.ReadAll(r)
-				Expect(string(data)).To(Equal("external image data"))
-				r.Close()
-			})
-
-			It("returns nil when ExternalImageURL is empty", func() {
-				reader := &playlistArtworkReader{
-					pl: model.Playlist{ExternalImageURL: ""},
-				}
-				r, path, err := reader.fromPlaylistExternalImage(ctx)()
-				Expect(err).ToNot(HaveOccurred())
-				Expect(r).To(BeNil())
-				Expect(path).To(BeEmpty())
-			})
-
-			It("returns error when local file does not exist", func() {
-				reader := &playlistArtworkReader{
-					pl: model.Playlist{ExternalImageURL: "/non/existent/path/cover.jpg"},
-				}
-				r, _, err := reader.fromPlaylistExternalImage(ctx)()
-				Expect(err).To(HaveOccurred())
-				Expect(r).To(BeNil())
-			})
-
-			It("skips HTTP URL when EnableM3UExternalAlbumArt is false", func() {
-				conf.Server.EnableM3UExternalAlbumArt = false
-
-				reader := &playlistArtworkReader{
-					pl: model.Playlist{ExternalImageURL: "https://example.com/cover.jpg"},
-				}
-				r, path, err := reader.fromPlaylistExternalImage(ctx)()
-				Expect(err).ToNot(HaveOccurred())
-				Expect(r).To(BeNil())
-				Expect(path).To(BeEmpty())
-			})
-
-			It("still opens local path when EnableM3UExternalAlbumArt is false", func() {
-				conf.Server.EnableM3UExternalAlbumArt = false
-
-				tmpDir := GinkgoT().TempDir()
-				imgPath := filepath.Join(tmpDir, "cover.jpg")
-				Expect(os.WriteFile(imgPath, []byte("local image"), 0600)).To(Succeed())
-
-				reader := &playlistArtworkReader{
-					pl: model.Playlist{ExternalImageURL: imgPath},
-				}
-				r, path, err := reader.fromPlaylistExternalImage(ctx)()
-				Expect(err).ToNot(HaveOccurred())
-				Expect(r).ToNot(BeNil())
-				Expect(path).To(Equal(imgPath))
-				r.Close()
-			})
-		})
-	})
-
-	Describe("resizedArtworkReader", func() {
-		BeforeEach(func() {
-			folderRepo.result = []model.Folder{{
-				Path:       "tests/fixtures/artist/an-album",
-				ImageFiles: []string{"cover.jpg", "front.png"},
-			}}
-			ds.Album(ctx).(*tests.MockAlbumRepo).SetData(model.Albums{
-				alMultipleCovers,
-			})
-		})
-		When("Square is false", func() {
-			It("returns PNG if original image is a PNG", func() {
-				conf.Server.CoverArtPriority = "front.png"
-				r, _, err := aw.Get(context.Background(), alMultipleCovers.CoverArtID(), 15, false)
-				Expect(err).ToNot(HaveOccurred())
-
-				img, format, err := image.Decode(r)
-				Expect(err).ToNot(HaveOccurred())
-				Expect(format).To(Equal("png"))
-				Expect(img.Bounds().Size().X).To(Equal(15))
-				Expect(img.Bounds().Size().Y).To(Equal(15))
-			})
-			It("returns JPEG if original image is not a PNG", func() {
-				conf.Server.CoverArtPriority = "cover.jpg"
-				r, _, err := aw.Get(context.Background(), alMultipleCovers.CoverArtID(), 200, false)
-				Expect(err).ToNot(HaveOccurred())
-
-				img, format, err := image.Decode(r)
-				Expect(format).To(Equal("jpeg"))
-				Expect(err).ToNot(HaveOccurred())
-				Expect(img.Bounds().Size().X).To(Equal(200))
-				Expect(img.Bounds().Size().Y).To(Equal(200))
-			})
-		})
-		When("When square is true", func() {
-			var alCover model.Album
-
-			DescribeTable("resize",
-				func(srcFormat string, expectedFormat string, landscape bool, size int) {
-					coverFileName := "cover." + srcFormat
-					dirName := createImage(srcFormat, landscape, size)
-					alCover = model.Album{
-						ID:        "444",
-						Name:      "Only external",
-						FolderIDs: []string{"tmp"},
-					}
-					folderRepo.result = []model.Folder{{ImageFiles: []string{coverFileName}}}
-					rootLibRepo := &tests.MockLibraryRepo{}
-					rootLibRepo.SetData(model.Libraries{{ID: 0, Path: testFileLibPath(dirName)}})
-					ds.(*tests.MockDataStore).MockedLibrary = rootLibRepo
-					ds.Album(ctx).(*tests.MockAlbumRepo).SetData(model.Albums{
-						alCover,
-					})
-
-					conf.Server.CoverArtPriority = coverFileName
-					r, _, err := aw.Get(context.Background(), alCover.CoverArtID(), size, true)
-					Expect(err).ToNot(HaveOccurred())
-
-					img, format, err := image.Decode(r)
-					Expect(err).ToNot(HaveOccurred())
-					Expect(format).To(Equal(expectedFormat))
-					Expect(img.Bounds().Size().X).To(Equal(size))
-					Expect(img.Bounds().Size().Y).To(Equal(size))
-				},
-				Entry("portrait png image", "png", "png", false, 200),
-				Entry("landscape png image", "png", "png", true, 200),
-				Entry("portrait jpg image", "jpg", "png", false, 200),
-				Entry("landscape jpg image", "jpg", "png", true, 200),
-			)
-		})
-		When("EnableWebPEncoding is true and square is false", func() {
-			BeforeEach(func() {
-				conf.Server.EnableWebPEncoding = true
-			})
-			It("returns WebP even if original image is a PNG", func() {
-				conf.Server.CoverArtPriority = "front.png"
-				r, _, err := aw.Get(context.Background(), alMultipleCovers.CoverArtID(), 15, false)
-				Expect(err).ToNot(HaveOccurred())
-
-				img, format, err := image.Decode(r)
-				Expect(err).ToNot(HaveOccurred())
-				Expect(format).To(Equal("webp"))
-				Expect(img.Bounds().Size().X).To(Equal(15))
-				Expect(img.Bounds().Size().Y).To(Equal(15))
-			})
-			It("returns WebP if original image is not a PNG", func() {
-				conf.Server.CoverArtPriority = "cover.jpg"
-				r, _, err := aw.Get(context.Background(), alMultipleCovers.CoverArtID(), 200, false)
-				Expect(err).ToNot(HaveOccurred())
-
-				img, format, err := image.Decode(r)
-				Expect(format).To(Equal("webp"))
-				Expect(err).ToNot(HaveOccurred())
-				Expect(img.Bounds().Size().X).To(Equal(200))
-				Expect(img.Bounds().Size().Y).To(Equal(200))
-			})
-		})
-		When("EnableWebPEncoding is false and square is false", func() {
-			BeforeEach(func() {
-				conf.Server.EnableWebPEncoding = false
-			})
-			It("returns PNG if original image is a PNG", func() {
-				conf.Server.CoverArtPriority = "front.png"
-				r, _, err := aw.Get(context.Background(), alMultipleCovers.CoverArtID(), 15, false)
-				Expect(err).ToNot(HaveOccurred())
-
-				img, format, err := image.Decode(r)
-				Expect(err).ToNot(HaveOccurred())
-				Expect(format).To(Equal("png"))
-				Expect(img.Bounds().Size().X).To(Equal(15))
-				Expect(img.Bounds().Size().Y).To(Equal(15))
-			})
-			It("returns JPEG if original image is a JPG", func() {
-				conf.Server.CoverArtPriority = "cover.jpg"
-				r, _, err := aw.Get(context.Background(), alMultipleCovers.CoverArtID(), 200, false)
-				Expect(err).ToNot(HaveOccurred())
-
-				img, format, err := image.Decode(r)
-				Expect(err).ToNot(HaveOccurred())
-				Expect(format).To(Equal("jpeg"))
-				Expect(img.Bounds().Size().X).To(Equal(200))
-				Expect(img.Bounds().Size().Y).To(Equal(200))
-			})
-		})
-		When("EnableWebPEncoding is false and square is true", func() {
-			var alCover model.Album
-
-			BeforeEach(func() {
-				conf.Server.EnableWebPEncoding = false
-			})
-			It("returns PNG for square mode", func() {
-				dirName := createImage("png", false, 200)
-				alCover = model.Album{
-					ID:        "444",
-					Name:      "Only external",
-					FolderIDs: []string{"tmp"},
-				}
-				folderRepo.result = []model.Folder{{ImageFiles: []string{"cover.png"}}}
-				rootLibRepo := &tests.MockLibraryRepo{}
-				rootLibRepo.SetData(model.Libraries{{ID: 0, Path: testFileLibPath(dirName)}})
-				ds.(*tests.MockDataStore).MockedLibrary = rootLibRepo
-				ds.Album(ctx).(*tests.MockAlbumRepo).SetData(model.Albums{alCover})
-
-				conf.Server.CoverArtPriority = "cover.png"
-				r, _, err := aw.Get(context.Background(), alCover.CoverArtID(), 200, true)
-				Expect(err).ToNot(HaveOccurred())
-
-				img, format, err := image.Decode(r)
-				Expect(err).ToNot(HaveOccurred())
-				Expect(format).To(Equal("png"))
-				Expect(img.Bounds().Size().X).To(Equal(200))
-				Expect(img.Bounds().Size().Y).To(Equal(200))
-			})
-		})
-		When("Requested size is larger than original", func() {
-			It("clamps size to original dimensions", func() {
-				conf.Server.CoverArtPriority = "front.png"
-				// front.png is 16x16, requesting 99999 should return at original size
-				r, _, err := aw.Get(context.Background(), alMultipleCovers.CoverArtID(), 99999, false)
-				Expect(err).ToNot(HaveOccurred())
-
-				img, _, err := image.Decode(r)
-				Expect(err).ToNot(HaveOccurred())
-				// Should be clamped to original size (16), not 99999
-				Expect(img.Bounds().Size().X).To(Equal(16))
-				Expect(img.Bounds().Size().Y).To(Equal(16))
-			})
-
-			It("clamps square size to original dimensions", func() {
-				conf.Server.CoverArtPriority = "front.png"
-				// front.png is 16x16, requesting 99999 with square should return 16x16 square
-				r, _, err := aw.Get(context.Background(), alMultipleCovers.CoverArtID(), 99999, true)
-				Expect(err).ToNot(HaveOccurred())
-
-				img, _, err := image.Decode(r)
-				Expect(err).ToNot(HaveOccurred())
-				// Should be clamped to original size (16), not 99999
-				Expect(img.Bounds().Size().X).To(Equal(16))
-				Expect(img.Bounds().Size().Y).To(Equal(16))
-			})
-		})
-	})
-})
-
-func createImage(format string, landscape bool, size int) string {
-	var img image.Image
-
-	if landscape {
-		img = image.NewRGBA(image.Rect(0, 0, size, size/2))
-	} else {
-		img = image.NewRGBA(image.Rect(0, 0, size/2, size))
-	}
-
-	tmpDir := GinkgoT().TempDir()
-	f, _ := os.Create(filepath.Join(tmpDir, "cover."+format))
-	defer f.Close()
-	switch format {
-	case "png":
-		_ = png.Encode(f, img)
-	case "jpg":
-		_ = jpeg.Encode(f, img, &jpeg.Options{Quality: 75})
-	}
-
-	return tmpDir
-}

core/artwork/artwork_suite_test.go

@@ -11,13 +11,26 @@ import (
 
 	"github.com/navidrome/navidrome/core/storage"
 	"github.com/navidrome/navidrome/log"
+	"github.com/navidrome/navidrome/model"
 	"github.com/navidrome/navidrome/model/metadata"
 	"github.com/navidrome/navidrome/tests"
 	. "github.com/onsi/ginkgo/v2"
 	. "github.com/onsi/gomega"
+	"go.uber.org/goleak"
 )
 
 func TestArtwork(t *testing.T) {
+	// Runs unconditionally: the two leaks below are pre-existing and out of this
+	// package's control, so they're ignored by exact top-function instead.
+	defer goleak.VerifyNone(t,
+		goleak.IgnoreTopFunction("github.com/onsi/ginkgo/v2/internal/interrupt_handler.(*InterruptHandler).registerForInterrupts.func2"),
+		// notify's own init() starts a singleton tree the moment it's imported (via
+		// core/storage/local or plugins); recursive on darwin, nonrecursive on linux.
+		goleak.IgnoreTopFunction("github.com/rjeczalik/notify.(*recursiveTree).dispatch"),
+		goleak.IgnoreTopFunction("github.com/rjeczalik/notify.(*nonrecursiveTree).dispatch"),
+		goleak.IgnoreTopFunction("github.com/rjeczalik/notify.(*nonrecursiveTree).internal"),
+	)
+
 	tests.Init(t, false)
 	log.SetLevel(log.LevelFatal)
 	RegisterFailHandler(Fail)
@@ -25,7 +38,6 @@ func TestArtwork(t *testing.T) {
 }
 
 // osDirFS wraps os.DirFS as a storage.MusicFS for integration tests.
-// ReadTags is not used by albumArtworkReader, so it is left as a stub.
 type osDirFS struct{ fs.FS }
 
 func (o osDirFS) ReadTags(...string) (map[string]metadata.Info, error) { return nil, nil }
@@ -69,3 +81,37 @@ func (s *osDirStorage) FS() (storage.MusicFS, error) {
 	}
 	return osDirFS{os.DirFS(s.root)}, nil
 }
+
+// fakeFolderRepo covers the three FolderRepository methods the resolvers reach for. The zero value
+// answers as an unremarkable library does; the fields drive the album-root lookup and its failures.
+type fakeFolderRepo struct {
+	model.FolderRepository
+	result       []model.Folder
+	err          error
+	parentResult *model.Folder
+	getErr       error
+	getCallCount int
+	// hasOtherAudio is returned by HasAudioOutsideFolders (the album-root check).
+	// False means the parent qualifies as an album root.
+	hasOtherAudio bool
+	otherAudioErr error
+}
+
+func (f *fakeFolderRepo) GetAll(...model.QueryOptions) ([]model.Folder, error) {
+	return f.result, f.err
+}
+
+func (f *fakeFolderRepo) HasAudioOutsideFolders(model.Folder, []string) (bool, error) {
+	return f.hasOtherAudio, f.otherAudioErr
+}
+
+func (f *fakeFolderRepo) Get(string) (*model.Folder, error) {
+	f.getCallCount++
+	if f.getErr != nil {
+		return nil, f.getErr
+	}
+	if f.parentResult != nil {
+		return f.parentResult, nil
+	}
+	return nil, model.ErrNotFound
+}

core/artwork/artwork_test.go

@@ -1,57 +1,523 @@
-package artwork_test
+package artwork
 
 import (
+	"bytes"
 	"context"
+	"image"
 	"io"
+	"os"
+	"path/filepath"
+	"time"
 
 	"github.com/navidrome/navidrome/conf"
 	"github.com/navidrome/navidrome/conf/configtest"
 	"github.com/navidrome/navidrome/consts"
-	"github.com/navidrome/navidrome/core/artwork"
 	"github.com/navidrome/navidrome/model"
 	"github.com/navidrome/navidrome/resources"
 	"github.com/navidrome/navidrome/tests"
+	"github.com/navidrome/navidrome/utils/cache"
 	. "github.com/onsi/ginkgo/v2"
 	. "github.com/onsi/gomega"
 )
 
 var _ = Describe("Artwork", func() {
-	var aw artwork.Artwork
-	var ds model.DataStore
-	var ffmpeg *tests.MockFFmpeg
+	var (
+		ctx        context.Context
+		ds         *tests.MockDataStore
+		artRepo    *tests.MockArtworkRepo
+		queueRepo  *tests.MockArtworkQueueRepo
+		albumRepo  *tests.MockAlbumRepo
+		mfRepo     *tests.MockMediaFileRepo
+		folderRepo *fakeFolderRepo
+		libRepo    *tests.MockLibraryRepo
+		ffm        *tests.MockFFmpeg
+		store      *ImageStore
+		imgCache   cache.FileCache
+		svc        Artwork
+		repoRoot   string
+		coverBytes []byte
+		seedEntity func(kind, id string)
+	)
+
+	primaryKey := func(kind, id string) string { return kind + "|" + id + "|" + model.ImageTypePrimary }
+
+	seedFoundStore := func(kind, id string, imgBytes []byte) string {
+		hash, err := hashImage(bytes.NewReader(imgBytes))
+		Expect(err).ToNot(HaveOccurred())
+		Expect(store.Write(hash, "image/jpeg", bytes.NewReader(imgBytes))).To(Succeed())
+		Expect(artRepo.PutImage(&model.Artwork{Hash: hash, Mime: "image/jpeg"})).To(Succeed())
+		Expect(artRepo.PutItemArtwork(&model.ItemArtwork{ItemKind: kind, ItemID: id, Hash: hash, Source: "external"})).To(Succeed())
+		seedEntity(kind, id)
+		return hash
+	}
+
+	// Without its owning entity, a state row is not served at all.
+	seedEntity = func(kind, id string) {
+		GinkgoHelper()
+		switch kind {
+		case "al":
+			Expect(albumRepo.Put(&model.Album{ID: id, Name: "Album"})).To(Succeed())
+		case "mf":
+			Expect(mfRepo.Put(&model.MediaFile{ID: id})).To(Succeed())
+		}
+	}
+
+	readAll := func(img *Image) []byte {
+		GinkgoHelper()
+		defer img.Close()
+		data, err := io.ReadAll(img)
+		Expect(err).ToNot(HaveOccurred())
+		return data
+	}
 
 	BeforeEach(func() {
 		DeferCleanup(configtest.SetupConfig())
-		conf.Server.ImageCacheSize = "0" // Disable cache
-		cache := artwork.GetImageCache()
-		ffmpeg = tests.NewMockFFmpeg("content from ffmpeg")
-		aw = artwork.NewArtwork(ds, cache, ffmpeg, nil)
+		ctx = context.Background()
+		var err error
+		repoRoot, err = os.Getwd()
+		Expect(err).ToNot(HaveOccurred())
+		coverBytes, err = os.ReadFile(filepath.Join(repoRoot, "tests/fixtures/artist/an-album/cover.jpg"))
+		Expect(err).ToNot(HaveOccurred())
+
+		conf.Server.EnableWebPEncoding = false
+		conf.Server.CoverArtQuality = 75
+		conf.Server.CoverArtPriority = "cover.*"
+		conf.Server.DiscArtPriority = "cover.*"
+		conf.Server.CacheFolder = conf.NewDir(GinkgoT().TempDir())
+
+		artRepo = tests.CreateMockArtworkRepo()
+		queueRepo = tests.CreateMockArtworkQueueRepo()
+		albumRepo = tests.CreateMockAlbumRepo()
+		mfRepo = tests.CreateMockMediaFileRepo()
+		folderRepo = &fakeFolderRepo{}
+		libRepo = &tests.MockLibraryRepo{}
+		libRepo.SetData(model.Libraries{{ID: 0, Path: testFileLibPath(repoRoot)}})
+		ds = &tests.MockDataStore{
+			MockedArtwork:      artRepo,
+			MockedArtworkQueue: queueRepo,
+			MockedAlbum:        albumRepo,
+			MockedMediaFile:    mfRepo,
+			MockedFolder:       folderRepo,
+			MockedLibrary:      libRepo,
+		}
+		ffm = tests.NewMockFFmpeg("")
+		store = NewImageStore(GinkgoT().TempDir())
+		imgCache = cache.NewFileCache("ServingTest", "100MB", "images", 0,
+			func(ctx context.Context, arg cache.Item) (io.Reader, error) {
+				return arg.(artworkReader).Reader(ctx)
+			})
+		Eventually(func() bool { return imgCache.Available(ctx) }, 10*time.Second).Should(BeTrue())
+		svc = NewArtwork(ds, imgCache, store, ffm)
 	})
 
-	Context("GetOrPlaceholder", func() {
-		Context("Empty ID", func() {
-			It("returns placeholder if album is not in the DB", func() {
-				r, _, err := aw.GetOrPlaceholder(context.Background(), "", 0, false)
-				Expect(err).ToNot(HaveOccurred())
+	Describe("found state", func() {
+		It("serves a store-backed found image sized (cache miss resizes, second call is a cache hit)", func() {
+			seedFoundStore("al", "al1", coverBytes)
 
-				ph, err := resources.FS().Open(consts.PlaceholderAlbumArt)
-				Expect(err).ToNot(HaveOccurred())
-				phBytes, err := io.ReadAll(ph)
-				Expect(err).ToNot(HaveOccurred())
+			img, err := svc.Get(ctx, model.MustParseArtworkID("al-al1"), 100, false)
+			Expect(err).ToNot(HaveOccurred())
+			// A resized response versions its ETag with the encode settings, not the pixel hash.
+			Expect(img.ETag).To(Equal(representationTag(img.Hash, 100, false)))
+			Expect(img.ETag).ToNot(Equal(img.Hash))
+			resized := readAll(img)
+			cfg, _, err := image.DecodeConfig(bytes.NewReader(resized))
+			Expect(err).ToNot(HaveOccurred())
+			Expect(cfg.Width).To(Equal(100))
 
-				result, err := io.ReadAll(r)
-				Expect(err).ToNot(HaveOccurred())
+			// Deleting the store file proves the warm entry serves without touching the original.
+			hash, _ := hashImage(bytes.NewReader(coverBytes))
+			Expect(os.Remove(store.path(hash, "image/jpeg"))).To(Succeed())
+			Eventually(func(g Gomega) {
+				img2, err := svc.Get(ctx, model.MustParseArtworkID("al-al1"), 100, false)
+				g.Expect(err).ToNot(HaveOccurred())
+				g.Expect(readAll(img2)).To(Equal(resized))
+			}).Should(Succeed())
+		})
 
-				Expect(result).To(Equal(phBytes))
-			})
+		It("treats a negative size as a full-size request, not a giant resize", func() {
+			seedFoundStore("al", "alneg", coverBytes)
+
+			img, err := svc.Get(ctx, model.MustParseArtworkID("al-alneg"), -2000000000, false)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(readAll(img)).To(Equal(coverBytes), "original bytes, no resize (would OOM)")
+		})
+
+		It("streams a file-backed found image at full size", func() {
+			dir := GinkgoT().TempDir()
+			imgPath := filepath.Join(dir, "cover.jpg")
+			Expect(os.WriteFile(imgPath, coverBytes, 0600)).To(Succeed())
+			mtime := fileMtime(imgPath)
+			Expect(artRepo.PutImage(&model.Artwork{Hash: "aaaaaaaaaaaaaaaa", Mime: "image/jpeg"})).To(Succeed())
+			seedEntity("al", "al2")
+			Expect(artRepo.PutItemArtwork(&model.ItemArtwork{
+				ItemKind: "al", ItemID: "al2", Hash: "aaaaaaaaaaaaaaaa",
+				Source: "folder", SourcePath: imgPath, RefMtime: mtime,
+			})).To(Succeed())
+
+			img, err := svc.Get(ctx, model.MustParseArtworkID("al-al2"), 0, false)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(readAll(img)).To(Equal(coverBytes))
+		})
+
+		It("treats a full-size mtime mismatch as dangling: unavailable, re-enqueued at Scan, state untouched", func() {
+			dir := GinkgoT().TempDir()
+			imgPath := filepath.Join(dir, "cover.jpg")
+			Expect(os.WriteFile(imgPath, coverBytes, 0600)).To(Succeed())
+			Expect(artRepo.PutImage(&model.Artwork{Hash: "bbbbbbbbbbbbbbbb", Mime: "image/jpeg"})).To(Succeed())
+			seedEntity("al", "al3")
+			Expect(artRepo.PutItemArtwork(&model.ItemArtwork{
+				ItemKind: "al", ItemID: "al3", Hash: "bbbbbbbbbbbbbbbb",
+				Source: "folder", SourcePath: imgPath, RefMtime: fileMtime(imgPath) + 999,
+			})).To(Succeed())
+
+			_, err := svc.Get(ctx, model.MustParseArtworkID("al-al3"), 0, false)
+			Expect(err).To(MatchError(ErrUnavailable))
+			Expect(queueRepo.Data[primaryKey("al", "al3")].Priority).To(Equal(model.ArtworkPriorityScan))
+			ia, err := artRepo.GetItemArtwork(model.KindAlbumArtwork, "al3", model.ImageTypePrimary)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(ia.Hash).To(Equal("bbbbbbbbbbbbbbbb"))
+		})
+
+		It("enforces the mtime rule on the sized (loader) path too", func() {
+			dir := GinkgoT().TempDir()
+			imgPath := filepath.Join(dir, "cover.jpg")
+			Expect(os.WriteFile(imgPath, coverBytes, 0600)).To(Succeed())
+			Expect(artRepo.PutImage(&model.Artwork{Hash: "cccccccccccccccc", Mime: "image/jpeg"})).To(Succeed())
+			seedEntity("al", "al3b")
+			Expect(artRepo.PutItemArtwork(&model.ItemArtwork{
+				ItemKind: "al", ItemID: "al3b", Hash: "cccccccccccccccc",
+				Source: "folder", SourcePath: imgPath, RefMtime: fileMtime(imgPath) + 999,
+			})).To(Succeed())
+
+			_, err := svc.Get(ctx, model.MustParseArtworkID("al-al3b"), 100, false)
+			Expect(err).To(MatchError(ErrUnavailable))
+			Expect(queueRepo.Data[primaryKey("al", "al3b")].Priority).To(Equal(model.ArtworkPriorityScan))
+		})
+
+		// State rows outlive a deleted entity until the next prune.
+		It("refuses to serve a found row whose entity is gone", func() {
+			hash := seedFoundStore("al", "alzz", coverBytes)
+			Expect(hash).ToNot(BeEmpty())
+			albumRepo.SetData(model.Albums{}) // the album is deleted; its artwork row survives
+
+			_, err := svc.Get(ctx, model.MustParseArtworkID("al-alzz"), 0, false)
+			Expect(err).To(MatchError(ErrUnavailable))
+		})
+
+		It("does not re-enqueue a recently-attempted absent state", func() {
+			Expect(artRepo.PutItemArtwork(&model.ItemArtwork{
+				ItemKind: "al", ItemID: "al4", AttemptedAt: time.Now(),
+			})).To(Succeed())
+
+			_, err := svc.Get(ctx, model.MustParseArtworkID("al-al4"), 0, false)
+			Expect(err).To(MatchError(ErrUnavailable))
+			Expect(queueRepo.Data).To(BeEmpty())
+		})
+
+		It("promotes a stale absent state at Bump priority on view", func() {
+			Expect(artRepo.PutItemArtwork(&model.ItemArtwork{
+				ItemKind: "al", ItemID: "al4b", AttemptedAt: time.Now().Add(-2 * requestRecheckAge),
+			})).To(Succeed())
+
+			_, err := svc.Get(ctx, model.MustParseArtworkID("al-al4b"), 0, false)
+			Expect(err).To(MatchError(ErrUnavailable))
+			Expect(queueRepo.Data[primaryKey("al", "al4b")].Priority).To(Equal(model.ArtworkPriorityBump))
+			ia, err := artRepo.GetItemArtwork(model.KindAlbumArtwork, "al4b", model.ImageTypePrimary)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(ia.Hash).To(BeEmpty())
 		})
 	})
-	Context("Get", func() {
-		Context("Empty ID", func() {
-			It("returns an ErrUnavailable error", func() {
-				_, _, err := aw.Get(context.Background(), model.ArtworkID{}, 0, false)
-				Expect(err).To(MatchError(artwork.ErrUnavailable))
-			})
+
+	Describe("provisional read-through", func() {
+		It("serves local folder art, enqueues a Bump, and writes no state row", func() {
+			folderRepo.result = []model.Folder{{Path: "tests/fixtures/artist/an-album", ImageFiles: []string{"cover.jpg"}}}
+			albumRepo.SetData(model.Albums{{ID: "al5", Name: "Album", FolderIDs: []string{"f1"}}})
+
+			img, err := svc.Get(ctx, model.MustParseArtworkID("al-al5"), 0, false)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(readAll(img)).To(Equal(coverBytes))
+
+			Expect(queueRepo.Data[primaryKey("al", "al5")].Priority).To(Equal(model.ArtworkPriorityBump))
+			_, err = artRepo.GetItemArtwork(model.KindAlbumArtwork, "al5", model.ImageTypePrimary)
+			Expect(err).To(MatchError(model.ErrNotFound))
+		})
+
+		It("returns ErrUnavailable and enqueues a Bump when nothing local resolves", func() {
+			folderRepo.result = nil
+			albumRepo.SetData(model.Albums{{ID: "al6", Name: "Album"}})
+
+			_, err := svc.Get(ctx, model.MustParseArtworkID("al-al6"), 0, false)
+			Expect(err).To(MatchError(ErrUnavailable))
+			Expect(queueRepo.Data[primaryKey("al", "al6")].Priority).To(Equal(model.ArtworkPriorityBump))
+			_, err = artRepo.GetItemArtwork(model.KindAlbumArtwork, "al6", model.ImageTypePrimary)
+			Expect(err).To(MatchError(model.ErrNotFound))
+		})
+	})
+
+	Describe("media file", func() {
+		It("serves a track's own found art", func() {
+			seedFoundStore("mf", "mf1", coverBytes)
+
+			img, err := svc.Get(ctx, model.MustParseArtworkID("mf-mf1"), 0, false)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(readAll(img)).To(Equal(coverBytes))
+		})
+
+		It("ignores a resolved mf row and delegates to the album when per-track art is disabled", func() {
+			conf.Server.EnableMediaFileCoverArt = false
+			seedFoundStore("mf", "mf7", []byte("stale embedded track art"))
+			seedFoundStore("al", "albz", coverBytes)
+			mfRepo.SetData(model.MediaFiles{{ID: "mf7", AlbumID: "albz"}})
+
+			img, err := svc.Get(ctx, model.MustParseArtworkID("mf-mf7"), 0, false)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(readAll(img)).To(Equal(coverBytes), "album art, not the persisted embedded art")
+		})
+
+		It("delegates to the album when the track's state is absent", func() {
+			seedFoundStore("al", "albm", coverBytes)
+			Expect(artRepo.PutItemArtwork(&model.ItemArtwork{ItemKind: "mf", ItemID: "mf2"})).To(Succeed())
+			mfRepo.SetData(model.MediaFiles{{ID: "mf2", AlbumID: "albm"}})
+
+			img, err := svc.Get(ctx, model.MustParseArtworkID("mf-mf2"), 0, false)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(readAll(img)).To(Equal(coverBytes))
+			_, mfEnq := queueRepo.Data[primaryKey("mf", "mf2")]
+			Expect(mfEnq).To(BeFalse())
+		})
+
+		It("delegates to the album (no enqueue) when the track is not embedded-eligible", func() {
+			conf.Server.EnableMediaFileCoverArt = true
+			seedFoundStore("al", "albn", coverBytes)
+			mfRepo.SetData(model.MediaFiles{{ID: "mf3", AlbumID: "albn", HasCoverArt: false}})
+
+			img, err := svc.Get(ctx, model.MustParseArtworkID("mf-mf3"), 0, false)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(readAll(img)).To(Equal(coverBytes))
+			_, mfEnq := queueRepo.Data[primaryKey("mf", "mf3")]
+			Expect(mfEnq).To(BeFalse())
+		})
+
+		It("extracts embedded art provisionally and enqueues the track when eligible", func() {
+			conf.Server.EnableMediaFileCoverArt = true
+			mfRepo.SetData(model.MediaFiles{{
+				ID: "mf4", AlbumID: "albo", HasCoverArt: true,
+				Path: "tests/fixtures/artist/an-album/test.mp3", LibraryID: 0,
+			}})
+
+			img, err := svc.Get(ctx, model.MustParseArtworkID("mf-mf4"), 0, false)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(len(readAll(img))).To(BeNumerically(">", 0))
+			Expect(queueRepo.Data[primaryKey("mf", "mf4")].Priority).To(Equal(model.ArtworkPriorityBump))
+			_, err = artRepo.GetItemArtwork(model.KindMediaFileArtwork, "mf4", model.ImageTypePrimary)
+			Expect(err).To(MatchError(model.ErrNotFound))
+		})
+
+		It("delegates a multi-disc track to its disc art, not straight to the album", func() {
+			folderRepo.result = []model.Folder{{Path: "tests/fixtures/artist/an-album", ImageFiles: []string{"cover.jpg"}}}
+			albumRepo.SetData(model.Albums{{ID: "aldd", Name: "Album", FolderIDs: []string{"f1"}, Discs: model.Discs{1: "One", 2: "Two"}}})
+			seedFoundStore("al", "aldd", []byte("album-art-distinct")) // album's own found art differs
+			mfRepo.SetData(model.MediaFiles{{ID: "mf5", AlbumID: "aldd", DiscNumber: 1, HasCoverArt: false}})
+
+			img, err := svc.Get(ctx, model.MustParseArtworkID("mf-mf5"), 0, false)
+			Expect(err).ToNot(HaveOccurred())
+			// The disc-folder image, not the album's own art: proof it routed through serveDisc.
+			Expect(readAll(img)).To(Equal(coverBytes))
+		})
+
+		It("falls back to the album when an eligible track's embedded art will not extract", func() {
+			conf.Server.EnableMediaFileCoverArt = true
+			// HasCoverArt is set, but the file is not audio, so nothing extracts.
+			mfRepo.SetData(model.MediaFiles{{
+				ID: "mfbad", AlbumID: "albad", LibraryID: 0, HasCoverArt: true,
+				Path: "tests/fixtures/artist/an-album/front.png",
+			}})
+			albumRepo.SetData(model.Albums{{ID: "albad", Name: "Album"}})
+			seedFoundStore("al", "albad", coverBytes)
+
+			img, err := svc.Get(ctx, model.MustParseArtworkID("mf-mfbad"), 0, false)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(readAll(img)).To(Equal(coverBytes), "a placeholder here would be worse than the album cover")
+		})
+
+		It("routes a single-disc track through disc resolution too", func() {
+			// DiscArtPriority applies to single-disc albums too, over the album's own found art.
+			folderRepo.result = []model.Folder{{Path: "tests/fixtures/artist/an-album", ImageFiles: []string{"cover.jpg"}}}
+			albumRepo.SetData(model.Albums{{ID: "alsd", Name: "Album", FolderIDs: []string{"f1"}, Discs: model.Discs{1: ""}}})
+			seedFoundStore("al", "alsd", []byte("album-art-distinct"))
+			mfRepo.SetData(model.MediaFiles{{ID: "mf6", AlbumID: "alsd", DiscNumber: 1, HasCoverArt: false}})
+
+			img, err := svc.Get(ctx, model.MustParseArtworkID("mf-mf6"), 0, false)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(readAll(img)).To(Equal(coverBytes))
+		})
+	})
+
+	Describe("disc", func() {
+		It("serves a local disc-folder image", func() {
+			folderRepo.result = []model.Folder{{Path: "tests/fixtures/artist/an-album", ImageFiles: []string{"cover.jpg"}}}
+			albumRepo.SetData(model.Albums{{ID: "aldc", Name: "Album", FolderIDs: []string{"f1"}}})
+
+			img, err := svc.Get(ctx, model.NewArtworkID(model.KindDiscArtwork, model.DiscArtworkID("aldc", 1), nil), 0, false)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(readAll(img)).To(Equal(coverBytes))
+		})
+
+		// The resize cache keys on id + album mtime, not on the bytes, so dropping the source
+		// between the two requests is what shows a warm hit never touches the filesystem.
+		It("serves a sized disc image from cache without re-reading the source", func() {
+			folderRepo.result = []model.Folder{{Path: "tests/fixtures/artist/an-album", ImageFiles: []string{"cover.jpg"}}}
+			albumRepo.SetData(model.Albums{{ID: "aldc3", Name: "Album", FolderIDs: []string{"f1"}}})
+			discID := model.NewArtworkID(model.KindDiscArtwork, model.DiscArtworkID("aldc3", 1), nil)
+
+			first, err := svc.Get(ctx, discID, 64, false)
+			Expect(err).ToNot(HaveOccurred())
+			warmed := readAll(first)
+			Expect(warmed).ToNot(BeEmpty())
+
+			folderRepo.result = nil
+
+			second, err := svc.Get(ctx, discID, 64, false)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(readAll(second)).To(Equal(warmed), "a warm sized request must not touch the source")
+		})
+
+		// A disc image can change without the album row changing, so the key folds in ImagesUpdatedAt.
+		It("invalidates the cached image when the folder's images change", func() {
+			folderRepo.result = []model.Folder{{
+				Path: "tests/fixtures/artist/an-album", ImageFiles: []string{"cover.jpg"},
+				ImagesUpdatedAt: time.Now().Add(-time.Hour),
+			}}
+			albumRepo.SetData(model.Albums{{ID: "aldc4", Name: "Album", FolderIDs: []string{"f1"}}})
+			discID := model.NewArtworkID(model.KindDiscArtwork, model.DiscArtworkID("aldc4", 1), nil)
+
+			first, err := svc.Get(ctx, discID, 64, false)
+			Expect(err).ToNot(HaveOccurred())
+			firstKey := first.ETag
+			readAll(first)
+
+			folderRepo.result[0].ImagesUpdatedAt = time.Now()
+			second, err := svc.Get(ctx, discID, 64, false)
+			Expect(err).ToNot(HaveOccurred())
+			readAll(second)
+			Expect(second.ETag).ToNot(Equal(firstKey), "a replaced image must not keep the old cache entry")
+		})
+
+		// Disc art has no content hash, so without an explicit validator every ETag would be empty.
+		It("gives a full-size disc image a validator that tracks the source", func() {
+			folderRepo.result = []model.Folder{{
+				Path: "tests/fixtures/artist/an-album", ImageFiles: []string{"cover.jpg"},
+				ImagesUpdatedAt: time.Now().Add(-time.Hour),
+			}}
+			albumRepo.SetData(model.Albums{{ID: "aldc5", Name: "Album", FolderIDs: []string{"f1"}}})
+			discID := model.NewArtworkID(model.KindDiscArtwork, model.DiscArtworkID("aldc5", 1), nil)
+
+			first, err := svc.Get(ctx, discID, 0, false)
+			Expect(err).ToNot(HaveOccurred())
+			readAll(first)
+			Expect(first.ETag).ToNot(BeEmpty())
+
+			folderRepo.result[0].ImagesUpdatedAt = time.Now()
+			second, err := svc.Get(ctx, discID, 0, false)
+			Expect(err).ToNot(HaveOccurred())
+			readAll(second)
+			Expect(second.ETag).ToNot(Equal(first.ETag), "a replaced image must not revalidate as unchanged")
+		})
+
+		It("falls back to album art when no disc image matches", func() {
+			folderRepo.result = nil
+			albumRepo.SetData(model.Albums{{ID: "aldc2", Name: "Album"}})
+			seedFoundStore("al", "aldc2", coverBytes)
+
+			img, err := svc.Get(ctx, model.NewArtworkID(model.KindDiscArtwork, model.DiscArtworkID("aldc2", 1), nil), 0, false)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(readAll(img)).To(Equal(coverBytes))
+		})
+	})
+
+	Describe("GetOrPlaceholder", func() {
+		It("accepts a raw entity id and serves its cover art", func() {
+			albumRepo.SetData(model.Albums{{ID: "rawal", Name: "Album"}})
+			seedFoundStore("al", "rawal", coverBytes)
+
+			img, err := svc.GetOrPlaceholder(ctx, "rawal", 0, false)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(img.Placeholder).To(BeFalse())
+			Expect(readAll(img)).To(Equal(coverBytes))
+		})
+
+		It("falls back to the album placeholder ignoring size and square", func() {
+			img, err := svc.GetOrPlaceholder(ctx, "", 300, true)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(img.Placeholder).To(BeTrue())
+			Expect(img.Hash).To(BeEmpty())
+			Expect(img.LastUpdated).To(BeZero())
+
+			ph, err := resources.FS().Open(consts.PlaceholderAlbumArt)
+			Expect(err).ToNot(HaveOccurred())
+			phBytes, _ := io.ReadAll(ph)
+			Expect(readAll(img)).To(Equal(phBytes))
+		})
+
+		It("falls back to the artist placeholder for an absent artist", func() {
+			Expect(artRepo.PutItemArtwork(&model.ItemArtwork{ItemKind: "ar", ItemID: "arph"})).To(Succeed())
+
+			img, err := svc.GetOrPlaceholder(ctx, "ar-arph", 300, false)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(img.Placeholder).To(BeTrue())
+
+			ph, err := resources.FS().Open(consts.PlaceholderArtistArt)
+			Expect(err).ToNot(HaveOccurred())
+			phBytes, _ := io.ReadAll(ph)
+			Expect(readAll(img)).To(Equal(phBytes))
+		})
+
+		// "No art" and "no such entity" are different answers: clients 404 only on the latter.
+		It("reports not-found rather than a placeholder for an id with no entity", func() {
+			_, err := svc.GetOrPlaceholder(ctx, "al-nosuchalbum", 0, false)
+			Expect(err).To(MatchError(model.ErrNotFound))
+
+			_, err = svc.GetOrPlaceholder(ctx, "nosuchrawid", 0, false)
+			Expect(err).To(MatchError(model.ErrNotFound))
 		})
 	})
 })
+
+func fileMtime(path string) int64 {
+	GinkgoHelper()
+	info, err := os.Stat(path)
+	Expect(err).ToNot(HaveOccurred())
+	return info.ModTime().UnixNano()
+}
+
+var _ = Describe("EntityExists", func() {
+	var ctx context.Context
+	var ds *tests.MockDataStore
+
+	BeforeEach(func() {
+		ctx = context.Background()
+		albumRepo := tests.CreateMockAlbumRepo()
+		albumRepo.SetData(model.Albums{{ID: "al1"}})
+		artistRepo := tests.CreateMockArtistRepo()
+		artistRepo.SetData(model.Artists{{ID: "ar1"}})
+		radioRepo := tests.CreateMockedRadioRepo()
+		Expect(radioRepo.Put(&model.Radio{ID: "ra1", Name: "R"})).To(Succeed())
+		ds = &tests.MockDataStore{MockedAlbum: albumRepo, MockedArtist: artistRepo, MockedRadio: radioRepo}
+	})
+
+	DescribeTable("reports whether the owning entity is still there",
+		func(id string, expected bool) {
+			Expect(entityExists(ctx, ds, model.MustParseArtworkID(id))).To(Equal(expected))
+		},
+		Entry("existing album", "al-al1", true),
+		Entry("deleted album", "al-gone", false),
+		Entry("existing artist", "ar-ar1", true),
+		Entry("deleted artist", "ar-gone", false),
+		Entry("existing radio", "ra-ra1", true),
+		Entry("deleted radio", "ra-gone", false),
+		// Disc art has no entity of its own; it stands or falls with its album.
+		Entry("disc of an existing album", "dc-al1:1", true),
+		Entry("disc of a deleted album", "dc-gone:1", false),
+		Entry("malformed disc id", "dc-nodiscnum", false),
+	)
+})

core/artwork/benchmark_e2e_test.go

@@ -1,189 +0,0 @@
-package artwork
-
-import (
-	"context"
-	"fmt"
-	"image/jpeg"
-	"io"
-	"os"
-	"path/filepath"
-	"runtime"
-	"sync"
-	"testing"
-	"time"
-
-	"github.com/navidrome/navidrome/conf"
-	"github.com/navidrome/navidrome/conf/configtest"
-	"github.com/navidrome/navidrome/model"
-	"github.com/navidrome/navidrome/tests"
-	"github.com/navidrome/navidrome/utils/cache"
-)
-
-// setupE2EBenchmark creates an artwork instance with a real album cover image on disk,
-// backed by either a real file cache or disabled cache depending on cacheSize.
-// Note: This benchmarks artwork.Get() directly (not the full HTTP handler), which covers
-// the critical path (source selection, decode, resize, encode, cache). This is a deliberate
-// spec deviation — the full HTTP round-trip benchmark requires significant infrastructure
-// (DB, scanner, fake filesystem) and can be added later if HTTP overhead proves significant.
-//
-// Depends on fakeFolderRepo defined in reader_artist_test.go (same package, compiled together).
-func setupE2EBenchmark(b *testing.B, cacheSize string) (Artwork, model.ArtworkID, func()) {
-	b.Helper()
-	cleanup := configtest.SetupConfig()
-	b.Cleanup(cleanup)
-
-	tmpDir, err := os.MkdirTemp("", "artwork-bench-*")
-	if err != nil {
-		b.Fatal(err)
-	}
-
-	// Create a realistic cover image on disk
-	coverPath := filepath.Join(tmpDir, "cover.jpg")
-	coverImg := generateGradientImage(1000, 1000)
-	f, err := os.Create(coverPath)
-	if err != nil {
-		b.Fatal(err)
-	}
-	if err := jpeg.Encode(f, coverImg, &jpeg.Options{Quality: 90}); err != nil {
-		f.Close()
-		b.Fatal(err)
-	}
-	f.Close()
-
-	// Configure cache
-	conf.Server.ImageCacheSize = cacheSize
-	conf.Server.CacheFolder = conf.NewDir(tmpDir)
-	conf.Server.CoverArtQuality = 75
-	conf.Server.CoverArtPriority = "cover.*"
-
-	// Set up mock data store with album pointing to our cover.
-	// Set UpdatedAt so CoverArtID().LastUpdate is consistent across calls.
-	album := model.Album{
-		ID:        "bench-album-1",
-		Name:      "Benchmark Album",
-		FolderIDs: []string{"f1"},
-		UpdatedAt: time.Date(2025, 1, 1, 0, 0, 0, 0, time.UTC),
-	}
-	folderRepo := &fakeFolderRepo{
-		result: []model.Folder{{
-			Path:       tmpDir,
-			ImageFiles: []string{"cover.jpg"},
-		}},
-	}
-	ds := &tests.MockDataStore{
-		MockedTranscoding: &tests.MockTranscodingRepo{},
-		MockedFolder:      folderRepo,
-	}
-	ds.Album(context.Background()).(*tests.MockAlbumRepo).SetData(model.Albums{album})
-
-	artID := album.CoverArtID()
-
-	imgCache := cache.NewFileCache("BenchImage", cacheSize, "bench-images", 0,
-		func(ctx context.Context, arg cache.Item) (io.Reader, error) {
-			r, _, err := arg.(artworkReader).Reader(ctx)
-			return r, err
-		})
-
-	// Wait for cache init if enabled
-	if cacheSize != "0" {
-		for !imgCache.Available(context.Background()) && !imgCache.Disabled(context.Background()) {
-			runtime.Gosched() // Yield to allow background init goroutine to run
-		}
-	}
-
-	ffmpeg := tests.NewMockFFmpeg("fallback content")
-	aw := NewArtwork(ds, imgCache, ffmpeg, nil)
-
-	cleanupAll := func() {
-		os.RemoveAll(tmpDir)
-	}
-	return aw, artID, cleanupAll
-}
-
-func BenchmarkArtworkGetE2E(b *testing.B) {
-	cacheConfigs := []struct {
-		name      string
-		cacheSize string
-	}{
-		{"no_cache", "0"},
-		{"with_cache", "100MB"},
-	}
-	sizes := []int{0, 300}
-
-	for _, cc := range cacheConfigs {
-		for _, size := range sizes {
-			b.Run(fmt.Sprintf("%s/size_%d", cc.name, size), func(b *testing.B) {
-				aw, artID, cleanup := setupE2EBenchmark(b, cc.cacheSize)
-				defer cleanup()
-
-				// Warm the cache on first call if cache is enabled
-				if cc.cacheSize != "0" {
-					r, _, err := aw.Get(context.Background(), artID, size, size > 0)
-					if err != nil {
-						b.Fatal(err)
-					}
-					_, _ = io.ReadAll(r)
-					r.Close()
-				}
-
-				b.ResetTimer()
-				for i := 0; i < b.N; i++ {
-					r, _, err := aw.Get(context.Background(), artID, size, size > 0)
-					if err != nil {
-						b.Fatal(err)
-					}
-					_, _ = io.ReadAll(r)
-					r.Close()
-				}
-			})
-		}
-	}
-}
-
-func BenchmarkArtworkGetE2EConcurrent(b *testing.B) {
-	cacheConfigs := []struct {
-		name      string
-		cacheSize string
-	}{
-		{"no_cache", "0"},
-		{"with_cache", "100MB"},
-	}
-	concurrencyLevels := []int{10, 50}
-
-	for _, cc := range cacheConfigs {
-		for _, n := range concurrencyLevels {
-			b.Run(fmt.Sprintf("%s/goroutines_%d", cc.name, n), func(b *testing.B) {
-				aw, artID, cleanup := setupE2EBenchmark(b, cc.cacheSize)
-				defer cleanup()
-
-				// Warm cache
-				if cc.cacheSize != "0" {
-					r, _, _ := aw.Get(context.Background(), artID, 300, true)
-					if r != nil {
-						_, _ = io.ReadAll(r)
-						r.Close()
-					}
-				}
-
-				b.ResetTimer()
-				for i := 0; i < b.N; i++ {
-					var wg sync.WaitGroup
-					wg.Add(n)
-					for range n {
-						go func() {
-							defer wg.Done()
-							r, _, err := aw.Get(context.Background(), artID, 300, true)
-							if err != nil {
-								b.Error(err)
-								return
-							}
-							_, _ = io.ReadAll(r)
-							r.Close()
-						}()
-					}
-					wg.Wait()
-				}
-			})
-		}
-	}
-}

core/artwork/benchmark_helpers_test.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"image"
 	"image/color"
+	"image/draw"
 	"image/jpeg"
 	"image/png"
 	"testing"
@@ -45,3 +46,11 @@ func generateGradientImage(width, height int) *image.RGBA {
 	}
 	return img
 }
+
+// gradientNRGBA mirrors generateGradientImage in the type makeThumbnail hands the encoders.
+func gradientNRGBA(size int) *image.NRGBA {
+	src := generateGradientImage(size, size)
+	dst := image.NewNRGBA(src.Bounds())
+	draw.Draw(dst, dst.Bounds(), src, src.Bounds().Min, draw.Src)
+	return dst
+}

core/artwork/blurhash/blurhash.go

@@ -0,0 +1,191 @@
+// Package blurhash implements the blurhash encoding (https://github.com/woltapp/blurhash),
+// parameterized to match Jellyfin so clients see equivalent hashes.
+package blurhash
+
+import (
+	"errors"
+	"image"
+	"image/draw"
+	"math"
+	"strings"
+	"sync"
+
+	xdraw "golang.org/x/image/draw"
+)
+
+const alphabet = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz#$%*+,-.:;=?@[]^_{|}~"
+
+// maxInputSize: larger inputs are slower with no visible difference in the result.
+const maxInputSize = 128
+
+// components picks x/y component counts targeting ~16 near-square tiles.
+func components(width, height int) (int, int) {
+	xf := math.Sqrt(16.0 * float64(width) / float64(height))
+	yf := xf * float64(height) / float64(width)
+	return min(int(xf)+1, 9), min(int(yf)+1, 9)
+}
+
+// Encode returns the blurhash of img, deriving the component counts from its aspect ratio.
+func Encode(img image.Image) (string, error) {
+	if img.Bounds().Dx() == 0 || img.Bounds().Dy() == 0 {
+		return "", errors.New("blurhash: empty image")
+	}
+	// Pre-downscale: its rounding can flip a component count, and the hash is a client cache key.
+	xComp, yComp := components(img.Bounds().Dx(), img.Bounds().Dy())
+	src := pixelsOf(downscale(img))
+	w, h := src.w, src.h
+
+	cosX := make([][]float64, xComp)
+	for i := range cosX {
+		cosX[i] = make([]float64, w)
+		for x := range cosX[i] {
+			cosX[i][x] = math.Cos(math.Pi * float64(i) * float64(x) / float64(w))
+		}
+	}
+	cosY := make([][]float64, yComp)
+	for j := range cosY {
+		cosY[j] = make([]float64, h)
+		for y := range cosY[j] {
+			cosY[j][y] = math.Cos(math.Pi * float64(j) * float64(y) / float64(h))
+		}
+	}
+
+	lin := srgbToLinearTable()
+	factors := make([][3]float64, xComp*yComp)
+	for y := range h {
+		row := src.pix[y*src.stride:]
+		for x := range w {
+			p := x * 4
+			r, g, b := row[p], row[p+1], row[p+2]
+			if src.straight {
+				r, g, b = premultiply(r, g, b, row[p+3])
+			}
+			lr, lg, lb := lin[r], lin[g], lin[b]
+			for j := range yComp {
+				for i := range xComp {
+					basis := cosX[i][x] * cosY[j][y]
+					f := &factors[j*xComp+i]
+					f[0] += basis * lr
+					f[1] += basis * lg
+					f[2] += basis * lb
+				}
+			}
+		}
+	}
+	for idx := range factors {
+		norm := 2.0
+		if idx == 0 {
+			norm = 1.0
+		}
+		scale := norm / float64(w*h)
+		factors[idx][0] *= scale
+		factors[idx][1] *= scale
+		factors[idx][2] *= scale
+	}
+
+	var sb strings.Builder
+	sb.WriteString(encode83((xComp-1)+(yComp-1)*9, 1))
+
+	// Derived counts are at least 1x9, so there is always at least one AC factor.
+	ac := factors[1:]
+	actualMax := 0.0
+	for _, f := range ac {
+		actualMax = max(actualMax, math.Abs(f[0]), math.Abs(f[1]), math.Abs(f[2]))
+	}
+	quantMax := int(max(0, min(82, math.Floor(actualMax*166-0.5))))
+	maxVal := float64(quantMax+1) / 166
+	sb.WriteString(encode83(quantMax, 1))
+
+	dc := factors[0]
+	sb.WriteString(encode83(linearToSRGB(dc[0])<<16|linearToSRGB(dc[1])<<8|linearToSRGB(dc[2]), 4))
+	for _, f := range ac {
+		sb.WriteString(encode83(quantAC(f[0], maxVal)*19*19+quantAC(f[1], maxVal)*19+quantAC(f[2], maxVal), 2))
+	}
+	return sb.String(), nil
+}
+
+// pixels is direct Pix access for the pixel loop, avoiding a per-pixel allocation via image.At.
+type pixels struct {
+	pix    []uint8
+	stride int
+	w, h   int
+	// straight marks non-premultiplied alpha, which the loop premultiplies to keep the hash
+	// identical to the one an equivalent *image.RGBA produces.
+	straight bool
+}
+
+// pixelsOf accepts the two types the artwork pipeline produces without copying, and converts
+// anything else.
+func pixelsOf(img image.Image) pixels {
+	b := img.Bounds()
+	switch src := img.(type) {
+	case *image.RGBA:
+		return pixels{pix: src.Pix, stride: src.Stride, w: b.Dx(), h: b.Dy()}
+	case *image.NRGBA:
+		return pixels{pix: src.Pix, stride: src.Stride, w: b.Dx(), h: b.Dy(), straight: true}
+	}
+	dst := image.NewRGBA(image.Rect(0, 0, b.Dx(), b.Dy()))
+	draw.Draw(dst, dst.Bounds(), img, b.Min, draw.Src)
+	return pixels{pix: dst.Pix, stride: dst.Stride, w: b.Dx(), h: b.Dy()}
+}
+
+func premultiply(r, g, b, a uint8) (uint8, uint8, uint8) {
+	if a == 255 {
+		return r, g, b
+	}
+	return uint8(uint32(r) * uint32(a) / 255), uint8(uint32(g) * uint32(a) / 255), uint8(uint32(b) * uint32(a) / 255)
+}
+
+var srgbToLinearTable = sync.OnceValue(func() *[256]float64 {
+	var t [256]float64
+	for i := range t {
+		t[i] = srgbToLinear(i)
+	}
+	return &t
+})
+
+func downscale(img image.Image) image.Image {
+	b := img.Bounds()
+	w, h := b.Dx(), b.Dy()
+	if w <= maxInputSize && h <= maxInputSize {
+		return img
+	}
+	scale := float64(maxInputSize) / float64(max(w, h))
+	dst := image.NewRGBA(image.Rect(0, 0, max(1, int(float64(w)*scale)), max(1, int(float64(h)*scale))))
+	xdraw.ApproxBiLinear.Scale(dst, dst.Bounds(), img, b, draw.Src, nil)
+	return dst
+}
+
+func quantAC(v, maxVal float64) int {
+	return int(max(0, min(18, math.Floor(signPow(v/maxVal, 0.5)*9+9.5))))
+}
+
+func signPow(v, exp float64) float64 {
+	return math.Copysign(math.Pow(math.Abs(v), exp), v)
+}
+
+func srgbToLinear(v int) float64 {
+	f := float64(v) / 255
+	if f <= 0.04045 {
+		return f / 12.92
+	}
+	return math.Pow((f+0.055)/1.055, 2.4)
+}
+
+func linearToSRGB(v float64) int {
+	v = min(max(0, v), 1)
+	if v <= 0.0031308 {
+		return int(v*12.92*255 + 0.5)
+	}
+	return int((1.055*math.Pow(v, 1/2.4)-0.055)*255 + 0.5)
+}
+
+// encode83 encodes value as a fixed-width, big-endian base83 string of the given length.
+func encode83(value, length int) string {
+	b := make([]byte, length)
+	for i := length - 1; i >= 0; i-- {
+		b[i] = alphabet[value%83]
+		value /= 83
+	}
+	return string(b)
+}

core/artwork/blurhash/blurhash_suite_test.go

@@ -0,0 +1,17 @@
+package blurhash_test
+
+import (
+	"testing"
+
+	"github.com/navidrome/navidrome/log"
+	"github.com/navidrome/navidrome/tests"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+func TestBlurHash(t *testing.T) {
+	tests.Init(t, false)
+	log.SetLevel(log.LevelFatal)
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "BlurHash Suite")
+}

core/artwork/blurhash/blurhash_test.go

@@ -0,0 +1,137 @@
+package blurhash_test
+
+import (
+	"image"
+	"image/color"
+	"strings"
+
+	"github.com/navidrome/navidrome/core/artwork/blurhash"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+const alphabet = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz#$%*+,-.:;=?@[]^_{|}~"
+
+func decode83(s string) int {
+	v := 0
+	for _, c := range s {
+		v = v*83 + strings.IndexRune(alphabet, c)
+	}
+	return v
+}
+
+func solidImage(w, h int, c color.NRGBA) image.Image {
+	img := image.NewNRGBA(image.Rect(0, 0, w, h))
+	for y := range h {
+		for x := range w {
+			img.SetNRGBA(x, y, c)
+		}
+	}
+	return img
+}
+
+func gradientImage(w, h int) image.Image {
+	img := image.NewNRGBA(image.Rect(0, 0, w, h))
+	for y := range h {
+		for x := range w {
+			img.SetNRGBA(x, y, color.NRGBA{R: uint8(255 * x / w), G: uint8(255 * y / h), B: 128, A: 255})
+		}
+	}
+	return img
+}
+
+var _ = Describe("Encode input types", func() {
+	// The pipeline hands Encode an *image.NRGBA; reading it must stay equivalent to the
+	// premultiplied *image.RGBA it used to receive, or every hash silently shifts.
+	buildPair := func(alpha uint8) (*image.NRGBA, *image.RGBA) {
+		const size = 40
+		nrgba := image.NewNRGBA(image.Rect(0, 0, size, size))
+		rgba := image.NewRGBA(image.Rect(0, 0, size, size))
+		for y := range size {
+			for x := range size {
+				c := color.NRGBA{
+					R: uint8(255 * x / size), G: uint8(255 * y / size),
+					B: uint8((x + y) * 255 / (2 * size)), A: alpha,
+				}
+				nrgba.SetNRGBA(x, y, c)
+				rgba.Set(x, y, c) // image.RGBA.Set premultiplies
+			}
+		}
+		return nrgba, rgba
+	}
+
+	DescribeTable("gives an NRGBA the same hash as the premultiplied RGBA it replaces",
+		func(alpha uint8) {
+			nrgba, rgba := buildPair(alpha)
+			fromNRGBA, err := blurhash.Encode(nrgba)
+			Expect(err).ToNot(HaveOccurred())
+			fromRGBA, err := blurhash.Encode(rgba)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(fromNRGBA).To(Equal(fromRGBA))
+		},
+		Entry("opaque", uint8(255)),
+		Entry("partly transparent", uint8(128)),
+		Entry("fully transparent, which premultiplication crushes to black", uint8(0)),
+	)
+})
+
+var _ = Describe("Encode", func() {
+	// The size flag encodes (xComp-1) + (yComp-1)*9.
+	DescribeTable("derives component counts from aspect ratio (Jellyfin formula)",
+		func(w, h, expectedX, expectedY int) {
+			hash, err := blurhash.Encode(gradientImage(w, h))
+			Expect(err).ToNot(HaveOccurred())
+			Expect(decode83(hash[:1])).To(Equal((expectedX - 1) + (expectedY-1)*9))
+		},
+		Entry("square album art", 60, 60, 5, 5),
+		Entry("smallest square", 1, 1, 5, 5),
+		Entry("landscape 16:9", 192, 108, 6, 4),
+		Entry("portrait 9:16", 108, 192, 4, 6),
+		Entry("extreme landscape capped at 9", 1000, 10, 9, 1),
+		Entry("extreme portrait capped at 9", 10, 1000, 1, 9),
+	)
+
+	It("rejects an empty image", func() {
+		_, err := blurhash.Encode(image.NewNRGBA(image.Rect(0, 0, 0, 0)))
+		Expect(err).To(HaveOccurred())
+	})
+
+	It("produces the spec-mandated length", func() {
+		// 1 (size flag) + 1 (max AC) + 4 (DC) + 2 per AC component; a square derives 5x5
+		h, err := blurhash.Encode(solidImage(8, 8, color.NRGBA{R: 10, G: 20, B: 30, A: 255}))
+		Expect(err).ToNot(HaveOccurred())
+		Expect(h).To(HaveLen(4 + 2 + 2*(5*5-1)))
+	})
+
+	It("stores the average color in the DC component", func() {
+		h, err := blurhash.Encode(solidImage(16, 16, color.NRGBA{R: 200, G: 100, B: 50, A: 255}))
+		Expect(err).ToNot(HaveOccurred())
+		dc := decode83(h[2:6])
+		Expect(dc >> 16).To(BeNumerically("~", 200, 1))
+		Expect((dc >> 8) & 0xFF).To(BeNumerically("~", 100, 1))
+		Expect(dc & 0xFF).To(BeNumerically("~", 50, 1))
+	})
+
+	It("is deterministic", func() {
+		img := gradientImage(64, 64)
+		h1, err1 := blurhash.Encode(img)
+		h2, err2 := blurhash.Encode(img)
+		Expect(err1).ToNot(HaveOccurred())
+		Expect(err2).ToNot(HaveOccurred())
+		Expect(h1).To(Equal(h2))
+	})
+
+	It("produces different hashes for different images", func() {
+		h1, _ := blurhash.Encode(solidImage(16, 16, color.NRGBA{R: 255, A: 255}))
+		h2, _ := blurhash.Encode(gradientImage(16, 16))
+		Expect(h1).ToNot(Equal(h2))
+	})
+
+	It("downscales large images internally without changing the result materially", func() {
+		big, err := blurhash.Encode(solidImage(1000, 1000, color.NRGBA{R: 60, G: 120, B: 180, A: 255}))
+		Expect(err).ToNot(HaveOccurred())
+		small, err := blurhash.Encode(solidImage(16, 16, color.NRGBA{R: 60, G: 120, B: 180, A: 255}))
+		Expect(err).ToNot(HaveOccurred())
+		Expect(big[2:6]).To(Equal(small[2:6]))
+	})
+})

core/artwork/cache_warmer.go

@@ -1,162 +0,0 @@
-package artwork
-
-import (
-	"context"
-	"fmt"
-	"io"
-	"maps"
-	"slices"
-	"sync"
-	"time"
-
-	"github.com/navidrome/navidrome/conf"
-	"github.com/navidrome/navidrome/log"
-	"github.com/navidrome/navidrome/model"
-	"github.com/navidrome/navidrome/model/request"
-	"github.com/navidrome/navidrome/utils/cache"
-	"github.com/navidrome/navidrome/utils/pl"
-)
-
-type CacheWarmer interface {
-	PreCache(artID model.ArtworkID)
-}
-
-// NewCacheWarmer creates a new CacheWarmer instance. The CacheWarmer will pre-cache Artwork images in the background
-// to speed up the response time when the image is requested by the UI. The cache is pre-populated with the original
-// image size, as well as the size defined by the UICoverArtSize config option.
-func NewCacheWarmer(artwork Artwork, cache cache.FileCache) CacheWarmer {
-	// If image cache is disabled, return a NOOP implementation
-	if conf.Server.ImageCacheSize == "0" || !conf.Server.EnableArtworkPrecache {
-		return &noopCacheWarmer{}
-	}
-
-	// If the file cache is disabled, return a NOOP implementation
-	if cache.Disabled(context.Background()) {
-		log.Debug("Image cache disabled. Cache warmer will not run")
-		return &noopCacheWarmer{}
-	}
-
-	a := &cacheWarmer{
-		artwork:      artwork,
-		cache:        cache,
-		buffer:       make(map[model.ArtworkID]struct{}),
-		wakeSignal:   make(chan struct{}, 1),
-		coverArtSize: conf.Server.UICoverArtSize,
-	}
-
-	// Create a context with a fake admin user, to be able to pre-cache Playlist CoverArts
-	ctx := request.WithUser(context.TODO(), model.User{IsAdmin: true})
-	go a.run(ctx)
-	return a
-}
-
-type cacheWarmer struct {
-	artwork      Artwork
-	buffer       map[model.ArtworkID]struct{}
-	mutex        sync.Mutex
-	cache        cache.FileCache
-	wakeSignal   chan struct{}
-	coverArtSize int
-}
-
-func (a *cacheWarmer) PreCache(artID model.ArtworkID) {
-	if a.cache.Disabled(context.Background()) {
-		return
-	}
-	a.mutex.Lock()
-	defer a.mutex.Unlock()
-	a.buffer[artID] = struct{}{}
-	a.sendWakeSignal()
-}
-
-func (a *cacheWarmer) sendWakeSignal() {
-	// Don't block if the previous signal was not read yet
-	select {
-	case a.wakeSignal <- struct{}{}:
-	default:
-	}
-}
-
-func (a *cacheWarmer) run(ctx context.Context) {
-	for {
-		a.waitSignal(ctx, 10*time.Second)
-		if ctx.Err() != nil {
-			break
-		}
-
-		if a.cache.Disabled(ctx) {
-			a.mutex.Lock()
-			pending := len(a.buffer)
-			a.buffer = make(map[model.ArtworkID]struct{})
-			a.mutex.Unlock()
-			if pending > 0 {
-				log.Trace(ctx, "Cache disabled, discarding precache buffer", "bufferLen", pending)
-			}
-			return
-		}
-
-		// If cache not available, keep waiting
-		if !a.cache.Available(ctx) {
-			a.mutex.Lock()
-			bufferLen := len(a.buffer)
-			a.mutex.Unlock()
-			if bufferLen > 0 {
-				log.Trace(ctx, "Cache not available, buffering precache request", "bufferLen", bufferLen)
-			}
-			continue
-		}
-
-		a.mutex.Lock()
-
-		// If there's nothing to send, keep waiting
-		if len(a.buffer) == 0 {
-			a.mutex.Unlock()
-			continue
-		}
-
-		batch := slices.Collect(maps.Keys(a.buffer))
-		a.buffer = make(map[model.ArtworkID]struct{})
-		a.mutex.Unlock()
-
-		a.processBatch(ctx, batch)
-	}
-}
-
-func (a *cacheWarmer) waitSignal(ctx context.Context, timeout time.Duration) {
-	select {
-	case <-time.After(timeout):
-	case <-a.wakeSignal:
-	case <-ctx.Done():
-	}
-}
-
-func (a *cacheWarmer) processBatch(ctx context.Context, batch []model.ArtworkID) {
-	log.Trace(ctx, "PreCaching a new batch of artwork", "batchSize", len(batch))
-	input := pl.FromSlice(ctx, batch)
-	errs := pl.Sink(ctx, 4, input, a.doCacheImage)
-	for err := range errs {
-		log.Debug(ctx, "Error warming cache", err)
-	}
-}
-
-func (a *cacheWarmer) doCacheImage(ctx context.Context, id model.ArtworkID) error {
-	ctx, cancel := context.WithTimeout(ctx, 10*time.Second)
-	defer cancel()
-
-	size := a.coverArtSize
-	r, _, err := a.artwork.Get(ctx, id, size, true)
-	if err != nil {
-		return fmt.Errorf("caching id='%s', size=%d: %w", id, size, err)
-	}
-	_, err = io.Copy(io.Discard, r)
-	r.Close()
-	return err
-}
-
-func NoopCacheWarmer() CacheWarmer {
-	return &noopCacheWarmer{}
-}
-
-type noopCacheWarmer struct{}
-
-func (a *noopCacheWarmer) PreCache(model.ArtworkID) {}

core/artwork/cache_warmer_test.go

@@ -1,245 +0,0 @@
-package artwork
-
-import (
-	"context"
-	"errors"
-	"fmt"
-	"io"
-	"strings"
-	"sync"
-	"sync/atomic"
-	"time"
-
-	"github.com/navidrome/navidrome/conf"
-	"github.com/navidrome/navidrome/conf/configtest"
-	"github.com/navidrome/navidrome/model"
-	"github.com/navidrome/navidrome/utils/cache"
-	. "github.com/onsi/ginkgo/v2"
-	. "github.com/onsi/gomega"
-)
-
-var _ = Describe("CacheWarmer", func() {
-	var (
-		fc *mockFileCache
-		aw *mockArtwork
-	)
-
-	BeforeEach(func() {
-		DeferCleanup(configtest.SetupConfig())
-		fc = &mockFileCache{}
-		aw = &mockArtwork{}
-	})
-
-	Context("initialization", func() {
-		It("returns noop when cache is disabled", func() {
-			fc.SetDisabled(true)
-			cw := NewCacheWarmer(aw, fc)
-			_, ok := cw.(*noopCacheWarmer)
-			Expect(ok).To(BeTrue())
-		})
-
-		It("returns noop when ImageCacheSize is 0", func() {
-			conf.Server.ImageCacheSize = "0"
-			cw := NewCacheWarmer(aw, fc)
-			_, ok := cw.(*noopCacheWarmer)
-			Expect(ok).To(BeTrue())
-		})
-
-		It("returns noop when EnableArtworkPrecache is false", func() {
-			conf.Server.EnableArtworkPrecache = false
-			cw := NewCacheWarmer(aw, fc)
-			_, ok := cw.(*noopCacheWarmer)
-			Expect(ok).To(BeTrue())
-		})
-
-		It("returns real implementation when properly configured", func() {
-			conf.Server.ImageCacheSize = "100MB"
-			conf.Server.EnableArtworkPrecache = true
-			fc.SetDisabled(false)
-			cw := NewCacheWarmer(aw, fc)
-			_, ok := cw.(*cacheWarmer)
-			Expect(ok).To(BeTrue())
-		})
-	})
-
-	Context("buffer management", func() {
-		BeforeEach(func() {
-			conf.Server.ImageCacheSize = "100MB"
-			conf.Server.EnableArtworkPrecache = true
-			fc.SetDisabled(false)
-		})
-
-		It("drops buffered items when cache becomes disabled", func() {
-			cw := NewCacheWarmer(aw, fc).(*cacheWarmer)
-			cw.PreCache(model.MustParseArtworkID("al-test"))
-			fc.SetDisabled(true)
-			Eventually(func() int {
-				cw.mutex.Lock()
-				defer cw.mutex.Unlock()
-				return len(cw.buffer)
-			}).Should(Equal(0))
-		})
-
-		It("adds multiple items to buffer", func() {
-			fc.SetReady(false) // Make cache unavailable so items stay in buffer
-			cw := NewCacheWarmer(aw, fc).(*cacheWarmer)
-			cw.PreCache(model.MustParseArtworkID("al-1"))
-			cw.PreCache(model.MustParseArtworkID("al-2"))
-			cw.mutex.Lock()
-			defer cw.mutex.Unlock()
-			Expect(len(cw.buffer)).To(Equal(2))
-		})
-
-		It("deduplicates items in buffer", func() {
-			fc.SetReady(false) // Make cache unavailable so items stay in buffer
-			cw := NewCacheWarmer(aw, fc).(*cacheWarmer)
-			cw.PreCache(model.MustParseArtworkID("al-1"))
-			cw.PreCache(model.MustParseArtworkID("al-1"))
-			cw.mutex.Lock()
-			defer cw.mutex.Unlock()
-			Expect(len(cw.buffer)).To(Equal(1))
-		})
-	})
-
-	Context("error handling", func() {
-		BeforeEach(func() {
-			conf.Server.ImageCacheSize = "100MB"
-			conf.Server.EnableArtworkPrecache = true
-			fc.SetDisabled(false)
-		})
-
-		It("continues processing after artwork retrieval error", func() {
-			aw.err = errors.New("artwork error")
-			cw := NewCacheWarmer(aw, fc).(*cacheWarmer)
-			cw.PreCache(model.MustParseArtworkID("al-error"))
-			cw.PreCache(model.MustParseArtworkID("al-1"))
-
-			Eventually(func() int {
-				cw.mutex.Lock()
-				defer cw.mutex.Unlock()
-				return len(cw.buffer)
-			}).Should(Equal(0))
-		})
-
-		It("continues processing after cache error", func() {
-			fc.err = errors.New("cache error")
-			cw := NewCacheWarmer(aw, fc).(*cacheWarmer)
-			cw.PreCache(model.MustParseArtworkID("al-error"))
-			cw.PreCache(model.MustParseArtworkID("al-1"))
-
-			Eventually(func() int {
-				cw.mutex.Lock()
-				defer cw.mutex.Unlock()
-				return len(cw.buffer)
-			}).Should(Equal(0))
-		})
-	})
-
-	Context("background processing", func() {
-		BeforeEach(func() {
-			conf.Server.ImageCacheSize = "100MB"
-			conf.Server.EnableArtworkPrecache = true
-			fc.SetDisabled(false)
-		})
-
-		It("processes items in batches", func() {
-			cw := NewCacheWarmer(aw, fc).(*cacheWarmer)
-			for i := range 5 {
-				cw.PreCache(model.MustParseArtworkID(fmt.Sprintf("al-%d", i)))
-			}
-
-			Eventually(func() int {
-				cw.mutex.Lock()
-				defer cw.mutex.Unlock()
-				return len(cw.buffer)
-			}).Should(Equal(0))
-		})
-
-		It("wakes up on new items", func() {
-			cw := NewCacheWarmer(aw, fc).(*cacheWarmer)
-
-			// Add first batch
-			cw.PreCache(model.MustParseArtworkID("al-1"))
-			Eventually(func() int {
-				cw.mutex.Lock()
-				defer cw.mutex.Unlock()
-				return len(cw.buffer)
-			}).Should(Equal(0))
-
-			// Add second batch
-			cw.PreCache(model.MustParseArtworkID("al-2"))
-			Eventually(func() int {
-				cw.mutex.Lock()
-				defer cw.mutex.Unlock()
-				return len(cw.buffer)
-			}).Should(Equal(0))
-		})
-
-		It("pre-caches UICoverArtSize", func() {
-			cw := NewCacheWarmer(aw, fc).(*cacheWarmer)
-			cw.PreCache(model.MustParseArtworkID("al-1"))
-
-			Eventually(func() []int {
-				return aw.getCachedSizes()
-			}).Should(ContainElements(conf.Server.UICoverArtSize))
-		})
-	})
-})
-
-type mockArtwork struct {
-	err         error
-	mu          sync.Mutex
-	cachedSizes []int
-}
-
-func (m *mockArtwork) Get(ctx context.Context, artID model.ArtworkID, size int, square bool) (io.ReadCloser, time.Time, error) {
-	if m.err != nil {
-		return nil, time.Time{}, m.err
-	}
-	m.mu.Lock()
-	m.cachedSizes = append(m.cachedSizes, size)
-	m.mu.Unlock()
-	return io.NopCloser(strings.NewReader("test")), time.Now(), nil
-}
-
-func (m *mockArtwork) getCachedSizes() []int {
-	m.mu.Lock()
-	defer m.mu.Unlock()
-	result := make([]int, len(m.cachedSizes))
-	copy(result, m.cachedSizes)
-	return result
-}
-
-func (m *mockArtwork) GetOrPlaceholder(ctx context.Context, id string, size int, square bool) (io.ReadCloser, time.Time, error) {
-	return m.Get(ctx, model.ArtworkID{}, size, square)
-}
-
-type mockFileCache struct {
-	disabled atomic.Bool
-	ready    atomic.Bool
-	err      error
-}
-
-func (f *mockFileCache) Get(ctx context.Context, item cache.Item) (*cache.CachedStream, error) {
-	if f.err != nil {
-		return nil, f.err
-	}
-	return &cache.CachedStream{Reader: io.NopCloser(strings.NewReader("cached"))}, nil
-}
-
-func (f *mockFileCache) Available(ctx context.Context) bool {
-	return f.ready.Load() && !f.disabled.Load()
-}
-
-func (f *mockFileCache) Disabled(ctx context.Context) bool {
-	return f.disabled.Load()
-}
-
-func (f *mockFileCache) SetDisabled(v bool) {
-	f.disabled.Store(v)
-	f.ready.Store(true)
-}
-
-func (f *mockFileCache) SetReady(v bool) {
-	f.ready.Store(v)
-}

core/artwork/disc.go

@@ -2,7 +2,6 @@ package artwork
 
 import (
 	"context"
-	"crypto/md5"
 	"fmt"
 	"io"
 	"path"
@@ -12,16 +11,16 @@ import (
 	"time"
 
 	"github.com/Masterminds/squirrel"
-	"github.com/navidrome/navidrome/conf"
 	"github.com/navidrome/navidrome/core/ffmpeg"
 	"github.com/navidrome/navidrome/log"
 	"github.com/navidrome/navidrome/model"
 	"github.com/navidrome/navidrome/utils"
+	"github.com/navidrome/navidrome/utils/slice"
 )
 
+// discArtworkReader resolves disc-level artwork from a library's folder images
+// and embedded tags. It is used by the serving path's provisional disc read-through.
 type discArtworkReader struct {
-	cacheKey
-	a              *artwork
 	album          model.Album
 	discNumber     int
 	imgFiles       []string        // library-relative, forward-slash, no leading slash
@@ -29,27 +28,40 @@ type discArtworkReader struct {
 	isMultiFolder  bool
 	firstTrackRel  string // library-relative; for fromTag / ffmpeg via lib.Abs
 	lib            libraryView
-	updatedAt      *time.Time
+	// Newest ImagesUpdatedAt across the album's and this disc's folders: an image can be
+	// replaced without the album row changing, so this is what makes a cache key notice it.
+	imagesUpdatedAt time.Time
 }
 
-func newDiscArtworkReader(ctx context.Context, a *artwork, artID model.ArtworkID) (*discArtworkReader, error) {
+// cacheTime is the disc image's validity stamp: any of these moving means the selection may
+// have changed.
+func (d *discArtworkReader) cacheTime() time.Time {
+	return utils.TimeNewest(d.album.UpdatedAt, d.album.ImportedAt, d.imagesUpdatedAt)
+}
+
+func newDiscArtworkReader(ctx context.Context, ds model.DataStore, artID model.ArtworkID) (*discArtworkReader, error) {
 	albumID, discNumber, err := model.ParseDiscArtworkID(artID.ID)
 	if err != nil {
 		return nil, fmt.Errorf("invalid disc artwork id '%s': %w", artID.ID, err)
 	}
 
-	al, err := a.ds.Album(ctx).Get(albumID)
+	al, err := ds.Album(ctx).Get(albumID)
 	if err != nil {
 		return nil, err
 	}
 
-	_, imgFiles, imagesUpdatedAt, err := loadAlbumFoldersPaths(ctx, a.ds, *al)
+	_, imgFiles, albumImagesAt, err := loadAlbumFoldersPaths(ctx, ds, *al)
 	if err != nil {
 		return nil, err
 	}
 
+	var imagesUpdatedAt time.Time
+	if albumImagesAt != nil {
+		imagesUpdatedAt = *albumImagesAt
+	}
+
 	// Query mediafiles for this album + disc to find folder associations and first track
-	mfs, err := a.ds.MediaFile(ctx).GetAll(model.QueryOptions{
+	mfs, err := ds.MediaFile(ctx).GetAll(model.QueryOptions{
 		Sort:    "track_number",
 		Order:   "ASC",
 		Filters: squirrel.Eq{"album_id": albumID, "disc_number": discNumber},
@@ -58,29 +70,25 @@ func newDiscArtworkReader(ctx context.Context, a *artwork, artID model.ArtworkID
 		return nil, err
 	}
 
-	lib, err := loadLibraryView(ctx, a.ds, al.LibraryID)
+	lib, err := loadLibraryView(ctx, ds, al.LibraryID)
 	if err != nil {
 		return nil, err
 	}
 
 	// Build disc folder set and find first track. mf.Path is already library-relative.
 	var firstTrackRel string
-	allFolderIDs := make(map[string]bool)
 	for _, mf := range mfs {
-		allFolderIDs[mf.FolderID] = true
-		if firstTrackRel == "" {
+		if mf.Path != "" {
 			firstTrackRel = filepath.ToSlash(mf.Path)
+			break
 		}
 	}
+	folderIDs := slice.Unique(slice.Map(mfs, func(mf model.MediaFile) string { return mf.FolderID }))
 
 	// Resolve folder IDs to library-relative paths
 	discFoldersRel := make(map[string]bool)
-	if len(allFolderIDs) > 0 {
-		folderIDs := make([]string, 0, len(allFolderIDs))
-		for id := range allFolderIDs {
-			folderIDs = append(folderIDs, id)
-		}
-		folders, err := a.ds.Folder(ctx).GetAll(model.QueryOptions{
+	if len(folderIDs) > 0 {
+		folders, err := ds.Folder(ctx).GetAll(model.QueryOptions{
 			Filters: squirrel.Eq{"folder.id": folderIDs},
 		})
 		if err != nil {
@@ -89,49 +97,20 @@ func newDiscArtworkReader(ctx context.Context, a *artwork, artID model.ArtworkID
 		for _, f := range folders {
 			rel := strings.TrimPrefix(path.Join(f.Path, f.Name), "/")
 			discFoldersRel[rel] = true
+			imagesUpdatedAt = utils.TimeNewest(imagesUpdatedAt, f.ImagesUpdatedAt)
 		}
 	}
 
-	isMultiFolder := len(al.FolderIDs) > 1
-
-	r := &discArtworkReader{
-		a:              a,
-		album:          *al,
-		discNumber:     discNumber,
-		imgFiles:       imgFiles,
-		discFoldersRel: discFoldersRel,
-		isMultiFolder:  isMultiFolder,
-		firstTrackRel:  firstTrackRel,
-		lib:            lib,
-		updatedAt:      imagesUpdatedAt,
-	}
-	r.cacheKey.artID = artID
-	r.cacheKey.lastUpdate = utils.TimeNewest(al.UpdatedAt, al.ImportedAt)
-	if imagesUpdatedAt != nil {
-		r.cacheKey.lastUpdate = utils.TimeNewest(r.cacheKey.lastUpdate, *imagesUpdatedAt)
-	}
-	return r, nil
-}
-
-func (d *discArtworkReader) Key() string {
-	hash := md5.Sum([]byte(conf.Server.DiscArtPriority))
-	return fmt.Sprintf(
-		"%s.%x",
-		d.cacheKey.Key(),
-		hash,
-	)
-}
-
-func (d *discArtworkReader) LastUpdated() time.Time {
-	return d.lastUpdate
-}
-
-func (d *discArtworkReader) Reader(ctx context.Context) (io.ReadCloser, string, error) {
-	var ff = d.fromDiscArtPriority(ctx, d.a.ffmpeg, conf.Server.DiscArtPriority)
-	// Fallback to album cover art
-	albumArtID := model.NewArtworkID(model.KindAlbumArtwork, d.album.ID, &d.album.UpdatedAt)
-	ff = append(ff, fromAlbum(ctx, d.a, albumArtID))
-	return selectImageReader(ctx, d.cacheKey.artID, ff...)
+	return &discArtworkReader{
+		album:           *al,
+		discNumber:      discNumber,
+		imgFiles:        imgFiles,
+		discFoldersRel:  discFoldersRel,
+		isMultiFolder:   len(al.FolderIDs) > 1,
+		firstTrackRel:   firstTrackRel,
+		lib:             lib,
+		imagesUpdatedAt: imagesUpdatedAt,
+	}, nil
 }
 
 func (d *discArtworkReader) fromDiscArtPriority(ctx context.Context, ffmpeg ffmpeg.FFmpeg, priority string) []sourceFunc {
@@ -162,14 +141,13 @@ func (d *discArtworkReader) fromDiscArtPriority(ctx context.Context, ffmpeg ffmp
 func (d *discArtworkReader) fromDiscSubtitle(ctx context.Context, subtitle string) sourceFunc {
 	return func() (io.ReadCloser, string, error) {
 		for _, file := range d.imgFiles {
-			name := path.Base(file)
-			stem := strings.TrimSuffix(name, path.Ext(name))
+			stem := utils.BaseName(file)
 			if !strings.EqualFold(stem, subtitle) {
 				continue
 			}
 			f, err := d.lib.FS.Open(file)
 			if err != nil {
-				log.Warn(ctx, "Could not open disc art file", "file", file, err)
+				log.Warn(ctx, "Artwork: Could not open disc art file", "file", file, err)
 				continue
 			}
 			return f, file, nil
@@ -178,19 +156,12 @@ func (d *discArtworkReader) fromDiscSubtitle(ctx context.Context, subtitle strin
 	}
 }
 
-// globMetaChars holds the substitution metacharacters understood by
-// filepath.Match. The '\' escape character is intentionally excluded:
-// disc art patterns come from user config and never include escaped
-// metachars in practice, and treating '\' as a metachar would misalign
-// the literal-prefix extraction in extractDiscNumber.
+// filepath.Match's '\' escape is excluded on purpose: treating it as a metachar
+// would misalign the literal-prefix extraction in extractDiscNumber.
 const globMetaChars = "*?["
 
-// extractDiscNumber parses the disc number from a filename matched by a
-// filepath.Match-style glob pattern.
-//
-// Both pattern and filename must already be lowercased by the caller, which
-// is also expected to have verified that filepath.Match(pattern, filename)
-// is true before calling this function.
+// extractDiscNumber parses the disc number from a filename matched by a filepath.Match-style
+// glob. Caller must lowercase both args and have already verified the match.
 func extractDiscNumber(pattern, filename string) (int, bool) {
 	metaIdx := strings.IndexAny(pattern, globMetaChars)
 	if metaIdx < 0 {
@@ -216,9 +187,8 @@ func extractDiscNumber(pattern, filename string) (int, bool) {
 	return num, true
 }
 
-// fromExternalFile returns a sourceFunc that matches image files against a glob
-// pattern. A numbered filename whose number equals the target disc wins over
-// any unnumbered candidate; callers must pass a lowercase pattern.
+// fromExternalFile matches image files against a (lowercase) glob pattern. A numbered
+// filename whose number equals the target disc wins over any unnumbered candidate.
 func (d *discArtworkReader) fromExternalFile(ctx context.Context, pattern string) sourceFunc {
 	isLiteral := !strings.ContainsAny(pattern, globMetaChars)
 	return func() (io.ReadCloser, string, error) {
@@ -227,7 +197,7 @@ func (d *discArtworkReader) fromExternalFile(ctx context.Context, pattern string
 			name := strings.ToLower(path.Base(file))
 			match, err := filepath.Match(pattern, name)
 			if err != nil {
-				log.Warn(ctx, "Error matching disc art file to pattern", "pattern", pattern, "file", file)
+				log.Warn(ctx, "Artwork: Error matching disc art file to pattern", "pattern", pattern, "file", file)
 				continue
 			}
 			if !match {
@@ -241,7 +211,7 @@ func (d *discArtworkReader) fromExternalFile(ctx context.Context, pattern string
 					}
 					f, err := d.lib.FS.Open(file)
 					if err != nil {
-						log.Warn(ctx, "Could not open disc art file", "file", file, err)
+						log.Warn(ctx, "Artwork: Could not open disc art file", "file", file, err)
 						continue
 					}
 					return f, file, nil
@@ -257,7 +227,7 @@ func (d *discArtworkReader) fromExternalFile(ctx context.Context, pattern string
 		for _, file := range fallbacks {
 			f, err := d.lib.FS.Open(file)
 			if err != nil {
-				log.Warn(ctx, "Could not open disc art file", "file", file, err)
+				log.Warn(ctx, "Artwork: Could not open disc art file", "file", file, err)
 				continue
 			}
 			return f, file, nil

core/artwork/dominant/dominant.go

@@ -0,0 +1,127 @@
+// Package dominant extracts an image's dominant colour, for use as a flat placeholder while the
+// real artwork loads.
+package dominant
+
+import (
+	"fmt"
+	"image"
+	"math"
+	"sort"
+)
+
+const (
+	// 4 bits per channel: coarse enough that near-identical pixels land together, fine enough that
+	// distinct colours stay apart.
+	bits  = 4
+	nBins = 1 << (3 * bits)
+	// Only the heaviest bins can win, and merging is O(n^2) over whatever survives.
+	maxBins = 64
+	// Oklab distance below which two bins are the same colour to the eye. Merging matters because a
+	// gradient splits across adjacent bins and would otherwise lose to a smaller flat region.
+	mergeDist = 0.10
+)
+
+type bin struct {
+	r, g, b float64
+	n       float64
+}
+
+// Color returns the dominant colour as "#rrggbb", or "" when the image has no pixels. It reports
+// presence, not salience: a mostly white sleeve returns white.
+func Color(img image.Image) string {
+	var bins [nBins]bin
+	total := 0
+	eachPixel(img, func(r, g, b uint8) {
+		i := int(r>>(8-bits))<<(2*bits) | int(g>>(8-bits))<<bits | int(b>>(8-bits))
+		bins[i].r += float64(r)
+		bins[i].g += float64(g)
+		bins[i].b += float64(b)
+		bins[i].n++
+		total++
+	})
+	if total == 0 {
+		return ""
+	}
+
+	used := make([]bin, 0, 32)
+	for i := range bins {
+		if bins[i].n > 0 {
+			used = append(used, bins[i])
+		}
+	}
+	sort.Slice(used, func(i, j int) bool { return used[i].n > used[j].n })
+	if len(used) > maxBins {
+		used = used[:maxBins]
+	}
+
+	merged := make([]bin, 0, len(used))
+	for _, b := range used {
+		if i := nearest(merged, b); i >= 0 {
+			merged[i].r += b.r
+			merged[i].g += b.g
+			merged[i].b += b.b
+			merged[i].n += b.n
+			continue
+		}
+		merged = append(merged, b)
+	}
+
+	best := merged[0]
+	for _, m := range merged[1:] {
+		if m.n > best.n {
+			best = m
+		}
+	}
+	return fmt.Sprintf("#%02x%02x%02x",
+		uint8(best.r/best.n+0.5), uint8(best.g/best.n+0.5), uint8(best.b/best.n+0.5))
+}
+
+func nearest(merged []bin, b bin) int {
+	bl, ba, bb := oklab(b.r/b.n, b.g/b.n, b.b/b.n)
+	for i, m := range merged {
+		ml, ma, mb := oklab(m.r/m.n, m.g/m.n, m.b/m.n)
+		if math.Sqrt((bl-ml)*(bl-ml)+(ba-ma)*(ba-ma)+(bb-mb)*(bb-mb)) < mergeDist {
+			return i
+		}
+	}
+	return -1
+}
+
+// eachPixel walks the image, taking the NRGBA fast path the artwork pipeline always hits: both hash
+// encoders already read the shared thumbnail in that form.
+func eachPixel(img image.Image, fn func(r, g, b uint8)) {
+	if p, ok := img.(*image.NRGBA); ok {
+		for y := range p.Rect.Dy() {
+			row := p.Pix[y*p.Stride : y*p.Stride+p.Rect.Dx()*4]
+			for x := 0; x < len(row); x += 4 {
+				fn(row[x], row[x+1], row[x+2])
+			}
+		}
+		return
+	}
+	b := img.Bounds()
+	for y := b.Min.Y; y < b.Max.Y; y++ {
+		for x := b.Min.X; x < b.Max.X; x++ {
+			r, g, bl, _ := img.At(x, y).RGBA()
+			fn(uint8(r>>8), uint8(g>>8), uint8(bl>>8))
+		}
+	}
+}
+
+func srgbToLinear(v float64) float64 {
+	v /= 255
+	if v <= 0.04045 {
+		return v / 12.92
+	}
+	return math.Pow((v+0.055)/1.055, 2.4)
+}
+
+func oklab(r, g, b float64) (float64, float64, float64) {
+	lr, lg, lb := srgbToLinear(r), srgbToLinear(g), srgbToLinear(b)
+	l := math.Cbrt(0.4122214708*lr + 0.5363325363*lg + 0.0514459929*lb)
+	m := math.Cbrt(0.2119034982*lr + 0.6806995451*lg + 0.1073969566*lb)
+	s := math.Cbrt(0.0883024619*lr + 0.2817188376*lg + 0.6299787005*lb)
+	return 0.2104542553*l + 0.7936177850*m - 0.0040720468*s,
+		1.9779984951*l - 2.4285922050*m + 0.4505937099*s,
+		0.0259040371*l + 0.7827717662*m - 0.8086757660*s
+}

core/artwork/dominant/dominant_suite_test.go

@@ -0,0 +1,17 @@
+package dominant_test
+
+import (
+	"testing"
+
+	"github.com/navidrome/navidrome/log"
+	"github.com/navidrome/navidrome/tests"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+func TestDominant(t *testing.T) {
+	tests.Init(t, false)
+	log.SetLevel(log.LevelFatal)
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "Dominant Suite")
+}

core/artwork/dominant/dominant_test.go

@@ -0,0 +1,91 @@
+package dominant_test
+
+import (
+	"image"
+	"image/color"
+
+	"github.com/navidrome/navidrome/core/artwork/dominant"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+// fill paints rect with c onto img.
+func fill(img *image.NRGBA, r image.Rectangle, c color.NRGBA) {
+	for y := r.Min.Y; y < r.Max.Y; y++ {
+		for x := r.Min.X; x < r.Max.X; x++ {
+			img.SetNRGBA(x, y, c)
+		}
+	}
+}
+
+func newImg(w, h int, c color.NRGBA) *image.NRGBA {
+	img := image.NewNRGBA(image.Rect(0, 0, w, h))
+	fill(img, img.Bounds(), c)
+	return img
+}
+
+var _ = Describe("Color", func() {
+	It("returns a solid image's own colour", func() {
+		Expect(dominant.Color(newImg(20, 20, color.NRGBA{0x33, 0x66, 0x99, 255}))).To(Equal("#336699"))
+	})
+
+	It("returns empty for an image with no pixels", func() {
+		Expect(dominant.Color(image.NewNRGBA(image.Rect(0, 0, 0, 0)))).To(Equal(""))
+	})
+
+	// Presence, not salience: this is a placeholder, so the large field wins even though the small
+	// patch is the more interesting colour.
+	It("picks the largest area, not the most vivid one", func() {
+		img := newImg(20, 20, color.NRGBA{0xfa, 0xfa, 0xfa, 255})
+		fill(img, image.Rect(0, 0, 4, 4), color.NRGBA{0xff, 0x00, 0x00, 255})
+		Expect(dominant.Color(img)).To(Equal("#fafafa"))
+	})
+
+	It("reports a near-black cover as near-black", func() {
+		img := newImg(20, 20, color.NRGBA{0x05, 0x05, 0x05, 255})
+		fill(img, image.Rect(0, 0, 5, 5), color.NRGBA{0x00, 0xff, 0x00, 255})
+		Expect(dominant.Color(img)).To(Equal("#050505"))
+	})
+
+	// A gradient splits across many quantisation bins. Without merging, each slice is smaller than
+	// the flat block and the block would win despite covering far less of the image.
+	It("merges a gradient's bins so it beats a smaller flat block", func() {
+		img := image.NewNRGBA(image.Rect(0, 0, 40, 40))
+		for y := range 40 {
+			for x := range 40 {
+				// 30 columns of blue gradient == 75% of the image
+				if x < 30 {
+					img.SetNRGBA(x, y, color.NRGBA{0x10, 0x20, uint8(0xa0 + x), 255})
+				} else {
+					img.SetNRGBA(x, y, color.NRGBA{0xff, 0xcc, 0x00, 255})
+				}
+			}
+		}
+		got := dominant.Color(img)
+		Expect(got).To(HavePrefix("#1020"), "expected the blue gradient, got "+got)
+	})
+
+	It("is deterministic", func() {
+		img := image.NewNRGBA(image.Rect(0, 0, 30, 30))
+		for y := range 30 {
+			for x := range 30 {
+				img.SetNRGBA(x, y, color.NRGBA{uint8(x * 7), uint8(y * 5), uint8(x + y), 255})
+			}
+		}
+		first := dominant.Color(img)
+		for range 5 {
+			Expect(dominant.Color(img)).To(Equal(first))
+		}
+	})
+
+	It("handles images that are not NRGBA", func() {
+		src := newImg(10, 10, color.NRGBA{0x20, 0x40, 0x60, 255})
+		rgba := image.NewRGBA(src.Bounds())
+		for y := range 10 {
+			for x := range 10 {
+				rgba.Set(x, y, src.At(x, y))
+			}
+		}
+		Expect(dominant.Color(rgba)).To(Equal("#204060"))
+	})
+})

core/artwork/e2e/acquire_serve_test.go

@@ -0,0 +1,326 @@
+package e2e
+
+import (
+	"context"
+	"encoding/base64"
+	"errors"
+	"io"
+	"os"
+	"time"
+
+	"github.com/navidrome/navidrome/conf"
+	"github.com/navidrome/navidrome/conf/configtest"
+	"github.com/navidrome/navidrome/consts"
+	"github.com/navidrome/navidrome/core/agents"
+	"github.com/navidrome/navidrome/core/artwork"
+	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/server/events"
+	"github.com/navidrome/navidrome/tests"
+	"github.com/navidrome/navidrome/utils/cache"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+// Covers the enqueue → drain → serve chain; per-source resolution rules live in the unit suites.
+var _ = Describe("Acquisition → serve loop", func() {
+	var (
+		ctx        context.Context
+		ds         *tests.MockDataStore
+		artRepo    *tests.MockArtworkRepo
+		queueRepo  *tests.MockArtworkQueueRepo
+		albumRepo  *tests.MockAlbumRepo
+		artistRepo *tests.MockArtistRepo
+		mfRepo     *tests.MockMediaFileRepo
+		plRepo     *tests.MockPlaylistRepo
+		radioRepo  *tests.MockedRadioRepo
+		folderRepo *fakeFolderRepo
+		libRepo    *tests.MockLibraryRepo
+		store      *artwork.ImageStore
+		svc        artwork.Artwork
+		worker     *artwork.Worker
+		coverBytes []byte
+	)
+
+	itemFound := func(kind model.Kind, id string) func() bool {
+		return func() bool {
+			ia, err := artRepo.GetItemArtwork(kind, id, model.ImageTypePrimary)
+			return err == nil && ia.Hash != ""
+		}
+	}
+	itemAbsent := func(kind model.Kind, id string) func() bool {
+		return func() bool {
+			ia, err := artRepo.GetItemArtwork(kind, id, model.ImageTypePrimary)
+			return err == nil && ia.Hash == ""
+		}
+	}
+	// Enqueues the way the serving paths do, so the drain is driven by a plain queue row.
+	bump := func(kind, id string) {
+		GinkgoHelper()
+		Expect(ds.ArtworkQueue(ctx).EnqueuePreservingBackoff(model.ArtworkQueueItem{
+			ItemKind: kind, ItemID: id, ImageType: model.ImageTypePrimary,
+			Priority: model.ArtworkPriorityBump,
+		})).To(Succeed())
+	}
+
+	BeforeEach(func() {
+		DeferCleanup(configtest.SetupConfig())
+		ctx = context.Background()
+		repoRoot, err := os.Getwd()
+		Expect(err).ToNot(HaveOccurred())
+		coverBytes = readFixture(coverFixture)
+
+		conf.Server.CacheFolder = conf.NewDir(GinkgoT().TempDir())
+		conf.Server.DataFolder = conf.NewDir(GinkgoT().TempDir())
+		conf.Server.CoverArtPriority = "cover.jpg"
+		conf.Server.ArtistArtPriority = "artist.png" // keeps artist resolution offline
+		conf.Server.EnableMediaFileCoverArt = true
+		conf.Server.DevArtworkWorkerConcurrency = 1
+
+		folderRepo = &fakeFolderRepo{}
+		libRepo = &tests.MockLibraryRepo{}
+		libRepo.SetData(model.Libraries{{ID: 0, Path: repoRoot}})
+		artRepo = tests.CreateMockArtworkRepo()
+		queueRepo = tests.CreateMockArtworkQueueRepo()
+		albumRepo = tests.CreateMockAlbumRepo()
+		artistRepo = tests.CreateMockArtistRepo()
+		mfRepo = tests.CreateMockMediaFileRepo()
+		plRepo = tests.CreateMockPlaylistRepo()
+		radioRepo = tests.CreateMockedRadioRepo()
+		radioRepo.Data = map[string]*model.Radio{}
+		ds = &tests.MockDataStore{
+			MockedArtwork:      artRepo,
+			MockedArtworkQueue: queueRepo,
+			MockedAlbum:        albumRepo,
+			MockedArtist:       artistRepo,
+			MockedMediaFile:    mfRepo,
+			MockedPlaylist:     plRepo,
+			MockedRadio:        radioRepo,
+			MockedFolder:       folderRepo,
+			MockedLibrary:      libRepo,
+		}
+		ffm := tests.NewMockFFmpeg("")
+		store = artwork.NewImageStore(GinkgoT().TempDir())
+		// size=0 requests stream originals, so this reader is never called (serving_test covers resizing).
+		imgCache := cache.NewFileCache("ArtworkPipelineE2E", "100MB", "images", 0,
+			func(context.Context, cache.Item) (io.Reader, error) {
+				return nil, errors.New("resize not exercised in e2e")
+			})
+		Eventually(func() bool { return imgCache.Available(ctx) }).Should(BeTrue())
+
+		svc = artwork.NewArtwork(ds, imgCache, store, ffm)
+		worker = artwork.NewWorker(ds, store, agents.GetAgents(ds, nil), ffm, events.NoopBroker(), imgCache)
+	})
+
+	seedFolderAlbum := func(albumID string) {
+		folderRepo.result = []model.Folder{{Path: albumFolderPath, ImageFiles: []string{"cover.jpg"}}}
+		albumRepo.SetData(model.Albums{{ID: albumID, Name: "Album", FolderIDs: []string{"f1"}, LibraryID: 0}})
+	}
+
+	It("acquires album folder art and serves the exact bytes under its hash", func() {
+		seedFolderAlbum("al1")
+		bump("al", "al1")
+		runWorkerUntil(ctx, worker, itemFound(model.KindAlbumArtwork, "al1"))
+
+		ia, err := artRepo.GetItemArtwork(model.KindAlbumArtwork, "al1", model.ImageTypePrimary)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(ia.Source).To(Equal("folder"))
+
+		img, err := svc.Get(ctx, model.MustParseArtworkID("al-al1"), 0, false)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(img.Hash).To(Equal(ia.Hash))
+		Expect(img.Placeholder).To(BeFalse())
+		Expect(readAll(img)).To(Equal(coverBytes))
+	})
+
+	It("acquires an artist's uploaded image and serves it", func() {
+		name := writeUpload(consts.EntityArtist, "artist-e2e.png", artistPngFixture)
+		artistRepo.SetData(model.Artists{{ID: "ar1", Name: "Artist", UploadedImage: name}})
+		bump("ar", "ar1")
+		runWorkerUntil(ctx, worker, itemFound(model.KindArtistArtwork, "ar1"))
+
+		ia, err := artRepo.GetItemArtwork(model.KindArtistArtwork, "ar1", model.ImageTypePrimary)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(ia.Source).To(Equal("upload"))
+
+		img, err := svc.Get(ctx, model.MustParseArtworkID("ar-ar1"), 0, false)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(img.Hash).To(Equal(ia.Hash))
+		Expect(readAll(img)).To(Equal(readFixture(artistPngFixture)))
+	})
+
+	It("generates a playlist grid from its tracks' album art and serves it from the store", func() {
+		seedFolderAlbum("al1")
+		plRepo.SetData(model.Playlists{{ID: "pl1", Name: "Playlist"}})
+		plRepo.TracksRepo = &tests.MockPlaylistTrackRepo{AlbumIDs: []string{"al1"}}
+		bump("pl", "pl1")
+		runWorkerUntil(ctx, worker, itemFound(model.KindPlaylistArtwork, "pl1"))
+
+		ia, err := artRepo.GetItemArtwork(model.KindPlaylistArtwork, "pl1", model.ImageTypePrimary)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(ia.Source).To(Equal("generated"))
+
+		img, err := svc.Get(ctx, model.MustParseArtworkID("pl-pl1"), 0, false)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(img.Hash).To(Equal(ia.Hash))
+		art, err := artRepo.GetImage(ia.Hash)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(art.Mime).To(Equal("image/png"))
+		Expect(len(readAll(img))).To(BeNumerically(">", 0))
+	})
+
+	It("acquires a radio station's uploaded image and serves it", func() {
+		name := writeUpload(consts.EntityRadio, "radio-e2e.jpg", coverFixture)
+		radioRepo.Data["ra1"] = &model.Radio{ID: "ra1", Name: "Station", UploadedImage: name}
+		bump("ra", "ra1")
+		runWorkerUntil(ctx, worker, itemFound(model.KindRadioArtwork, "ra1"))
+
+		ia, err := artRepo.GetItemArtwork(model.KindRadioArtwork, "ra1", model.ImageTypePrimary)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(ia.Source).To(Equal("upload"))
+
+		img, err := svc.Get(ctx, model.MustParseArtworkID("ra-ra1"), 0, false)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(img.Hash).To(Equal(ia.Hash))
+		Expect(readAll(img)).To(Equal(coverBytes))
+	})
+
+	It("serves an unresolved track provisionally, then upgrades to the worker's state row", func() {
+		mfRepo.SetData(model.MediaFiles{{
+			ID: "mf1", AlbumID: "al1", HasCoverArt: true, LibraryID: 0, Path: mp3Fixture,
+		}})
+
+		provisional, err := svc.Get(ctx, model.MustParseArtworkID("mf-mf1"), 0, false)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(provisional.Placeholder).To(BeFalse())
+		Expect(provisional.Hash).ToNot(BeEmpty())
+		provisionalBytes := readAll(provisional)
+		Expect(len(provisionalBytes)).To(BeNumerically(">", 0))
+
+		_, err = artRepo.GetItemArtwork(model.KindMediaFileArtwork, "mf1", model.ImageTypePrimary)
+		Expect(err).To(MatchError(model.ErrNotFound), "provisional serving must not write a state row")
+
+		// The provisional read enqueued a Bump; drain it.
+		runWorkerUntil(ctx, worker, itemFound(model.KindMediaFileArtwork, "mf1"))
+		ia, err := artRepo.GetItemArtwork(model.KindMediaFileArtwork, "mf1", model.ImageTypePrimary)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(ia.Source).To(Equal("embedded"))
+		Expect(ia.Hash).To(Equal(provisional.Hash))
+
+		resolved, err := svc.Get(ctx, model.MustParseArtworkID("mf-mf1"), 0, false)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(resolved.Hash).To(Equal(ia.Hash))
+		Expect(readAll(resolved)).To(Equal(provisionalBytes))
+	})
+
+	It("stores dimensions, mime and a real blurhash alongside the acquired bytes", func() {
+		seedFolderAlbum("al1")
+		bump("al", "al1")
+		runWorkerUntil(ctx, worker, itemFound(model.KindAlbumArtwork, "al1"))
+
+		ia, err := artRepo.GetItemArtwork(model.KindAlbumArtwork, "al1", model.ImageTypePrimary)
+		Expect(err).ToNot(HaveOccurred())
+		art, err := artRepo.GetImage(ia.Hash)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(art.Mime).To(Equal("image/jpeg"))
+		Expect(art.Width).To(BeNumerically(">", 0))
+		Expect(art.Height).To(BeNumerically(">", 0))
+		Expect(art.SizeBytes).To(BeNumerically("==", len(coverBytes)))
+		// Never a synthesized value: both hashes are encoded from the real pixels.
+		Expect(art.BlurHash).ToNot(BeEmpty())
+		Expect(art.ThumbHash).ToNot(BeEmpty())
+		raw, err := base64.StdEncoding.DecodeString(art.ThumbHash)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(len(raw)).To(BeNumerically(">=", 5))
+	})
+
+	It("acquires GIF artwork, whose decoder only core/artwork's blank import registers", func() {
+		writeUploadedImage(consts.EntityRadio, "station.gif", gifFixture)
+		radioRepo.Data["ra1"] = &model.Radio{ID: "ra1", Name: "Station", UploadedImage: "station.gif"}
+		bump("ra", "ra1")
+		runWorkerUntil(ctx, worker, itemFound(model.KindRadioArtwork, "ra1"))
+
+		ia, err := artRepo.GetItemArtwork(model.KindRadioArtwork, "ra1", model.ImageTypePrimary)
+		Expect(err).ToNot(HaveOccurred())
+		art, err := artRepo.GetImage(ia.Hash)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(art.Mime).To(Equal("image/gif"))
+		Expect(art.Width).To(BeNumerically("==", 4))
+	})
+
+	It("deduplicates byte-identical art across entities onto one image row", func() {
+		folderRepo.result = []model.Folder{{Path: albumFolderPath, ImageFiles: []string{"cover.jpg"}}}
+		albumRepo.SetData(model.Albums{
+			{ID: "al1", Name: "Album", FolderIDs: []string{"f1"}, LibraryID: 0},
+			{ID: "al2", Name: "Same Cover", FolderIDs: []string{"f1"}, LibraryID: 0},
+		})
+		bump("al", "al1")
+		bump("al", "al2")
+		runWorkerUntil(ctx, worker, func() bool {
+			return itemFound(model.KindAlbumArtwork, "al1")() && itemFound(model.KindAlbumArtwork, "al2")()
+		})
+
+		ia1, err := artRepo.GetItemArtwork(model.KindAlbumArtwork, "al1", model.ImageTypePrimary)
+		Expect(err).ToNot(HaveOccurred())
+		ia2, err := artRepo.GetItemArtwork(model.KindAlbumArtwork, "al2", model.ImageTypePrimary)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(ia1.Hash).To(Equal(ia2.Hash), "identical bytes must share one content hash")
+		Expect(readAll(mustGet(svc.Get(ctx, model.MustParseArtworkID("al-al2"), 0, false)))).To(Equal(coverBytes))
+	})
+
+	It("stops serving a file-backed image once its source file changes underneath", func() {
+		name := writeUpload(consts.EntityRadio, "radio-stale.jpg", coverFixture)
+		radioRepo.Data["ra1"] = &model.Radio{ID: "ra1", Name: "Station", UploadedImage: name}
+		bump("ra", "ra1")
+		runWorkerUntil(ctx, worker, itemFound(model.KindRadioArtwork, "ra1"))
+
+		ia, err := artRepo.GetItemArtwork(model.KindRadioArtwork, "ra1", model.ImageTypePrimary)
+		Expect(err).ToNot(HaveOccurred())
+		staleHash := ia.Hash
+
+		path := model.UploadedImagePath(consts.EntityRadio, name)
+		Expect(os.WriteFile(path, readFixture(artistPngFixture), 0o600)).To(Succeed())
+		newer := time.Now().Add(2 * time.Second)
+		Expect(os.Chtimes(path, newer, newer)).To(Succeed())
+
+		// The mtime no longer matches the state row, so the stale bytes are not served.
+		_, err = svc.Get(ctx, model.MustParseArtworkID("ra-ra1"), 0, false)
+		Expect(err).To(MatchError(artwork.ErrUnavailable))
+
+		// That failed read enqueued a re-resolution.
+		runWorkerUntil(ctx, worker, func() bool {
+			cur, gerr := artRepo.GetItemArtwork(model.KindRadioArtwork, "ra1", model.ImageTypePrimary)
+			return gerr == nil && cur.Hash != "" && cur.Hash != staleHash
+		})
+		img, err := svc.Get(ctx, model.MustParseArtworkID("ra-ra1"), 0, false)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(readAll(img)).To(Equal(readFixture(artistPngFixture)))
+	})
+
+	It("records an absent state for an entity with no art and reports it unavailable", func() {
+		albumRepo.SetData(model.Albums{{ID: "alx", Name: "Artless", LibraryID: 0}})
+		bump("al", "alx")
+		runWorkerUntil(ctx, worker, itemAbsent(model.KindAlbumArtwork, "alx"))
+
+		_, err := svc.Get(ctx, model.MustParseArtworkID("al-alx"), 0, false)
+		Expect(err).To(MatchError(artwork.ErrUnavailable))
+
+		img, err := svc.GetOrPlaceholder(ctx, "al-alx", 0, false)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(img.Placeholder).To(BeTrue())
+	})
+})
+
+func mustGet(img *artwork.Image, err error) *artwork.Image {
+	GinkgoHelper()
+	Expect(err).ToNot(HaveOccurred())
+	return img
+}
+
+// Raw bytes on purpose: encoding a GIF here would register image/gif in the test binary, masking
+// the production import the spec above guards.
+var gifFixture = []byte{
+	0x47, 0x49, 0x46, 0x38, 0x39, 0x61, 0x04, 0x00, 0x04, 0x00, 0x80, 0x00,
+	0x00, 0x2e, 0x86, 0xc1, 0xf4, 0xd0, 0x3f, 0x2c, 0x00, 0x00, 0x00, 0x00,
+	0x04, 0x00, 0x04, 0x00, 0x00, 0x02, 0x05, 0x44, 0x7c, 0x67, 0xb8, 0x05,
+	0x00, 0x3b,
+}

core/artwork/e2e/album_test.go

@@ -1,4 +1,4 @@
-package artworke2e_test
+package e2e
 
 import (
 	"testing/fstest"
@@ -9,14 +9,11 @@ import (
 	. "github.com/onsi/gomega"
 )
 
-const (
-	defaultCoverPriority = "cover.*, folder.*, front.*, embedded, external"
-	defaultDiscPriority  = "disc*.*, cd*.*, cover.*, folder.*, front.*, discsubtitle, embedded"
-)
-
+// The in-memory library FS cannot satisfy the os.Open(SourcePath) used to serve folder art, so
+// folder scenarios assert on the worker's state row (Source + SourcePath) instead of the bytes.
 var _ = Describe("Album artwork resolution", func() {
 	BeforeEach(func() {
-		setupHarness()
+		setupResolutionHarness()
 	})
 
 	When("an album has a single folder with cover.jpg at the album root", func() {
@@ -28,12 +25,10 @@ var _ = Describe("Album artwork resolution", func() {
 			conf.Server.CoverArtPriority = defaultCoverPriority
 			setLayout(fstest.MapFS{
 				"Artist/Album/01 - Track.mp3": trackFile(1, "Track"),
-				"Artist/Album/cover.jpg":      imageFile("album-root"),
+				"Artist/Album/cover.jpg":      smallPNG("album-root"),
 			})
 			scan()
-
-			al := firstAlbum()
-			Expect(readArtwork(al.CoverArtID())).To(Equal(imageBytes("album-root")))
+			expectAlbumFolderCover(firstAlbum(), "Artist/Album/cover.jpg")
 		})
 	})
 
@@ -55,16 +50,16 @@ var _ = Describe("Album artwork resolution", func() {
 			setLayout(fstest.MapFS{
 				"Artist/Album/CD1/01 - Track.mp3": trackFile(1, "Track CD1"),
 				"Artist/Album/CD2/01 - Track.mp3": trackFile(1, "Track CD2"),
-				"Artist/Album/cover.jpg":          imageFile("album-root"),
-				"Artist/Album/CD1/cover.jpg":      imageFile("disc1"),
-				"Artist/Album/CD2/cover.jpg":      imageFile("disc2"),
+				"Artist/Album/cover.jpg":          smallPNG("album-root"),
+				"Artist/Album/CD1/cover.jpg":      smallPNG("disc1"),
+				"Artist/Album/CD2/cover.jpg":      smallPNG("disc2"),
 			})
 			scan()
 
 			al := firstAlbum()
 			Expect(al.FolderIDs).To(HaveLen(2),
-				"sanity check: scanner should treat the two disc subfolders as one multi-disc album")
-			Expect(readArtwork(al.CoverArtID())).To(Equal(imageBytes("album-root")))
+				"sanity check: the two disc subfolders should form one multi-disc album")
+			expectAlbumFolderCover(al, "Artist/Album/cover.jpg")
 		})
 	})
 
@@ -86,14 +81,12 @@ var _ = Describe("Album artwork resolution", func() {
 			setLayout(fstest.MapFS{
 				"Artist/Album/CD1/01 - Track.mp3": trackFile(1, "Track CD1"),
 				"Artist/Album/CD2/01 - Track.mp3": trackFile(1, "Track CD2"),
-				"Artist/Album/folder.jpg":         imageFile("album-root"),
-				"Artist/Album/CD1/folder.jpg":     imageFile("disc1"),
-				"Artist/Album/CD2/folder.jpg":     imageFile("disc2"),
+				"Artist/Album/folder.jpg":         smallPNG("album-root"),
+				"Artist/Album/CD1/folder.jpg":     smallPNG("disc1"),
+				"Artist/Album/CD2/folder.jpg":     smallPNG("disc2"),
 			})
 			scan()
-
-			al := firstAlbum()
-			Expect(readArtwork(al.CoverArtID())).To(Equal(imageBytes("album-root")))
+			expectAlbumFolderCover(firstAlbum(), "Artist/Album/folder.jpg")
 		})
 	})
 
@@ -109,12 +102,10 @@ var _ = Describe("Album artwork resolution", func() {
 			conf.Server.CoverArtPriority = defaultCoverPriority
 			setLayout(fstest.MapFS{
 				"Artist/Album/disc1/01 - Track.mp3": trackFile(1, "Track"),
-				"Artist/Album/cover.jpg":            imageFile("album-root"),
+				"Artist/Album/cover.jpg":            smallPNG("album-root"),
 			})
 			scan()
-
-			al := firstAlbum()
-			Expect(readArtwork(al.CoverArtID())).To(Equal(imageBytes("album-root")))
+			expectAlbumFolderCover(firstAlbum(), "Artist/Album/cover.jpg")
 		})
 	})
 
@@ -133,14 +124,12 @@ var _ = Describe("Album artwork resolution", func() {
 			setLayout(fstest.MapFS{
 				"Album/CD1/01 - Track.mp3": trackFile(1, "Track CD1"),
 				"Album/CD2/01 - Track.mp3": trackFile(1, "Track CD2"),
-				"Album/cover.jpg":          imageFile("album-root"),
-				"Album/CD1/folder.jpg":     imageFile("disc1"),
-				"Album/CD2/folder.jpg":     imageFile("disc2"),
+				"Album/cover.jpg":          smallPNG("album-root"),
+				"Album/CD1/folder.jpg":     smallPNG("disc1"),
+				"Album/CD2/folder.jpg":     smallPNG("disc2"),
 			})
 			scan()
-
-			al := firstAlbum()
-			Expect(readArtwork(al.CoverArtID())).To(Equal(imageBytes("album-root")))
+			expectAlbumFolderCover(firstAlbum(), "Album/cover.jpg")
 		})
 	})
 
@@ -153,14 +142,14 @@ var _ = Describe("Album artwork resolution", func() {
 			conf.Server.CoverArtPriority = "embedded, cover.*, folder.*, front.*, external"
 			setLayout(fstest.MapFS{
 				"Artist/Album/01 - Track.mp3": trackFile(1, "Track", map[string]any{"has_picture": "true"}),
-				"Artist/Album/cover.jpg":      imageFile("external"),
+				"Artist/Album/cover.jpg":      smallPNG("external"),
 			})
 			scan()
-			// Swap in real MP3 bytes so libFS.Open returns a taglib-readable stream.
 			replaceWithRealMP3("Artist/Album/01 - Track.mp3")
 
-			al := firstAlbum()
-			Expect(readArtwork(al.CoverArtID())).To(Equal(embeddedArtBytes))
+			ia := acquire(model.KindAlbumArtwork, firstAlbum().ID)
+			Expect(ia.Source).To(Equal("embedded"))
+			Expect(storedBytes(ia)).To(Equal(embeddedArtBytes))
 		})
 	})
 
@@ -176,8 +165,9 @@ var _ = Describe("Album artwork resolution", func() {
 			scan()
 			replaceWithRealMP3("Artist/Album/01 - Track.mp3")
 
-			al := firstAlbum()
-			Expect(readArtwork(al.CoverArtID())).To(Equal(embeddedArtBytes))
+			ia := acquire(model.KindAlbumArtwork, firstAlbum().ID)
+			Expect(ia.Source).To(Equal("embedded"))
+			Expect(storedBytes(ia)).To(Equal(embeddedArtBytes))
 		})
 	})
 
@@ -190,12 +180,10 @@ var _ = Describe("Album artwork resolution", func() {
 			conf.Server.CoverArtPriority = "cover.*, folder.*"
 			setLayout(fstest.MapFS{
 				"Artist/Album/01 - Track.mp3": trackFile(1, "Track"),
-				"Artist/Album/Cover.JPG":      imageFile("case-insensitive"),
+				"Artist/Album/Cover.JPG":      smallPNG("case-insensitive"),
 			})
 			scan()
-
-			al := firstAlbum()
-			Expect(readArtwork(al.CoverArtID())).To(Equal(imageBytes("case-insensitive")))
+			expectAlbumFolderCover(firstAlbum(), "Artist/Album/Cover.JPG")
 		})
 	})
 
@@ -209,30 +197,25 @@ var _ = Describe("Album artwork resolution", func() {
 			conf.Server.CoverArtPriority = "cover.*"
 			setLayout(fstest.MapFS{
 				"Artist/Album/01 - Track.mp3": trackFile(1, "Track"),
-				"Artist/Album/cover.jpg":      imageFile("primary"),
-				"Artist/Album/cover.1.jpg":    imageFile("secondary"),
+				"Artist/Album/cover.jpg":      smallPNG("primary"),
+				"Artist/Album/cover.1.jpg":    smallPNG("secondary"),
 			})
 			scan()
-
-			al := firstAlbum()
-			Expect(readArtwork(al.CoverArtID())).To(Equal(imageBytes("primary")))
+			expectAlbumFolderCover(firstAlbum(), "Artist/Album/cover.jpg")
 		})
 	})
 
 	When("the album has no cover and CoverArtPriority lists only file patterns", func() {
 		// Artist/
 		// └── Album/
-		//     └── 01 - Track.mp3       (no image files — returns ErrUnavailable)
-		It("returns ErrUnavailable", func() {
+		//     └── 01 - Track.mp3       (no image files — settles absent)
+		It("settles absent", func() {
 			conf.Server.CoverArtPriority = "cover.*, folder.*"
 			setLayout(fstest.MapFS{
 				"Artist/Album/01 - Track.mp3": trackFile(1, "Track"),
 			})
 			scan()
-
-			al := firstAlbum()
-			_, err := readArtworkOrErr(model.NewArtworkID(model.KindAlbumArtwork, al.ID, &al.UpdatedAt))
-			Expect(err).To(HaveOccurred())
+			expectAlbumAbsent(firstAlbum())
 		})
 	})
 
@@ -248,12 +231,10 @@ var _ = Describe("Album artwork resolution", func() {
 			conf.Server.CoverArtPriority = defaultCoverPriority
 			setLayout(fstest.MapFS{
 				"Artist/Album/01 - Track.mp3": trackFile(1, "Track"),
-				"Artist/Album/folder.jpg":     imageFile("folder"),
+				"Artist/Album/folder.jpg":     smallPNG("folder"),
 			})
 			scan()
-
-			al := firstAlbum()
-			Expect(readArtwork(al.CoverArtID())).To(Equal(imageBytes("folder")))
+			expectAlbumFolderCover(firstAlbum(), "Artist/Album/folder.jpg")
 		})
 	})
 
@@ -266,12 +247,10 @@ var _ = Describe("Album artwork resolution", func() {
 			conf.Server.CoverArtPriority = defaultCoverPriority
 			setLayout(fstest.MapFS{
 				"Artist/Album/01 - Track.mp3": trackFile(1, "Track"),
-				"Artist/Album/front.jpg":      imageFile("front"),
+				"Artist/Album/front.jpg":      smallPNG("front"),
 			})
 			scan()
-
-			al := firstAlbum()
-			Expect(readArtwork(al.CoverArtID())).To(Equal(imageBytes("front")))
+			expectAlbumFolderCover(firstAlbum(), "Artist/Album/front.jpg")
 		})
 	})
 
@@ -286,14 +265,12 @@ var _ = Describe("Album artwork resolution", func() {
 			conf.Server.CoverArtPriority = defaultCoverPriority
 			setLayout(fstest.MapFS{
 				"Artist/Album/01 - Track.mp3": trackFile(1, "Track"),
-				"Artist/Album/cover.jpg":      imageFile("cover"),
-				"Artist/Album/folder.jpg":     imageFile("folder"),
-				"Artist/Album/front.jpg":      imageFile("front"),
+				"Artist/Album/cover.jpg":      smallPNG("cover"),
+				"Artist/Album/folder.jpg":     smallPNG("folder"),
+				"Artist/Album/front.jpg":      smallPNG("front"),
 			})
 			scan()
-
-			al := firstAlbum()
-			Expect(readArtwork(al.CoverArtID())).To(Equal(imageBytes("cover")))
+			expectAlbumFolderCover(firstAlbum(), "Artist/Album/cover.jpg")
 		})
 	})
 
@@ -307,13 +284,11 @@ var _ = Describe("Album artwork resolution", func() {
 			conf.Server.CoverArtPriority = defaultCoverPriority
 			setLayout(fstest.MapFS{
 				"Artist/Album/01 - Track.mp3": trackFile(1, "Track"),
-				"Artist/Album/folder.jpg":     imageFile("folder"),
-				"Artist/Album/front.jpg":      imageFile("front"),
+				"Artist/Album/folder.jpg":     smallPNG("folder"),
+				"Artist/Album/front.jpg":      smallPNG("front"),
 			})
 			scan()
-
-			al := firstAlbum()
-			Expect(readArtwork(al.CoverArtID())).To(Equal(imageBytes("folder")))
+			expectAlbumFolderCover(firstAlbum(), "Artist/Album/folder.jpg")
 		})
 	})
 
@@ -328,14 +303,12 @@ var _ = Describe("Album artwork resolution", func() {
 			conf.Server.CoverArtPriority = "cover.*"
 			setLayout(fstest.MapFS{
 				"Artist/Album/01 - Track.mp3": trackFile(1, "Track"),
-				"Artist/Album/cover.2.jpg":    imageFile("second"),
-				"Artist/Album/cover.jpg":      imageFile("primary"),
-				"Artist/Album/cover.1.jpg":    imageFile("first"),
+				"Artist/Album/cover.2.jpg":    smallPNG("second"),
+				"Artist/Album/cover.jpg":      smallPNG("primary"),
+				"Artist/Album/cover.1.jpg":    smallPNG("first"),
 			})
 			scan()
-
-			al := firstAlbum()
-			Expect(readArtwork(al.CoverArtID())).To(Equal(imageBytes("primary")))
+			expectAlbumFolderCover(firstAlbum(), "Artist/Album/cover.jpg")
 		})
 	})
 
@@ -348,12 +321,10 @@ var _ = Describe("Album artwork resolution", func() {
 			conf.Server.CoverArtPriority = "bogus.*, cover.*"
 			setLayout(fstest.MapFS{
 				"Artist/Album/01 - Track.mp3": trackFile(1, "Track"),
-				"Artist/Album/cover.jpg":      imageFile("cover"),
+				"Artist/Album/cover.jpg":      smallPNG("cover"),
 			})
 			scan()
-
-			al := firstAlbum()
-			Expect(readArtwork(al.CoverArtID())).To(Equal(imageBytes("cover")))
+			expectAlbumFolderCover(firstAlbum(), "Artist/Album/cover.jpg")
 		})
 	})
 
@@ -371,21 +342,16 @@ var _ = Describe("Album artwork resolution", func() {
 		It("does not use the artist image as album art", func() {
 			conf.Server.CoverArtPriority = defaultCoverPriority
 			setLayout(fstest.MapFS{
-				"Artist/folder.jpg":             imageFile("artist-thumbnail"),
+				"Artist/folder.jpg":             smallPNG("artist-thumbnail"),
 				"Artist/Album A/01 - Track.mp3": trackFile(1, "Track A", map[string]any{"album": "Album A", "albumartist": "Artist"}),
 				"Artist/Album B/01 - Track.mp3": trackFile(1, "Track B", map[string]any{"album": "Album B", "albumartist": "Artist"}),
-				"Artist/Album B/cover.jpg":      imageFile("album-b"),
+				"Artist/Album B/cover.jpg":      smallPNG("album-b"),
 			})
 			scan()
 
-			alA := albumByName("Album A")
-			_, err := readArtworkOrErr(alA.CoverArtID())
-			Expect(err).To(HaveOccurred(),
-				"Album A has no images of its own, so it must fall through to the placeholder "+
-					"instead of inheriting the artist folder's folder.jpg")
-
-			alB := albumByName("Album B")
-			Expect(readArtwork(alB.CoverArtID())).To(Equal(imageBytes("album-b")))
+			// Album B first: the acquire in expectAlbumAbsent would settle Album B too.
+			expectAlbumFolderCover(albumByName("Album B"), "Artist/Album B/cover.jpg")
+			expectAlbumAbsent(albumByName("Album A"))
 		})
 	})
 
@@ -402,21 +368,58 @@ var _ = Describe("Album artwork resolution", func() {
 		It("does not use the artist image as album art for the spread album", func() {
 			conf.Server.CoverArtPriority = defaultCoverPriority
 			setLayout(fstest.MapFS{
-				"Artist/folder.jpg":                   imageFile("artist-thumbnail"),
+				"Artist/folder.jpg":                   smallPNG("artist-thumbnail"),
 				"Artist/Album A/01 - Track.mp3":       trackFile(1, "Track A1", map[string]any{"album": "Album A", "albumartist": "Artist"}),
 				"Artist/Album A bonus/02 - Track.mp3": trackFile(2, "Track A2", map[string]any{"album": "Album A", "albumartist": "Artist"}),
 				"Artist/Album B/01 - Track.mp3":       trackFile(1, "Track B", map[string]any{"album": "Album B", "albumartist": "Artist"}),
-				"Artist/Album B/cover.jpg":            imageFile("album-b"),
+				"Artist/Album B/cover.jpg":            smallPNG("album-b"),
 			})
 			scan()
 
 			alA := albumByName("Album A")
 			Expect(alA.FolderIDs).To(HaveLen(2),
-				"sanity check: scanner should treat the two sibling folders as one spread album")
-			_, err := readArtworkOrErr(alA.CoverArtID())
-			Expect(err).To(HaveOccurred(),
-				"the spread album has no images of its own, so it must fall through to the "+
-					"placeholder instead of inheriting the artist folder's folder.jpg")
+				"sanity check: the two sibling folders should form one spread album")
+			expectAlbumAbsent(alA)
+		})
+	})
+
+	// albumRootParent refuses the library root as an album root (parent.ParentID == "").
+	When("a multi-disc album sits directly at the library root with a cover.jpg beside it", func() {
+		// (library root)
+		// ├── cover.jpg                ← must NOT be adopted
+		// ├── CD1/
+		// │   └── 01 - Track.mp3
+		// └── CD2/
+		//     └── 01 - Track.mp3
+		It("does not adopt the library-root image as album art", func() {
+			conf.Server.CoverArtPriority = defaultCoverPriority
+			setLayout(fstest.MapFS{
+				"cover.jpg":          smallPNG("library-root"),
+				"CD1/01 - Track.mp3": trackFile(1, "T1", map[string]any{"album": "Rootless", "disc": "1"}),
+				"CD2/01 - Track.mp3": trackFile(1, "T2", map[string]any{"album": "Rootless", "disc": "2"}),
+			})
+			scan()
+			expectAlbumAbsent(firstAlbum())
+		})
+	})
+
+	// The shallower artist-folder cover.jpg would win the basename tie, but albumRootParent skips
+	// the parent folder for a single-folder album that has images of its own.
+	When("a single-folder album has its own cover.jpg and the artist folder has one too", func() {
+		// Artist/
+		// ├── cover.jpg                ← shallower, but must NOT win
+		// └── Album/
+		//     ├── 01 - Track.mp3
+		//     └── cover.jpg            ← should win
+		It("prefers the album's own cover over the shallower artist-folder cover", func() {
+			conf.Server.CoverArtPriority = defaultCoverPriority
+			setLayout(fstest.MapFS{
+				"Artist/cover.jpg":            smallPNG("artist-image"),
+				"Artist/Album/01 - Track.mp3": trackFile(1, "Track", map[string]any{"albumartist": "Artist"}),
+				"Artist/Album/cover.jpg":      smallPNG("album-own"),
+			})
+			scan()
+			expectAlbumFolderCover(firstAlbum(), "Artist/Album/cover.jpg")
 		})
 	})
 
@@ -430,13 +433,13 @@ var _ = Describe("Album artwork resolution", func() {
 		// ├── Album A bonus/
 		// │   └── 02 - Track.mp3       (album: "Album A")
 		// └── Album B/
-		//     └── 01 - Track.mp3
+		//     └── 01 - Track.mp3       (other-album audio: rejects the artist folder as a root)
 		It("prefers the album's own art over the artist image", func() {
 			conf.Server.CoverArtPriority = defaultCoverPriority
 			setLayout(fstest.MapFS{
-				"Artist/cover.jpg":                    imageFile("artist-image"),
+				"Artist/cover.jpg":                    smallPNG("artist-image"),
 				"Artist/Album A/01 - Track.mp3":       trackFile(1, "Track A1", map[string]any{"album": "Album A", "albumartist": "Artist"}),
-				"Artist/Album A/front.jpg":            imageFile("album-a-front"),
+				"Artist/Album A/front.jpg":            smallPNG("album-a-front"),
 				"Artist/Album A bonus/02 - Track.mp3": trackFile(2, "Track A2", map[string]any{"album": "Album A", "albumartist": "Artist"}),
 				"Artist/Album B/01 - Track.mp3":       trackFile(1, "Track B", map[string]any{"album": "Album B", "albumartist": "Artist"}),
 			})
@@ -444,8 +447,8 @@ var _ = Describe("Album artwork resolution", func() {
 
 			alA := albumByName("Album A")
 			Expect(alA.FolderIDs).To(HaveLen(2),
-				"sanity check: scanner should treat the two sibling folders as one spread album")
-			Expect(readArtwork(alA.CoverArtID())).To(Equal(imageBytes("album-a-front")))
+				"sanity check: the two sibling folders should form one spread album")
+			expectAlbumFolderCover(alA, "Artist/Album A/front.jpg")
 		})
 	})
 
@@ -458,12 +461,10 @@ var _ = Describe("Album artwork resolution", func() {
 			conf.Server.CoverArtPriority = "embedded, cover.*"
 			setLayout(fstest.MapFS{
 				"Artist/Album/01 - Track.mp3": trackFile(1, "Track"),
-				"Artist/Album/cover.jpg":      imageFile("cover"),
+				"Artist/Album/cover.jpg":      smallPNG("cover"),
 			})
 			scan()
-
-			al := firstAlbum()
-			Expect(readArtwork(al.CoverArtID())).To(Equal(imageBytes("cover")))
+			expectAlbumFolderCover(firstAlbum(), "Artist/Album/cover.jpg")
 		})
 	})
 })

core/artwork/e2e/artist_test.go

@@ -1,4 +1,4 @@
-package artworke2e_test
+package e2e
 
 import (
 	"os"
@@ -8,6 +8,7 @@ import (
 	"github.com/Masterminds/squirrel"
 	"github.com/navidrome/navidrome/conf"
 	"github.com/navidrome/navidrome/consts"
+	"github.com/navidrome/navidrome/core/artwork"
 	"github.com/navidrome/navidrome/model"
 	. "github.com/onsi/ginkgo/v2"
 	. "github.com/onsi/gomega"
@@ -16,9 +17,11 @@ import (
 // Doc reference:
 // https://www.navidrome.org/docs/usage/library/artwork/#artists
 // Default ArtistArtPriority is "artist.*, album/artist.*, external".
+// Library-folder images are file-backed (asserted on the worker state row); uploaded and
+// image-folder images are real files on disk (asserted byte-for-byte).
 var _ = Describe("Artist artwork resolution", func() {
 	BeforeEach(func() {
-		setupHarness()
+		setupResolutionHarness()
 	})
 
 	When("the artist folder contains an artist.jpg", func() {
@@ -30,13 +33,10 @@ var _ = Describe("Artist artwork resolution", func() {
 			conf.Server.ArtistArtPriority = "artist.*, album/artist.*, external"
 			setLayout(fstest.MapFS{
 				"Artist/Album/01 - Track.mp3": trackFile(1, "Track", map[string]any{"albumartist": "Artist"}),
-				"Artist/artist.jpg":           imageFile("artist-folder"),
+				"Artist/artist.jpg":           smallPNG("artist-folder"),
 			})
 			scan()
-
-			ar := soleArtist()
-			artID := model.NewArtworkID(model.KindArtistArtwork, ar.ID, nil)
-			Expect(readArtwork(artID)).To(Equal(imageBytes("artist-folder")))
+			expectArtistFolder(soleArtist(), "Artist/artist.jpg")
 		})
 	})
 
@@ -49,13 +49,10 @@ var _ = Describe("Artist artwork resolution", func() {
 			conf.Server.ArtistArtPriority = "artist.*, album/artist.*, external"
 			setLayout(fstest.MapFS{
 				"Artist/Album/01 - Track.mp3": trackFile(1, "Track", map[string]any{"albumartist": "Artist"}),
-				"Artist/Album/artist.jpg":     imageFile("album-artist"),
+				"Artist/Album/artist.jpg":     smallPNG("album-artist"),
 			})
 			scan()
-
-			ar := soleArtist()
-			artID := model.NewArtworkID(model.KindArtistArtwork, ar.ID, nil)
-			Expect(readArtwork(artID)).To(Equal(imageBytes("album-artist")))
+			expectArtistFolder(soleArtist(), "Artist/Album/artist.jpg")
 		})
 	})
 
@@ -69,14 +66,11 @@ var _ = Describe("Artist artwork resolution", func() {
 			conf.Server.ArtistArtPriority = "artist.*, album/artist.*, external"
 			setLayout(fstest.MapFS{
 				"Artist/Album/01 - Track.mp3": trackFile(1, "Track", map[string]any{"albumartist": "Artist"}),
-				"Artist/artist.jpg":           imageFile("artist-folder"),
-				"Artist/Album/artist.jpg":     imageFile("album-artist"),
+				"Artist/artist.jpg":           smallPNG("artist-folder"),
+				"Artist/Album/artist.jpg":     smallPNG("album-artist"),
 			})
 			scan()
-
-			ar := soleArtist()
-			artID := model.NewArtworkID(model.KindArtistArtwork, ar.ID, nil)
-			Expect(readArtwork(artID)).To(Equal(imageBytes("artist-folder")))
+			expectArtistFolder(soleArtist(), "Artist/artist.jpg")
 		})
 	})
 
@@ -89,13 +83,10 @@ var _ = Describe("Artist artwork resolution", func() {
 			conf.Server.ArtistArtPriority = "artist.*"
 			setLayout(fstest.MapFS{
 				"Artist/Album/01 - Track.mp3": trackFile(1, "Track", map[string]any{"albumartist": "Artist"}),
-				"Artist/artist.jpg":           imageFile("artist-folder"),
+				"Artist/artist.jpg":           smallPNG("artist-folder"),
 			})
 			scan()
-
-			ar := soleArtist()
-			artID := model.NewArtworkID(model.KindArtistArtwork, ar.ID, nil)
-			Expect(readArtwork(artID)).To(Equal(imageBytes("artist-folder")))
+			expectArtistFolder(soleArtist(), "Artist/artist.jpg")
 		})
 	})
 
@@ -111,14 +102,11 @@ var _ = Describe("Artist artwork resolution", func() {
 			setLayout(fstest.MapFS{
 				"Artist/Album/CD1/01 - Track.mp3": trackFile(1, "Track 1", map[string]any{"albumartist": "Artist", "album": "Album"}),
 				"Artist/Album/CD2/02 - Track.mp3": trackFile(2, "Track 2", map[string]any{"albumartist": "Artist", "album": "Album"}),
-				"Artist/artist.jpg":               imageFile("artist-folder"),
-				"Artist/Album/artist.jpg":         imageFile("album-artist"),
+				"Artist/artist.jpg":               smallPNG("artist-folder"),
+				"Artist/Album/artist.jpg":         smallPNG("album-artist"),
 			})
 			scan()
-
-			ar := soleArtist()
-			artID := model.NewArtworkID(model.KindArtistArtwork, ar.ID, nil)
-			Expect(readArtwork(artID)).To(Equal(imageBytes("artist-folder")))
+			expectArtistFolder(soleArtist(), "Artist/artist.jpg")
 		})
 	})
 
@@ -136,14 +124,11 @@ var _ = Describe("Artist artwork resolution", func() {
 				"Artist/Album1/CD1/01 - Track.mp3": trackFile(1, "Track 1", map[string]any{"albumartist": "Artist", "album": "Album1"}),
 				"Artist/Album1/CD2/02 - Track.mp3": trackFile(2, "Track 2", map[string]any{"albumartist": "Artist", "album": "Album1"}),
 				"Artist/Album2/03 - Track.mp3":     trackFile(3, "Track 3", map[string]any{"albumartist": "Artist", "album": "Album2"}),
-				"Artist/artist.jpg":                imageFile("artist-folder"),
-				"Artist/Album1/artist.jpg":         imageFile("album-artist"),
+				"Artist/artist.jpg":                smallPNG("artist-folder"),
+				"Artist/Album1/artist.jpg":         smallPNG("album-artist"),
 			})
 			scan()
-
-			ar := soleArtist()
-			artID := model.NewArtworkID(model.KindArtistArtwork, ar.ID, nil)
-			Expect(readArtwork(artID)).To(Equal(imageBytes("artist-folder")))
+			expectArtistFolder(soleArtist(), "Artist/artist.jpg")
 		})
 	})
 
@@ -164,14 +149,11 @@ var _ = Describe("Artist artwork resolution", func() {
 				"Artist/Album1/CD2/02 - Track.mp3": trackFile(2, "Track 2", map[string]any{"albumartist": "Artist", "album": "Album1"}),
 				"Artist/Album2/CD1/03 - Track.mp3": trackFile(3, "Track 3", map[string]any{"albumartist": "Artist", "album": "Album2"}),
 				"Artist/Album2/CD2/04 - Track.mp3": trackFile(4, "Track 4", map[string]any{"albumartist": "Artist", "album": "Album2"}),
-				"Artist/artist.jpg":                imageFile("artist-folder"),
-				"Artist/Album1/artist.jpg":         imageFile("album-artist"),
+				"Artist/artist.jpg":                smallPNG("artist-folder"),
+				"Artist/Album1/artist.jpg":         smallPNG("album-artist"),
 			})
 			scan()
-
-			ar := soleArtist()
-			artID := model.NewArtworkID(model.KindArtistArtwork, ar.ID, nil)
-			Expect(readArtwork(artID)).To(Equal(imageBytes("artist-folder")))
+			expectArtistFolder(soleArtist(), "Artist/artist.jpg")
 		})
 	})
 
@@ -189,18 +171,19 @@ var _ = Describe("Artist artwork resolution", func() {
 			conf.Server.ArtistArtPriority = "artist.*, album/artist.*, external"
 			setLayout(fstest.MapFS{
 				"Artist/Album/01 - Track.mp3": trackFile(1, "Track", map[string]any{"albumartist": "Artist"}),
-				"Artist/artist.jpg":           imageFile("artist-folder"),
+				"Artist/artist.jpg":           smallPNG("artist-folder"),
 			})
 			scan()
 			ar := soleArtist()
 
 			uploaded := ar.ID + "_upload.jpg"
-			writeUploadedImage(consts.EntityArtist, uploaded, imageBytes("artist-uploaded"))
+			writeUploadedImage(consts.EntityArtist, uploaded, pngBytes("artist-uploaded"))
 			ar.UploadedImage = uploaded
-			Expect(ds.Artist(ctx).Put(&ar)).To(Succeed())
+			Expect(rds.Artist(rctx).Put(&ar)).To(Succeed())
 
-			artID := model.NewArtworkID(model.KindArtistArtwork, ar.ID, nil)
-			Expect(readArtwork(artID)).To(Equal(imageBytes("artist-uploaded")))
+			ia := acquire(model.KindArtistArtwork, ar.ID)
+			Expect(ia.Source).To(Equal("upload"))
+			Expect(serveBytes(model.NewArtworkID(model.KindArtistArtwork, ar.ID, nil))).To(Equal(pngBytes("artist-uploaded")))
 		})
 	})
 
@@ -213,13 +196,36 @@ var _ = Describe("Artist artwork resolution", func() {
 			conf.Server.ArtistArtPriority = "album/artist.*, external"
 			setLayout(fstest.MapFS{
 				"Artist/Album/01 - Track.mp3": trackFile(1, "Track", map[string]any{"albumartist": "Artist"}),
-				"Artist/Album/artist.jpg":     imageFile("album-artist"),
+				"Artist/Album/artist.jpg":     smallPNG("album-artist"),
 			})
 			scan()
+			expectArtistFolder(soleArtist(), "Artist/Album/artist.jpg")
+		})
+	})
+
+	// resolveArtist only samples albums where this artist is the SOLE album artist, so a
+	// collaboration or compilation never donates its images as the artist's own.
+	When("the artist's only album is credited to two album artists", func() {
+		// Artist/
+		// └── Collab Album/            (album artists: "Artist" + a collaborator)
+		//     ├── 01 - Track.mp3
+		//     └── artist.jpg           ← must NOT become the artist image
+		It("ignores the album's images and settles absent", func() {
+			conf.Server.ArtistArtPriority = "album/artist.*"
+			// " / " is a default artists split separator, so this single tag yields two album artists.
+			setLayout(fstest.MapFS{
+				"Artist/Collab Album/01 - Track.mp3": trackFile(1, "Track", map[string]any{"albumartist": "Artist / Collaborator"}),
+				"Artist/Collab Album/artist.jpg":     smallPNG("collab-artist"),
+			})
+			scan()
+			Expect(firstAlbum().Participants[model.RoleAlbumArtist]).To(HaveLen(2),
+				"sanity check: the album must be credited to two album artists")
 
 			ar := soleArtist()
-			artID := model.NewArtworkID(model.KindArtistArtwork, ar.ID, nil)
-			Expect(readArtwork(artID)).To(Equal(imageBytes("album-artist")))
+			ia := acquire(model.KindArtistArtwork, ar.ID)
+			Expect(ia.Hash).To(BeEmpty())
+			Expect(serveErr(model.NewArtworkID(model.KindArtistArtwork, ar.ID, nil))).
+				To(MatchError(artwork.ErrUnavailable))
 		})
 	})
 
@@ -232,7 +238,7 @@ var _ = Describe("Artist artwork resolution", func() {
 		//     └── 01 - Track.mp3       (no artist.* present in library)
 		It("returns the image from the configured artist image folder", func() {
 			imgFolder := GinkgoT().TempDir()
-			Expect(os.WriteFile(filepath.Join(imgFolder, "Artist.jpg"), imageBytes("image-folder"), 0600)).To(Succeed())
+			Expect(os.WriteFile(filepath.Join(imgFolder, "Artist.jpg"), pngBytes("image-folder"), 0o600)).To(Succeed())
 			conf.Server.ArtistImageFolder = imgFolder
 			conf.Server.ArtistArtPriority = "image-folder, artist.*, album/artist.*"
 
@@ -242,15 +248,16 @@ var _ = Describe("Artist artwork resolution", func() {
 			scan()
 
 			ar := soleArtist()
-			artID := model.NewArtworkID(model.KindArtistArtwork, ar.ID, nil)
-			Expect(readArtwork(artID)).To(Equal(imageBytes("image-folder")))
+			ia := acquire(model.KindArtistArtwork, ar.ID)
+			Expect(ia.Source).To(Equal("folder"))
+			Expect(serveBytes(model.NewArtworkID(model.KindArtistArtwork, ar.ID, nil))).To(Equal(pngBytes("image-folder")))
 		})
 	})
 })
 
 func soleArtist() model.Artist {
 	GinkgoHelper()
-	artists, err := ds.Artist(ctx).GetAll(model.QueryOptions{
+	artists, err := rds.Artist(rctx).GetAll(model.QueryOptions{
 		Filters: squirrel.Eq{"artist.name": "Artist"},
 	})
 	Expect(err).ToNot(HaveOccurred())

core/artwork/e2e/disc_test.go

@@ -1,18 +1,20 @@
-package artworke2e_test
+package e2e
 
 import (
 	"fmt"
 	"testing/fstest"
 
 	"github.com/navidrome/navidrome/conf"
-	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/core/artwork"
 	. "github.com/onsi/ginkgo/v2"
 	. "github.com/onsi/gomega"
 )
 
+// Disc art is a serve-time read through the library FS (no worker state row), so per-disc images
+// are asserted byte-for-byte, while album-root covers are asserted on the state row.
 var _ = Describe("Disc artwork resolution", func() {
 	BeforeEach(func() {
-		setupHarness()
+		setupResolutionHarness()
 	})
 
 	When("the album is single-disc with a disc1.jpg in the only folder", func() {
@@ -24,32 +26,25 @@ var _ = Describe("Disc artwork resolution", func() {
 			conf.Server.DiscArtPriority = "disc*.*, cd*.*, cover.*, folder.*, front.*, embedded"
 			setLayout(fstest.MapFS{
 				"Artist/Album/01 - Track.mp3": trackFile(1, "Track"),
-				"Artist/Album/disc1.jpg":      imageFile("disc1-image"),
+				"Artist/Album/disc1.jpg":      smallPNG("disc1-image"),
 			})
 			scan()
-
-			al := firstAlbum()
-			discID := model.NewArtworkID(model.KindDiscArtwork, model.DiscArtworkID(al.ID, 1), &al.UpdatedAt)
-			Expect(readArtwork(discID)).To(Equal(imageBytes("disc1-image")))
+			expectDiscImage(firstAlbum(), 1, "disc1-image")
 		})
 	})
 
 	When("the album has no per-disc image and no album cover", func() {
 		// Artist/
 		// └── Album/
-		//     └── 01 - Track.mp3       (no disc or album art — returns ErrUnavailable)
-		It("returns ErrUnavailable for the disc lookup", func() {
+		//     └── 01 - Track.mp3       (no disc or album art — nothing to serve)
+		It("reports the disc lookup as unavailable", func() {
 			conf.Server.DiscArtPriority = "disc*.*, cd*.*"
 			conf.Server.CoverArtPriority = "cover.*, folder.*"
 			setLayout(fstest.MapFS{
 				"Artist/Album/01 - Track.mp3": trackFile(1, "Track"),
 			})
 			scan()
-
-			al := firstAlbum()
-			discID := model.NewArtworkID(model.KindDiscArtwork, model.DiscArtworkID(al.ID, 1), &al.UpdatedAt)
-			_, err := readArtworkOrErr(discID)
-			Expect(err).To(HaveOccurred())
+			Expect(serveErr(discArtID(firstAlbum(), 1))).To(MatchError(artwork.ErrUnavailable))
 		})
 	})
 
@@ -63,13 +58,10 @@ var _ = Describe("Disc artwork resolution", func() {
 			conf.Server.CoverArtPriority = defaultCoverPriority
 			setLayout(fstest.MapFS{
 				"Artist/Album/01 - Track.mp3": trackFile(1, "Track"),
-				"Artist/Album/cover.jpg":      imageFile("album-cover"),
+				"Artist/Album/cover.jpg":      smallPNG("album-cover"),
 			})
 			scan()
-
-			al := firstAlbum()
-			discID := model.NewArtworkID(model.KindDiscArtwork, model.DiscArtworkID(al.ID, 1), &al.UpdatedAt)
-			Expect(readArtwork(discID)).To(Equal(imageBytes("album-cover")))
+			expectDiscImage(firstAlbum(), 1, "album-cover")
 		})
 	})
 
@@ -83,14 +75,11 @@ var _ = Describe("Disc artwork resolution", func() {
 			conf.Server.DiscArtPriority = "disc*.*"
 			setLayout(fstest.MapFS{
 				"Artist/Album/01 - Track.mp3": trackFile(1, "Track"),
-				"Artist/Album/disc1.jpg":      imageFile("disc-one"),
-				"Artist/Album/disc10.jpg":     imageFile("disc-ten"),
+				"Artist/Album/disc1.jpg":      smallPNG("disc-one"),
+				"Artist/Album/disc10.jpg":     smallPNG("disc-ten"),
 			})
 			scan()
-
-			al := firstAlbum()
-			discID := model.NewArtworkID(model.KindDiscArtwork, model.DiscArtworkID(al.ID, 1), &al.UpdatedAt)
-			Expect(readArtwork(discID)).To(Equal(imageBytes("disc-one")))
+			expectDiscImage(firstAlbum(), 1, "disc-one")
 		})
 	})
 
@@ -108,14 +97,11 @@ var _ = Describe("Disc artwork resolution", func() {
 			setLayout(fstest.MapFS{
 				"Artist/Album/CD1/01 - Track.mp3": trackFile(1, "T1", map[string]any{"disc": "1"}),
 				"Artist/Album/CD2/01 - Track.mp3": trackFile(1, "T2", map[string]any{"disc": "2"}),
-				"Artist/Album/CD1/disc1.jpg":      imageFile("disc-1"),
-				"Artist/Album/CD2/disc2.jpg":      imageFile("disc-2"),
+				"Artist/Album/CD1/disc1.jpg":      smallPNG("disc-1"),
+				"Artist/Album/CD2/disc2.jpg":      smallPNG("disc-2"),
 			})
 			scan()
-
-			al := firstAlbum()
-			discID := model.NewArtworkID(model.KindDiscArtwork, model.DiscArtworkID(al.ID, 2), &al.UpdatedAt)
-			Expect(readArtwork(discID)).To(Equal(imageBytes("disc-2")))
+			expectDiscImage(firstAlbum(), 2, "disc-2")
 		})
 	})
 
@@ -136,14 +122,11 @@ var _ = Describe("Disc artwork resolution", func() {
 			setLayout(fstest.MapFS{
 				"Artist/Album/CD1/01 - Track.mp3": trackFile(1, "T1", map[string]any{"disc": "1"}),
 				"Artist/Album/CD2/01 - Track.mp3": trackFile(1, "T2", map[string]any{"disc": "2"}),
-				"Artist/Album/CD1/disc1.jpg":      imageFile("disc-1"),
-				"Artist/Album/CD2/cd2.png":        imageFile("cd-2"),
+				"Artist/Album/CD1/disc1.jpg":      smallPNG("disc-1"),
+				"Artist/Album/CD2/cd2.png":        smallPNG("cd-2"),
 			})
 			scan()
-
-			al := firstAlbum()
-			discID := model.NewArtworkID(model.KindDiscArtwork, model.DiscArtworkID(al.ID, 2), &al.UpdatedAt)
-			Expect(readArtwork(discID)).To(Equal(imageBytes("cd-2")))
+			expectDiscImage(firstAlbum(), 2, "cd-2")
 		})
 	})
 
@@ -161,14 +144,11 @@ var _ = Describe("Disc artwork resolution", func() {
 			setLayout(fstest.MapFS{
 				"Artist/Album/CD1/01 - Track.mp3": trackFile(1, "T1", map[string]any{"disc": "1"}),
 				"Artist/Album/CD2/01 - Track.mp3": trackFile(1, "T2", map[string]any{"disc": "2"}),
-				"Artist/Album/CD1/cover.jpg":      imageFile("disc1-cover"),
-				"Artist/Album/CD2/cover.jpg":      imageFile("disc2-cover"),
+				"Artist/Album/CD1/cover.jpg":      smallPNG("disc1-cover"),
+				"Artist/Album/CD2/cover.jpg":      smallPNG("disc2-cover"),
 			})
 			scan()
-
-			al := firstAlbum()
-			discID := model.NewArtworkID(model.KindDiscArtwork, model.DiscArtworkID(al.ID, 1), &al.UpdatedAt)
-			Expect(readArtwork(discID)).To(Equal(imageBytes("disc1-cover")))
+			expectDiscImage(firstAlbum(), 1, "disc1-cover")
 		})
 	})
 
@@ -188,17 +168,15 @@ var _ = Describe("Disc artwork resolution", func() {
 			setLayout(fstest.MapFS{
 				"Artist/Album/CD1/01 - Track.mp3": trackFile(1, "T1", map[string]any{"disc": "1"}),
 				"Artist/Album/CD2/01 - Track.mp3": trackFile(1, "T2", map[string]any{"disc": "2"}),
-				"Artist/Album/CD1/disc1.jpg":      imageFile("disc-1"),
-				"Artist/Album/CD2/cd2.png":        imageFile("cd-2"),
-				"Artist/Album/cover.jpg":          imageFile("album-cover"),
+				"Artist/Album/CD1/disc1.jpg":      smallPNG("disc-1"),
+				"Artist/Album/CD2/cd2.png":        smallPNG("cd-2"),
+				"Artist/Album/cover.jpg":          smallPNG("album-cover"),
 			})
 			scan()
 
 			al := firstAlbum()
 			for _, n := range []int{1, 2} {
-				discID := model.NewArtworkID(model.KindDiscArtwork, model.DiscArtworkID(al.ID, n), &al.UpdatedAt)
-				Expect(readArtwork(discID)).To(Equal(imageBytes("album-cover")),
-					"disc %d should use the album cover when DiscArtPriority is empty", n)
+				expectDiscImage(al, n, "album-cover")
 			}
 		})
 	})
@@ -223,17 +201,15 @@ var _ = Describe("Disc artwork resolution", func() {
 				"Artist/Album/disc1/02 - Track.mp3": trackFile(2, "T2", map[string]any{"disc": "1"}),
 				"Artist/Album/disc2/01 - Track.mp3": trackFile(1, "T3", map[string]any{"disc": "2"}),
 				"Artist/Album/disc2/02 - Track.mp3": trackFile(2, "T4", map[string]any{"disc": "2"}),
-				"Artist/Album/disc1/disc1.jpg":      imageFile("disc-1"),
-				"Artist/Album/disc2/cd2.png":        imageFile("cd-2"),
-				"Artist/Album/cover.jpg":            imageFile("album-root"),
+				"Artist/Album/disc1/disc1.jpg":      smallPNG("disc-1"),
+				"Artist/Album/disc2/cd2.png":        smallPNG("cd-2"),
+				"Artist/Album/cover.jpg":            smallPNG("album-root"),
 			})
 			scan()
 
 			al := firstAlbum()
-			disc1ID := model.NewArtworkID(model.KindDiscArtwork, model.DiscArtworkID(al.ID, 1), &al.UpdatedAt)
-			disc2ID := model.NewArtworkID(model.KindDiscArtwork, model.DiscArtworkID(al.ID, 2), &al.UpdatedAt)
-			Expect(readArtwork(disc1ID)).To(Equal(imageBytes("disc-1")))
-			Expect(readArtwork(disc2ID)).To(Equal(imageBytes("cd-2")))
+			expectDiscImage(al, 1, "disc-1")
+			expectDiscImage(al, 2, "cd-2")
 		})
 	})
 
@@ -246,13 +222,10 @@ var _ = Describe("Disc artwork resolution", func() {
 			conf.Server.DiscArtPriority = "discsubtitle"
 			setLayout(fstest.MapFS{
 				"Artist/Album/01 - Track.mp3":   trackFile(1, "T1", map[string]any{"disc": "1", "discsubtitle": "Bonus Tracks"}),
-				"Artist/Album/Bonus Tracks.jpg": imageFile("bonus-tracks"),
+				"Artist/Album/Bonus Tracks.jpg": smallPNG("bonus-tracks"),
 			})
 			scan()
-
-			al := firstAlbum()
-			discID := model.NewArtworkID(model.KindDiscArtwork, model.DiscArtworkID(al.ID, 1), &al.UpdatedAt)
-			Expect(readArtwork(discID)).To(Equal(imageBytes("bonus-tracks")))
+			expectDiscImage(firstAlbum(), 1, "bonus-tracks")
 		})
 	})
 
@@ -286,26 +259,22 @@ var _ = Describe("Disc artwork resolution", func() {
 				"Disc 12 (History of the Grateful Dead, Volume One (Bear's Choice))",
 			}
 			layout := fstest.MapFS{
-				"Pop; Rock/Grateful Dead/(2001) The Golden Road/cover.jpg": imageFile("album-root-cover"),
+				"Pop; Rock/Grateful Dead/(2001) The Golden Road/cover.jpg": smallPNG("album-root-cover"),
 			}
 			for i, name := range discNames {
 				discNum := i + 1
 				prefix := fmt.Sprintf("Pop; Rock/Grateful Dead/(2001) The Golden Road/%s/", name)
 				layout[prefix+"01 - Track.mp3"] = trackFile(1, fmt.Sprintf("T%d", discNum), map[string]any{"disc": fmt.Sprintf("%d", discNum)})
-				layout[prefix+"folder.jpg"] = imageFile(fmt.Sprintf("disc-%02d-folder", discNum))
+				layout[prefix+"folder.jpg"] = smallPNG(fmt.Sprintf("disc-%02d-folder", discNum))
 			}
 			setLayout(layout)
 			scan()
 
 			al := firstAlbum()
-
-			Expect(readArtwork(al.CoverArtID())).To(Equal(imageBytes("album-root-cover")))
-
+			expectAlbumFolderCover(al, "(2001) The Golden Road/cover.jpg")
 			for i := range discNames {
 				discNum := i + 1
-				discID := model.NewArtworkID(model.KindDiscArtwork, model.DiscArtworkID(al.ID, discNum), &al.UpdatedAt)
-				Expect(readArtwork(discID)).To(Equal(imageBytes(fmt.Sprintf("disc-%02d-folder", discNum))),
-					"disc %d should use its own folder.jpg", discNum)
+				expectDiscImage(al, discNum, fmt.Sprintf("disc-%02d-folder", discNum))
 			}
 		})
 	})
@@ -328,24 +297,20 @@ var _ = Describe("Disc artwork resolution", func() {
 			conf.Server.DiscArtPriority = defaultDiscPriority
 			conf.Server.CoverArtPriority = defaultCoverPriority
 			layout := fstest.MapFS{
-				"Album/cover.jpg": imageFile("album-root-cover"),
+				"Album/cover.jpg": smallPNG("album-root-cover"),
 			}
 			for i := 1; i <= 3; i++ {
 				prefix := fmt.Sprintf("Album/Disc %02d/", i)
 				layout[prefix+"01 - Track.mp3"] = trackFile(1, fmt.Sprintf("T%d", i), map[string]any{"disc": fmt.Sprintf("%d", i)})
-				layout[prefix+"folder.jpg"] = imageFile(fmt.Sprintf("disc-%02d-folder", i))
+				layout[prefix+"folder.jpg"] = smallPNG(fmt.Sprintf("disc-%02d-folder", i))
 			}
 			setLayout(layout)
 			scan()
 
 			al := firstAlbum()
-
-			Expect(readArtwork(al.CoverArtID())).To(Equal(imageBytes("album-root-cover")))
-
+			expectAlbumFolderCover(al, "Album/cover.jpg")
 			for i := 1; i <= 3; i++ {
-				discID := model.NewArtworkID(model.KindDiscArtwork, model.DiscArtworkID(al.ID, i), &al.UpdatedAt)
-				Expect(readArtwork(discID)).To(Equal(imageBytes(fmt.Sprintf("disc-%02d-folder", i))),
-					"disc %d should use its own folder.jpg", i)
+				expectDiscImage(al, i, fmt.Sprintf("disc-%02d-folder", i))
 			}
 		})
 	})
@@ -359,13 +324,10 @@ var _ = Describe("Disc artwork resolution", func() {
 			conf.Server.DiscArtPriority = "discsubtitle, cover.*"
 			setLayout(fstest.MapFS{
 				"Artist/Album/01 - Track.mp3": trackFile(1, "T1", map[string]any{"disc": "1", "discsubtitle": "Bonus Tracks"}),
-				"Artist/Album/cover.jpg":      imageFile("cover"),
+				"Artist/Album/cover.jpg":      smallPNG("cover"),
 			})
 			scan()
-
-			al := firstAlbum()
-			discID := model.NewArtworkID(model.KindDiscArtwork, model.DiscArtworkID(al.ID, 1), &al.UpdatedAt)
-			Expect(readArtwork(discID)).To(Equal(imageBytes("cover")))
+			expectDiscImage(firstAlbum(), 1, "cover")
 		})
 	})
 })

core/artwork/e2e/e2e_suite_test.go

@@ -0,0 +1,83 @@
+// Package e2e exercises the artwork pipeline end to end: the real Worker drains the queue and the
+// real Service serves the result, over a real ImageStore and real library files.
+package e2e
+
+import (
+	"context"
+	"io"
+	"os"
+	"path/filepath"
+	"testing"
+	"time"
+
+	_ "github.com/navidrome/navidrome/adapters/gotaglib" // registers the "taglib" local-storage extractor
+	"github.com/navidrome/navidrome/core/artwork"
+	_ "github.com/navidrome/navidrome/core/storage/local"
+	"github.com/navidrome/navidrome/log"
+	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/tests"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+func TestArtworkE2E(t *testing.T) {
+	tests.Init(t, false)
+	log.SetLevel(log.LevelFatal)
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "Artwork Pipeline E2E Suite")
+}
+
+// Fixtures relative to the project root (tests.Init chdirs there).
+const (
+	coverFixture     = "tests/fixtures/artist/an-album/cover.jpg"
+	mp3Fixture       = "tests/fixtures/artist/an-album/test.mp3"
+	artistPngFixture = "tests/fixtures/artist/an-album/artist.png"
+	albumFolderPath  = "tests/fixtures/artist/an-album"
+)
+
+func readFixture(rel string) []byte {
+	GinkgoHelper()
+	data, err := os.ReadFile(rel)
+	Expect(err).ToNot(HaveOccurred(), "reading fixture %q", rel)
+	return data
+}
+
+func readAll(img *artwork.Image) []byte {
+	GinkgoHelper()
+	Expect(img).ToNot(BeNil())
+	defer img.Close()
+	data, err := io.ReadAll(img)
+	Expect(err).ToNot(HaveOccurred())
+	return data
+}
+
+func runWorkerUntil(ctx context.Context, worker *artwork.Worker, until func() bool) {
+	GinkgoHelper()
+	runCtx, cancel := context.WithCancel(ctx)
+	done := make(chan error, 1)
+	go func() { done <- worker.Run(runCtx) }()
+	Eventually(until, 5*time.Second, 10*time.Millisecond).Should(BeTrue())
+	cancel()
+	Eventually(done, 2*time.Second).Should(Receive(BeNil()))
+}
+
+type fakeFolderRepo struct {
+	model.FolderRepository
+	result []model.Folder
+}
+
+func (f *fakeFolderRepo) GetAll(...model.QueryOptions) ([]model.Folder, error) { return f.result, nil }
+
+func (f *fakeFolderRepo) HasAudioOutsideFolders(model.Folder, []string) (bool, error) {
+	return false, nil
+}
+
+func (f *fakeFolderRepo) Get(string) (*model.Folder, error) { return nil, model.ErrNotFound }
+
+func writeUpload(entityType, name, srcFixture string) string {
+	GinkgoHelper()
+	dst := model.UploadedImagePath(entityType, name)
+	Expect(os.MkdirAll(filepath.Dir(dst), 0o755)).To(Succeed())
+	Expect(os.WriteFile(dst, readFixture(srcFixture), 0o600)).To(Succeed())
+	return name
+}

core/artwork/e2e/helpers_test.go

@@ -1,184 +0,0 @@
-package artworke2e_test
-
-import (
-	"bytes"
-	"context"
-	_ "embed"
-	"errors"
-	"hash/fnv"
-	"image"
-	"image/color"
-	"image/png"
-	"io"
-	"maps"
-	"net/url"
-	"os"
-	"path/filepath"
-	"testing/fstest"
-
-	"github.com/navidrome/navidrome/consts"
-	"github.com/navidrome/navidrome/core/external"
-	"github.com/navidrome/navidrome/core/storage/storagetest"
-	"github.com/navidrome/navidrome/model"
-	"github.com/navidrome/navidrome/resources"
-	"github.com/navidrome/navidrome/tests"
-	. "github.com/onsi/ginkgo/v2"
-	. "github.com/onsi/gomega"
-	"go.senan.xyz/taglib"
-)
-
-// realMP3WithEmbeddedArt is the bytes of the canonical test fixture that
-// contains a valid MP3 stream with an embedded picture. Used in the
-// embedded-art e2e scenarios where FakeFS's JSON-encoded tag data isn't
-// readable by taglib. Swap this into fakeFS.MapFS *after* scanning so the
-// scanner still populates EmbedArtPath via the JSON-tagged track, and the
-// artwork reader gets real bytes when it calls libFS.Open.
-//
-//go:embed testdata/embedded_art.mp3
-var realMP3WithEmbeddedArt []byte
-
-// embeddedArtBytes is the exact image payload that the artwork reader will
-// extract from realMP3WithEmbeddedArt. Computed once via taglib so tests can
-// assert byte-for-byte equality — if this ever differs it means the reader
-// pulled from a different source.
-var embeddedArtBytes = extractEmbeddedArt(realMP3WithEmbeddedArt)
-
-func extractEmbeddedArt(mp3 []byte) []byte {
-	tf, err := taglib.OpenStream(bytes.NewReader(mp3))
-	if err != nil {
-		panic("embedded-art fixture: taglib.OpenStream failed: " + err.Error())
-	}
-	defer tf.Close()
-	images := tf.Properties().Images
-	if len(images) == 0 {
-		panic("embedded-art fixture has no embedded images")
-	}
-	data, err := tf.Image(0)
-	if err != nil || len(data) == 0 {
-		panic("embedded-art fixture: could not read image 0")
-	}
-	return data
-}
-
-// replaceWithRealMP3 swaps the FakeFS entry at the given library-relative
-// path so libFS.Open returns an MP3 stream taglib can parse.
-func replaceWithRealMP3(relPath string) {
-	GinkgoHelper()
-	fakeFS.MapFS[relPath] = &fstest.MapFile{Data: realMP3WithEmbeddedArt}
-}
-
-// placeholderBytes returns the bundled album-placeholder image bytes — the
-// same stream the artwork reader emits when every source falls through.
-func placeholderBytes() []byte {
-	GinkgoHelper()
-	r, err := resources.FS().Open(consts.PlaceholderAlbumArt)
-	Expect(err).ToNot(HaveOccurred())
-	defer r.Close()
-	data, err := io.ReadAll(r)
-	Expect(err).ToNot(HaveOccurred())
-	return data
-}
-
-// writeUploadedImage drops `filename` into <DataFolder>/artwork/<entity>/ with
-// the given bytes, matching the on-disk layout expected by
-// model.UploadedImagePath.
-func writeUploadedImage(entity, filename string, data []byte) {
-	GinkgoHelper()
-	dir := filepath.Dir(model.UploadedImagePath(entity, filename))
-	Expect(os.MkdirAll(dir, 0755)).To(Succeed())
-	Expect(os.WriteFile(filepath.Join(dir, filename), data, 0600)).To(Succeed())
-}
-
-func newNoopFFmpeg() *tests.MockFFmpeg {
-	ff := tests.NewMockFFmpeg("")
-	ff.Error = errors.New("noop")
-	return ff
-}
-
-// trackFile builds a FakeFS MP3 entry with optional tag overrides.
-func trackFile(num int, title string, extra ...map[string]any) *fstest.MapFile {
-	tags := storagetest.Track(num, title)
-	for _, e := range extra {
-		maps.Copy(tags, e)
-	}
-	return storagetest.MP3(tags)
-}
-
-// imageFile builds a label-keyed image entry. The bytes are deterministic
-// per-label so tests can assert which file won.
-func imageFile(label string) *fstest.MapFile {
-	return &fstest.MapFile{Data: []byte("image:" + label)}
-}
-
-// realPNG builds a minimal 2x2 PNG with a color derived from label. Needed by
-// tests that feed the bytes into image.Decode (e.g. playlist tiled covers).
-func realPNG(label string) *fstest.MapFile {
-	img := image.NewRGBA(image.Rect(0, 0, 2, 2))
-	// Derive a deterministic color per label.
-	h := fnv.New32a()
-	_, _ = h.Write([]byte(label))
-	sum := h.Sum32()
-	c := color.RGBA{R: byte(sum), G: byte(sum >> 8), B: byte(sum >> 16), A: 255}
-	for y := range 2 {
-		for x := range 2 {
-			img.Set(x, y, c)
-		}
-	}
-	var buf bytes.Buffer
-	Expect(png.Encode(&buf, img)).To(Succeed())
-	return &fstest.MapFile{Data: buf.Bytes()}
-}
-
-// imageBytes returns the bytes that imageFile(label) writes.
-func imageBytes(label string) []byte { return imageFile(label).Data }
-
-// setLayout populates fakeFS with the given map. Call after setupHarness.
-// All paths must be forward-slash and relative (no leading "/").
-func setLayout(files fstest.MapFS) {
-	GinkgoHelper()
-	fakeFS.SetFiles(files)
-}
-
-func readArtwork(artID model.ArtworkID) []byte {
-	GinkgoHelper()
-	r, _, err := aw.Get(ctx, artID, 0, false)
-	Expect(err).ToNot(HaveOccurred())
-	defer r.Close()
-	b, err := io.ReadAll(r)
-	Expect(err).ToNot(HaveOccurred())
-	return b
-}
-
-func readArtworkOrErr(artID model.ArtworkID) ([]byte, error) {
-	r, _, err := aw.Get(ctx, artID, 0, false)
-	if err != nil {
-		return nil, err
-	}
-	defer r.Close()
-	return io.ReadAll(r)
-}
-
-// noopProvider implements external.Provider with not-found returns so the
-// "external" priority entry never produces a result.
-type noopProvider struct{}
-
-func (n *noopProvider) UpdateAlbumInfo(context.Context, string) (*model.Album, error) {
-	return nil, model.ErrNotFound
-}
-func (n *noopProvider) UpdateArtistInfo(context.Context, string, int, bool) (*model.Artist, error) {
-	return nil, model.ErrNotFound
-}
-func (n *noopProvider) SimilarSongs(context.Context, string, int) (model.MediaFiles, error) {
-	return nil, nil
-}
-func (n *noopProvider) TopSongs(context.Context, string, string, int) (model.MediaFiles, error) {
-	return nil, nil
-}
-func (n *noopProvider) ArtistImage(context.Context, string) (*url.URL, error) {
-	return nil, model.ErrNotFound
-}
-func (n *noopProvider) AlbumImage(context.Context, string) (*url.URL, error) {
-	return nil, model.ErrNotFound
-}
-
-var _ external.Provider = (*noopProvider)(nil)

core/artwork/e2e/mediafile_test.go

@@ -1,4 +1,4 @@
-package artworke2e_test
+package e2e
 
 import (
 	"testing/fstest"
@@ -17,13 +17,11 @@ import (
 //  2. For multi-disc albums, disc-level artwork
 //  3. Album cover art
 //
-// FakeFS cannot synthesize taglib-readable embedded JPEGs, so scenario (1)
-// is covered by the existing embedded-art album tests (which currently
-// Skip under FakeFS). The tests below cover (2) and (3): the fallback
-// chain for tracks without embedded art.
-var _ = Describe("MediaFile artwork fallback", func() {
+// Embedded art lands in the content-addressed store (asserted byte-for-byte); disc-level art is a
+// serve-time read through the library FS.
+var _ = Describe("MediaFile artwork resolution", func() {
 	BeforeEach(func() {
-		setupHarness()
+		setupResolutionHarness()
 	})
 
 	When("a multi-disc album track has no embedded art", func() {
@@ -42,14 +40,14 @@ var _ = Describe("MediaFile artwork fallback", func() {
 			setLayout(fstest.MapFS{
 				"Artist/Album/CD1/01 - Track.mp3": trackFile(1, "T1", map[string]any{"disc": "1"}),
 				"Artist/Album/CD2/01 - Track.mp3": trackFile(1, "T2", map[string]any{"disc": "2"}),
-				"Artist/Album/CD1/disc1.jpg":      imageFile("disc-1"),
-				"Artist/Album/CD2/disc2.jpg":      imageFile("disc-2"),
-				"Artist/Album/cover.jpg":          imageFile("album-root"),
+				"Artist/Album/CD1/disc1.jpg":      smallPNG("disc-1"),
+				"Artist/Album/CD2/disc2.jpg":      smallPNG("disc-2"),
+				"Artist/Album/cover.jpg":          smallPNG("album-root"),
 			})
 			scan()
 
 			mf := mediafileOn("Artist/Album/CD2/01 - Track.mp3")
-			Expect(readArtwork(mf.CoverArtID())).To(Equal(imageBytes("disc-2")))
+			Expect(serveBytes(mf.CoverArtID())).To(Equal(pngBytes("disc-2")))
 		})
 	})
 
@@ -63,12 +61,12 @@ var _ = Describe("MediaFile artwork fallback", func() {
 			conf.Server.DiscArtPriority = defaultDiscPriority
 			setLayout(fstest.MapFS{
 				"Artist/Album/01 - Track.mp3": trackFile(1, "Track"),
-				"Artist/Album/cover.jpg":      imageFile("album-cover"),
+				"Artist/Album/cover.jpg":      smallPNG("album-cover"),
 			})
 			scan()
 
 			mf := mediafileOn("Artist/Album/01 - Track.mp3")
-			Expect(readArtwork(mf.CoverArtID())).To(Equal(imageBytes("album-cover")))
+			Expect(serveBytes(mf.CoverArtID())).To(Equal(pngBytes("album-cover")))
 		})
 	})
 
@@ -86,19 +84,60 @@ var _ = Describe("MediaFile artwork fallback", func() {
 			setLayout(fstest.MapFS{
 				"Artist/Album/CD1/01 - Track.mp3": trackFile(1, "T1", map[string]any{"disc": "1"}),
 				"Artist/Album/CD2/01 - Track.mp3": trackFile(1, "T2", map[string]any{"disc": "2"}),
-				"Artist/Album/cover.jpg":          imageFile("album-root"),
+				"Artist/Album/cover.jpg":          smallPNG("album-root"),
 			})
 			scan()
 
 			mf := mediafileOn("Artist/Album/CD2/01 - Track.mp3")
-			Expect(readArtwork(mf.CoverArtID())).To(Equal(imageBytes("album-root")))
+			Expect(serveBytes(mf.CoverArtID())).To(Equal(pngBytes("album-root")))
+		})
+	})
+
+	When("a track has its own embedded art", func() {
+		// Artist/
+		// └── Album/
+		//     └── 01 - Track.mp3       ← has embedded picture (wins over every fallback)
+		It("resolves the track's embedded image into the store", func() {
+			conf.Server.CoverArtPriority = defaultCoverPriority
+			setLayout(fstest.MapFS{
+				"Artist/Album/01 - Track.mp3": trackFile(1, "Track", map[string]any{"has_picture": "true"}),
+			})
+			scan()
+			replaceWithRealMP3("Artist/Album/01 - Track.mp3")
+
+			mf := mediafileOn("Artist/Album/01 - Track.mp3")
+			ia := acquire(model.KindMediaFileArtwork, mf.ID)
+			Expect(ia.Source).To(Equal("embedded"))
+			Expect(storedBytes(ia)).To(Equal(embeddedArtBytes))
+		})
+	})
+
+	When("EnableMediaFileCoverArt is turned off after the track was scanned", func() {
+		// Artist/
+		// └── Album/
+		//     ├── 01 - Track.mp3       ← has embedded picture (must NOT be served)
+		//     └── cover.jpg            ← wins (per-track art disabled at serve time)
+		It("serves the album cover instead of the track's embedded art", func() {
+			conf.Server.CoverArtPriority = defaultCoverPriority
+			setLayout(fstest.MapFS{
+				"Artist/Album/01 - Track.mp3": trackFile(1, "Track", map[string]any{"has_picture": "true"}),
+				"Artist/Album/cover.jpg":      smallPNG("album-cover"),
+			})
+			scan()
+			replaceWithRealMP3("Artist/Album/01 - Track.mp3")
+
+			// The setting is not part of the artwork fingerprint, so it must be honored at serve time.
+			conf.Server.EnableMediaFileCoverArt = false
+			mf := mediafileOn("Artist/Album/01 - Track.mp3")
+			trackArtID := model.NewArtworkID(model.KindMediaFileArtwork, mf.ID, nil)
+			Expect(serveBytes(trackArtID)).To(Equal(pngBytes("album-cover")))
 		})
 	})
 })
 
 func mediafileOn(relPath string) model.MediaFile {
 	GinkgoHelper()
-	mfs, err := ds.MediaFile(ctx).GetAll(model.QueryOptions{
+	mfs, err := rds.MediaFile(rctx).GetAll(model.QueryOptions{
 		Filters: squirrel.Like{"media_file.path": relPath},
 	})
 	Expect(err).ToNot(HaveOccurred())

core/artwork/e2e/playlist_test.go

@@ -1,13 +1,16 @@
-package artworke2e_test
+package e2e
 
 import (
+	"image/color"
 	"os"
 	"path/filepath"
 	"testing/fstest"
 
 	"github.com/navidrome/navidrome/conf"
 	"github.com/navidrome/navidrome/consts"
+	"github.com/navidrome/navidrome/core/artwork"
 	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/utils/slice"
 	. "github.com/onsi/ginkgo/v2"
 	. "github.com/onsi/gomega"
 )
@@ -17,14 +20,13 @@ import (
 //  2. Sidecar image next to the .m3u file (same basename, any image ext)
 //  3. ExternalImageURL (http/https requires EnableM3UExternalAlbumArt; local path always allowed)
 //  4. Generated 2x2 tiled cover from the playlist's albums
-//  5. Album placeholder image
+//  5. Absent
 //
-// The library FS is FakeFS, but uploaded/sidecar/local-external images are
-// real files on disk — the reader reads them via os.Open, so the tests
-// place them in a real tempdir under DataFolder.
+// The library is an in-memory FS, but uploaded/sidecar/local-external images are real files on
+// disk — the resolver reads them via os.Open, so those tests place them in a real tempdir.
 var _ = Describe("Playlist artwork resolution", func() {
 	BeforeEach(func() {
-		setupHarness()
+		setupResolutionHarness()
 	})
 
 	When("a playlist has an uploaded image", func() {
@@ -33,11 +35,12 @@ var _ = Describe("Playlist artwork resolution", func() {
 		//     └── playlist/
 		//         └── pl-1_upload.jpg   ← matched by UploadedImagePath() (highest priority)
 		It("returns the uploaded image bytes", func() {
-			writeUploadedImage(consts.EntityPlaylist, "pl-1_upload.jpg", imageBytes("playlist-upload"))
-
+			writeUploadedImage(consts.EntityPlaylist, "pl-1_upload.jpg", pngBytes("playlist-upload"))
 			pl := putPlaylist(model.Playlist{ID: "pl-1", Name: "Test", UploadedImage: "pl-1_upload.jpg"})
 
-			Expect(readArtwork(pl.CoverArtID())).To(Equal(imageBytes("playlist-upload")))
+			ia := acquire(model.KindPlaylistArtwork, pl.ID)
+			Expect(ia.Source).To(Equal("upload"))
+			Expect(serveBytes(pl.CoverArtID())).To(Equal(pngBytes("playlist-upload")))
 		})
 	})
 
@@ -48,12 +51,14 @@ var _ = Describe("Playlist artwork resolution", func() {
 		It("returns the sidecar image", func() {
 			dir := GinkgoT().TempDir()
 			m3uPath := filepath.Join(dir, "MyList.m3u")
-			Expect(os.WriteFile(m3uPath, []byte("#EXTM3U\n"), 0600)).To(Succeed())
-			Expect(os.WriteFile(filepath.Join(dir, "MyList.jpg"), imageBytes("sidecar"), 0600)).To(Succeed())
+			Expect(os.WriteFile(m3uPath, []byte("#EXTM3U\n"), 0o600)).To(Succeed())
+			Expect(os.WriteFile(filepath.Join(dir, "MyList.jpg"), pngBytes("sidecar"), 0o600)).To(Succeed())
 
 			pl := putPlaylist(model.Playlist{ID: "pl-2", Name: "MyList", Path: m3uPath})
 
-			Expect(readArtwork(pl.CoverArtID())).To(Equal(imageBytes("sidecar")))
+			ia := acquire(model.KindPlaylistArtwork, pl.ID)
+			Expect(ia.Source).To(Equal("folder"))
+			Expect(serveBytes(pl.CoverArtID())).To(Equal(pngBytes("sidecar")))
 		})
 	})
 
@@ -64,12 +69,12 @@ var _ = Describe("Playlist artwork resolution", func() {
 		It("matches case-insensitively", func() {
 			dir := GinkgoT().TempDir()
 			m3uPath := filepath.Join(dir, "MyList.m3u")
-			Expect(os.WriteFile(m3uPath, []byte("#EXTM3U\n"), 0600)).To(Succeed())
-			Expect(os.WriteFile(filepath.Join(dir, "MyList.PNG"), imageBytes("sidecar-png"), 0600)).To(Succeed())
+			Expect(os.WriteFile(m3uPath, []byte("#EXTM3U\n"), 0o600)).To(Succeed())
+			Expect(os.WriteFile(filepath.Join(dir, "MyList.PNG"), pngBytes("sidecar-png"), 0o600)).To(Succeed())
 
 			pl := putPlaylist(model.Playlist{ID: "pl-3", Name: "MyList", Path: m3uPath})
 
-			Expect(readArtwork(pl.CoverArtID())).To(Equal(imageBytes("sidecar-png")))
+			Expect(serveBytes(pl.CoverArtID())).To(Equal(pngBytes("sidecar-png")))
 		})
 	})
 
@@ -80,31 +85,39 @@ var _ = Describe("Playlist artwork resolution", func() {
 			conf.Server.EnableM3UExternalAlbumArt = false // local paths bypass the toggle
 			dir := GinkgoT().TempDir()
 			imgPath := filepath.Join(dir, "cover.jpg")
-			Expect(os.WriteFile(imgPath, imageBytes("external-local"), 0600)).To(Succeed())
+			Expect(os.WriteFile(imgPath, pngBytes("external-local"), 0o600)).To(Succeed())
 
 			pl := putPlaylist(model.Playlist{ID: "pl-4", Name: "WithExt", ExternalImageURL: imgPath})
 
-			Expect(readArtwork(pl.CoverArtID())).To(Equal(imageBytes("external-local")))
+			Expect(serveBytes(pl.CoverArtID())).To(Equal(pngBytes("external-local")))
 		})
 	})
 
 	When("a playlist has an http(s) ExternalImageURL and EnableM3UExternalAlbumArt is false", func() {
-		// (no local files — http source is gated off, reader falls through to placeholder)
-		It("skips the URL and falls through to the bundled placeholder", func() {
+		// (no local files — the http source is gated off, so resolution settles absent)
+		It("skips the URL and settles absent", func() {
 			conf.Server.EnableM3UExternalAlbumArt = false
-
 			pl := putPlaylist(model.Playlist{ID: "pl-5", Name: "HttpGated", ExternalImageURL: "https://example.com/cover.jpg"})
 
-			Expect(readArtwork(pl.CoverArtID())).To(Equal(placeholderBytes()))
+			ia := acquire(model.KindPlaylistArtwork, pl.ID)
+			Expect(ia.Hash).To(BeEmpty())
+			Expect(serveErr(pl.CoverArtID())).To(MatchError(artwork.ErrUnavailable))
+
+			img, err := rsvc.GetOrPlaceholder(rctx, pl.CoverArtID().String(), 0, false)
+			Expect(err).ToNot(HaveOccurred())
+			defer img.Close()
+			Expect(img.Placeholder).To(BeTrue())
 		})
 	})
 
 	When("a playlist has no images and no tracks", func() {
-		// (reader falls all the way through to the bundled album placeholder)
-		It("returns the album placeholder", func() {
+		// (no uploaded/sidecar/external image and no album art to sample)
+		It("settles absent", func() {
 			pl := putPlaylist(model.Playlist{ID: "pl-6", Name: "Empty"})
 
-			Expect(readArtwork(pl.CoverArtID())).To(Equal(placeholderBytes()))
+			ia := acquire(model.KindPlaylistArtwork, pl.ID)
+			Expect(ia.Hash).To(BeEmpty())
+			Expect(serveErr(pl.CoverArtID())).To(MatchError(artwork.ErrUnavailable))
 		})
 	})
 
@@ -113,37 +126,79 @@ var _ = Describe("Playlist artwork resolution", func() {
 		// Artist/
 		// ├── AlbumA/
 		// │   ├── 01 - Track.mp3
-		// │   └── cover.png          (real PNG — wins as tile 1 source)
+		// │   └── cover.png          ← tile 1 source
 		// └── AlbumB/
 		//     ├── 01 - Track.mp3
-		//     └── cover.png          (real PNG — wins as tile 2 source)
-		// Playlist "pl-7" references tracks from both albums, so the reader
-		// generates a 2x2 tiled cover from 2 distinct album art tiles (the
-		// tiled generator mirrors when it has fewer than 4 unique tiles).
+		//     └── cover.png          ← tile 2 source
+		// Playlist "pl-7" references tracks from both albums, so the worker generates a tiled
+		// cover from 2 distinct album art tiles (mirrored to fill the 2x2 grid).
 		It("generates a tiled cover from album art", func() {
 			conf.Server.CoverArtPriority = "cover.*"
 			setLayout(fstest.MapFS{
 				"Artist/AlbumA/01 - Track.mp3": trackFile(1, "TA", map[string]any{"album": "AlbumA"}),
-				"Artist/AlbumA/cover.png":      realPNG("albumA"),
+				"Artist/AlbumA/cover.png":      smallPNG("albumA"),
 				"Artist/AlbumB/01 - Track.mp3": trackFile(1, "TB", map[string]any{"album": "AlbumB"}),
-				"Artist/AlbumB/cover.png":      realPNG("albumB"),
+				"Artist/AlbumB/cover.png":      smallPNG("albumB"),
 			})
 			scan()
 
-			// Pull the scanned mediafile IDs so we can attach them to the playlist.
-			mfs, err := ds.MediaFile(ctx).GetAll(model.QueryOptions{})
+			mfs, err := rds.MediaFile(rctx).GetAll(model.QueryOptions{})
 			Expect(err).ToNot(HaveOccurred())
 			Expect(mfs).To(HaveLen(2))
 
 			pl := model.Playlist{ID: "pl-7", Name: "Mix", OwnerID: "admin-1"}
 			pl.AddMediaFilesByID([]string{mfs[0].ID, mfs[1].ID})
-			Expect(ds.Playlist(ctx).Put(&pl)).To(Succeed())
+			Expect(rds.Playlist(rctx).Put(&pl)).To(Succeed())
 
-			data := readArtwork(pl.CoverArtID())
-			// The tiled cover is a PNG-encoded 600x600 image (tileSize const).
-			// Exact bytes vary (random album order), so assert format + non-trivial size.
+			ia := acquire(model.KindPlaylistArtwork, pl.ID)
+			Expect(ia.Source).To(Equal("generated"))
+			data := storedBytes(ia)
+			// The tiled cover is a PNG-encoded image; exact bytes vary (random album order).
 			Expect(data[:8]).To(Equal([]byte{0x89, 'P', 'N', 'G', 0x0d, 0x0a, 0x1a, 0x0a}))
-			Expect(len(data)).To(BeNumerically(">", 1000))
+			// Two tiles are mirrored into the 2x2 grid as [A B B A], so opposite corners match.
+			q := gridQuadrants(data)
+			Expect(q[0]).To(Equal(q[3]))
+			Expect(q[1]).To(Equal(q[2]))
+			Expect(q[0]).ToNot(Equal(q[1]))
+		})
+	})
+
+	When("a playlist has tracks from four albums, each with its own cover", func() {
+		// Library:
+		// Artist/
+		// ├── AlbumA/{01 - Track.mp3, cover.png}   ← tile 1
+		// ├── AlbumB/{01 - Track.mp3, cover.png}   ← tile 2
+		// ├── AlbumC/{01 - Track.mp3, cover.png}   ← tile 3
+		// └── AlbumD/{01 - Track.mp3, cover.png}   ← tile 4
+		It("fills all four grid quadrants with distinct album art", func() {
+			conf.Server.CoverArtPriority = "cover.*"
+			layout := fstest.MapFS{}
+			for _, name := range []string{"AlbumA", "AlbumB", "AlbumC", "AlbumD"} {
+				layout["Artist/"+name+"/01 - Track.mp3"] = trackFile(1, "T"+name, map[string]any{"album": name})
+				layout["Artist/"+name+"/cover.png"] = smallPNG(name)
+			}
+			setLayout(layout)
+			scan()
+
+			mfs, err := rds.MediaFile(rctx).GetAll(model.QueryOptions{})
+			Expect(err).ToNot(HaveOccurred())
+			Expect(mfs).To(HaveLen(4))
+			ids := slice.Map(mfs, func(mf model.MediaFile) string { return mf.ID })
+
+			pl := model.Playlist{ID: "pl-8", Name: "Four", OwnerID: "admin-1"}
+			pl.AddMediaFilesByID(ids)
+			Expect(rds.Playlist(rctx).Put(&pl)).To(Succeed())
+
+			ia := acquire(model.KindPlaylistArtwork, pl.ID)
+			Expect(ia.Source).To(Equal("generated"))
+			q := gridQuadrants(storedBytes(ia))
+			Expect([]color.RGBA{q[0], q[1], q[2], q[3]}).To(HaveLen(4))
+			Expect(q[0]).ToNot(Equal(q[1]))
+			Expect(q[0]).ToNot(Equal(q[2]))
+			Expect(q[0]).ToNot(Equal(q[3]))
+			Expect(q[1]).ToNot(Equal(q[2]))
+			Expect(q[1]).ToNot(Equal(q[3]))
+			Expect(q[2]).ToNot(Equal(q[3]))
 		})
 	})
 })
@@ -153,6 +208,6 @@ func putPlaylist(pl model.Playlist) model.Playlist {
 	if pl.OwnerID == "" {
 		pl.OwnerID = "admin-1"
 	}
-	Expect(ds.Playlist(ctx).Put(&pl)).To(Succeed())
+	Expect(rds.Playlist(rctx).Put(&pl)).To(Succeed())
 	return pl
 }

core/artwork/e2e/radio_test.go

@@ -1,15 +1,18 @@
-package artworke2e_test
+package e2e
 
 import (
 	"github.com/navidrome/navidrome/consts"
+	"github.com/navidrome/navidrome/core/artwork"
 	"github.com/navidrome/navidrome/model"
 	. "github.com/onsi/ginkgo/v2"
 	. "github.com/onsi/gomega"
 )
 
+// Radio art is uploaded-image-only, with no fallback. Uploads are real files on disk, so they
+// serve back byte-for-byte; a radio with no upload settles absent.
 var _ = Describe("Radio artwork resolution", func() {
 	BeforeEach(func() {
-		setupHarness()
+		setupResolutionHarness()
 	})
 
 	When("a radio has an uploaded image", func() {
@@ -18,25 +21,25 @@ var _ = Describe("Radio artwork resolution", func() {
 		//     └── radio/
 		//         └── rd-1_logo.jpg   ← matched by UploadedImagePath()
 		It("returns the uploaded image bytes", func() {
-			writeUploadedImage(consts.EntityRadio, "rd-1_logo.jpg", imageBytes("radio-logo"))
-
+			writeUploadedImage(consts.EntityRadio, "rd-1_logo.jpg", pngBytes("radio-logo"))
 			rd := model.Radio{ID: "rd-1", Name: "Test Radio", StreamUrl: "https://example.com/stream", UploadedImage: "rd-1_logo.jpg"}
-			Expect(ds.Radio(ctx).Put(&rd)).To(Succeed())
+			Expect(rds.Radio(rctx).Put(&rd)).To(Succeed())
 
-			artID := model.NewArtworkID(model.KindRadioArtwork, rd.ID, nil)
-			Expect(readArtwork(artID)).To(Equal(imageBytes("radio-logo")))
+			ia := acquire(model.KindRadioArtwork, rd.ID)
+			Expect(ia.Source).To(Equal("upload"))
+			Expect(serveBytes(model.NewArtworkID(model.KindRadioArtwork, rd.ID, nil))).To(Equal(pngBytes("radio-logo")))
 		})
 	})
 
 	When("a radio has no uploaded image", func() {
-		// (no files on disk — reader has no sources to fall back to)
-		It("returns ErrUnavailable", func() {
+		// (no files on disk — the resolver has no sources to fall back to)
+		It("settles absent", func() {
 			rd := model.Radio{ID: "rd-2", Name: "Bare Radio", StreamUrl: "https://example.com/stream"}
-			Expect(ds.Radio(ctx).Put(&rd)).To(Succeed())
+			Expect(rds.Radio(rctx).Put(&rd)).To(Succeed())
 
-			artID := model.NewArtworkID(model.KindRadioArtwork, rd.ID, nil)
-			_, err := readArtworkOrErr(artID)
-			Expect(err).To(HaveOccurred())
+			ia := acquire(model.KindRadioArtwork, rd.ID)
+			Expect(ia.Hash).To(BeEmpty())
+			Expect(serveErr(model.NewArtworkID(model.KindRadioArtwork, rd.ID, nil))).To(MatchError(artwork.ErrUnavailable))
 		})
 	})
 })

core/artwork/e2e/resolution_harness_test.go

@@ -0,0 +1,365 @@
+package e2e
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"hash/fnv"
+	"image"
+	"image/color"
+	"image/png"
+	"io"
+	"maps"
+	"os"
+	"path/filepath"
+	"strings"
+	"sync"
+	"testing/fstest"
+	"time"
+
+	_ "github.com/navidrome/navidrome/adapters/gotaglib"
+	"github.com/navidrome/navidrome/conf"
+	"github.com/navidrome/navidrome/conf/configtest"
+	"github.com/navidrome/navidrome/consts"
+	"github.com/navidrome/navidrome/core/agents"
+	"github.com/navidrome/navidrome/core/artwork"
+	"github.com/navidrome/navidrome/core/metrics"
+	"github.com/navidrome/navidrome/core/playlists"
+	"github.com/navidrome/navidrome/core/storage/storagetest"
+	"github.com/navidrome/navidrome/db"
+	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/model/request"
+	"github.com/navidrome/navidrome/persistence"
+	"github.com/navidrome/navidrome/scanner"
+	"github.com/navidrome/navidrome/server/events"
+	"github.com/navidrome/navidrome/tests"
+	"github.com/navidrome/navidrome/tests/harness"
+	"github.com/navidrome/navidrome/utils/cache"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+	"go.senan.xyz/taglib"
+)
+
+const fakeLibScheme = "artworkfake"
+const fakeLibPath = fakeLibScheme + ":///music"
+
+const (
+	defaultCoverPriority = "cover.*, folder.*, front.*, embedded, external"
+	defaultDiscPriority  = "disc*.*, cd*.*, cover.*, folder.*, front.*, discsubtitle, embedded"
+)
+
+var (
+	rctx    context.Context
+	rds     *tests.MockDataStore
+	rstore  *artwork.ImageStore
+	rsvc    artwork.Artwork
+	rworker *artwork.Worker
+	fakeFS  *storagetest.FakeFS
+)
+
+// The go-sqlite3 singleton holds the file open for the whole suite, and Windows cannot unlink a
+// file with a live handle, so the DB cannot live in Ginkgo's per-spec TempDir.
+var suiteDBTempDir string
+
+// Migrating the schema costs ~400ms, so it runs once per suite and specs reset by truncating.
+var userTables []string
+
+var _ = BeforeSuite(func() {
+	suiteDBTempDir = GinkgoT().TempDir()
+
+	DeferCleanup(configtest.SetupConfig())
+	conf.Server.DbPath = filepath.Join(suiteDBTempDir, "artwork-resolution-e2e.db") + "?_journal_mode=WAL"
+	conf.Server.DataFolder = conf.NewDir(GinkgoT().TempDir())
+	db.Db().SetMaxOpenConns(1)
+	db.Init(request.WithUser(context.Background(), model.User{ID: "admin-1", IsAdmin: true}))
+
+	userTables = harness.ResettableTables()
+})
+
+var _ = AfterSuite(func() {
+	db.Close(context.Background())
+})
+
+func setupResolutionHarness() {
+	DeferCleanup(configtest.SetupConfig())
+
+	tempDir := GinkgoT().TempDir()
+	conf.Server.DbPath = filepath.Join(suiteDBTempDir, "artwork-resolution-e2e.db") + "?_journal_mode=WAL"
+	conf.Server.DataFolder = conf.NewDir(tempDir)
+	conf.Server.MusicFolder = fakeLibPath
+	conf.Server.DevExternalScanner = false
+	conf.Server.ImageCacheSize = "0"
+	conf.Server.EnableExternalServices = false
+	conf.Server.EnableMediaFileCoverArt = true
+	conf.Server.DevArtworkWorkerConcurrency = 1
+
+	rctx = request.WithUser(GinkgoT().Context(), model.User{ID: "admin-1", UserName: "admin", IsAdmin: true})
+	harness.TruncateDB(userTables)
+
+	rds = &tests.MockDataStore{RealDS: persistence.New(db.Db())}
+
+	adminUser := model.User{ID: "admin-1", UserName: "admin", Name: "Admin", IsAdmin: true, NewPassword: "password"}
+	Expect(rds.User(rctx).Put(&adminUser)).To(Succeed())
+
+	lib := model.Library{ID: 1, Name: "Music", Path: fakeLibPath}
+	Expect(rds.Library(rctx).Put(&lib)).To(Succeed())
+	Expect(rds.User(rctx).SetUserLibraries(adminUser.ID, []int{lib.ID})).To(Succeed())
+
+	loadEmbeddedFixture()
+
+	fakeFS = &storagetest.FakeFS{}
+	storagetest.Register(fakeLibScheme, fakeFS)
+
+	ffm := tests.NewMockFFmpeg("")
+	rstore = artwork.NewImageStore(filepath.Join(tempDir, consts.HashedArtworkFolder))
+	// size=0 requests stream originals, so this reader is never called (serving_test covers resizing).
+	imgCache := cache.NewFileCache("ArtworkResolutionE2E", "100MB", "images", 0,
+		func(context.Context, cache.Item) (io.Reader, error) {
+			return nil, fmt.Errorf("resize not exercised in e2e")
+		})
+	Eventually(func() bool { return imgCache.Available(rctx) }).Should(BeTrue())
+
+	rsvc = artwork.NewArtwork(rds, imgCache, rstore, ffm)
+	rworker = artwork.NewWorker(rds, rstore, agents.GetAgents(rds, nil), ffm, events.NoopBroker(), imgCache)
+}
+
+// setLayout paths must be relative and forward-slash.
+func setLayout(files fstest.MapFS) {
+	GinkgoHelper()
+	fakeFS.SetFiles(files)
+}
+
+func scan() {
+	GinkgoHelper()
+	s := scanner.New(rctx, rds, events.NoopBroker(),
+		playlists.NewPlaylists(rds, artwork.NewUploader(rds)), metrics.NewNoopInstance())
+	_, err := s.ScanAll(rctx, true)
+	Expect(err).ToNot(HaveOccurred())
+}
+
+func acquire(kind model.Kind, id string) model.ItemArtwork {
+	GinkgoHelper()
+	// Enqueues the way the serving paths do, so the drain is driven by a plain queue row.
+	Expect(rds.ArtworkQueue(rctx).EnqueuePreservingBackoff(model.ArtworkQueueItem{
+		ItemKind: kind.Prefix(), ItemID: id, ImageType: model.ImageTypePrimary,
+		Priority: model.ArtworkPriorityBump,
+	})).To(Succeed())
+	var ia *model.ItemArtwork
+	runResolutionWorkerUntil(func() bool {
+		got, err := rds.Artwork(rctx).GetItemArtwork(kind, id, model.ImageTypePrimary)
+		if err != nil {
+			return false
+		}
+		ia = got
+		return true
+	})
+	return *ia
+}
+
+func runResolutionWorkerUntil(until func() bool) {
+	GinkgoHelper()
+	runCtx, cancel := context.WithCancel(rctx)
+	done := make(chan error, 1)
+	go func() { done <- rworker.Run(runCtx) }()
+	Eventually(until, 5*time.Second, 10*time.Millisecond).Should(BeTrue())
+	cancel()
+	Eventually(done, 2*time.Second).Should(Receive(BeNil()))
+}
+
+func serveBytes(artID model.ArtworkID) []byte {
+	GinkgoHelper()
+	img, err := rsvc.Get(rctx, artID, 0, false)
+	Expect(err).ToNot(HaveOccurred())
+	defer img.Close()
+	data, err := io.ReadAll(img)
+	Expect(err).ToNot(HaveOccurred())
+	return data
+}
+
+func serveErr(artID model.ArtworkID) error {
+	img, err := rsvc.Get(rctx, artID, 0, false)
+	if img != nil {
+		img.Close()
+	}
+	return err
+}
+
+func libFileBytes(suffix string) []byte {
+	GinkgoHelper()
+	var match string
+	for name := range fakeFS.MapFS {
+		if strings.HasSuffix(name, suffix) {
+			Expect(match).To(BeEmpty(), "suffix %q is ambiguous: %q and %q", suffix, match, name)
+			match = name
+		}
+	}
+	Expect(match).ToNot(BeEmpty(), "no library file ends with %q", suffix)
+	return fakeFS.MapFS[match].Data
+}
+
+// Serving before acquiring is deliberate: with no state row the request resolves through the
+// library FS, while a settled folder row is read with os.Open, which the in-memory FS cannot serve.
+func expectAlbumFolderCover(al model.Album, suffix string) {
+	GinkgoHelper()
+	requireNoStateRow(model.KindAlbumArtwork, al.ID)
+	Expect(serveBytes(al.CoverArtID())).To(Equal(libFileBytes(suffix)))
+	ia := acquire(model.KindAlbumArtwork, al.ID)
+	Expect(ia.Source).To(Equal("folder"))
+	Expect(filepath.ToSlash(ia.SourcePath)).To(HaveSuffix(suffix))
+}
+
+// A drain settles every ready item, so byte-level folder assertions must precede any acquire.
+func requireNoStateRow(kind model.Kind, id string) {
+	GinkgoHelper()
+	_, err := rds.Artwork(rctx).GetItemArtwork(kind, id, model.ImageTypePrimary)
+	Expect(err).To(MatchError(model.ErrNotFound),
+		"assert %s %q before acquiring any other entity in this spec", kind, id)
+}
+
+func expectAlbumAbsent(al model.Album) {
+	GinkgoHelper()
+	ia := acquire(model.KindAlbumArtwork, al.ID)
+	Expect(ia.Hash).To(BeEmpty())
+	Expect(serveErr(al.CoverArtID())).To(MatchError(artwork.ErrUnavailable))
+}
+
+func expectArtistFolder(ar model.Artist, suffix string) {
+	GinkgoHelper()
+	requireNoStateRow(model.KindArtistArtwork, ar.ID)
+	Expect(serveBytes(model.NewArtworkID(model.KindArtistArtwork, ar.ID, nil))).To(Equal(libFileBytes(suffix)))
+	ia := acquire(model.KindArtistArtwork, ar.ID)
+	Expect(ia.Source).To(Equal("folder"))
+	Expect(filepath.ToSlash(ia.SourcePath)).To(HaveSuffix(suffix))
+}
+
+func writeUploadedImage(entity, filename string, data []byte) {
+	GinkgoHelper()
+	dst := model.UploadedImagePath(entity, filename)
+	Expect(os.MkdirAll(filepath.Dir(dst), 0o755)).To(Succeed())
+	Expect(os.WriteFile(dst, data, 0o600)).To(Succeed())
+}
+
+func discArtID(al model.Album, disc int) model.ArtworkID {
+	return model.NewArtworkID(model.KindDiscArtwork, model.DiscArtworkID(al.ID, disc), &al.UpdatedAt)
+}
+
+// Disc art is a pure serve-time read through the library FS: no worker, no state row.
+func expectDiscImage(al model.Album, disc int, label string) {
+	GinkgoHelper()
+	Expect(serveBytes(discArtID(al, disc))).To(Equal(pngBytes(label)))
+}
+
+// Samples in rect() order: top-left, top-right, bottom-left, bottom-right.
+func gridQuadrants(data []byte) [4]color.RGBA {
+	GinkgoHelper()
+	img, _, err := image.Decode(bytes.NewReader(data))
+	Expect(err).ToNot(HaveOccurred())
+	b := img.Bounds()
+	qw, qh := b.Dx()/4, b.Dy()/4
+	at := func(x, y int) color.RGBA {
+		c := color.RGBAModel.Convert(img.At(b.Min.X+x, b.Min.Y+y))
+		return c.(color.RGBA)
+	}
+	return [4]color.RGBA{at(qw, qh), at(3*qw, qh), at(qw, 3*qh), at(3*qw, 3*qh)}
+}
+
+// Store-backed sources only (embedded/generated); file-backed ones assert on ia.SourcePath.
+func storedBytes(ia model.ItemArtwork) []byte {
+	GinkgoHelper()
+	art, err := rds.Artwork(rctx).GetImage(ia.Hash)
+	Expect(err).ToNot(HaveOccurred())
+	r, err := rstore.Open(ia.Hash, art.Mime)
+	Expect(err).ToNot(HaveOccurred())
+	defer r.Close()
+	data, err := io.ReadAll(r)
+	Expect(err).ToNot(HaveOccurred())
+	return data
+}
+
+// The pixel color derives from label, so each label yields distinct, still-decodable bytes.
+func smallPNG(label string) *fstest.MapFile {
+	h := fnv.New32a()
+	_, _ = h.Write([]byte(label))
+	sum := h.Sum32()
+	c := color.RGBA{R: byte(sum), G: byte(sum >> 8), B: byte(sum >> 16), A: 255}
+	img := image.NewRGBA(image.Rect(0, 0, 2, 2))
+	for y := range 2 {
+		for x := range 2 {
+			img.Set(x, y, c)
+		}
+	}
+	var buf bytes.Buffer
+	Expect(png.Encode(&buf, img)).To(Succeed())
+	return &fstest.MapFile{Data: buf.Bytes()}
+}
+
+func pngBytes(label string) []byte {
+	GinkgoHelper()
+	return smallPNG(label).Data
+}
+
+func trackFile(num int, title string, extra ...map[string]any) *fstest.MapFile {
+	tags := storagetest.Track(num, title)
+	for _, e := range extra {
+		maps.Copy(tags, e)
+	}
+	return storagetest.MP3(tags)
+}
+
+// FakeFS's JSON-encoded tags aren't taglib-readable, so embedded-art specs swap in these real MP3
+// bytes after scanning. Loaded lazily: tests.Init must chdir to the project root first.
+var (
+	embeddedFixtureOnce sync.Once
+	embeddedArtFixture  []byte
+	embeddedArtBytes    []byte
+)
+
+func loadEmbeddedFixture() {
+	embeddedFixtureOnce.Do(func() {
+		embeddedArtFixture = readFixture(mp3Fixture)
+		embeddedArtBytes = extractEmbeddedArt(embeddedArtFixture)
+	})
+}
+
+func extractEmbeddedArt(mp3 []byte) []byte {
+	tf, err := taglib.OpenStream(bytes.NewReader(mp3))
+	if err != nil {
+		panic("embedded-art fixture: taglib.OpenStream failed: " + err.Error())
+	}
+	defer tf.Close()
+	images := tf.Properties().Images
+	if len(images) == 0 {
+		panic("embedded-art fixture has no embedded images")
+	}
+	data, err := tf.Image(0)
+	if err != nil || len(data) == 0 {
+		panic("embedded-art fixture: could not read image 0")
+	}
+	return data
+}
+
+func replaceWithRealMP3(relPath string) {
+	GinkgoHelper()
+	fakeFS.MapFS[relPath] = &fstest.MapFile{Data: embeddedArtFixture}
+}
+
+func firstAlbum() model.Album {
+	GinkgoHelper()
+	albums, err := rds.Album(rctx).GetAll(model.QueryOptions{})
+	Expect(err).ToNot(HaveOccurred())
+	Expect(albums).To(HaveLen(1), "expected exactly one album, got %d", len(albums))
+	return albums[0]
+}
+
+func albumByName(name string) model.Album {
+	GinkgoHelper()
+	albums, err := rds.Album(rctx).GetAll(model.QueryOptions{})
+	Expect(err).ToNot(HaveOccurred())
+	for _, al := range albums {
+		if al.Name == name {
+			return al
+		}
+	}
+	Fail(fmt.Sprintf("album %q not found among %d albums", name, len(albums)))
+	return model.Album{}
+}

core/artwork/e2e/suite_test.go

@@ -1,120 +0,0 @@
-package artworke2e_test
-
-import (
-	"context"
-	"fmt"
-	"path/filepath"
-	"testing"
-
-	_ "github.com/navidrome/navidrome/adapters/gotaglib"
-	"github.com/navidrome/navidrome/conf"
-	"github.com/navidrome/navidrome/conf/configtest"
-	"github.com/navidrome/navidrome/core"
-	"github.com/navidrome/navidrome/core/artwork"
-	"github.com/navidrome/navidrome/core/metrics"
-	"github.com/navidrome/navidrome/core/playlists"
-	"github.com/navidrome/navidrome/core/storage/storagetest"
-	"github.com/navidrome/navidrome/db"
-	"github.com/navidrome/navidrome/log"
-	"github.com/navidrome/navidrome/model"
-	"github.com/navidrome/navidrome/model/request"
-	"github.com/navidrome/navidrome/persistence"
-	"github.com/navidrome/navidrome/scanner"
-	"github.com/navidrome/navidrome/server/events"
-	"github.com/navidrome/navidrome/tests"
-	. "github.com/onsi/ginkgo/v2"
-	. "github.com/onsi/gomega"
-)
-
-func TestArtworkE2E(t *testing.T) {
-	tests.Init(t, false)
-	log.SetLevel(log.LevelFatal)
-	RegisterFailHandler(Fail)
-	RunSpecs(t, "Artwork E2E Suite")
-}
-
-const fakeLibScheme = "artworkfake"
-const fakeLibPath = fakeLibScheme + ":///music"
-
-var (
-	ctx    context.Context
-	ds     *tests.MockDataStore
-	aw     artwork.Artwork
-	fakeFS *storagetest.FakeFS
-)
-
-// The DB file lives in a suite-level tempdir: the go-sqlite3 singleton keeps
-// the file open for the whole suite, and Ginkgo's per-spec TempDir cleanup
-// can't unlink a file with a live handle on Windows. A suite-level tempdir
-// combined with an AfterSuite close avoids the lock conflict.
-var suiteDBTempDir string
-
-var _ = BeforeSuite(func() {
-	suiteDBTempDir = GinkgoT().TempDir()
-})
-
-var _ = AfterSuite(func() {
-	db.Close(GinkgoT().Context())
-})
-
-func setupHarness() {
-	DeferCleanup(configtest.SetupConfig())
-
-	tempDir := GinkgoT().TempDir()
-	// Reuse the suite-level DB path so the singleton connection keeps working
-	// across specs (see suiteDBTempDir comment).
-	conf.Server.DbPath = filepath.Join(suiteDBTempDir, "artwork-e2e.db") + "?_journal_mode=WAL"
-	conf.Server.DataFolder = conf.NewDir(tempDir)
-	conf.Server.MusicFolder = fakeLibPath
-	conf.Server.DevExternalScanner = false
-	conf.Server.ImageCacheSize = "0" // disabled cache → reader runs on every call
-	conf.Server.EnableExternalServices = false
-
-	db.Db().SetMaxOpenConns(1)
-	ctx = request.WithUser(GinkgoT().Context(), model.User{ID: "admin-1", UserName: "admin", IsAdmin: true})
-	db.Init(ctx)
-	DeferCleanup(func() { Expect(tests.ClearDB()).To(Succeed()) })
-
-	ds = &tests.MockDataStore{RealDS: persistence.New(db.Db())}
-
-	adminUser := model.User{ID: "admin-1", UserName: "admin", Name: "Admin", IsAdmin: true, NewPassword: "password"}
-	Expect(ds.User(ctx).Put(&adminUser)).To(Succeed())
-
-	lib := model.Library{ID: 1, Name: "Music", Path: fakeLibPath}
-	Expect(ds.Library(ctx).Put(&lib)).To(Succeed())
-	Expect(ds.User(ctx).SetUserLibraries(adminUser.ID, []int{lib.ID})).To(Succeed())
-
-	fakeFS = &storagetest.FakeFS{}
-	storagetest.Register(fakeLibScheme, fakeFS)
-
-	aw = artwork.NewArtwork(ds, artwork.GetImageCache(), newNoopFFmpeg(), &noopProvider{})
-}
-
-func scan() {
-	GinkgoHelper()
-	s := scanner.New(ctx, ds, artwork.NoopCacheWarmer(), events.NoopBroker(),
-		playlists.NewPlaylists(ds, core.NewImageUploadService()), metrics.NewNoopInstance())
-	_, err := s.ScanAll(ctx, true)
-	Expect(err).ToNot(HaveOccurred())
-}
-
-func firstAlbum() model.Album {
-	GinkgoHelper()
-	albums, err := ds.Album(ctx).GetAll(model.QueryOptions{})
-	Expect(err).ToNot(HaveOccurred())
-	Expect(albums).To(HaveLen(1), "expected exactly one album, got %d", len(albums))
-	return albums[0]
-}
-
-func albumByName(name string) model.Album {
-	GinkgoHelper()
-	albums, err := ds.Album(ctx).GetAll(model.QueryOptions{})
-	Expect(err).ToNot(HaveOccurred())
-	for _, al := range albums {
-		if al.Name == name {
-			return al
-		}
-	}
-	Fail(fmt.Sprintf("album %q not found among %d albums", name, len(albums)))
-	return model.Album{}
-}

core/artwork/folders_album.go

@@ -3,107 +3,19 @@ package artwork
 import (
 	"cmp"
 	"context"
-	"crypto/md5"
 	"errors"
-	"fmt"
-	"io"
 	"path"
 	"slices"
 	"strings"
 	"time"
 
 	"github.com/Masterminds/squirrel"
-	"github.com/navidrome/navidrome/conf"
-	"github.com/navidrome/navidrome/core/external"
-	"github.com/navidrome/navidrome/core/ffmpeg"
 	"github.com/navidrome/navidrome/log"
 	"github.com/navidrome/navidrome/model"
-	"github.com/navidrome/navidrome/utils"
 	"github.com/navidrome/navidrome/utils/natural"
 	"github.com/navidrome/navidrome/utils/slice"
 )
 
-type albumArtworkReader struct {
-	cacheKey
-	a         *artwork
-	provider  external.Provider
-	album     model.Album
-	updatedAt *time.Time
-	imgFiles  []string // library-relative, forward-slash, no leading slash
-	lib       libraryView
-}
-
-func newAlbumArtworkReader(ctx context.Context, artwork *artwork, artID model.ArtworkID, provider external.Provider) (*albumArtworkReader, error) {
-	al, err := artwork.ds.Album(ctx).Get(artID.ID)
-	if err != nil {
-		return nil, err
-	}
-	_, imgFiles, imagesUpdateAt, err := loadAlbumFoldersPaths(ctx, artwork.ds, *al)
-	if err != nil {
-		return nil, err
-	}
-	lib, err := loadLibraryView(ctx, artwork.ds, al.LibraryID)
-	if err != nil {
-		return nil, err
-	}
-	a := &albumArtworkReader{
-		a:         artwork,
-		provider:  provider,
-		album:     *al,
-		updatedAt: imagesUpdateAt,
-		imgFiles:  imgFiles,
-		lib:       lib,
-	}
-	a.cacheKey.artID = artID
-	a.cacheKey.lastUpdate = utils.TimeNewest(al.UpdatedAt, al.ImportedAt)
-	if imagesUpdateAt != nil {
-		a.cacheKey.lastUpdate = utils.TimeNewest(a.cacheKey.lastUpdate, *imagesUpdateAt)
-	}
-	return a, nil
-}
-
-func (a *albumArtworkReader) Key() string {
-	hashInput := conf.Server.CoverArtPriority
-	if conf.Server.EnableExternalServices {
-		hashInput = conf.Server.Agents + hashInput
-	}
-	hash := md5.Sum([]byte(hashInput))
-	return fmt.Sprintf(
-		"%s.%x.%t",
-		a.cacheKey.Key(),
-		hash,
-		conf.Server.EnableExternalServices,
-	)
-}
-func (a *albumArtworkReader) LastUpdated() time.Time {
-	return a.lastUpdate
-}
-
-func (a *albumArtworkReader) Reader(ctx context.Context) (io.ReadCloser, string, error) {
-	var ff = a.fromCoverArtPriority(ctx, a.a.ffmpeg, conf.Server.CoverArtPriority)
-	return selectImageReader(ctx, a.artID, ff...)
-}
-
-func (a *albumArtworkReader) fromCoverArtPriority(ctx context.Context, ffmpeg ffmpeg.FFmpeg, priority string) []sourceFunc {
-	var ff []sourceFunc
-	for pattern := range strings.SplitSeq(strings.ToLower(priority), ",") {
-		pattern = strings.TrimSpace(pattern)
-		switch {
-		case pattern == "embedded":
-			embedRel := a.album.EmbedArtPath
-			ff = append(ff,
-				fromTag(ctx, a.lib.FS, embedRel),
-				fromFFmpegTag(ctx, ffmpeg, a.lib.Abs(embedRel)),
-			)
-		case pattern == "external":
-			ff = append(ff, fromAlbumExternalSource(ctx, a.album, a.provider))
-		case len(a.imgFiles) > 0:
-			ff = append(ff, fromExternalFile(ctx, a.lib.FS, a.imgFiles, pattern))
-		}
-	}
-	return ff
-}
-
 func loadAlbumFoldersPaths(ctx context.Context, ds model.DataStore, album model.Album) ([]string, []string, *time.Time, error) {
 	folders, err := loadFolders(ctx, ds, album.FolderIDs)
 	if err != nil {
@@ -169,7 +81,7 @@ func albumRootParent(ctx context.Context, ds model.DataStore, folders []model.Fo
 	}
 	parent, err := ds.Folder(ctx).Get(commonParentID)
 	if errors.Is(err, model.ErrNotFound) {
-		log.Warn(ctx, "Parent folder not found for album cover art lookup", "parentID", commonParentID)
+		log.Warn(ctx, "Artwork: Parent folder not found for album cover art lookup", "parentID", commonParentID)
 		return nil, nil
 	}
 	if err != nil {

core/artwork/folders_album_test.go

@@ -0,0 +1,214 @@
+package artwork
+
+import (
+	"context"
+	"errors"
+	"time"
+
+	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/tests"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+// The e2e specs cover which image wins for a layout; these pin what a layout cannot reach: that
+// the album-root parent is only fetched when it could qualify, and what happens when that fails.
+var _ = Describe("loadAlbumFoldersPaths", func() {
+	var (
+		ctx   context.Context
+		ds    *tests.MockDataStore
+		repo  *fakeFolderRepo
+		album model.Album
+		now   time.Time
+	)
+
+	BeforeEach(func() {
+		ctx = context.Background()
+		now = time.Now().Truncate(time.Second)
+		repo = &fakeFolderRepo{}
+		ds = &tests.MockDataStore{MockedFolder: repo}
+		album = model.Album{
+			ID:        "album1",
+			Name:      "Album",
+			FolderIDs: []string{"folder1", "folder2", "folder3"},
+		}
+	})
+
+	It("does not query the parent when it is already one of the album's folders", func() {
+		repo.result = []model.Folder{
+			{ID: "folder1", Path: "Artist", Name: "Album", ParentID: "folder2",
+				ImagesUpdatedAt: now, ImageFiles: []string{"cover.jpg"}},
+			{ID: "folder2", Path: "", Name: "Artist", ImagesUpdatedAt: now},
+		}
+
+		_, imgFiles, _, err := loadAlbumFoldersPaths(ctx, ds, album)
+
+		Expect(err).ToNot(HaveOccurred())
+		Expect(imgFiles).To(ConsistOf("Artist/Album/cover.jpg"))
+		Expect(repo.getCallCount).To(BeZero())
+	})
+
+	It("does not query the parent when the album's folders have different parents", func() {
+		repo.result = []model.Folder{
+			{ID: "folder1", Path: "Artist1/Album", Name: "part1", ParentID: "parentA",
+				ImagesUpdatedAt: now, ImageFiles: []string{"cover.jpg"}},
+			{ID: "folder2", Path: "Artist2/Album", Name: "part2", ParentID: "parentB",
+				ImagesUpdatedAt: now},
+		}
+
+		_, imgFiles, _, err := loadAlbumFoldersPaths(ctx, ds, album)
+
+		Expect(err).ToNot(HaveOccurred())
+		Expect(imgFiles).To(ConsistOf("Artist1/Album/part1/cover.jpg"))
+		Expect(repo.getCallCount).To(BeZero())
+	})
+
+	It("does not query the parent for a single-folder album that has images of its own", func() {
+		repo.result = []model.Folder{
+			{ID: "folder1", Path: "Artist", Name: "Album", ParentID: "artistFolder",
+				ImagesUpdatedAt: now, ImageFiles: []string{"cover.jpg"}},
+		}
+
+		_, imgFiles, _, err := loadAlbumFoldersPaths(ctx, ds, album)
+
+		Expect(err).ToNot(HaveOccurred())
+		Expect(imgFiles).To(ConsistOf("Artist/Album/cover.jpg"))
+		Expect(repo.getCallCount).To(BeZero())
+	})
+
+	It("does not promote the library root, so its images never become album art", func() {
+		repo.result = []model.Folder{
+			{ID: "folder1", Path: ".", Name: "AlbumPart1", ParentID: "rootFolder",
+				ImagesUpdatedAt: now, ImageFiles: []string{"cover.jpg"}},
+			{ID: "folder2", Path: ".", Name: "AlbumPart2", ParentID: "rootFolder",
+				ImagesUpdatedAt: now},
+		}
+		repo.parentResult = &model.Folder{ID: "rootFolder", Name: ".", ImageFiles: []string{"unrelated.jpg"}}
+
+		_, imgFiles, _, err := loadAlbumFoldersPaths(ctx, ds, album)
+
+		Expect(err).ToNot(HaveOccurred())
+		Expect(imgFiles).To(ConsistOf("AlbumPart1/cover.jpg"))
+		Expect(repo.getCallCount).To(Equal(1))
+	})
+
+	It("does not promote a parent that holds another album's audio", func() {
+		repo.result = []model.Folder{
+			{ID: "folder1", Path: "Artist/Album", Name: "CD1", ParentID: "albumFolder",
+				ImagesUpdatedAt: now, ImageFiles: []string{"cover.jpg"}},
+			{ID: "folder2", Path: "Artist/Album", Name: "CD2", ParentID: "albumFolder",
+				ImagesUpdatedAt: now},
+		}
+		repo.parentResult = &model.Folder{ID: "albumFolder", Path: "Artist", Name: "Album",
+			ParentID: "artistFolder", ImageFiles: []string{"artist.jpg"}}
+		repo.hasOtherAudio = true
+
+		_, imgFiles, _, err := loadAlbumFoldersPaths(ctx, ds, album)
+
+		Expect(err).ToNot(HaveOccurred())
+		Expect(imgFiles).To(ConsistOf("Artist/Album/CD1/cover.jpg"))
+	})
+
+	It("promotes the album root parent into the returned paths", func() {
+		repo.result = []model.Folder{
+			{ID: "folder1", Path: "Artist/Album", Name: "CD1", ParentID: "albumFolder",
+				ImagesUpdatedAt: now},
+			{ID: "folder2", Path: "Artist/Album", Name: "CD2", ParentID: "albumFolder",
+				ImagesUpdatedAt: now},
+		}
+		repo.parentResult = &model.Folder{ID: "albumFolder", Path: "Artist", Name: "Album",
+			ParentID: "artistFolder", ImageFiles: []string{"cover.jpg"}}
+
+		paths, imgFiles, _, err := loadAlbumFoldersPaths(ctx, ds, album)
+
+		Expect(err).ToNot(HaveOccurred())
+		Expect(imgFiles).To(ConsistOf("Artist/Album/cover.jpg"))
+		Expect(paths).To(HaveLen(3))
+	})
+
+	It("propagates errors from the album-root check", func() {
+		repo.result = []model.Folder{
+			{ID: "folder1", Path: "Artist/Album", Name: "disc1", ParentID: "albumFolder",
+				ImagesUpdatedAt: now},
+		}
+		repo.parentResult = &model.Folder{ID: "albumFolder", Path: "Artist", Name: "Album",
+			ParentID: "artistFolder", ImageFiles: []string{"cover.jpg"}}
+		repo.otherAudioErr = errors.New("db connection failed")
+
+		_, _, _, err := loadAlbumFoldersPaths(ctx, ds, album)
+
+		Expect(err).To(MatchError("db connection failed"))
+	})
+
+	It("propagates non-ErrNotFound errors from the parent folder lookup", func() {
+		repo.result = []model.Folder{
+			{ID: "folder1", Path: "Artist/Album", Name: "CD1", ParentID: "parentFolder",
+				ImagesUpdatedAt: now, ImageFiles: []string{"cover.jpg"}},
+			{ID: "folder2", Path: "Artist/Album", Name: "CD2", ParentID: "parentFolder",
+				ImagesUpdatedAt: now},
+		}
+		repo.getErr = errors.New("db connection failed")
+
+		_, _, _, err := loadAlbumFoldersPaths(ctx, ds, album)
+
+		Expect(err).To(MatchError("db connection failed"))
+		Expect(repo.getCallCount).To(Equal(1))
+	})
+
+	It("continues when the parent folder has been deleted", func() {
+		repo.result = []model.Folder{
+			{ID: "folder1", Path: "Artist/Album", Name: "CD1", ParentID: "missingParent",
+				ImagesUpdatedAt: now, ImageFiles: []string{"cover.jpg"}},
+			{ID: "folder2", Path: "Artist/Album", Name: "CD2", ParentID: "missingParent",
+				ImagesUpdatedAt: now},
+		}
+
+		_, imgFiles, _, err := loadAlbumFoldersPaths(ctx, ds, album)
+
+		Expect(err).ToNot(HaveOccurred())
+		Expect(imgFiles).To(ConsistOf("Artist/Album/CD1/cover.jpg"))
+		Expect(repo.getCallCount).To(Equal(1))
+	})
+})
+
+// folderImages is the sort that decides which of several same-named images wins, so it is pinned
+// directly rather than through a layout that can only show the winner.
+var _ = Describe("folderImages", func() {
+	It("prefers base filenames over numeric-suffixed ones", func() {
+		imgFiles, _ := folderImages([]model.Folder{
+			{Path: "Artist", Name: "Album", ImageFiles: []string{"cover.1.jpg", "cover.jpg", "cover.2.jpg"}},
+		})
+
+		Expect(imgFiles).To(HaveExactElements(
+			"Artist/Album/cover.jpg", "Artist/Album/cover.1.jpg", "Artist/Album/cover.2.jpg"))
+	})
+
+	It("prefers shallower paths when the base filenames tie", func() {
+		imgFiles, _ := folderImages([]model.Folder{
+			{Path: "Artist/Album", Name: "CD1", ImageFiles: []string{"cover.jpg"}},
+			{Path: "Artist", Name: "Album", ImageFiles: []string{"cover.jpg"}},
+		})
+
+		Expect(imgFiles).To(HaveExactElements("Artist/Album/cover.jpg", "Artist/Album/CD1/cover.jpg"))
+	})
+
+	It("sorts case-insensitively", func() {
+		imgFiles, _ := folderImages([]model.Folder{
+			{Path: "Artist", Name: "Album", ImageFiles: []string{"Cover.jpg", "back.JPG"}},
+		})
+
+		Expect(imgFiles).To(HaveExactElements("Artist/Album/back.JPG", "Artist/Album/Cover.jpg"))
+	})
+
+	It("reports the newest ImagesUpdatedAt across the folders", func() {
+		now := time.Now().Truncate(time.Second)
+		newest := now.Add(5 * time.Minute)
+
+		_, updatedAt := folderImages([]model.Folder{
+			{Path: "Artist", Name: "Album", ImagesUpdatedAt: now},
+			{Path: "Artist/Album", Name: "CD1", ImagesUpdatedAt: newest},
+		})
+
+		Expect(updatedAt).To(Equal(newest))
+	})
+})

core/artwork/folders_artist.go

@@ -0,0 +1,210 @@
+package artwork
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"io/fs"
+	"os"
+	"path"
+	"path/filepath"
+	"slices"
+	"strings"
+	"time"
+
+	"github.com/Masterminds/squirrel"
+	"github.com/navidrome/navidrome/core"
+	"github.com/navidrome/navidrome/log"
+	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/utils"
+	"github.com/navidrome/navidrome/utils/slice"
+	"github.com/navidrome/navidrome/utils/str"
+)
+
+const (
+	maxArtistFolderTraversalDepth = 3
+)
+
+func fromArtistFolder(ctx context.Context, libFS fs.FS, libPath, artistFolder, pattern string) sourceFunc {
+	return func() (io.ReadCloser, string, error) {
+		if libFS == nil {
+			return nil, "", fmt.Errorf("artist folder lookup unavailable")
+		}
+		rel, err := filepath.Rel(libPath, artistFolder)
+		if err != nil || rel == ".." || strings.HasPrefix(rel, ".."+string(filepath.Separator)) {
+			return nil, "", fmt.Errorf(`artist folder '%s' is outside library '%s'`, artistFolder, libPath)
+		}
+		// fs.Glob needs forward slashes; filepath.Rel returns backslashes on Windows.
+		rel = filepath.ToSlash(rel)
+		current := artistFolder
+		var unreadable error
+		for range maxArtistFolderTraversalDepth {
+			reader, hit, err := findImageInFolder(ctx, libFS, rel, current, pattern)
+			if err == nil {
+				return reader, hit, nil
+			}
+			if errors.Is(err, errSourceUnreadable) {
+				unreadable = err
+			}
+			if rel == "." {
+				break // reached library root
+			}
+			rel = path.Dir(rel)
+			current = filepath.Dir(current)
+		}
+		if unreadable != nil {
+			return nil, "", unreadable
+		}
+		return nil, "", fmt.Errorf(`no matches for '%s' in '%s' or its parent directories (within library)`, pattern, artistFolder)
+	}
+}
+
+// findImageInFolder returns the first image matching pattern; absFolder is only used for
+// the returned display path and log messages.
+func findImageInFolder(ctx context.Context, libFS fs.FS, relFolder, absFolder, pattern string) (io.ReadCloser, string, error) {
+	log.Trace(ctx, "Artwork: Looking for artist image", "pattern", pattern, "folder", absFolder)
+	globPattern := pattern
+	if relFolder != "." {
+		globPattern = path.Join(escapeGlobLiteral(relFolder), pattern)
+	}
+	matches, err := fs.Glob(libFS, globPattern)
+	if err != nil {
+		log.Warn(ctx, "Artwork: Error matching artist image pattern", "pattern", pattern, "folder", absFolder, err)
+		return nil, "", err
+	}
+
+	imagePaths := slice.Filter(matches, model.IsImageFile)
+
+	// Prefer base filenames over numeric-suffixed ones (artist.jpg before artist.1.jpg)
+	slices.SortFunc(imagePaths, compareImageFiles)
+
+	var openErr error
+	for _, p := range imagePaths {
+		f, err := libFS.Open(p)
+		if err != nil {
+			log.Warn(ctx, "Artwork: Could not open cover art file", "file", p, err)
+			openErr = fmt.Errorf("%w: %s: %w", errSourceUnreadable, p, err)
+			continue
+		}
+		_, name := path.Split(p)
+		return f, filepath.Join(absFolder, name), nil
+	}
+	if openErr != nil {
+		return nil, "", openErr
+	}
+
+	return nil, "", fmt.Errorf(`no matches for '%s' in '%s'`, pattern, absFolder)
+}
+
+func escapeGlobLiteral(s string) string {
+	var b strings.Builder
+	b.Grow(len(s))
+	for _, r := range s {
+		switch r {
+		case '\\', '*', '?', '[', ']':
+			b.WriteByte('\\')
+		}
+		b.WriteRune(r)
+	}
+	return b.String()
+}
+
+// loadArtistAlbumRoots returns one path per album — the deepest folder holding
+// all of that album's tracks — so an album split into disc subfolders can't
+// pull the artist folder's common prefix below the artist level.
+func loadArtistAlbumRoots(ctx context.Context, ds model.DataStore, albums model.Albums) ([]string, []string, *time.Time, error) {
+	var folderIDs []string
+	for _, album := range albums {
+		folderIDs = append(folderIDs, album.FolderIDs...)
+	}
+	folders, err := loadFolders(ctx, ds, folderIDs)
+	if err != nil {
+		return nil, nil, nil, err
+	}
+
+	pathByID := slice.ToMap(folders, func(f model.Folder) (string, string) {
+		return f.ID, f.AbsolutePath()
+	})
+	var roots []string
+	for _, album := range albums {
+		var albumPaths []string
+		for _, fid := range album.FolderIDs {
+			if p, ok := pathByID[fid]; ok {
+				albumPaths = append(albumPaths, p)
+			}
+		}
+		if len(albumPaths) > 0 {
+			roots = append(roots, commonDir(albumPaths))
+		}
+	}
+
+	imgFiles, updatedAt := folderImages(folders)
+	return roots, imgFiles, &updatedAt, nil
+}
+
+// commonDir returns the deepest directory containing all paths. Trailing
+// separators keep the comparison on segment boundaries, so a shared name
+// fragment (".../Album" and ".../Album2") is never read as a shared directory.
+func commonDir(paths []string) string {
+	sep := string(filepath.Separator)
+	common := str.LongestCommonPrefix(slice.Map(paths, func(p string) string { return p + sep }))
+	if !strings.HasSuffix(common, sep) {
+		common, _ = filepath.Split(common)
+	}
+	return filepath.Clean(common)
+}
+
+func loadArtistFolder(ctx context.Context, ds model.DataStore, albums model.Albums, paths []string) (string, time.Time, error) {
+	if len(albums) == 0 {
+		return "", time.Time{}, nil
+	}
+	libID := albums[0].LibraryID // TODO: Support albums spanning multiple libraries
+
+	// paths holds one root per album: two or more distinct roots already meet at
+	// the artist folder, while a single root is an album folder needing a climb.
+	roots := slices.Compact(slices.Sorted(slices.Values(paths)))
+	folderPath := commonDir(roots)
+	if len(roots) < 2 {
+		folderPath = filepath.Dir(folderPath)
+	}
+
+	// TODO: Hacky, but the easiest way to get the folder ID ATM
+	libPath := core.AbsolutePath(ctx, ds, libID, "")
+	folderID := model.FolderID(model.Library{ID: libID, Path: libPath}, folderPath)
+
+	log.Trace(ctx, "Artwork: Calculating artist folder details", "folderPath", folderPath, "folderID", folderID,
+		"libPath", libPath, "libID", libID, "albumPaths", paths)
+
+	folders, err := ds.Folder(ctx).GetAll(model.QueryOptions{Filters: squirrel.Eq{"folder.id": folderID, "missing": false}})
+	if err != nil || len(folders) == 0 {
+		log.Warn(ctx, "Artwork: Could not find folder for artist", "folderPath", folderPath, "id", folderID,
+			"libPath", libPath, "libID", libID, err)
+		return "", time.Time{}, err
+	}
+	return folderPath, folders[0].ImagesUpdatedAt, nil
+}
+
+// findImageInArtistFolder matches an image by MBID or artist name (case-insensitive), "" if none.
+func findImageInArtistFolder(folder, mbzArtistID, artistName string) string {
+	entries, err := os.ReadDir(folder)
+	if err != nil {
+		return ""
+	}
+	for _, candidate := range []string{mbzArtistID, artistName} {
+		if candidate == "" {
+			continue
+		}
+		for _, entry := range entries {
+			if entry.IsDir() {
+				continue
+			}
+			name := entry.Name()
+			base := utils.BaseName(name)
+			if strings.EqualFold(base, candidate) && model.IsImageFile(name) {
+				return filepath.Join(folder, name)
+			}
+		}
+	}
+	return ""
+}

core/artwork/folders_artist_paths_test.go

@@ -0,0 +1,117 @@
+package artwork
+
+import (
+	"context"
+	"errors"
+	"path/filepath"
+	"time"
+
+	"github.com/navidrome/navidrome/core"
+	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/tests"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+// commonDir and loadArtistFolder decide how far above the albums the artist folder sits. A layout
+// can only show the image that won, so the arithmetic is pinned here.
+var _ = Describe("commonDir", func() {
+	It("returns the folder itself for a single path", func() {
+		Expect(commonDir([]string{filepath.FromSlash("/music/artist/album")})).
+			To(Equal(filepath.FromSlash("/music/artist/album")))
+	})
+
+	It("returns the deepest shared folder", func() {
+		Expect(commonDir([]string{
+			filepath.FromSlash("/music/artist/album/cd1"),
+			filepath.FromSlash("/music/artist/album/cd2"),
+		})).To(Equal(filepath.FromSlash("/music/artist/album")))
+	})
+
+	It("does not read a shared name fragment as a shared folder", func() {
+		Expect(commonDir([]string{
+			filepath.FromSlash("/music/artist/Album"),
+			filepath.FromSlash("/music/artist/Album2"),
+		})).To(Equal(filepath.FromSlash("/music/artist")))
+	})
+})
+
+var _ = Describe("loadArtistFolder", func() {
+	var (
+		ctx       context.Context
+		ds        *tests.MockDataStore
+		repo      *fakeFolderRepo
+		albums    model.Albums
+		updatedAt time.Time
+	)
+
+	BeforeEach(func() {
+		ctx = context.Background()
+		DeferCleanup(stubCoreAbsolutePath())
+
+		updatedAt = time.Now().Truncate(time.Second).Add(5 * time.Minute)
+		repo = &fakeFolderRepo{result: []model.Folder{{ImagesUpdatedAt: updatedAt}}}
+		ds = &tests.MockDataStore{MockedFolder: repo}
+		albums = model.Albums{{LibraryID: 1, ID: "album1", Name: "Album 1"}}
+	})
+
+	It("returns empty when the artist has no albums", func() {
+		folder, upd, err := loadArtistFolder(ctx, ds, model.Albums{}, []string{"/dummy/path"})
+
+		Expect(err).ToNot(HaveOccurred())
+		Expect(folder).To(BeEmpty())
+		Expect(upd).To(BeZero())
+	})
+
+	It("climbs above the album folder when the artist has a single album root", func() {
+		folder, upd, err := loadArtistFolder(ctx, ds, albums,
+			[]string{filepath.FromSlash("/music/artist/album1")})
+
+		Expect(err).ToNot(HaveOccurred())
+		Expect(folder).To(Equal(filepath.FromSlash("/music/artist")))
+		Expect(upd).To(Equal(updatedAt))
+	})
+
+	It("climbs above the shared folder when two albums live in the same one", func() {
+		folder, upd, err := loadArtistFolder(ctx, ds, albums, []string{
+			filepath.FromSlash("/music/artist/split"),
+			filepath.FromSlash("/music/artist/split"),
+		})
+
+		Expect(err).ToNot(HaveOccurred())
+		Expect(folder).To(Equal(filepath.FromSlash("/music/artist")))
+		Expect(upd).To(Equal(updatedAt))
+	})
+
+	It("stops at the folder where distinct album roots already meet", func() {
+		folder, upd, err := loadArtistFolder(ctx, ds, albums, []string{
+			filepath.FromSlash("/music/artist/album1"),
+			filepath.FromSlash("/music/artist/album2"),
+		})
+
+		Expect(err).ToNot(HaveOccurred())
+		Expect(folder).To(Equal(filepath.FromSlash("/music/artist")))
+		Expect(upd).To(Equal(updatedAt))
+	})
+
+	It("returns the error when the folder lookup fails", func() {
+		repo.err = errors.New("fake error")
+
+		folder, upd, err := loadArtistFolder(ctx, ds, albums, []string{
+			filepath.FromSlash("/music/artist/album1"),
+			filepath.FromSlash("/music/artist/album2"),
+		})
+
+		Expect(err).To(MatchError(ContainSubstring("fake error")))
+		Expect(folder).To(BeEmpty())
+		Expect(upd).To(BeZero())
+	})
+})
+
+func stubCoreAbsolutePath() func() {
+	original := core.AbsolutePath
+	core.AbsolutePath = func(context.Context, model.DataStore, int, string) string {
+		return filepath.FromSlash("/music")
+	}
+	return func() { core.AbsolutePath = original }
+}

core/artwork/folders_artist_test.go

@@ -0,0 +1,47 @@
+package artwork
+
+import (
+	"context"
+	"errors"
+	"io/fs"
+	"testing/fstest"
+
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+// unreadableFS globs like its embedded MapFS but refuses to open anything. Injecting the error
+// keeps this independent of the filesystem: os.Chmod does not restrict read access on Windows.
+type unreadableFS struct{ fstest.MapFS }
+
+func (u unreadableFS) Open(string) (fs.File, error) { return nil, fs.ErrPermission }
+
+var _ = Describe("findImageInFolder", func() {
+	var ctx context.Context
+	var files fstest.MapFS
+
+	BeforeEach(func() {
+		ctx = context.Background()
+		files = fstest.MapFS{"artist.jpg": &fstest.MapFile{Data: []byte("img")}}
+	})
+
+	It("returns the first matching image", func() {
+		r, hit, err := findImageInFolder(ctx, files, ".", "/lib", "artist.*")
+		Expect(err).ToNot(HaveOccurred())
+		defer r.Close()
+		Expect(hit).To(HaveSuffix("artist.jpg"))
+	})
+
+	// The glob matched, so the image exists; failing to open it says nothing about whether the
+	// artist has one, and must not let the resolver settle on absent.
+	It("reports a matched but unreadable image as unreadable, not as a miss", func() {
+		_, _, err := findImageInFolder(ctx, unreadableFS{files}, ".", "/lib", "artist.*")
+		Expect(err).To(MatchError(errSourceUnreadable))
+	})
+
+	It("reports a plain miss when nothing matches", func() {
+		_, _, err := findImageInFolder(ctx, files, ".", "/lib", "nothing.*")
+		Expect(err).To(HaveOccurred())
+		Expect(errors.Is(err, errSourceUnreadable)).To(BeFalse(), "no match is definitive, not transient")
+	})
+})

core/artwork/gate.go

@@ -0,0 +1,120 @@
+package artwork
+
+import (
+	"errors"
+	"io"
+	"sync"
+	"time"
+
+	"github.com/navidrome/navidrome/conf"
+	"github.com/navidrome/navidrome/core/agents"
+	"github.com/navidrome/navidrome/log"
+	"github.com/navidrome/navidrome/model"
+	"golang.org/x/time/rate"
+)
+
+const (
+	breakerThreshold  = 5
+	breakerProbeAfter = time.Minute
+)
+
+var errBreakerOpen = errors.New("artwork: external circuit breaker open")
+
+// gateFunc gates one named external fetch (rate limit + circuit breaker per name).
+type gateFunc = func(name string, f func() (io.ReadCloser, string, error)) (io.ReadCloser, string, error)
+
+func passthroughGate(_ string, f func() (io.ReadCloser, string, error)) (io.ReadCloser, string, error) {
+	return f()
+}
+
+// isTransientExternal reports whether an external failure is worth retrying; a not-found
+// (from either package) is a definitive answer, not a fault.
+func isTransientExternal(err error) bool {
+	return err != nil && !errors.Is(err, agents.ErrNotFound) && !errors.Is(err, model.ErrNotFound)
+}
+
+// extGate is one agent's rate limiter and circuit breaker, so a failing provider backs off
+// in isolation from the others.
+type extGate struct {
+	limiter *rate.Limiter
+	breaker *breaker
+}
+
+// gate runs a named external step through that agent's rate limiter and circuit breaker.
+func (w *Worker) gate(name string, f func() (io.ReadCloser, string, error)) (io.ReadCloser, string, error) {
+	g := w.gateFor(name)
+	if !g.breaker.allow() {
+		log.Debug(w.runCtx, "Artwork: Skipping agent, circuit breaker open", "agent", name)
+		return nil, "", errBreakerOpen
+	}
+	// Timed separately so a throttled agent isn't mistaken for a slow provider.
+	waitStart := time.Now()
+	if err := g.limiter.Wait(w.runCtx); err != nil {
+		return nil, "", err
+	}
+	callStart := time.Now()
+	r, path, err := f()
+	g.breaker.record(name, err)
+	log.Trace(w.runCtx, "Artwork: External agent call", "agent", name, "hit", r != nil,
+		"limiterWait", callStart.Sub(waitStart), "elapsed", time.Since(callStart), err)
+	return r, path, err
+}
+
+// gateFor lazily creates the per-name gate on first use.
+func (w *Worker) gateFor(name string) *extGate {
+	w.gatesMu.Lock()
+	defer w.gatesMu.Unlock()
+	if g, ok := w.gates[name]; ok {
+		return g
+	}
+	rps := conf.Server.DevArtworkExternalMaxRPS
+	limit := rate.Inf
+	if rps > 0 {
+		limit = rate.Limit(rps)
+	}
+	g := &extGate{limiter: rate.NewLimiter(limit, max(1, rps)), breaker: newBreaker()}
+	w.gates[name] = g
+	return g
+}
+
+// breaker opens after breakerThreshold consecutive errors and admits a single probe once
+// breakerProbeAfter has elapsed; a success re-closes it.
+type breaker struct {
+	mu       sync.Mutex
+	failures int
+	openedAt time.Time
+}
+
+func newBreaker() *breaker { return &breaker{} }
+
+func (b *breaker) allow() bool {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	if b.failures < breakerThreshold {
+		return true
+	}
+	if time.Since(b.openedAt) >= breakerProbeAfter {
+		b.openedAt = time.Now() // start a fresh probe window so only one caller passes
+		return true
+	}
+	return false
+}
+
+func (b *breaker) record(name string, err error) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	// A not-found is a definitive answer, not a fault; keep in sync with isTransientExternal.
+	if err == nil || errors.Is(err, model.ErrNotFound) || errors.Is(err, agents.ErrNotFound) {
+		if b.failures >= breakerThreshold {
+			log.Info("Artwork: Circuit breaker closed for agent", "agent", name)
+		}
+		b.failures = 0
+		return
+	}
+	b.failures++
+	if b.failures == breakerThreshold {
+		b.openedAt = time.Now()
+		log.Warn("Artwork: Circuit breaker opened for agent", "agent", name,
+			"consecutiveFailures", b.failures, "probeAfter", breakerProbeAfter, err)
+	}
+}

core/artwork/hash_encoder_bench_test.go

@@ -0,0 +1,51 @@
+package artwork
+
+import (
+	"fmt"
+	"image"
+	"testing"
+
+	"github.com/navidrome/navidrome/core/artwork/blurhash"
+	"github.com/navidrome/navidrome/core/artwork/thumbhash"
+)
+
+// hashEncoders are the two placeholder hashes decodeArtwork computes from one shared thumbnail.
+var hashEncoders = []struct {
+	name   string
+	encode func(image.Image) error
+}{
+	{"blurhash", func(img image.Image) error { _, err := blurhash.Encode(img); return err }},
+	{"thumbhash", func(img image.Image) error { _, err := thumbhash.Encode(img); return err }},
+}
+
+func benchEncoder(b *testing.B, encode func(image.Image) error, img image.Image) {
+	b.Helper()
+	b.ReportAllocs()
+	for b.Loop() {
+		if err := encode(img); err != nil {
+			b.Fatal(err)
+		}
+	}
+}
+
+// BenchmarkHashEncodersAtInputSize is the bar: both encoders are handed the identical image
+// makeThumbnail produces, so neither is measured with a conversion the other avoids.
+func BenchmarkHashEncodersAtInputSize(b *testing.B) {
+	img := gradientNRGBA(thumbnailSize)
+	for _, e := range hashEncoders {
+		b.Run(e.name, func(b *testing.B) { benchEncoder(b, e.encode, img) })
+	}
+}
+
+// BenchmarkHashEncoders sweeps past the pipeline's input size, where each package's own defensive
+// downscale starts to dominate. thumbnailSize itself is covered by the benchmark above.
+func BenchmarkHashEncoders(b *testing.B) {
+	for _, size := range []int{300, 600, 900, 1200, 1500} {
+		img := gradientNRGBA(size)
+		for _, e := range hashEncoders {
+			b.Run(fmt.Sprintf("%s/%dx%d", e.name, size, size), func(b *testing.B) {
+				benchEncoder(b, e.encode, img)
+			})
+		}
+	}
+}

core/artwork/housekeeping.go

@@ -0,0 +1,129 @@
+package artwork
+
+import (
+	"context"
+	"crypto/md5"
+	"encoding/hex"
+	"fmt"
+	"slices"
+	"time"
+
+	"github.com/navidrome/navidrome/conf"
+	"github.com/navidrome/navidrome/consts"
+	"github.com/navidrome/navidrome/core/auth"
+	"github.com/navidrome/navidrome/log"
+	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/utils/slice"
+)
+
+const staleAbsentAge = 24 * time.Hour
+
+// recheckKinds omits media files: they resolve embedded-only, at scan or on view.
+var recheckKinds = []model.Kind{
+	model.KindArtistArtwork, model.KindAlbumArtwork, model.KindPlaylistArtwork, model.KindRadioArtwork,
+}
+
+// hasRecheckPath reports whether a periodic job will revisit this kind, making an absent settle recoverable.
+func hasRecheckPath(prefix string) bool {
+	kind, ok := model.ParseKind(prefix)
+	return ok && slices.Contains(recheckKinds, kind)
+}
+
+// artworkEpoch invalidates all resolution state when bumped; bump it whenever resolution semantics change.
+const artworkEpoch = 1
+
+// fingerprint covers the inputs that affect resolution outcomes; a change invalidates stored state.
+func fingerprint() string {
+	raw := fmt.Sprintf("%s|%s|%s|%s|%t|%t|%d",
+		conf.Server.CoverArtPriority, conf.Server.ArtistArtPriority, conf.Server.ArtistImageFolder,
+		conf.Server.Agents, conf.Server.EnableExternalServices, conf.Server.EnableM3UExternalAlbumArt, artworkEpoch)
+	sum := md5.Sum([]byte(raw)) //nolint:gosec // fingerprint, not security-sensitive
+	return hex.EncodeToString(sum[:])
+}
+
+// backfill enqueues artwork resolution for every entity when the config fingerprint changed.
+func backfill(ctx context.Context, ds model.DataStore) (bool, error) {
+	start := time.Now()
+	ctx = auth.WithAdminUser(ctx, ds)
+	current := fingerprint()
+	props := ds.Property(ctx)
+	stored, err := props.DefaultGet(consts.ArtConfFingerprintPropertyKey, "")
+	if err != nil {
+		return false, err
+	}
+	if stored == current {
+		return false, nil
+	}
+
+	// Artists first: few entities, most external-dependent, so they get a queue headstart.
+	kinds := []struct {
+		kind  model.Kind
+		fetch func() ([]string, error)
+	}{
+		{model.KindArtistArtwork, func() ([]string, error) { return ds.Artist(ctx).GetAllIDs() }},
+		{model.KindAlbumArtwork, func() ([]string, error) { return ds.Album(ctx).GetAllIDs() }},
+		{model.KindPlaylistArtwork, func() ([]string, error) { return ds.Playlist(ctx).GetAllIDs() }},
+		{model.KindRadioArtwork, func() ([]string, error) { return ds.Radio(ctx).GetAllIDs() }},
+	}
+	for _, k := range kinds {
+		ids, err := k.fetch()
+		if err != nil {
+			return false, err
+		}
+		if err := enqueueBackfillKind(ctx, ds, k.kind, ids); err != nil {
+			return false, err
+		}
+	}
+
+	if err := props.Put(consts.ArtConfFingerprintPropertyKey, current); err != nil {
+		return false, err
+	}
+	log.Info(ctx, "Artwork: Config fingerprint changed, backfill enqueued", "elapsed", time.Since(start))
+	return true, nil
+}
+
+func enqueueBackfillKind(ctx context.Context, ds model.DataStore, kind model.Kind, ids []string) error {
+	if len(ids) == 0 {
+		return nil
+	}
+	items := slice.Map(ids, func(id string) model.ArtworkQueueItem {
+		return model.ArtworkQueueItem{
+			ItemKind: kind.Prefix(), ItemID: id, ImageType: model.ImageTypePrimary, Priority: model.ArtworkPriorityBackfill,
+		}
+	})
+	return ds.ArtworkQueue(ctx).Enqueue(items...)
+}
+
+func enqueueStaleAbsentAll(ctx context.Context, ds model.DataStore) error {
+	cutoff := time.Now().Add(-staleAbsentAge)
+	queue := ds.ArtworkQueue(ctx)
+	for _, kind := range recheckKinds {
+		if _, err := queue.EnqueueStaleAbsent(kind, cutoff); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// enqueueMissingAll is the safety net for entities a scan never enqueued (added between scans, or scanner off).
+func enqueueMissingAll(ctx context.Context, ds model.DataStore) error {
+	queue := ds.ArtworkQueue(ctx)
+	for _, kind := range recheckKinds {
+		if _, err := queue.EnqueueAllMissing(kind, model.ArtworkPriorityRecheck); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// Refresh drops an item's resolved artwork state and re-queues it at Bump priority.
+func Refresh(ctx context.Context, ds model.DataStore, kind model.Kind, id string) error {
+	if err := ds.Artwork(ctx).DeleteForItems(kind, []string{id}); err != nil {
+		return fmt.Errorf("clearing artwork state: %w", err)
+	}
+	item := model.ArtworkQueueItem{ItemKind: kind.Prefix(), ItemID: id, ImageType: model.ImageTypePrimary, Priority: model.ArtworkPriorityBump}
+	if err := ds.ArtworkQueue(ctx).Enqueue(item); err != nil {
+		return fmt.Errorf("enqueuing artwork refresh: %w", err)
+	}
+	return nil
+}

core/artwork/housekeeping_test.go

@@ -0,0 +1,261 @@
+package artwork
+
+import (
+	"context"
+	"slices"
+	"time"
+
+	"github.com/navidrome/navidrome/conf"
+	"github.com/navidrome/navidrome/conf/configtest"
+	"github.com/navidrome/navidrome/consts"
+	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/model/request"
+	"github.com/navidrome/navidrome/tests"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+// visibilityPlaylistDS models playlist_repository's userFilter: a private playlist is only
+// visible when the ctx carries an admin, so headless work must wrap ctx with one first.
+type visibilityPlaylistDS struct {
+	*tests.MockDataStore
+	private model.Playlist
+	tracks  model.PlaylistTrackRepository
+}
+
+func (v *visibilityPlaylistDS) Playlist(ctx context.Context) model.PlaylistRepository {
+	repo := tests.CreateMockPlaylistRepo()
+	repo.TracksRepo = v.tracks
+	if u, ok := request.UserFrom(ctx); ok && u.IsAdmin {
+		repo.SetData(model.Playlists{v.private})
+	}
+	return repo
+}
+
+func adminUserRepo() *tests.MockedUserRepo {
+	repo := tests.CreateMockUserRepo()
+	Expect(repo.Put(&model.User{ID: "admin", UserName: "admin", IsAdmin: true})).To(Succeed())
+	return repo
+}
+
+// orderTrackingQueueRepo records the item kind of each Enqueue call, so tests can
+// assert phase ordering (artists-first) that same-priority timestamps can't guarantee.
+type orderTrackingQueueRepo struct {
+	*tests.MockArtworkQueueRepo
+	callKinds []string
+}
+
+func (o *orderTrackingQueueRepo) Enqueue(items ...model.ArtworkQueueItem) error {
+	if len(items) > 0 {
+		o.callKinds = append(o.callKinds, items[0].ItemKind)
+	}
+	return o.MockArtworkQueueRepo.Enqueue(items...)
+}
+
+var _ = Describe("Housekeeping", func() {
+	var (
+		ctx       context.Context
+		ds        *tests.MockDataStore
+		queueRepo *orderTrackingQueueRepo
+		propRepo  *tests.MockedPropertyRepo
+	)
+
+	BeforeEach(func() {
+		DeferCleanup(configtest.SetupConfig())
+		ctx = context.Background()
+		conf.Server.CoverArtPriority = "embedded, folder"
+		conf.Server.ArtistArtPriority = "artist.jpg"
+		conf.Server.Agents = "spotify"
+		conf.Server.EnableExternalServices = true
+
+		queueRepo = &orderTrackingQueueRepo{MockArtworkQueueRepo: tests.CreateMockArtworkQueueRepo()}
+		propRepo = &tests.MockedPropertyRepo{}
+		ds = &tests.MockDataStore{MockedArtworkQueue: queueRepo, MockedProperty: propRepo}
+	})
+
+	seedEntities := func() {
+		artistRepo := tests.CreateMockArtistRepo()
+		artistRepo.SetData(model.Artists{{ID: "ar1"}, {ID: "ar2"}})
+		ds.MockedArtist = artistRepo
+
+		albumRepo := tests.CreateMockAlbumRepo()
+		albumRepo.SetData(model.Albums{{ID: "al1"}})
+		ds.MockedAlbum = albumRepo
+
+		playlistRepo := tests.CreateMockPlaylistRepo()
+		playlistRepo.SetData(model.Playlists{{ID: "pl1"}})
+		ds.MockedPlaylist = playlistRepo
+
+		radioRepo := tests.CreateMockedRadioRepo()
+		radioRepo.All = model.Radios{{ID: "ra1"}}
+		ds.MockedRadio = radioRepo
+	}
+
+	Describe("Fingerprint", func() {
+		It("changes when a fingerprint-affecting config value changes", func() {
+			f1 := fingerprint()
+			conf.Server.CoverArtPriority = "folder, embedded"
+			f2 := fingerprint()
+			Expect(f1).NotTo(Equal(f2))
+		})
+
+		It("changes when ArtistImageFolder changes", func() {
+			conf.Server.ArtistImageFolder = "/before"
+			f1 := fingerprint()
+			conf.Server.ArtistImageFolder = "/after"
+			Expect(fingerprint()).NotTo(Equal(f1))
+		})
+
+		It("changes when EnableM3UExternalAlbumArt is toggled", func() {
+			conf.Server.EnableM3UExternalAlbumArt = false
+			f1 := fingerprint()
+			conf.Server.EnableM3UExternalAlbumArt = true
+			Expect(fingerprint()).NotTo(Equal(f1))
+		})
+
+		It("does not change when the server version changes", func() {
+			original := consts.Version
+			DeferCleanup(func() { consts.Version = original })
+			f1 := fingerprint()
+			consts.Version = original + "-next"
+			Expect(fingerprint()).To(Equal(f1),
+				"the version must not invalidate artwork state: it would re-resolve every entity on every build")
+		})
+	})
+
+	Describe("Backfill", func() {
+		It("enqueues nothing and returns false when the stored fingerprint matches", func() {
+			seedEntities()
+			Expect(propRepo.Put(consts.ArtConfFingerprintPropertyKey, fingerprint())).To(Succeed())
+
+			did, err := backfill(ctx, ds)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(did).To(BeFalse())
+
+			count, err := queueRepo.Count()
+			Expect(err).ToNot(HaveOccurred())
+			Expect(count).To(BeZero())
+		})
+
+		It("runs the backfill when no fingerprint was ever stored", func() {
+			seedEntities()
+
+			did, err := backfill(ctx, ds)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(did).To(BeTrue())
+
+			count, err := queueRepo.Count()
+			Expect(err).ToNot(HaveOccurred())
+			Expect(count).To(Equal(int64(5))) // 2 artists + 1 album + 1 playlist + 1 radio
+
+			stored, err := propRepo.Get(consts.ArtConfFingerprintPropertyKey)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(stored).To(Equal(fingerprint()))
+		})
+
+		It("enqueues a private playlist by resolving it under an admin context", func() {
+			ds.MockedUser = adminUserRepo()
+			vds := &visibilityPlaylistDS{
+				MockDataStore: ds,
+				private:       model.Playlist{ID: "plPrivate", OwnerID: "admin"},
+				tracks:        &tests.MockPlaylistTrackRepo{},
+			}
+
+			did, err := backfill(ctx, vds)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(did).To(BeTrue())
+			Expect(findQueued(queueRepo.MockArtworkQueueRepo, "pl", "plPrivate")).ToNot(BeNil())
+		})
+
+		It("enqueues artists before albums/playlists/radios, all at Backfill priority", func() {
+			seedEntities()
+			Expect(propRepo.Put(consts.ArtConfFingerprintPropertyKey, "stale-fingerprint")).To(Succeed())
+
+			did, err := backfill(ctx, ds)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(did).To(BeTrue())
+
+			Expect(queueRepo.callKinds).ToNot(BeEmpty())
+			firstOther := slices.IndexFunc(queueRepo.callKinds, func(k string) bool { return k != "ar" })
+			Expect(firstOther).ToNot(Equal(0), "artists must be the first Enqueue call")
+			if firstOther >= 0 {
+				Expect(queueRepo.callKinds[firstOther:]).ToNot(ContainElement("ar"),
+					"no artist Enqueue may follow another kind")
+			}
+
+			for _, it := range queueRepo.Data {
+				Expect(it.Priority).To(Equal(model.ArtworkPriorityBackfill))
+				Expect(it.ItemKind).To(BeElementOf("ar", "al", "pl", "ra"))
+			}
+		})
+	})
+
+	Describe("EnqueueStaleAbsentAll", func() {
+		var artRepo *tests.MockArtworkRepo
+
+		BeforeEach(func() {
+			artRepo = tests.CreateMockArtworkRepo()
+			ds.MockedArtwork = artRepo
+			queueRepo.ItemArtworkSource = artRepo
+		})
+
+		It("enqueues only absent entries older than the recheck window, across all kinds", func() {
+			old := time.Now().Add(-48 * time.Hour)
+			recent := time.Now().Add(-time.Hour)
+
+			artRepo.ItemData["ar-stale"] = model.ItemArtwork{ItemKind: "ar", ItemID: "ar1", ImageType: model.ImageTypePrimary, Hash: "", AttemptedAt: old}
+			artRepo.ItemData["al-stale"] = model.ItemArtwork{ItemKind: "al", ItemID: "al1", ImageType: model.ImageTypePrimary, Hash: "", AttemptedAt: old}
+			artRepo.ItemData["pl-stale"] = model.ItemArtwork{ItemKind: "pl", ItemID: "pl1", ImageType: model.ImageTypePrimary, Hash: "", AttemptedAt: old}
+			artRepo.ItemData["ra-stale"] = model.ItemArtwork{ItemKind: "ra", ItemID: "ra1", ImageType: model.ImageTypePrimary, Hash: "", AttemptedAt: old}
+			artRepo.ItemData["ar-recent"] = model.ItemArtwork{ItemKind: "ar", ItemID: "ar2", ImageType: model.ImageTypePrimary, Hash: "", AttemptedAt: recent}
+			artRepo.ItemData["al-resolved"] = model.ItemArtwork{ItemKind: "al", ItemID: "al2", ImageType: model.ImageTypePrimary, Hash: "somehash", AttemptedAt: old}
+
+			err := enqueueStaleAbsentAll(ctx, ds)
+			Expect(err).ToNot(HaveOccurred())
+
+			Expect(queueRepo.Data).To(HaveLen(4))
+			for _, it := range queueRepo.Data {
+				Expect(it.Priority).To(Equal(model.ArtworkPriorityRecheck))
+			}
+			Expect(findQueued(queueRepo.MockArtworkQueueRepo, "ar", "ar1")).ToNot(BeNil())
+			Expect(findQueued(queueRepo.MockArtworkQueueRepo, "al", "al1")).ToNot(BeNil())
+			Expect(findQueued(queueRepo.MockArtworkQueueRepo, "pl", "pl1")).ToNot(BeNil())
+			Expect(findQueued(queueRepo.MockArtworkQueueRepo, "ra", "ra1")).ToNot(BeNil())
+			Expect(findQueued(queueRepo.MockArtworkQueueRepo, "ar", "ar2")).To(BeNil())
+			Expect(findQueued(queueRepo.MockArtworkQueueRepo, "al", "al2")).To(BeNil())
+		})
+	})
+
+	Describe("EnqueueMissingAll", func() {
+		var artRepo *tests.MockArtworkRepo
+
+		BeforeEach(func() {
+			artRepo = tests.CreateMockArtworkRepo()
+			ds.MockedArtwork = artRepo
+			queueRepo.ItemArtworkSource = artRepo
+			queueRepo.ExistingIDs = map[string]map[string]bool{
+				"al": {"al1": true, "al2": true},
+				"ar": {"ar1": true},
+				"pl": {"pl1": true},
+				"ra": {"ra1": true},
+			}
+		})
+
+		It("enqueues only entities that have no item_artwork row, across all kinds", func() {
+			artRepo.ItemData["al-resolved"] = model.ItemArtwork{ItemKind: "al", ItemID: "al1", ImageType: model.ImageTypePrimary, Hash: "somehash", AttemptedAt: time.Now()}
+			artRepo.ItemData["ar-absent"] = model.ItemArtwork{ItemKind: "ar", ItemID: "ar1", ImageType: model.ImageTypePrimary, Hash: "", AttemptedAt: time.Now()}
+
+			err := enqueueMissingAll(ctx, ds)
+			Expect(err).ToNot(HaveOccurred())
+
+			for _, it := range queueRepo.Data {
+				Expect(it.Priority).To(Equal(model.ArtworkPriorityRecheck))
+			}
+			Expect(findQueued(queueRepo.MockArtworkQueueRepo, "al", "al2")).ToNot(BeNil())
+			Expect(findQueued(queueRepo.MockArtworkQueueRepo, "pl", "pl1")).ToNot(BeNil())
+			Expect(findQueued(queueRepo.MockArtworkQueueRepo, "ra", "ra1")).ToNot(BeNil())
+			Expect(findQueued(queueRepo.MockArtworkQueueRepo, "al", "al1")).To(BeNil())
+			Expect(findQueued(queueRepo.MockArtworkQueueRepo, "ar", "ar1")).To(BeNil())
+		})
+	})
+})

core/artwork/image_cache.go

@@ -1,30 +1,22 @@
 package artwork
 
 import (
+	"bytes"
 	"context"
-	"fmt"
 	"io"
-	"time"
 
 	"github.com/navidrome/navidrome/conf"
 	"github.com/navidrome/navidrome/consts"
-	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/core/ffmpeg"
 	"github.com/navidrome/navidrome/utils/cache"
 	"github.com/navidrome/navidrome/utils/singleton"
 )
 
-type cacheKey struct {
-	artID      model.ArtworkID
-	lastUpdate time.Time
-}
-
-func (k *cacheKey) Key() string {
-	return fmt.Sprintf(
-		"%s-%s.%d",
-		k.artID.Kind,
-		k.artID.ID,
-		k.lastUpdate.UnixMilli(),
-	)
+// artworkReader is the cache.Item the image cache loader dispatches on: Reader
+// produces the (possibly resized) bytes to store under Key.
+type artworkReader interface {
+	cache.Item
+	Reader(ctx context.Context) (io.ReadCloser, error)
 }
 
 type imageCache struct {
@@ -36,9 +28,45 @@ func GetImageCache() cache.FileCache {
 		return &imageCache{
 			FileCache: cache.NewFileCache("Image", conf.Server.ImageCacheSize, consts.ImageCacheDir, consts.DefaultImageCacheMaxItems,
 				func(ctx context.Context, arg cache.Item) (io.Reader, error) {
-					r, _, err := arg.(artworkReader).Reader(ctx)
-					return r, err
+					return arg.(artworkReader).Reader(ctx)
 				}),
 		}
 	})
 }
+
+// resizedItem is an artworkReader that resizes bytes opened by open() and caches the
+// result under a hash-derived key.
+type resizedItem struct {
+	hash   string
+	size   int
+	square bool
+	ffmpeg ffmpeg.FFmpeg
+	open   func() (io.ReadCloser, error)
+}
+
+// Key is the ETag namespaced for the cache, so the validator a client holds and the entry it
+// validates can never drift apart.
+func (r *resizedItem) Key() string {
+	return "h-" + representationTag(r.hash, r.size, r.square)
+}
+
+func (r *resizedItem) Reader(ctx context.Context) (io.ReadCloser, error) {
+	orig, err := r.open()
+	if err != nil {
+		return nil, err
+	}
+	defer orig.Close()
+	data, err := readCapped(orig)
+	if err != nil {
+		return nil, err
+	}
+	resized, _, err := resizeImageData(ctx, r.ffmpeg, data, r.size, r.square)
+	if err != nil || resized == nil {
+		// Resize failed or image already within bounds: serve the original bytes.
+		return io.NopCloser(bytes.NewReader(data)), nil
+	}
+	if rc, ok := resized.(io.ReadCloser); ok {
+		return rc, nil
+	}
+	return io.NopCloser(resized), nil
+}

core/artwork/image_store.go

@@ -0,0 +1,155 @@
+package artwork
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"io/fs"
+	"os"
+	"path/filepath"
+	"strings"
+	"time"
+
+	"github.com/navidrome/navidrome/conf"
+	"github.com/navidrome/navidrome/consts"
+	"github.com/navidrome/navidrome/log"
+	"github.com/zeebo/xxh3"
+)
+
+// ImageStore is the content-addressed store for artwork images with no library file backing them.
+type ImageStore struct {
+	root string
+}
+
+func NewImageStore(rootDir string) *ImageStore {
+	return &ImageStore{root: rootDir}
+}
+
+func GetImageStore() *ImageStore {
+	return NewImageStore(filepath.Join(conf.Server.DataFolder.String(), consts.ArtworkFolder, consts.HashedArtworkFolder))
+}
+
+// extForMime must stay stable across OSes: extensions are baked into stored paths and re-derived on Open.
+func extForMime(m string) string {
+	switch m {
+	case "image/jpeg":
+		return ".jpg"
+	case "image/png":
+		return ".png"
+	case "image/gif":
+		return ".gif"
+	case "image/webp":
+		return ".webp"
+	}
+	return ".img"
+}
+
+func hashImage(r io.Reader) (string, error) {
+	d := xxh3.New()
+	if _, err := io.Copy(d, r); err != nil {
+		return "", err
+	}
+	return fmt.Sprintf("%016x", d.Sum64()), nil
+}
+
+// validHash guards path sharding: a malformed hash would slice-panic or inject path separators.
+func validHash(hash string) bool {
+	if len(hash) != 16 {
+		return false
+	}
+	for _, c := range []byte(hash) {
+		if (c < '0' || c > '9') && (c < 'a' || c > 'f') {
+			return false
+		}
+	}
+	return true
+}
+
+func (s *ImageStore) path(hash, mimeType string) string {
+	return filepath.Join(s.root, hash[0:2], hash[2:4], hash+extForMime(mimeType))
+}
+
+func (s *ImageStore) Write(hash, mimeType string, r io.Reader) error {
+	if !validHash(hash) {
+		return fmt.Errorf("imagestore: invalid hash %q", hash)
+	}
+	dst := s.path(hash, mimeType)
+	if _, err := os.Stat(dst); err == nil {
+		// A touched mtime marks the file live so a concurrent prune spares it.
+		now := time.Now()
+		if err := os.Chtimes(dst, now, now); err == nil {
+			return nil
+		}
+		// touch failed (likely pruned concurrently) — fall through and rewrite it
+	}
+	if err := os.MkdirAll(filepath.Dir(dst), 0755); err != nil {
+		return err
+	}
+	tmp, err := os.CreateTemp(filepath.Dir(dst), "."+hash+".tmp*")
+	if err != nil {
+		return err
+	}
+	defer os.Remove(tmp.Name())
+	if _, err := io.Copy(tmp, r); err != nil {
+		tmp.Close()
+		return err
+	}
+	if err := tmp.Close(); err != nil {
+		return err
+	}
+	return os.Rename(tmp.Name(), dst)
+}
+
+func (s *ImageStore) Open(hash, mimeType string) (io.ReadCloser, error) {
+	if !validHash(hash) {
+		return nil, fmt.Errorf("imagestore: invalid hash %q", hash)
+	}
+	return os.Open(s.path(hash, mimeType))
+}
+
+// Sweep removes store files not accepted by keep. Files modified after cutoff are always
+// kept: their acquisition row may not be committed yet.
+func (s *ImageStore) Sweep(ctx context.Context, cutoff time.Time, keep func(hash, ext string) bool) (int, error) {
+	removed, failed := 0, 0
+	var lastErr error
+	err := filepath.WalkDir(s.root, func(path string, d fs.DirEntry, err error) error {
+		if err != nil || d.IsDir() {
+			return err
+		}
+		if err := ctx.Err(); err != nil {
+			return err
+		}
+		info, err := d.Info()
+		if err != nil {
+			return err
+		}
+		if info.ModTime().After(cutoff) {
+			return nil
+		}
+		name := d.Name()
+		remove := strings.HasPrefix(name, ".") // abandoned temp file past the grace window
+		if !remove {
+			ext := filepath.Ext(name)
+			remove = !keep(strings.TrimSuffix(name, ext), ext)
+		}
+		if remove {
+			// #nosec G122 -- path comes from WalkDir over our own store root, no attacker-controlled symlinks
+			if err := os.Remove(path); err != nil {
+				// One unremovable file must not strand the rest of the store until the next prune.
+				failed, lastErr = failed+1, err
+				return nil //nolint:nilerr // counted and reported in aggregate below
+			}
+			removed++
+		}
+		return nil
+	})
+	// Aggregated: a store that has gone read-only would otherwise warn once per file, every prune.
+	if failed > 0 {
+		log.Warn(ctx, "Artwork: Could not remove store files", "count", failed, "swept", removed, lastErr)
+	}
+	if errors.Is(err, fs.ErrNotExist) {
+		return removed, nil
+	}
+	return removed, err
+}

core/artwork/image_store_test.go

@@ -0,0 +1,228 @@
+package artwork
+
+import (
+	"bytes"
+	"context"
+	"io"
+	"os"
+	"path/filepath"
+	"time"
+
+	"github.com/navidrome/navidrome/tests"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("ImageStore", func() {
+	var store *ImageStore
+	var root string
+	var ctx context.Context
+
+	BeforeEach(func() {
+		root = GinkgoT().TempDir()
+		store = NewImageStore(root)
+		ctx = context.Background()
+	})
+
+	It("hashes deterministically", func() {
+		h1, err := hashImage(bytes.NewReader([]byte("some image bytes")))
+		Expect(err).ToNot(HaveOccurred())
+		h2, _ := hashImage(bytes.NewReader([]byte("some image bytes")))
+		Expect(h1).To(Equal(h2))
+		Expect(h1).To(HaveLen(16))
+		h3, _ := hashImage(bytes.NewReader([]byte("other bytes")))
+		Expect(h3).ToNot(Equal(h1))
+	})
+
+	It("writes sharded and reads back", func() {
+		data := []byte("jpeg-bytes")
+		h, _ := hashImage(bytes.NewReader(data))
+		Expect(store.Write(h, "image/jpeg", bytes.NewReader(data))).To(Succeed())
+
+		Expect(filepath.Join(root, h[0:2], h[2:4], h+".jpg")).To(BeAnExistingFile())
+
+		rc, err := store.Open(h, "image/jpeg")
+		Expect(err).ToNot(HaveOccurred())
+		defer rc.Close()
+		got, _ := io.ReadAll(rc)
+		Expect(got).To(Equal(data))
+	})
+
+	It("is idempotent on duplicate writes and preserves the original content", func() {
+		data := []byte("dup")
+		h, _ := hashImage(bytes.NewReader(data))
+		Expect(store.Write(h, "image/png", bytes.NewReader(data))).To(Succeed())
+		// A duplicate write only touches mtime; passing different bytes under the same
+		// hash proves the second reader is never consumed to overwrite the file.
+		Expect(store.Write(h, "image/png", bytes.NewReader([]byte("not-dup")))).To(Succeed())
+
+		rc, err := store.Open(h, "image/png")
+		Expect(err).ToNot(HaveOccurred())
+		defer rc.Close()
+		got, err := io.ReadAll(rc)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(got).To(Equal(data))
+	})
+
+	It("refreshes the mtime on a duplicate write", func() {
+		data := []byte("touch-me")
+		h, _ := hashImage(bytes.NewReader(data))
+		Expect(store.Write(h, "image/png", bytes.NewReader(data))).To(Succeed())
+		old := time.Now().Add(-2 * time.Hour)
+		Expect(os.Chtimes(store.path(h, "image/png"), old, old)).To(Succeed())
+
+		Expect(store.Write(h, "image/png", bytes.NewReader(data))).To(Succeed())
+
+		info, err := os.Stat(store.path(h, "image/png"))
+		Expect(err).ToNot(HaveOccurred())
+		Expect(info.ModTime()).To(BeTemporally(">", time.Now().Add(-time.Minute)))
+	})
+
+	It("rewrites the bytes when the existing file vanished before the liveness touch", func() {
+		data := []byte("vanishing")
+		h, _ := hashImage(bytes.NewReader(data))
+		for range 10 {
+			Expect(store.Write(h, "image/png", bytes.NewReader(data))).To(Succeed())
+			Expect(os.Remove(store.path(h, "image/png"))).To(Succeed())
+			Expect(store.Write(h, "image/png", bytes.NewReader(data))).To(Succeed())
+
+			rc, err := store.Open(h, "image/png")
+			Expect(err).ToNot(HaveOccurred())
+			got, _ := io.ReadAll(rc)
+			rc.Close()
+			Expect(got).To(Equal(data))
+		}
+	})
+
+	It("returns fs.ErrNotExist for missing images", func() {
+		_, err := store.Open("beefbeefbeefbeef", "image/jpeg")
+		Expect(os.IsNotExist(err)).To(BeTrue())
+	})
+
+	It("rejects invalid hashes instead of panicking", func() {
+		for _, h := range []string{"", "ab", "BEEFBEEFBEEFBEEF", "../../../../etcpw", "beefbeefbeefbee/"} {
+			Expect(store.Write(h, "image/jpeg", bytes.NewReader([]byte("x")))).To(MatchError(ContainSubstring("invalid hash")))
+			_, err := store.Open(h, "image/jpeg")
+			Expect(err).To(MatchError(ContainSubstring("invalid hash")))
+		}
+	})
+
+	It("sweeps unknown files, keeps known ones", func() {
+		d1 := []byte("keep-me")
+		h1, _ := hashImage(bytes.NewReader(d1))
+		Expect(store.Write(h1, "image/jpeg", bytes.NewReader(d1))).To(Succeed())
+		d2 := []byte("orphan")
+		h2, _ := hashImage(bytes.NewReader(d2))
+		Expect(store.Write(h2, "image/jpeg", bytes.NewReader(d2))).To(Succeed())
+
+		old := time.Now().Add(-2 * time.Hour)
+		Expect(os.Chtimes(store.path(h2, "image/jpeg"), old, old)).To(Succeed())
+
+		removed, err := store.Sweep(ctx, time.Now().Add(-time.Hour), func(h, _ string) bool { return h == h1 })
+		Expect(err).ToNot(HaveOccurred())
+		Expect(removed).To(Equal(1))
+		_, err = store.Open(h2, "image/jpeg")
+		Expect(os.IsNotExist(err)).To(BeTrue())
+		rc, err := store.Open(h1, "image/jpeg")
+		Expect(err).ToNot(HaveOccurred())
+		rc.Close()
+	})
+
+	It("sweeps a stale mime variant of a known hash, keeps the current one", func() {
+		data := []byte("same-bytes")
+		h, _ := hashImage(bytes.NewReader(data))
+		Expect(store.Write(h, "image/png", bytes.NewReader(data))).To(Succeed())
+		Expect(store.Write(h, "image/jpeg", bytes.NewReader(data))).To(Succeed())
+		old := time.Now().Add(-2 * time.Hour)
+		Expect(os.Chtimes(store.path(h, "image/png"), old, old)).To(Succeed())
+		Expect(os.Chtimes(store.path(h, "image/jpeg"), old, old)).To(Succeed())
+
+		// The recorded mime is image/jpeg, so the .png variant is obsolete.
+		removed, err := store.Sweep(ctx, time.Now().Add(-time.Hour), func(hash, ext string) bool {
+			return hash == h && ext == ".jpg"
+		})
+		Expect(err).ToNot(HaveOccurred())
+		Expect(removed).To(Equal(1))
+		_, err = store.Open(h, "image/png")
+		Expect(os.IsNotExist(err)).To(BeTrue())
+		rc, err := store.Open(h, "image/jpeg")
+		Expect(err).ToNot(HaveOccurred())
+		rc.Close()
+	})
+
+	It("keeps young unknown files inside the grace window", func() {
+		d := []byte("fresh-orphan")
+		h, _ := hashImage(bytes.NewReader(d))
+		Expect(store.Write(h, "image/jpeg", bytes.NewReader(d))).To(Succeed())
+
+		removed, err := store.Sweep(ctx, time.Now().Add(-time.Hour), func(string, string) bool { return false })
+		Expect(err).ToNot(HaveOccurred())
+		Expect(removed).To(Equal(0))
+		rc, err := store.Open(h, "image/jpeg")
+		Expect(err).ToNot(HaveOccurred())
+		rc.Close()
+	})
+
+	It("removes abandoned temp files past the grace window, keeps fresh ones", func() {
+		oldTmp := filepath.Join(root, ".old.tmp")
+		Expect(os.WriteFile(oldTmp, []byte("x"), 0600)).To(Succeed())
+		old := time.Now().Add(-2 * time.Hour)
+		Expect(os.Chtimes(oldTmp, old, old)).To(Succeed())
+
+		freshTmp := filepath.Join(root, ".fresh.tmp")
+		Expect(os.WriteFile(freshTmp, []byte("y"), 0600)).To(Succeed())
+
+		removed, err := store.Sweep(ctx, time.Now().Add(-time.Hour), func(string, string) bool { return true })
+		Expect(err).ToNot(HaveOccurred())
+		Expect(removed).To(Equal(1))
+		Expect(oldTmp).ToNot(BeAnExistingFile())
+		Expect(freshTmp).To(BeAnExistingFile())
+	})
+
+	It("keeps sweeping past a file it cannot remove", func() {
+		tests.SkipOnWindows("uses Unix file permission bits")
+		if os.Geteuid() == 0 {
+			Skip("read-only dir cannot block root (e.g. tests in a container)")
+		}
+		old := time.Now().Add(-2 * time.Hour)
+		// "blocked" sorts before "ok", so the walk hits the unremovable file first.
+		blockedDir := filepath.Join(root, "blocked")
+		Expect(os.MkdirAll(blockedDir, 0755)).To(Succeed())
+		blocked := filepath.Join(blockedDir, "a.jpg")
+		Expect(os.WriteFile(blocked, []byte("x"), 0600)).To(Succeed())
+		Expect(os.Chtimes(blocked, old, old)).To(Succeed())
+
+		okDir := filepath.Join(root, "ok")
+		Expect(os.MkdirAll(okDir, 0755)).To(Succeed())
+		reachable := filepath.Join(okDir, "b.jpg")
+		Expect(os.WriteFile(reachable, []byte("y"), 0600)).To(Succeed())
+		Expect(os.Chtimes(reachable, old, old)).To(Succeed())
+
+		Expect(os.Chmod(blockedDir, 0500)).To(Succeed())
+		DeferCleanup(func() { _ = os.Chmod(blockedDir, 0755) })
+
+		removed, err := store.Sweep(ctx, time.Now().Add(-time.Hour), func(string, string) bool { return false })
+		Expect(err).ToNot(HaveOccurred())
+		Expect(removed).To(Equal(1))
+		Expect(blocked).To(BeAnExistingFile())
+		Expect(reachable).ToNot(BeAnExistingFile())
+	})
+
+	// Prune holds the worker's write lock for the whole sweep, and shutdown waits on the
+	// worker, so an uncancellable walk over a large store stalls it until SIGKILL.
+	It("abandons the walk when the context is cancelled", func() {
+		old := time.Now().Add(-2 * time.Hour)
+		for _, name := range []string{"a", "b", "c", "d"} {
+			p := filepath.Join(root, name+".jpg")
+			Expect(os.WriteFile(p, []byte("x"), 0600)).To(Succeed())
+			Expect(os.Chtimes(p, old, old)).To(Succeed())
+		}
+		cancelCtx, cancel := context.WithCancel(ctx)
+		cancel()
+
+		_, err := store.Sweep(cancelCtx, time.Now().Add(-time.Hour), func(string, string) bool { return false })
+		Expect(err).To(MatchError(context.Canceled))
+		matches, _ := filepath.Glob(filepath.Join(root, "*.jpg"))
+		Expect(matches).To(HaveLen(4), "a cancelled sweep must not keep deleting")
+	})
+})

core/artwork/library_fs.go

@@ -2,7 +2,9 @@ package artwork
 
 import (
 	"context"
+	"net/url"
 	"path/filepath"
+	"strings"
 
 	"github.com/navidrome/navidrome/core/storage"
 	"github.com/navidrome/navidrome/model"
@@ -40,5 +42,23 @@ func loadLibraryView(ctx context.Context, ds model.DataStore, libID int) (librar
 	if err != nil {
 		return libraryView{}, err
 	}
-	return libraryView{FS: fs, absRoot: lib.Path}, nil
+	return libraryView{FS: fs, absRoot: localOSRoot(lib.Path)}, nil
+}
+
+// localOSRoot maps a library path to its on-disk root so Abs() yields paths os.Open/os.Stat accept:
+// a file:// URL becomes its parsed OS path (bare paths already are; non-local schemes stay unchanged).
+func localOSRoot(libPath string) string {
+	if !strings.Contains(libPath, "://") {
+		return libPath
+	}
+	u, err := url.Parse(libPath)
+	if err != nil || u.Scheme != storage.LocalSchemaID {
+		return libPath
+	}
+	// Windows drive URLs (file://C:/Music) put the volume in Host; rejoin it, matching
+	// core/storage/local's newLocalStorage so os.Open/os.Stat get a valid path.
+	if filepath.VolumeName(u.Host) != "" {
+		return filepath.Join(u.Host, u.Path)
+	}
+	return u.Path
 }

core/artwork/library_fs_test.go

@@ -32,6 +32,13 @@ var _ = Describe("loadLibraryView", Ordered, func() {
 		Expect(lib.absRoot).To(Equal("fake:///music"))
 	})
 
+	It("normalizes a library path to an OS root that Abs can join for os.Open/os.Stat", func() {
+		// file:// URLs become their parsed OS path; bare paths and non-local schemes are unchanged.
+		Expect(localOSRoot("file:///music/library")).To(Equal("/music/library"))
+		Expect(localOSRoot("/music/library")).To(Equal("/music/library"))
+		Expect(localOSRoot("fake:///music")).To(Equal("fake:///music"))
+	})
+
 	It("returns an error when the library does not exist", func() {
 		_, err := loadLibraryView(ctx, ds, 999)
 		Expect(err).To(HaveOccurred())

core/artwork/playlist_cover.go

@@ -0,0 +1,116 @@
+package artwork
+
+import (
+	"bytes"
+	"context"
+	"image"
+	"image/draw"
+	"image/png"
+	"io"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/navidrome/navidrome/log"
+	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/utils"
+	xdraw "golang.org/x/image/draw"
+)
+
+const tileSize = 600
+
+// findPlaylistSidecarPath finds an image beside plsPath with the same base name (case-insensitive).
+func findPlaylistSidecarPath(ctx context.Context, plsPath string) string {
+	if plsPath == "" {
+		return ""
+	}
+	dir := filepath.Dir(plsPath)
+	base := strings.TrimSuffix(filepath.Base(plsPath), filepath.Ext(plsPath))
+
+	entries, err := os.ReadDir(dir)
+	if err != nil {
+		log.Warn(ctx, "Artwork: Could not read directory for playlist sidecar", "dir", dir, err)
+		return ""
+	}
+	for _, entry := range entries {
+		name := entry.Name()
+		nameBase := utils.BaseName(name)
+		if !entry.IsDir() && strings.EqualFold(nameBase, base) && model.IsImageFile(name) {
+			return filepath.Join(dir, name)
+		}
+	}
+	return ""
+}
+
+func rect(pos int) image.Rectangle {
+	r := image.Rectangle{}
+	switch pos {
+	case 1:
+		r.Min.X = tileSize / 2
+	case 2:
+		r.Min.Y = tileSize / 2
+	case 3:
+		r.Min.X = tileSize / 2
+		r.Min.Y = tileSize / 2
+	}
+	r.Max.X = r.Min.X + tileSize/2
+	r.Max.Y = r.Min.Y + tileSize/2
+	return r
+}
+
+// fillCenter center-crops src and scales it to fill dstW x dstH exactly.
+func fillCenter(src image.Image, dstW, dstH int) image.Image {
+	srcBounds := src.Bounds()
+	srcW := srcBounds.Dx()
+	srcH := srcBounds.Dy()
+
+	srcAspect := float64(srcW) / float64(srcH)
+	dstAspect := float64(dstW) / float64(dstH)
+
+	var cropRect image.Rectangle
+	if srcAspect > dstAspect {
+		cropW := int(float64(srcH) * dstAspect)
+		cropX := (srcW - cropW) / 2
+		cropRect = image.Rect(srcBounds.Min.X+cropX, srcBounds.Min.Y, srcBounds.Min.X+cropX+cropW, srcBounds.Max.Y)
+	} else {
+		cropH := int(float64(srcW) / dstAspect)
+		cropY := (srcH - cropH) / 2
+		cropRect = image.Rect(srcBounds.Min.X, srcBounds.Min.Y+cropY, srcBounds.Max.X, srcBounds.Min.Y+cropY+cropH)
+	}
+
+	dst := image.NewNRGBA(image.Rect(0, 0, dstW, dstH))
+	xdraw.CatmullRom.Scale(dst, dst.Bounds(), src, cropRect, draw.Src, nil)
+	return dst
+}
+
+// decodeTile runs before the processor's size guards apply, so it enforces the caps itself.
+func decodeTile(r io.ReadCloser) (image.Image, error) {
+	data, err := readCapped(r)
+	if err != nil {
+		return nil, err
+	}
+	img, _, err := decodeCapped(data)
+	if err != nil {
+		return nil, err
+	}
+	return fillCenter(img, tileSize/2, tileSize/2), nil
+}
+
+func assembleTiles(tiles []image.Image) (io.ReadCloser, error) {
+	buf := new(bytes.Buffer)
+	var err error
+	if len(tiles) == 4 {
+		rgba := image.NewRGBA(image.Rectangle{Max: image.Point{X: tileSize - 1, Y: tileSize - 1}})
+		draw.Draw(rgba, rect(0), tiles[0], image.Point{}, draw.Src)
+		draw.Draw(rgba, rect(1), tiles[1], image.Point{}, draw.Src)
+		draw.Draw(rgba, rect(2), tiles[2], image.Point{}, draw.Src)
+		draw.Draw(rgba, rect(3), tiles[3], image.Point{}, draw.Src)
+		err = png.Encode(buf, rgba)
+	} else {
+		err = png.Encode(buf, tiles[0])
+	}
+	if err != nil {
+		return nil, err
+	}
+	return io.NopCloser(buf), nil
+}

core/artwork/processor.go

@@ -0,0 +1,311 @@
+package artwork
+
+import (
+	"bytes"
+	"context"
+	"encoding/base64"
+	"errors"
+	"fmt"
+	"image"
+	"image/draw"
+	_ "image/gif" // the only artwork format with no other importer in this package
+	"io"
+	"sync"
+	"time"
+
+	"github.com/navidrome/navidrome/core/artwork/blurhash"
+	"github.com/navidrome/navidrome/core/artwork/dominant"
+	"github.com/navidrome/navidrome/core/artwork/thumbhash"
+	"github.com/navidrome/navidrome/log"
+	"github.com/navidrome/navidrome/model"
+	xdraw "golang.org/x/image/draw"
+)
+
+// outcome tells the worker whether to delete the queue row (found/absent) or reschedule it.
+type outcome int
+
+const (
+	outcomeFound outcome = iota
+	// outcomeFoundStale: state was written and is served, but a higher-priority external
+	// source failed, so the row must retry to give it another chance.
+	outcomeFoundStale
+	outcomeAbsent
+	outcomeFailed
+)
+
+func (o outcome) String() string {
+	switch o {
+	case outcomeFound:
+		return "found"
+	case outcomeFoundStale:
+		return "foundStale"
+	case outcomeAbsent:
+		return "absent"
+	default:
+		return "failed"
+	}
+}
+
+// thumbnailSize is the max dimension fed to both hash encoders; thumbhash rejects anything larger.
+const thumbnailSize = 100
+
+// maxImageBytes caps a resolved image read: a user-editable ExternalImageURL could point at
+// an arbitrarily large endpoint.
+const maxImageBytes = 20 << 20
+
+// maxImagePixels guards against decompression bombs: a tiny file can declare a canvas that
+// image.Decode would expand into gigabytes.
+const maxImagePixels = 64 << 20
+
+// acquired is what a successful acquire persisted, handed back so the caller can warm the resize
+// cache without re-reading the rows and the file it just wrote.
+type acquired struct {
+	ia   *model.ItemArtwork
+	mime string
+	data []byte
+}
+
+// processor turns one queue item into stored artwork; settling the queue row is the Worker's job.
+type processor struct {
+	ds        model.DataStore
+	store     *ImageStore
+	resolver  *resolver
+	pruneLock sync.Locker
+}
+
+// acquire resolves one queue item end to end: find an image, hash/decode/
+// blurhash it, place its bytes, and persist the resulting state.
+func (p *processor) acquire(ctx context.Context, item model.ArtworkQueueItem) (out outcome, got *acquired) {
+	repo := p.ds.Artwork(ctx)
+	start := time.Now()
+	defer func() {
+		log.Debug(ctx, "Artwork: Acquisition finished", "kind", item.ItemKind, "id", item.ItemID,
+			"outcome", out, "elapsed", time.Since(start))
+	}()
+
+	res, err := p.resolver.resolve(ctx, item)
+	if err != nil {
+		log.Warn(ctx, "Artwork: Could not resolve item", "kind", item.ItemKind, "id", item.ItemID, err)
+		return outcomeFailed, nil
+	}
+	if res.reader == nil {
+		if res.extError || res.localError {
+			// A fault is not a definitive "no image": never settle absent, keep serving old state.
+			log.Debug(ctx, "Artwork: No image, but a source faulted; keeping previous state",
+				"kind", item.ItemKind, "id", item.ItemID, "extError", res.extError, "localError", res.localError)
+			return outcomeFailed, nil
+		}
+		return writeAbsent(ctx, repo, item), nil
+	}
+	defer res.reader.Close()
+
+	readStart := time.Now()
+	data, err := readCapped(res.reader)
+	if err != nil {
+		log.Warn(ctx, "Artwork: Failed to read resolved image", "kind", item.ItemKind, "id", item.ItemID, "source", res.source, err)
+		return outcomeFailed, nil
+	}
+	log.Debug(ctx, "Artwork: Read resolved image", "kind", item.ItemKind, "id", item.ItemID,
+		"source", res.source, "bytes", len(data), "elapsed", time.Since(readStart))
+
+	hashStart := time.Now()
+	hash, err := hashImage(bytes.NewReader(data))
+	if err != nil {
+		log.Warn(ctx, "Artwork: Failed to hash image", "kind", item.ItemKind, "id", item.ItemID, err)
+		return outcomeFailed, nil
+	}
+	log.Trace(ctx, "Artwork: Hashed image", "kind", item.ItemKind, "id", item.ItemID,
+		"hash", hash, "bytes", len(data), "elapsed", time.Since(hashStart))
+
+	art, err := repo.GetImage(hash)
+	switch {
+	case err == nil:
+		log.Debug(ctx, "Artwork: Reusing a known image, skipping decode", "kind", item.ItemKind,
+			"id", item.ItemID, "hash", hash)
+	case errors.Is(err, model.ErrNotFound):
+		decodeStart := time.Now()
+		art, err = decodeArtwork(ctx, hash, data)
+		if err != nil {
+			log.Warn(ctx, "Artwork: Failed to decode resolved image", "kind", item.ItemKind, "id", item.ItemID, err)
+			return outcomeFailed, nil
+		}
+		log.Debug(ctx, "Artwork: Decoded new image", "kind", item.ItemKind, "id", item.ItemID, "hash", hash,
+			"width", art.Width, "height", art.Height, "mime", art.Mime, "elapsed", time.Since(decodeStart))
+	default:
+		log.Warn(ctx, "Artwork: Failed to look up image hash", "kind", item.ItemKind, "id", item.ItemID, err)
+		return outcomeFailed, nil
+	}
+	art.SizeBytes = int64(len(data))
+
+	ia, err := p.persist(repo, item, art, res, data)
+	if err != nil {
+		log.Warn(ctx, "Artwork: Failed to persist resolved image", "kind", item.ItemKind, "id", item.ItemID, err)
+		return outcomeFailed, nil
+	}
+	got = &acquired{ia: ia, mime: art.Mime, data: data}
+	if res.extError {
+		log.Debug(ctx, "Artwork: Serving a lower-priority source after an external failure",
+			"kind", item.ItemKind, "id", item.ItemID, "source", res.source)
+		return outcomeFoundStale, got
+	}
+	return outcomeFound, got
+}
+
+// persist places the bytes and commits the rows referencing them, excluding Prune for that
+// window only so a slow resolution can never hold it off.
+func (p *processor) persist(repo model.ArtworkRepository, item model.ArtworkQueueItem,
+	art *model.Artwork, res resolution, data []byte,
+) (*model.ItemArtwork, error) {
+	if p.pruneLock != nil {
+		p.pruneLock.Lock()
+		defer p.pruneLock.Unlock()
+	}
+	sourcePath, refMtime, err := placeBytes(p.store, art, res, data)
+	if err != nil {
+		return nil, fmt.Errorf("writing image store: %w", err)
+	}
+	if err := repo.PutImage(art); err != nil {
+		return nil, fmt.Errorf("persisting artwork image: %w", err)
+	}
+	ia := &model.ItemArtwork{
+		ItemKind:    item.ItemKind,
+		ItemID:      item.ItemID,
+		ImageType:   item.ImageType,
+		Hash:        art.Hash,
+		Source:      res.source,
+		SourcePath:  sourcePath,
+		RefMtime:    refMtime,
+		AttemptedAt: time.Now(),
+	}
+	// PutItemArtwork stamps UpdatedAt on ia, so the returned struct matches the persisted row.
+	if err := repo.PutItemArtwork(ia); err != nil {
+		return nil, fmt.Errorf("persisting item artwork state: %w", err)
+	}
+	return ia, nil
+}
+
+// writeAbsent records a known-absent state: every source answered definitively "no".
+func writeAbsent(ctx context.Context, repo model.ArtworkRepository, item model.ArtworkQueueItem) outcome {
+	err := repo.PutItemArtwork(&model.ItemArtwork{
+		ItemKind:    item.ItemKind,
+		ItemID:      item.ItemID,
+		ImageType:   item.ImageType,
+		AttemptedAt: time.Now(),
+	})
+	if err != nil {
+		log.Warn(ctx, "Artwork: Failed to persist absent state", "kind", item.ItemKind, "id", item.ItemID, err)
+		return outcomeFailed
+	}
+	log.Debug(ctx, "Artwork: Settled absent, every source answered definitively",
+		"kind", item.ItemKind, "id", item.ItemID)
+	return outcomeAbsent
+}
+
+func readCapped(r io.Reader) ([]byte, error) {
+	data, err := io.ReadAll(io.LimitReader(r, maxImageBytes+1))
+	if err != nil {
+		return nil, err
+	}
+	if len(data) > maxImageBytes {
+		return nil, fmt.Errorf("image exceeds size cap %d", maxImageBytes)
+	}
+	return data, nil
+}
+
+// decodeCapped rejects declared dimensions over maxImagePixels before the full-decode allocation.
+func decodeCapped(data []byte) (image.Image, string, error) {
+	cfg, format, err := image.DecodeConfig(bytes.NewReader(data))
+	if err != nil {
+		return nil, "", fmt.Errorf("decode image config: %w", err)
+	}
+	// Compared by division so the cap cannot be defeated by an int64 overflow.
+	if cfg.Width <= 0 || cfg.Height <= 0 || cfg.Width > maxImagePixels/cfg.Height {
+		return nil, "", fmt.Errorf("image dimensions %dx%d exceed pixel cap %d", cfg.Width, cfg.Height, maxImagePixels)
+	}
+	img, _, err := image.Decode(bytes.NewReader(data))
+	if err != nil {
+		return nil, "", fmt.Errorf("decode image: %w", err)
+	}
+	return img, format, nil
+}
+
+// decodeArtwork builds a new Artwork row from raw bytes: dimensions, mime and the two
+// placeholder hashes, both encoded from one shared downscaled thumbnail.
+func decodeArtwork(ctx context.Context, hash string, data []byte) (*model.Artwork, error) {
+	img, format, err := decodeCapped(data)
+	if err != nil {
+		return nil, err
+	}
+
+	thumb := makeThumbnail(img, thumbnailSize)
+	bh, err := blurhash.Encode(thumb)
+	if err != nil {
+		log.Warn(ctx, "Artwork: Blurhash encoding failed", "hash", hash, err)
+		bh = ""
+	}
+
+	var th string
+	if raw, err := thumbhash.Encode(thumb); err != nil {
+		log.Warn(ctx, "Artwork: Thumbhash encoding failed", "hash", hash, err)
+	} else {
+		th = base64.StdEncoding.EncodeToString(raw)
+	}
+
+	return &model.Artwork{
+		Hash:          hash,
+		Mime:          mimeForFormat(format),
+		Width:         img.Bounds().Dx(),
+		Height:        img.Bounds().Dy(),
+		BlurHash:      bh,
+		ThumbHash:     th,
+		DominantColor: dominant.Color(thumb),
+	}, nil
+}
+
+// makeThumbnail downscales img to fit within maxSize on its longest side; it never upscales.
+func makeThumbnail(img image.Image, maxSize int) image.Image {
+	b := img.Bounds()
+	w, h := b.Dx(), b.Dy()
+	if w <= maxSize && h <= maxSize {
+		return toFastScaleType(img)
+	}
+	scale := float64(maxSize) / float64(max(w, h))
+	// NRGBA, not RGBA: thumbhash requires straight alpha, and blurhash reads this type without
+	// converting, so neither encoder allocates a second copy of the thumbnail.
+	dst := image.NewNRGBA(image.Rect(0, 0, max(1, int(float64(w)*scale)), max(1, int(float64(h)*scale))))
+	xdraw.CatmullRom.Scale(dst, dst.Bounds(), toFastScaleType(img), b, draw.Src, nil)
+	return dst
+}
+
+// isFileBacked reports whether the bytes already live in a library/upload file, so the
+// content-addressed store must not duplicate them.
+func isFileBacked(source string) bool {
+	return source == "folder" || source == "upload"
+}
+
+// placeBytes reports the item's backing-file provenance and writes the bytes into the store
+// for the sources that have none.
+func placeBytes(store *ImageStore, art *model.Artwork, res resolution, data []byte) (sourcePath string, refMtime int64, err error) {
+	if isFileBacked(res.source) {
+		return res.sourcePath, res.refMtime, nil
+	}
+	if res.source == "embedded" {
+		sourcePath, refMtime = res.sourcePath, res.refMtime
+	}
+	return sourcePath, refMtime, store.Write(art.Hash, art.Mime, bytes.NewReader(data))
+}
+
+// mimeForFormat maps an image.Decode format name to its MIME type; extForMime is the inverse.
+func mimeForFormat(format string) string {
+	switch format {
+	case "jpeg":
+		return "image/jpeg"
+	case "png":
+		return "image/png"
+	case "gif":
+		return "image/gif"
+	case "webp":
+		return "image/webp"
+	}
+	return "application/octet-stream"
+}

core/artwork/processor_test.go

@@ -0,0 +1,495 @@
+package artwork
+
+import (
+	"context"
+	"encoding/binary"
+	"errors"
+	"hash/crc32"
+	"image"
+	"image/color"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"path/filepath"
+	"runtime"
+	"time"
+
+	"github.com/navidrome/navidrome/conf"
+	"github.com/navidrome/navidrome/conf/configtest"
+	"github.com/navidrome/navidrome/consts"
+	"github.com/navidrome/navidrome/core/agents"
+	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/tests"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+// DecodeConfig reads only the header, so the pixel data can be omitted entirely.
+func pngHeaderWithDims(w, h uint32) []byte {
+	ihdr := make([]byte, 13)
+	binary.BigEndian.PutUint32(ihdr[0:], w)
+	binary.BigEndian.PutUint32(ihdr[4:], h)
+	ihdr[8] = 8 // bit depth
+	ihdr[9] = 2 // color type: truecolor
+	chunk := append([]byte("IHDR"), ihdr...)
+	out := []byte{0x89, 'P', 'N', 'G', 0x0d, 0x0a, 0x1a, 0x0a}
+	out = binary.BigEndian.AppendUint32(out, uint32(len(ihdr)))
+	out = append(out, chunk...)
+	return binary.BigEndian.AppendUint32(out, crc32.ChecksumIEEE(chunk))
+}
+
+var _ = Describe("processor.acquire", func() {
+	var (
+		ctx        context.Context
+		ds         *tests.MockDataStore
+		folderRepo *fakeFolderRepo
+		libRepo    *tests.MockLibraryRepo
+		ffm        *tests.MockFFmpeg
+		ag         *agents.Agents
+		store      *ImageStore
+		artRepo    *tests.MockArtworkRepo
+		repoRoot   string
+		proc       *processor
+	)
+
+	BeforeEach(func() {
+		DeferCleanup(configtest.SetupConfig())
+		ctx = context.Background()
+		var err error
+		repoRoot, err = os.Getwd()
+		Expect(err).ToNot(HaveOccurred())
+
+		folderRepo = &fakeFolderRepo{}
+		libRepo = &tests.MockLibraryRepo{}
+		libRepo.SetData(model.Libraries{{ID: 0, Path: testFileLibPath(repoRoot)}})
+		ffm = tests.NewMockFFmpeg("")
+		ag = agents.GetAgents(&tests.MockDataStore{}, nil)
+		artRepo = tests.CreateMockArtworkRepo()
+		ds = &tests.MockDataStore{
+			MockedFolder:  folderRepo,
+			MockedLibrary: libRepo,
+			MockedArtwork: artRepo,
+		}
+		ds.MockedAlbum = tests.CreateMockAlbumRepo()
+		store = NewImageStore(GinkgoT().TempDir())
+		proc = &processor{ds: ds, store: store, resolver: newResolver(ds, ag, ffm, nil)}
+
+		conf.Server.CoverArtPriority = "cover.jpg, embedded"
+	})
+
+	It("found-folder: persists state from a folder image, writes no store file, keeps sourcePath/refMtime", func() {
+		folderRepo.result = []model.Folder{{
+			Path:       "tests/fixtures/artist/an-album",
+			ImageFiles: []string{"cover.jpg"},
+		}}
+		ds.MockedAlbum.(*tests.MockAlbumRepo).SetData(model.Albums{
+			{ID: "al1", Name: "Album", FolderIDs: []string{"f1"}},
+		})
+
+		out, _ := proc.acquire(ctx, model.ArtworkQueueItem{ItemKind: "al", ItemID: "al1"})
+		Expect(out).To(Equal(outcomeFound))
+
+		ia, err := artRepo.GetItemArtwork(model.KindAlbumArtwork, "al1", model.ImageTypePrimary)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(ia.Hash).ToNot(BeEmpty())
+		Expect(ia.Source).To(Equal("folder"))
+		Expect(filepath.ToSlash(ia.SourcePath)).To(HaveSuffix("tests/fixtures/artist/an-album/cover.jpg"))
+		Expect(ia.RefMtime).To(BeNumerically(">", 0))
+
+		art, err := artRepo.GetImage(ia.Hash)
+		Expect(err).ToNot(HaveOccurred())
+		// Every placeholder is derived from the one shared thumbnail, so all three land together.
+		Expect(art.BlurHash).ToNot(BeEmpty())
+		Expect(art.ThumbHash).ToNot(BeEmpty())
+		Expect(art.DominantColor).To(MatchRegexp(`^#[0-9a-f]{6}$`))
+		_, err = store.Open(ia.Hash, art.Mime)
+		Expect(os.IsNotExist(err)).To(BeTrue(), "folder-backed art must not be duplicated into the store")
+	})
+
+	Describe("prune lock scope", func() {
+		var lock *countingLocker
+
+		BeforeEach(func() {
+			lock = &countingLocker{}
+			proc.pruneLock = lock
+		})
+
+		It("holds it once across the write window", func() {
+			folderRepo.result = []model.Folder{{
+				Path:       "tests/fixtures/artist/an-album",
+				ImageFiles: []string{"cover.jpg"},
+			}}
+			ds.MockedAlbum.(*tests.MockAlbumRepo).SetData(model.Albums{
+				{ID: "alL1", Name: "Album", FolderIDs: []string{"f1"}},
+			})
+
+			out, _ := proc.acquire(ctx, model.ArtworkQueueItem{ItemKind: "al", ItemID: "alL1"})
+			Expect(out).To(Equal(outcomeFound))
+			Expect(lock.locks).To(BeNumerically(">", 0), "the write window must exclude prune")
+			Expect(lock.held()).To(BeFalse(), "the window must close before acquire returns")
+		})
+
+		// Resolution can reach the network, so holding the lock across it would let one slow
+		// provider block prune, and every drain queued behind prune's writer.
+		It("never takes it while only resolving", func() {
+			folderRepo.result = nil
+			ds.MockedAlbum.(*tests.MockAlbumRepo).SetData(model.Albums{
+				{ID: "alL2", Name: "Album", FolderIDs: []string{"f1"}},
+			})
+
+			out, _ := proc.acquire(ctx, model.ArtworkQueueItem{ItemKind: "al", ItemID: "alL2"})
+			Expect(out).To(Equal(outcomeAbsent))
+			Expect(lock.locks).To(BeZero())
+		})
+	})
+
+	It("found-embedded: writes a store file and computes a non-empty blurhash from a real fixture", func() {
+		ds.MockedAlbum.(*tests.MockAlbumRepo).SetData(model.Albums{
+			{ID: "al2", Name: "Album", EmbedArtPath: "tests/fixtures/artist/an-album/test.mp3", FolderIDs: []string{"f1"}},
+		})
+		folderRepo.result = nil
+
+		out, _ := proc.acquire(ctx, model.ArtworkQueueItem{ItemKind: "al", ItemID: "al2"})
+		Expect(out).To(Equal(outcomeFound))
+
+		ia, err := artRepo.GetItemArtwork(model.KindAlbumArtwork, "al2", model.ImageTypePrimary)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(ia.Source).To(Equal("embedded"))
+		Expect(filepath.ToSlash(ia.SourcePath)).To(HaveSuffix("tests/fixtures/artist/an-album/test.mp3"))
+
+		art, err := artRepo.GetImage(ia.Hash)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(art.BlurHash).ToNot(BeEmpty())
+
+		rc, err := store.Open(ia.Hash, art.Mime)
+		Expect(err).ToNot(HaveOccurred())
+		rc.Close()
+	})
+
+	It("absent: no local source and no external error persists a known-absent state", func() {
+		folderRepo.result = nil
+		ds.MockedAlbum.(*tests.MockAlbumRepo).SetData(model.Albums{
+			{ID: "al3", Name: "Album"},
+		})
+
+		out, _ := proc.acquire(ctx, model.ArtworkQueueItem{ItemKind: "al", ItemID: "al3"})
+		Expect(out).To(Equal(outcomeAbsent))
+
+		ia, err := artRepo.GetItemArtwork(model.KindAlbumArtwork, "al3", model.ImageTypePrimary)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(ia.Hash).To(BeEmpty())
+		Expect(ia.Source).To(BeEmpty())
+		Expect(ia.AttemptedAt).To(BeTemporally("~", time.Now(), time.Second))
+	})
+
+	It("failed-on-unreadable-local: a listed cover that will not open never records absent", func() {
+		conf.Server.CoverArtPriority = "cover.jpg"
+		// A folder listing that names a cover the FS will not hand over: a stale mount.
+		libRoot := GinkgoT().TempDir()
+		Expect(os.MkdirAll(filepath.Join(libRoot, "an-album"), 0o755)).To(Succeed())
+		libRepo.SetData(model.Libraries{{ID: 0, Path: testFileLibPath(libRoot)}})
+		folderRepo.result = []model.Folder{{Path: "an-album", ImageFiles: []string{"cover.jpg"}}}
+		ds.MockedAlbum.(*tests.MockAlbumRepo).SetData(model.Albums{
+			{ID: "al-io", Name: "Album", FolderIDs: []string{"f1"}},
+		})
+
+		out, _ := proc.acquire(ctx, model.ArtworkQueueItem{ItemKind: "al", ItemID: "al-io"})
+		Expect(out).To(Equal(outcomeFailed))
+
+		_, err := artRepo.GetItemArtwork(model.KindAlbumArtwork, "al-io", model.ImageTypePrimary)
+		Expect(err).To(MatchError(model.ErrNotFound), "an I/O fault must not be recorded as absent")
+	})
+
+	// An upload outranks every source, so an unreadable one must not let a lower one take over.
+	It("failed-on-unreadable-upload: an upload that will not open never records absent", func() {
+		if runtime.GOOS == "windows" {
+			// The file would still open, so the spec would pass on the decode error instead.
+			Skip("chmod does not restrict read access on Windows")
+		}
+		radioRepo := tests.CreateMockedRadioRepo()
+		radioRepo.Data = map[string]*model.Radio{}
+		ds.MockedRadio = radioRepo
+		dir := GinkgoT().TempDir()
+		conf.Server.DataFolder = conf.NewDir(dir)
+		upload := model.UploadedImagePath(consts.EntityRadio, "ra-io.jpg")
+		Expect(os.MkdirAll(filepath.Dir(upload), 0o755)).To(Succeed())
+		Expect(os.WriteFile(upload, []byte("x"), 0o600)).To(Succeed())
+		Expect(os.Chmod(upload, 0o000)).To(Succeed()) // present, but unreadable
+		DeferCleanup(func() { _ = os.Chmod(upload, 0o600) })
+		radioRepo.Data["ra-io"] = &model.Radio{ID: "ra-io", Name: "Station", UploadedImage: "ra-io.jpg"}
+
+		out, _ := proc.acquire(ctx, model.ArtworkQueueItem{ItemKind: "ra", ItemID: "ra-io"})
+		Expect(out).To(Equal(outcomeFailed))
+
+		_, err := artRepo.GetItemArtwork(model.KindRadioArtwork, "ra-io", model.ImageTypePrimary)
+		Expect(err).To(MatchError(model.ErrNotFound), "an unreadable upload must not be recorded as absent")
+	})
+
+	It("failed-on-extError: leaves the item's state untouched", func() {
+		conf.Server.CoverArtPriority = "external"
+		ds.MockedAlbum.(*tests.MockAlbumRepo).SetData(model.Albums{
+			{ID: "al4", Name: "Album"},
+		})
+		imageAgents(&fakeImageAgent{name: "failAgent", err: errors.New("agent timed out")})
+
+		out, _ := proc.acquire(ctx, model.ArtworkQueueItem{ItemKind: "al", ItemID: "al4"})
+		Expect(out).To(Equal(outcomeFailed))
+
+		_, err := artRepo.GetItemArtwork(model.KindAlbumArtwork, "al4", model.ImageTypePrimary)
+		Expect(err).To(MatchError(model.ErrNotFound))
+	})
+
+	It("found-stale: a fallback hit after a transient external failure persists state and returns outcomeFoundStale", func() {
+		conf.Server.CoverArtPriority = "external, cover.jpg"
+		folderRepo.result = []model.Folder{{
+			Path:       "tests/fixtures/artist/an-album",
+			ImageFiles: []string{"cover.jpg"},
+		}}
+		ds.MockedAlbum.(*tests.MockAlbumRepo).SetData(model.Albums{
+			{ID: "alstale", Name: "Album", FolderIDs: []string{"f1"}},
+		})
+		imageAgents(&fakeImageAgent{name: "failAgent", err: errors.New("agent timed out")})
+
+		out, _ := proc.acquire(ctx, model.ArtworkQueueItem{ItemKind: "al", ItemID: "alstale"})
+		Expect(out).To(Equal(outcomeFoundStale))
+
+		ia, err := artRepo.GetItemArtwork(model.KindAlbumArtwork, "alstale", model.ImageTypePrimary)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(ia.Hash).ToNot(BeEmpty())
+		Expect(ia.Source).To(Equal("folder"))
+	})
+
+	It("found-external: persists source as external:<agentName> and stores the fetched bytes", func() {
+		conf.Server.CoverArtPriority = "external"
+		imgBytes, err := os.ReadFile(filepath.Join(repoRoot, "tests/fixtures/artist/an-album/cover.jpg"))
+		Expect(err).ToNot(HaveOccurred())
+		srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+			_, _ = w.Write(imgBytes)
+		}))
+		DeferCleanup(srv.Close)
+
+		ds.MockedAlbum.(*tests.MockAlbumRepo).SetData(model.Albums{{ID: "alext", Name: "Album"}})
+		imageAgents(&fakeImageAgent{name: "deezerFake", imgs: []agents.ExternalImage{{URL: srv.URL, Size: 500}}})
+
+		out, _ := proc.acquire(ctx, model.ArtworkQueueItem{ItemKind: "al", ItemID: "alext"})
+		Expect(out).To(Equal(outcomeFound))
+
+		ia, err := artRepo.GetItemArtwork(model.KindAlbumArtwork, "alext", model.ImageTypePrimary)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(ia.Source).To(Equal("external:deezerFake"))
+		Expect(ia.Hash).ToNot(BeEmpty())
+
+		art, err := artRepo.GetImage(ia.Hash)
+		Expect(err).ToNot(HaveOccurred())
+		rc, err := store.Open(ia.Hash, art.Mime)
+		Expect(err).ToNot(HaveOccurred())
+		rc.Close()
+	})
+
+	It("dedup: a second item with identical bytes skips decode and reuses the artwork row", func() {
+		folderRepo.result = []model.Folder{{
+			Path:       "tests/fixtures/artist/an-album",
+			ImageFiles: []string{"cover.jpg"},
+		}}
+		ds.MockedAlbum.(*tests.MockAlbumRepo).SetData(model.Albums{
+			{ID: "al5", Name: "Album A", FolderIDs: []string{"f1"}},
+			{ID: "al6", Name: "Album B", FolderIDs: []string{"f1"}},
+		})
+
+		out1, _ := proc.acquire(ctx, model.ArtworkQueueItem{ItemKind: "al", ItemID: "al5"})
+		Expect(out1).To(Equal(outcomeFound))
+		ia1, err := artRepo.GetItemArtwork(model.KindAlbumArtwork, "al5", model.ImageTypePrimary)
+		Expect(err).ToNot(HaveOccurred())
+
+		// A re-decode instead of a hash dedup would overwrite this sentinel.
+		poisoned := artRepo.Data[ia1.Hash]
+		poisoned.BlurHash = "SENTINEL"
+		artRepo.Data[ia1.Hash] = poisoned
+
+		out2, _ := proc.acquire(ctx, model.ArtworkQueueItem{ItemKind: "al", ItemID: "al6"})
+		Expect(out2).To(Equal(outcomeFound))
+		ia2, err := artRepo.GetItemArtwork(model.KindAlbumArtwork, "al6", model.ImageTypePrimary)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(ia2.Hash).To(Equal(ia1.Hash))
+
+		reused, err := artRepo.GetImage(ia1.Hash)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(reused.BlurHash).To(Equal("SENTINEL"))
+	})
+
+	It("two items, two files, identical bytes: each item keeps its own provenance; the shared artwork row is written once", func() {
+		// Byte-identical files share one hash, but provenance is per item.
+		libRoot := GinkgoT().TempDir()
+		imgBytes, err := os.ReadFile(filepath.Join(repoRoot, "tests/fixtures/artist/an-album/cover.jpg"))
+		Expect(err).ToNot(HaveOccurred())
+		for sub, mtime := range map[string]int64{"album-a": 1000, "album-b": 2000} {
+			dir := filepath.Join(libRoot, sub)
+			Expect(os.MkdirAll(dir, 0755)).To(Succeed())
+			img := filepath.Join(dir, "cover.jpg")
+			Expect(os.WriteFile(img, imgBytes, 0600)).To(Succeed())
+			Expect(os.Chtimes(img, time.Unix(mtime, 0), time.Unix(mtime, 0))).To(Succeed())
+		}
+		libRepo.SetData(model.Libraries{{ID: 0, Path: testFileLibPath(libRoot)}})
+		ds.MockedAlbum.(*tests.MockAlbumRepo).SetData(model.Albums{
+			{ID: "alA", Name: "Album A", FolderIDs: []string{"fa"}},
+			{ID: "alB", Name: "Album B", FolderIDs: []string{"fb"}},
+		})
+
+		folderRepo.result = []model.Folder{{Path: "album-a", ImageFiles: []string{"cover.jpg"}}}
+		outN, _ := proc.acquire(ctx, model.ArtworkQueueItem{ItemKind: "al", ItemID: "alA"})
+		Expect(outN).To(Equal(outcomeFound))
+		iaA, err := artRepo.GetItemArtwork(model.KindAlbumArtwork, "alA", model.ImageTypePrimary)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(iaA.Source).To(Equal("folder"))
+		Expect(filepath.ToSlash(iaA.SourcePath)).To(HaveSuffix("album-a/cover.jpg"))
+		Expect(iaA.RefMtime).To(Equal(time.Unix(1000, 0).UnixNano()))
+
+		// A re-decode instead of a hash dedup would overwrite this sentinel.
+		poisoned := artRepo.Data[iaA.Hash]
+		poisoned.BlurHash = "SENTINEL"
+		artRepo.Data[iaA.Hash] = poisoned
+
+		folderRepo.result = []model.Folder{{Path: "album-b", ImageFiles: []string{"cover.jpg"}}}
+		outN, _ = proc.acquire(ctx, model.ArtworkQueueItem{ItemKind: "al", ItemID: "alB"})
+		Expect(outN).To(Equal(outcomeFound))
+		iaB, err := artRepo.GetItemArtwork(model.KindAlbumArtwork, "alB", model.ImageTypePrimary)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(iaB.Hash).To(Equal(iaA.Hash))
+		Expect(filepath.ToSlash(iaB.SourcePath)).To(HaveSuffix("album-b/cover.jpg"))
+		Expect(iaB.RefMtime).To(Equal(time.Unix(2000, 0).UnixNano()))
+
+		iaAafter, err := artRepo.GetItemArtwork(model.KindAlbumArtwork, "alA", model.ImageTypePrimary)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(filepath.ToSlash(iaAafter.SourcePath)).To(HaveSuffix("album-a/cover.jpg"))
+		Expect(iaAafter.RefMtime).To(Equal(time.Unix(1000, 0).UnixNano()))
+
+		Expect(artRepo.Data).To(HaveLen(1))
+		reused, err := artRepo.GetImage(iaA.Hash)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(reused.BlurHash).To(Equal("SENTINEL"))
+	})
+
+	It("decode failure on found bytes: fails without writing state", func() {
+		tmpDir := GinkgoT().TempDir()
+		conf.Server.DataFolder = conf.NewDir(tmpDir)
+		Expect(os.MkdirAll(filepath.Join(tmpDir, "artwork", "radio"), 0755)).To(Succeed())
+		imgPath := filepath.Join(tmpDir, "artwork", "radio", "ra1_test.jpg")
+		Expect(os.WriteFile(imgPath, []byte("not actually an image"), 0600)).To(Succeed())
+
+		radioRepo := tests.CreateMockedRadioRepo()
+		radioRepo.Data = map[string]*model.Radio{"ra1": {ID: "ra1", Name: "Radio", UploadedImage: "ra1_test.jpg"}}
+		ds.MockedRadio = radioRepo
+
+		out, _ := proc.acquire(ctx, model.ArtworkQueueItem{ItemKind: "ra", ItemID: "ra1"})
+		Expect(out).To(Equal(outcomeFailed))
+
+		_, err := artRepo.GetItemArtwork(model.KindRadioArtwork, "ra1", model.ImageTypePrimary)
+		Expect(err).To(MatchError(model.ErrNotFound))
+	})
+
+	It("oversized read: a resolved image larger than the cap fails without writing state", func() {
+		tmpDir := GinkgoT().TempDir()
+		conf.Server.DataFolder = conf.NewDir(tmpDir)
+		Expect(os.MkdirAll(filepath.Join(tmpDir, "artwork", "radio"), 0755)).To(Succeed())
+		imgPath := filepath.Join(tmpDir, "artwork", "radio", "big_test.jpg")
+		f, err := os.Create(imgPath)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(f.Truncate(maxImageBytes + 1)).To(Succeed())
+		Expect(f.Close()).To(Succeed())
+
+		radioRepo := tests.CreateMockedRadioRepo()
+		radioRepo.Data = map[string]*model.Radio{"big": {ID: "big", Name: "Radio", UploadedImage: "big_test.jpg"}}
+		ds.MockedRadio = radioRepo
+
+		out, _ := proc.acquire(ctx, model.ArtworkQueueItem{ItemKind: "ra", ItemID: "big"})
+		Expect(out).To(Equal(outcomeFailed))
+
+		_, err = artRepo.GetItemArtwork(model.KindRadioArtwork, "big", model.ImageTypePrimary)
+		Expect(err).To(MatchError(model.ErrNotFound))
+	})
+
+	// The cap is compared by division so an overflowing product cannot slip past it; no supported
+	// format can declare these dimensions, so this pins the arithmetic, not a live hole.
+	DescribeTable("rejects out-of-range declared dimensions",
+		func(w, h uint32) {
+			_, err := decodeArtwork(ctx, "bomb", pngHeaderWithDims(w, h))
+			Expect(err).To(HaveOccurred())
+		},
+		Entry("both dimensions at the 32-bit maximum", uint32(0xffffffff), uint32(0xffffffff)),
+		Entry("both dimensions at the signed 32-bit maximum", uint32(0x7fffffff), uint32(0x7fffffff)),
+		Entry("zero width", uint32(0), uint32(100)),
+		Entry("zero height", uint32(100), uint32(0)),
+	)
+
+	It("decompression bomb: rejects huge declared dimensions before the full decode", func() {
+		data := pngHeaderWithDims(50000, 50000) // 2.5 gigapixels, far above the cap
+		_, err := decodeArtwork(ctx, "bomb", data)
+		Expect(err).To(HaveOccurred())
+		Expect(err.Error()).To(ContainSubstring("dimensions"))
+	})
+
+	It("store write failure: fails without writing state", func() {
+		ds.MockedAlbum.(*tests.MockAlbumRepo).SetData(model.Albums{
+			{ID: "al7", Name: "Album", EmbedArtPath: "tests/fixtures/artist/an-album/test.mp3", FolderIDs: []string{"f1"}},
+		})
+		folderRepo.result = nil
+
+		// A store root that is a plain file makes every MkdirAll under it fail.
+		blockedRoot := filepath.Join(GinkgoT().TempDir(), "not-a-dir")
+		Expect(os.WriteFile(blockedRoot, []byte("x"), 0600)).To(Succeed())
+		proc.store = NewImageStore(blockedRoot)
+
+		out, _ := proc.acquire(ctx, model.ArtworkQueueItem{ItemKind: "al", ItemID: "al7"})
+		Expect(out).To(Equal(outcomeFailed))
+
+		_, err := artRepo.GetItemArtwork(model.KindAlbumArtwork, "al7", model.ImageTypePrimary)
+		Expect(err).To(MatchError(model.ErrNotFound))
+	})
+})
+
+type countingLocker struct {
+	locks   int
+	unlocks int
+}
+
+func (l *countingLocker) Lock()      { l.locks++ }
+func (l *countingLocker) Unlock()    { l.unlocks++ }
+func (l *countingLocker) held() bool { return l.locks != l.unlocks }
+
+var _ = Describe("makeThumbnail", func() {
+	// Both encoders read Pix directly and thumbhash needs straight alpha, so emitting NRGBA is
+	// what keeps either of them from allocating a converted copy of the thumbnail.
+	It("emits NRGBA when it downscales", func() {
+		src := image.NewRGBA(image.Rect(0, 0, 400, 300))
+		Expect(makeThumbnail(src, 100)).To(BeAssignableToTypeOf(&image.NRGBA{}))
+	})
+
+	It("fits the longest side to maxSize and keeps the aspect ratio", func() {
+		src := image.NewRGBA(image.Rect(0, 0, 400, 300))
+		b := makeThumbnail(src, 100).Bounds()
+		Expect(b.Dx()).To(Equal(100))
+		Expect(b.Dy()).To(Equal(75))
+	})
+
+	It("never upscales an image already within bounds", func() {
+		src := image.NewRGBA(image.Rect(0, 0, 40, 30))
+		Expect(makeThumbnail(src, 100).Bounds()).To(Equal(src.Bounds()))
+	})
+
+	// A fully transparent pixel's colour cannot survive any resample, since the scaler works in
+	// premultiplied space and multiplying by zero is not invertible. Partial alpha is the case
+	// that distinguishes straight storage from premultiplied.
+	It("keeps partly transparent colour straight rather than premultiplied", func() {
+		src := image.NewNRGBA(image.Rect(0, 0, 400, 400))
+		for y := range 400 {
+			for x := range 400 {
+				src.SetNRGBA(x, y, color.NRGBA{R: 200, G: 40, B: 90, A: 128})
+			}
+		}
+		thumb, ok := makeThumbnail(src, 100).(*image.NRGBA)
+		Expect(ok).To(BeTrue())
+		// Premultiplied storage would have halved this to ~100.
+		Expect(thumb.Pix[0]).To(BeNumerically("==", 200))
+		Expect(thumb.Pix[3]).To(BeNumerically("==", 128))
+	})
+})

core/artwork/prune.go

@@ -0,0 +1,63 @@
+package artwork
+
+import (
+	"context"
+	"time"
+
+	"github.com/navidrome/navidrome/log"
+	"github.com/navidrome/navidrome/model"
+)
+
+// pruneMinAge guards the window between artwork insert and item_artwork upsert.
+const pruneMinAge = time.Hour
+
+func prune(ctx context.Context, ds model.DataStore, store *ImageStore) error {
+	start := time.Now()
+	defer func() { log.Debug(ctx, "Artwork: Prune finished", "elapsed", time.Since(start)) }()
+	repo := ds.Artwork(ctx)
+
+	purged, err := repo.PurgeDanglingItems()
+	if err != nil {
+		return err
+	}
+	if purged > 0 {
+		log.Info(ctx, "Artwork: Purged dangling item state", "count", purged)
+	}
+
+	// Queue rows for deleted entities would otherwise retry forever (Get -> not found -> failed).
+	queuePurged, err := ds.ArtworkQueue(ctx).PurgeDangling()
+	if err != nil {
+		return err
+	}
+	if queuePurged > 0 {
+		log.Info(ctx, "Artwork: Purged dangling queue rows", "count", queuePurged)
+	}
+
+	// Files younger than the grace window may belong to acquisitions whose rows aren't committed yet.
+	cutoff := time.Now().Add(-pruneMinAge)
+	orphans, err := repo.PurgeOrphans(cutoff)
+	if err != nil {
+		return err
+	}
+	if orphans > 0 {
+		log.Info(ctx, "Artwork: Removed orphan image rows", "count", orphans)
+	}
+
+	// Read after the delete, so the sweep below reclaims the files of the rows just removed.
+	mimes, err := repo.GetMimeByHash()
+	if err != nil {
+		return err
+	}
+	removed, err := store.Sweep(ctx, cutoff, func(hash, ext string) bool {
+		// A known hash under a stale extension is a superseded mime variant — reclaim it.
+		m, ok := mimes[hash]
+		return ok && ext == extForMime(m)
+	})
+	if err != nil {
+		return err
+	}
+	if removed > 0 {
+		log.Info(ctx, "Artwork: Swept stray files", "count", removed)
+	}
+	return nil
+}

core/artwork/prune_test.go

@@ -0,0 +1,239 @@
+package artwork
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"os"
+	"path/filepath"
+	"time"
+
+	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/tests"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+type flakyGetArtworkRepo struct {
+	*tests.MockArtworkRepo
+}
+
+func (f *flakyGetArtworkRepo) GetMimeByHash() (map[string]string, error) {
+	return nil, errors.New("db locked")
+}
+
+var _ = Describe("Prune", func() {
+	var ds *tests.MockDataStore
+	var store *ImageStore
+	var awRepo *tests.MockArtworkRepo
+
+	BeforeEach(func() {
+		ds = &tests.MockDataStore{}
+		awRepo = ds.Artwork(context.Background()).(*tests.MockArtworkRepo)
+		store = NewImageStore(GinkgoT().TempDir())
+	})
+
+	// PutImage refreshes created_at like the SQL repo, so fixtures are aged directly.
+	ageArtwork := func(h string, t time.Time) {
+		a := awRepo.Data[h]
+		a.CreatedAt = t
+		awRepo.Data[h] = a
+	}
+
+	It("purges dangling item_artwork state for gone entities, summed across kinds", func() {
+		Expect(awRepo.PutItemArtwork(&model.ItemArtwork{ItemKind: "al", ItemID: "gone-album", ImageType: model.ImageTypePrimary})).To(Succeed())
+		Expect(awRepo.PutItemArtwork(&model.ItemArtwork{ItemKind: "ar", ItemID: "gone-artist", ImageType: model.ImageTypePrimary})).To(Succeed())
+		Expect(awRepo.PutItemArtwork(&model.ItemArtwork{ItemKind: "ar", ItemID: "live-artist", ImageType: model.ImageTypePrimary})).To(Succeed())
+		awRepo.ExistingIDs = map[string]map[string]bool{
+			"al": {},
+			"ar": {"live-artist": true},
+		}
+
+		Expect(prune(context.Background(), ds, store)).To(Succeed())
+
+		_, err := awRepo.GetItemArtwork(model.KindAlbumArtwork, "gone-album", model.ImageTypePrimary)
+		Expect(err).To(MatchError(model.ErrNotFound))
+		_, err = awRepo.GetItemArtwork(model.KindArtistArtwork, "gone-artist", model.ImageTypePrimary)
+		Expect(err).To(MatchError(model.ErrNotFound))
+		_, err = awRepo.GetItemArtwork(model.KindArtistArtwork, "live-artist", model.ImageTypePrimary)
+		Expect(err).ToNot(HaveOccurred())
+	})
+
+	It("purges dangling artwork_queue rows for gone entities", func() {
+		queueRepo := tests.CreateMockArtworkQueueRepo()
+		Expect(queueRepo.Enqueue(
+			model.ArtworkQueueItem{ItemKind: "al", ItemID: "gone-album", ImageType: model.ImageTypePrimary},
+			model.ArtworkQueueItem{ItemKind: "al", ItemID: "live-album", ImageType: model.ImageTypePrimary},
+		)).To(Succeed())
+		queueRepo.ExistingIDs = map[string]map[string]bool{"al": {"live-album": true}}
+		ds.MockedArtworkQueue = queueRepo
+
+		Expect(prune(context.Background(), ds, store)).To(Succeed())
+
+		Expect(findQueued(queueRepo, "al", "gone-album")).To(BeNil())
+		Expect(findQueued(queueRepo, "al", "live-album")).ToNot(BeNil())
+	})
+
+	It("deletes orphan rows and their store files, keeps referenced ones", func() {
+		data := []byte("orphan-bytes")
+		h, _ := hashImage(bytes.NewReader(data))
+		Expect(store.Write(h, "image/jpeg", bytes.NewReader(data))).To(Succeed())
+		old := time.Now().Add(-2 * time.Hour)
+		Expect(os.Chtimes(store.path(h, "image/jpeg"), old, old)).To(Succeed())
+		Expect(awRepo.PutImage(&model.Artwork{Hash: h, Mime: "image/jpeg"})).To(Succeed())
+		ageArtwork(h, old)
+
+		kept := []byte("kept-bytes")
+		hk, _ := hashImage(bytes.NewReader(kept))
+		Expect(store.Write(hk, "image/jpeg", bytes.NewReader(kept))).To(Succeed())
+		Expect(awRepo.PutImage(&model.Artwork{Hash: hk, Mime: "image/jpeg"})).To(Succeed())
+
+		Expect(prune(context.Background(), ds, store)).To(Succeed())
+
+		_, err := awRepo.GetImage(h)
+		Expect(err).To(MatchError(model.ErrNotFound))
+		_, err = store.Open(h, "image/jpeg")
+		Expect(os.IsNotExist(err)).To(BeTrue())
+		rc, err := store.Open(hk, "image/jpeg")
+		Expect(err).ToNot(HaveOccurred())
+		rc.Close()
+	})
+
+	It("spares an aged row that item_artwork state still references", func() {
+		data := []byte("reacquired-bytes")
+		h, _ := hashImage(bytes.NewReader(data))
+		Expect(store.Write(h, "image/jpeg", bytes.NewReader(data))).To(Succeed())
+		Expect(awRepo.PutImage(&model.Artwork{Hash: h, Mime: "image/jpeg"})).To(Succeed())
+		ageArtwork(h, time.Now().Add(-2*time.Hour))
+		Expect(awRepo.PutItemArtwork(&model.ItemArtwork{ItemKind: "al", ItemID: "a1",
+			ImageType: model.ImageTypePrimary, Hash: h, Source: "folder"})).To(Succeed())
+
+		Expect(prune(context.Background(), ds, store)).To(Succeed())
+
+		_, err := awRepo.GetImage(h)
+		Expect(err).ToNot(HaveOccurred())
+		rc, err := store.Open(h, "image/jpeg")
+		Expect(err).ToNot(HaveOccurred())
+		rc.Close()
+	})
+
+	It("spares an unreferenced row recreated inside the grace window", func() {
+		data := []byte("fresh-reacquired-bytes")
+		h, _ := hashImage(bytes.NewReader(data))
+		Expect(store.Write(h, "image/jpeg", bytes.NewReader(data))).To(Succeed())
+		// Reacquisition refreshed created_at, so the row is unreferenced but too young to drop.
+		Expect(awRepo.PutImage(&model.Artwork{Hash: h, Mime: "image/jpeg"})).To(Succeed())
+
+		Expect(prune(context.Background(), ds, store)).To(Succeed())
+
+		_, err := awRepo.GetImage(h)
+		Expect(err).ToNot(HaveOccurred())
+		rc, err := store.Open(h, "image/jpeg")
+		Expect(err).ToNot(HaveOccurred())
+		rc.Close()
+	})
+
+	It("spares an orphan file freshly touched by an overlapping acquisition", func() {
+		data := []byte("racing-bytes")
+		h, _ := hashImage(bytes.NewReader(data))
+		Expect(store.Write(h, "image/jpeg", bytes.NewReader(data))).To(Succeed())
+		Expect(awRepo.PutImage(&model.Artwork{Hash: h, Mime: "image/jpeg"})).To(Succeed())
+		ageArtwork(h, time.Now().Add(-2*time.Hour))
+		// The row is orphaned, but a concurrent acquisition just touched the file's mtime.
+
+		Expect(prune(context.Background(), ds, store)).To(Succeed())
+
+		rc, err := store.Open(h, "image/jpeg")
+		Expect(err).ToNot(HaveOccurred())
+		rc.Close()
+	})
+
+	It("sweeps store files that have no artwork row", func() {
+		stray := []byte("no-row-bytes")
+		h, _ := hashImage(bytes.NewReader(stray))
+		Expect(store.Write(h, "image/jpeg", bytes.NewReader(stray))).To(Succeed())
+		old := time.Now().Add(-2 * time.Hour)
+		Expect(os.Chtimes(store.path(h, "image/jpeg"), old, old)).To(Succeed())
+
+		Expect(prune(context.Background(), ds, store)).To(Succeed())
+
+		_, err := store.Open(h, "image/jpeg")
+		Expect(os.IsNotExist(err)).To(BeTrue())
+	})
+
+	It("sweeps an obsolete mime variant of a reacquired hash", func() {
+		data := []byte("variant-bytes")
+		h, _ := hashImage(bytes.NewReader(data))
+		Expect(store.Write(h, "image/png", bytes.NewReader(data))).To(Succeed())
+		Expect(store.Write(h, "image/jpeg", bytes.NewReader(data))).To(Succeed())
+		old := time.Now().Add(-2 * time.Hour)
+		Expect(os.Chtimes(store.path(h, "image/png"), old, old)).To(Succeed())
+		Expect(os.Chtimes(store.path(h, "image/jpeg"), old, old)).To(Succeed())
+		// The row records the current mime; the .png file is a superseded variant.
+		Expect(awRepo.PutImage(&model.Artwork{Hash: h, Mime: "image/jpeg"})).To(Succeed())
+
+		Expect(prune(context.Background(), ds, store)).To(Succeed())
+
+		_, err := store.Open(h, "image/png")
+		Expect(os.IsNotExist(err)).To(BeTrue())
+		rc, err := store.Open(h, "image/jpeg")
+		Expect(err).ToNot(HaveOccurred())
+		rc.Close()
+	})
+
+	It("reclaims the other orphan files when one of them cannot be removed", func() {
+		tests.SkipOnWindows("uses Unix file permission bits")
+		if os.Geteuid() == 0 {
+			Skip("read-only dir cannot block root (e.g. tests in a container)")
+		}
+		old := time.Now().Add(-2 * time.Hour)
+
+		blocked := []byte("blocked-bytes")
+		hb, _ := hashImage(bytes.NewReader(blocked))
+		Expect(store.Write(hb, "image/jpeg", bytes.NewReader(blocked))).To(Succeed())
+		Expect(os.Chtimes(store.path(hb, "image/jpeg"), old, old)).To(Succeed())
+		Expect(awRepo.PutImage(&model.Artwork{Hash: hb, Mime: "image/jpeg"})).To(Succeed())
+		ageArtwork(hb, old)
+
+		good := []byte("good-bytes")
+		hg, _ := hashImage(bytes.NewReader(good))
+		Expect(store.Write(hg, "image/jpeg", bytes.NewReader(good))).To(Succeed())
+		Expect(os.Chtimes(store.path(hg, "image/jpeg"), old, old)).To(Succeed())
+		Expect(awRepo.PutImage(&model.Artwork{Hash: hg, Mime: "image/jpeg"})).To(Succeed())
+		ageArtwork(hg, old)
+
+		// A read-only shard directory makes os.Remove fail (EACCES) for hb's file only.
+		shardDir := filepath.Dir(store.path(hb, "image/jpeg"))
+		Expect(shardDir).ToNot(Equal(filepath.Dir(store.path(hg, "image/jpeg"))), "fixtures must land in different shards")
+		Expect(os.Chmod(shardDir, 0500)).To(Succeed())
+		DeferCleanup(func() { _ = os.Chmod(shardDir, 0755) })
+
+		Expect(prune(context.Background(), ds, store)).To(Succeed())
+
+		_, err := awRepo.GetImage(hg)
+		Expect(err).To(MatchError(model.ErrNotFound))
+		_, err = store.Open(hg, "image/jpeg")
+		Expect(os.IsNotExist(err)).To(BeTrue())
+
+		// The row purge does not depend on file removal, so only the file survives.
+		_, err = awRepo.GetImage(hb)
+		Expect(err).To(MatchError(model.ErrNotFound))
+		rc, err := store.Open(hb, "image/jpeg")
+		Expect(err).ToNot(HaveOccurred())
+		rc.Close()
+	})
+
+	It("never sweeps files on a transient DB error", func() {
+		ds.MockedArtwork = &flakyGetArtworkRepo{MockArtworkRepo: tests.CreateMockArtworkRepo()}
+
+		data := []byte("live-bytes")
+		h, _ := hashImage(bytes.NewReader(data))
+		Expect(store.Write(h, "image/jpeg", bytes.NewReader(data))).To(Succeed())
+
+		Expect(prune(context.Background(), ds, store)).ToNot(Succeed())
+
+		rc, err := store.Open(h, "image/jpeg")
+		Expect(err).ToNot(HaveOccurred())
+		rc.Close()
+	})
+})

core/artwork/reader_album_test.go

@@ -1,481 +0,0 @@
-package artwork
-
-import (
-	"context"
-	"errors"
-	"path/filepath"
-	"time"
-
-	"github.com/navidrome/navidrome/model"
-	. "github.com/onsi/ginkgo/v2"
-	. "github.com/onsi/gomega"
-)
-
-var _ = Describe("Album Artwork Reader", func() {
-	Describe("loadAlbumFoldersPaths", func() {
-		var (
-			ctx        context.Context
-			ds         *fakeDataStore
-			repo       *fakeFolderRepo
-			album      model.Album
-			now        time.Time
-			expectedAt time.Time
-		)
-
-		BeforeEach(func() {
-			ctx = context.Background()
-			now = time.Now().Truncate(time.Second)
-			expectedAt = now.Add(5 * time.Minute)
-
-			// Set up the test folders with image files
-			repo = &fakeFolderRepo{}
-			ds = &fakeDataStore{
-				folderRepo: repo,
-			}
-			album = model.Album{
-				ID:        "album1",
-				Name:      "Album",
-				FolderIDs: []string{"folder1", "folder2", "folder3"},
-			}
-		})
-
-		It("returns sorted image files", func() {
-			repo.result = []model.Folder{
-				{
-					Path:            "Artist/Album/Disc1",
-					ImagesUpdatedAt: expectedAt,
-					ImageFiles:      []string{"cover.jpg", "back.jpg", "cover.1.jpg"},
-				},
-				{
-					Path:            "Artist/Album/Disc2",
-					ImagesUpdatedAt: now,
-					ImageFiles:      []string{"cover.jpg"},
-				},
-				{
-					Path:            "Artist/Album/Disc10",
-					ImagesUpdatedAt: now,
-					ImageFiles:      []string{"cover.jpg"},
-				},
-			}
-
-			_, imgFiles, imagesUpdatedAt, err := loadAlbumFoldersPaths(ctx, ds, album)
-
-			Expect(err).ToNot(HaveOccurred())
-			Expect(*imagesUpdatedAt).To(Equal(expectedAt))
-
-			// Check that image files are sorted by base name (without extension)
-			Expect(imgFiles).To(HaveLen(5))
-
-			// Files should be sorted by base filename without extension, then by full path
-			// "back" < "cover", so back.jpg comes first
-			// Then all cover.jpg files, sorted by path
-			Expect(imgFiles[0]).To(Equal("Artist/Album/Disc1/back.jpg"))
-			Expect(imgFiles[1]).To(Equal("Artist/Album/Disc1/cover.jpg"))
-			Expect(imgFiles[2]).To(Equal("Artist/Album/Disc2/cover.jpg"))
-			Expect(imgFiles[3]).To(Equal("Artist/Album/Disc10/cover.jpg"))
-			Expect(imgFiles[4]).To(Equal("Artist/Album/Disc1/cover.1.jpg"))
-		})
-
-		It("prioritizes files without numeric suffixes", func() {
-			// Test case for issue #4683: cover.jpg should come before cover.1.jpg
-			repo.result = []model.Folder{
-				{
-					Path:            "Artist/Album",
-					ImagesUpdatedAt: now,
-					ImageFiles:      []string{"cover.1.jpg", "cover.jpg", "cover.2.jpg"},
-				},
-			}
-
-			_, imgFiles, _, err := loadAlbumFoldersPaths(ctx, ds, album)
-
-			Expect(err).ToNot(HaveOccurred())
-			Expect(imgFiles).To(HaveLen(3))
-
-			// cover.jpg should come first because "cover" < "cover.1" < "cover.2"
-			Expect(imgFiles[0]).To(Equal("Artist/Album/cover.jpg"))
-			Expect(imgFiles[1]).To(Equal("Artist/Album/cover.1.jpg"))
-			Expect(imgFiles[2]).To(Equal("Artist/Album/cover.2.jpg"))
-		})
-
-		It("handles case-insensitive sorting", func() {
-			// Test that Cover.jpg and cover.jpg are treated as equivalent
-			repo.result = []model.Folder{
-				{
-					Path:            "Artist/Album",
-					ImagesUpdatedAt: now,
-					ImageFiles:      []string{"Folder.jpg", "cover.jpg", "BACK.jpg"},
-				},
-			}
-
-			_, imgFiles, _, err := loadAlbumFoldersPaths(ctx, ds, album)
-
-			Expect(err).ToNot(HaveOccurred())
-			Expect(imgFiles).To(HaveLen(3))
-
-			// Files should be sorted case-insensitively: BACK, cover, Folder
-			Expect(imgFiles[0]).To(Equal("Artist/Album/BACK.jpg"))
-			Expect(imgFiles[1]).To(Equal("Artist/Album/cover.jpg"))
-			Expect(imgFiles[2]).To(Equal("Artist/Album/Folder.jpg"))
-		})
-
-		It("includes images from parent folder for multi-disc albums", func() {
-			// Simulates: Artist/Album/cover.jpg with tracks in Artist/Album/CD1/ and Artist/Album/CD2/
-			repo.result = []model.Folder{
-				{
-					ID:              "folder1",
-					Path:            "Artist/Album",
-					Name:            "CD1",
-					ParentID:        "parentFolder",
-					ImagesUpdatedAt: now,
-					ImageFiles:      []string{},
-				},
-				{
-					ID:              "folder2",
-					Path:            "Artist/Album",
-					Name:            "CD2",
-					ParentID:        "parentFolder",
-					ImagesUpdatedAt: now,
-					ImageFiles:      []string{},
-				},
-			}
-			repo.parentResult = &model.Folder{
-				ID:              "parentFolder",
-				Path:            "Artist",
-				Name:            "Album",
-				ParentID:        "artistFolder",
-				ImagesUpdatedAt: expectedAt,
-				ImageFiles:      []string{"cover.jpg", "back.jpg"},
-			}
-
-			_, imgFiles, imagesUpdatedAt, err := loadAlbumFoldersPaths(ctx, ds, album)
-
-			Expect(err).ToNot(HaveOccurred())
-			Expect(*imagesUpdatedAt).To(Equal(expectedAt))
-			Expect(imgFiles).To(HaveLen(2))
-			Expect(imgFiles[0]).To(Equal("Artist/Album/back.jpg"))
-			Expect(imgFiles[1]).To(Equal("Artist/Album/cover.jpg"))
-		})
-
-		It("does not query parent when parent ID is already in album folders", func() {
-			// When the parent folder is already one of the album's folders, skip it
-			repo.result = []model.Folder{
-				{
-					ID:              "folder1",
-					Path:            "Artist",
-					Name:            "Album",
-					ParentID:        "folder2",
-					ImagesUpdatedAt: now,
-					ImageFiles:      []string{"cover.jpg"},
-				},
-				{
-					ID:              "folder2",
-					Path:            "",
-					Name:            "Artist",
-					ImagesUpdatedAt: now,
-					ImageFiles:      []string{},
-				},
-			}
-
-			_, imgFiles, _, err := loadAlbumFoldersPaths(ctx, ds, album)
-
-			Expect(err).ToNot(HaveOccurred())
-			Expect(imgFiles).To(HaveLen(1))
-			Expect(imgFiles[0]).To(Equal("Artist/Album/cover.jpg"))
-			// Get should not have been called (parent already in folder set)
-			Expect(repo.getCallCount).To(Equal(0))
-		})
-
-		It("does not query parent when folders have different parents", func() {
-			// When album folders span different parents, don't search any parent
-			repo.result = []model.Folder{
-				{
-					ID:              "folder1",
-					Path:            "Artist1/Album",
-					Name:            "part1",
-					ParentID:        "parentA",
-					ImagesUpdatedAt: now,
-					ImageFiles:      []string{"cover.jpg"},
-				},
-				{
-					ID:              "folder2",
-					Path:            "Artist2/Album",
-					Name:            "part2",
-					ParentID:        "parentB",
-					ImagesUpdatedAt: now,
-					ImageFiles:      []string{},
-				},
-			}
-
-			_, imgFiles, _, err := loadAlbumFoldersPaths(ctx, ds, album)
-
-			Expect(err).ToNot(HaveOccurred())
-			Expect(imgFiles).To(HaveLen(1))
-			Expect(imgFiles[0]).To(Equal("Artist1/Album/part1/cover.jpg"))
-			// Get should not have been called (different parents)
-			Expect(repo.getCallCount).To(Equal(0))
-		})
-
-		It("does not include library root parent for multi-folder albums", func() {
-			// Two album parts directly under the library root — parent is the root itself
-			repo.result = []model.Folder{
-				{
-					ID:              "folder1",
-					Path:            ".",
-					Name:            "AlbumPart1",
-					ParentID:        "rootFolder",
-					ImagesUpdatedAt: now,
-					ImageFiles:      []string{"cover.jpg"},
-				},
-				{
-					ID:              "folder2",
-					Path:            ".",
-					Name:            "AlbumPart2",
-					ParentID:        "rootFolder",
-					ImagesUpdatedAt: now,
-					ImageFiles:      []string{},
-				},
-			}
-			repo.parentResult = &model.Folder{
-				ID:         "rootFolder",
-				Path:       "",
-				Name:       ".",
-				ParentID:   "",
-				ImageFiles: []string{"unrelated.jpg"},
-			}
-
-			_, imgFiles, _, err := loadAlbumFoldersPaths(ctx, ds, album)
-
-			Expect(err).ToNot(HaveOccurred())
-			Expect(imgFiles).To(HaveLen(1))
-			Expect(imgFiles[0]).To(Equal("AlbumPart1/cover.jpg"))
-			Expect(repo.getCallCount).To(Equal(1))
-		})
-
-		It("includes top-level album folder for multi-disc albums", func() {
-			// Album folder directly under library root, with disc subfolders
-			repo.result = []model.Folder{
-				{
-					ID:              "folder1",
-					Path:            "Album",
-					Name:            "Disc1",
-					ParentID:        "albumFolder",
-					ImagesUpdatedAt: now,
-					ImageFiles:      []string{"folder.jpg"},
-				},
-				{
-					ID:              "folder2",
-					Path:            "Album",
-					Name:            "Disc2",
-					ParentID:        "albumFolder",
-					ImagesUpdatedAt: now,
-					ImageFiles:      []string{"folder.jpg"},
-				},
-			}
-			repo.parentResult = &model.Folder{
-				ID:              "albumFolder",
-				Path:            ".",
-				Name:            "Album",
-				ParentID:        "rootFolder",
-				ImagesUpdatedAt: expectedAt,
-				ImageFiles:      []string{"cover.jpg"},
-			}
-
-			_, imgFiles, imagesUpdatedAt, err := loadAlbumFoldersPaths(ctx, ds, album)
-
-			Expect(err).ToNot(HaveOccurred())
-			Expect(*imagesUpdatedAt).To(Equal(expectedAt))
-			Expect(imgFiles).To(HaveLen(3))
-			Expect(imgFiles[0]).To(Equal("Album/cover.jpg"))
-			Expect(imgFiles[1]).To(Equal("Album/Disc1/folder.jpg"))
-			Expect(imgFiles[2]).To(Equal("Album/Disc2/folder.jpg"))
-			Expect(repo.getCallCount).To(Equal(1))
-		})
-
-		It("does not query parent for single-folder albums that already have images", func() {
-			repo.result = []model.Folder{
-				{
-					ID:              "folder1",
-					Path:            "Artist",
-					Name:            "Album",
-					ParentID:        "artistFolder",
-					ImagesUpdatedAt: now,
-					ImageFiles:      []string{"cover.jpg"},
-				},
-			}
-
-			_, imgFiles, _, err := loadAlbumFoldersPaths(ctx, ds, album)
-
-			Expect(err).ToNot(HaveOccurred())
-			Expect(imgFiles).To(HaveLen(1))
-			Expect(imgFiles[0]).To(Equal("Artist/Album/cover.jpg"))
-			Expect(repo.getCallCount).To(Equal(0))
-		})
-
-		It("includes parent images for single-disc-subfolder albums", func() {
-			repo.result = []model.Folder{
-				{
-					ID:              "folder1",
-					Path:            "Artist/Album",
-					Name:            "disc1",
-					ParentID:        "albumFolder",
-					ImagesUpdatedAt: now,
-					ImageFiles:      []string{},
-				},
-			}
-			repo.parentResult = &model.Folder{
-				ID:              "albumFolder",
-				Path:            "Artist",
-				Name:            "Album",
-				ParentID:        "artistFolder",
-				ImagesUpdatedAt: expectedAt,
-				ImageFiles:      []string{"cover.jpg"},
-			}
-
-			_, imgFiles, imagesUpdatedAt, err := loadAlbumFoldersPaths(ctx, ds, album)
-
-			Expect(err).ToNot(HaveOccurred())
-			Expect(*imagesUpdatedAt).To(Equal(expectedAt))
-			Expect(imgFiles).To(HaveLen(1))
-			Expect(imgFiles[0]).To(Equal("Artist/Album/cover.jpg"))
-			Expect(repo.getCallCount).To(Equal(1))
-		})
-
-		It("promotes the album root parent into the returned paths", func() {
-			repo.result = []model.Folder{
-				{
-					ID:              "folder1",
-					Path:            "Artist",
-					Name:            "Album",
-					ParentID:        "artistFolder",
-					ImagesUpdatedAt: now,
-					ImageFiles:      []string{},
-				},
-			}
-			repo.parentResult = &model.Folder{
-				ID:              "artistFolder",
-				Path:            ".",
-				Name:            "Artist",
-				ParentID:        "libraryRoot",
-				ImagesUpdatedAt: expectedAt,
-				ImageFiles:      []string{"folder.jpg"},
-			}
-
-			paths, _, _, err := loadAlbumFoldersPaths(ctx, ds, album)
-
-			Expect(err).ToNot(HaveOccurred())
-			Expect(paths).To(Equal([]string{filepath.Join("Artist", "Album"), "Artist"}))
-		})
-
-		It("does not include parent images when other albums' audio lives under the parent", func() {
-			// Simulates: Artist/folder.jpg with Artist/Album (no images) and
-			// another album's tracks elsewhere under the artist folder
-			repo.result = []model.Folder{
-				{
-					ID:              "folder1",
-					Path:            "Artist",
-					Name:            "Album",
-					ParentID:        "artistFolder",
-					ImagesUpdatedAt: now,
-					ImageFiles:      []string{},
-				},
-			}
-			repo.parentResult = &model.Folder{
-				ID:              "artistFolder",
-				Path:            ".",
-				Name:            "Artist",
-				ParentID:        "libraryRoot",
-				ImagesUpdatedAt: expectedAt,
-				ImageFiles:      []string{"folder.jpg"},
-			}
-			repo.hasOtherAudio = true
-
-			_, imgFiles, _, err := loadAlbumFoldersPaths(ctx, ds, album)
-
-			Expect(err).ToNot(HaveOccurred())
-			Expect(imgFiles).To(BeEmpty())
-		})
-
-		It("propagates errors from the album-root check", func() {
-			repo.result = []model.Folder{
-				{
-					ID:              "folder1",
-					Path:            "Artist/Album",
-					Name:            "disc1",
-					ParentID:        "albumFolder",
-					ImagesUpdatedAt: now,
-					ImageFiles:      []string{},
-				},
-			}
-			repo.parentResult = &model.Folder{
-				ID:              "albumFolder",
-				Path:            "Artist",
-				Name:            "Album",
-				ParentID:        "artistFolder",
-				ImagesUpdatedAt: expectedAt,
-				ImageFiles:      []string{"cover.jpg"},
-			}
-			repo.otherAudioErr = errors.New("db connection failed")
-
-			_, _, _, err := loadAlbumFoldersPaths(ctx, ds, album)
-
-			Expect(err).To(MatchError("db connection failed"))
-		})
-
-		It("propagates non-ErrNotFound errors from parent folder lookup", func() {
-			repo.result = []model.Folder{
-				{
-					ID:              "folder1",
-					Path:            "Artist/Album",
-					Name:            "CD1",
-					ParentID:        "parentFolder",
-					ImagesUpdatedAt: now,
-					ImageFiles:      []string{"cover.jpg"},
-				},
-				{
-					ID:              "folder2",
-					Path:            "Artist/Album",
-					Name:            "CD2",
-					ParentID:        "parentFolder",
-					ImagesUpdatedAt: now,
-					ImageFiles:      []string{},
-				},
-			}
-			repo.getErr = errors.New("db connection failed")
-
-			_, _, _, err := loadAlbumFoldersPaths(ctx, ds, album)
-
-			Expect(err).To(MatchError("db connection failed"))
-			Expect(repo.getCallCount).To(Equal(1))
-		})
-
-		It("continues gracefully when parent folder is not found", func() {
-			// Parent folder may have been deleted; should log a warning and continue
-			repo.result = []model.Folder{
-				{
-					ID:              "folder1",
-					Path:            "Artist/Album",
-					Name:            "CD1",
-					ParentID:        "missingParent",
-					ImagesUpdatedAt: now,
-					ImageFiles:      []string{"cover.jpg"},
-				},
-				{
-					ID:              "folder2",
-					Path:            "Artist/Album",
-					Name:            "CD2",
-					ParentID:        "missingParent",
-					ImagesUpdatedAt: now,
-					ImageFiles:      []string{},
-				},
-			}
-			// parentResult is nil, so Get will return ErrNotFound
-
-			_, imgFiles, _, err := loadAlbumFoldersPaths(ctx, ds, album)
-
-			Expect(err).ToNot(HaveOccurred())
-			Expect(imgFiles).To(HaveLen(1))
-			Expect(imgFiles[0]).To(Equal("Artist/Album/CD1/cover.jpg"))
-			Expect(repo.getCallCount).To(Equal(1))
-		})
-	})
-})

core/artwork/reader_artist.go

@@ -1,359 +0,0 @@
-package artwork
-
-import (
-	"context"
-	"crypto/md5"
-	"fmt"
-	"io"
-	"io/fs"
-	"os"
-	"path"
-	"path/filepath"
-	"slices"
-	"strings"
-	"time"
-
-	"github.com/Masterminds/squirrel"
-	"github.com/navidrome/navidrome/conf"
-	"github.com/navidrome/navidrome/core"
-	"github.com/navidrome/navidrome/core/external"
-	"github.com/navidrome/navidrome/log"
-	"github.com/navidrome/navidrome/model"
-	"github.com/navidrome/navidrome/utils/slice"
-	"github.com/navidrome/navidrome/utils/str"
-)
-
-const (
-	// maxArtistFolderTraversalDepth defines how many directory levels to search
-	// when looking for artist images (artist folder + parent directories)
-	maxArtistFolderTraversalDepth = 3
-)
-
-type artistReader struct {
-	cacheKey
-	a                *artwork
-	provider         external.Provider
-	artist           model.Artist
-	artistFolder     string
-	imgFiles         []string
-	imgFolderImgPath string // cached path from ArtistImageFolder lookup
-	lib              libraryView
-}
-
-func newArtistArtworkReader(ctx context.Context, artwork *artwork, artID model.ArtworkID, provider external.Provider) (*artistReader, error) {
-	ar, err := artwork.ds.Artist(ctx).Get(artID.ID)
-	if err != nil {
-		return nil, err
-	}
-	// Only consider albums where the artist is the sole album artist.
-	als, err := artwork.ds.Album(ctx).GetAll(model.QueryOptions{
-		Filters: squirrel.And{
-			squirrel.Eq{"album_artist_id": artID.ID},
-			squirrel.Eq{"json_array_length(participants, '$.albumartist')": 1},
-		},
-	})
-	if err != nil {
-		return nil, err
-	}
-	albumPaths, imgFiles, imagesUpdatedAt, err := loadArtistAlbumRoots(ctx, artwork.ds, als)
-	if err != nil {
-		return nil, err
-	}
-	artistFolder, artistFolderLastUpdate, err := loadArtistFolder(ctx, artwork.ds, als, albumPaths)
-	if err != nil {
-		return nil, err
-	}
-	var lib libraryView
-	if len(als) > 0 {
-		lib, err = loadLibraryView(ctx, artwork.ds, als[0].LibraryID)
-		if err != nil {
-			return nil, err
-		}
-	}
-	a := &artistReader{
-		a:            artwork,
-		provider:     provider,
-		artist:       *ar,
-		artistFolder: artistFolder,
-		imgFiles:     imgFiles,
-		lib:          lib,
-	}
-	// TODO Find a way to factor in the ExternalUpdateInfoAt in the cache key. Problem is that it can
-	// change _after_ retrieving from external sources, making the key invalid
-	//a.cacheKey.lastUpdate = ar.ExternalInfoUpdatedAt
-
-	a.cacheKey.lastUpdate = *imagesUpdatedAt
-	if ar.UpdatedAt != nil && ar.UpdatedAt.After(a.cacheKey.lastUpdate) {
-		a.cacheKey.lastUpdate = *ar.UpdatedAt
-	}
-	if artistFolderLastUpdate.After(a.cacheKey.lastUpdate) {
-		a.cacheKey.lastUpdate = artistFolderLastUpdate
-	}
-	if conf.Server.ArtistImageFolder != "" && strings.Contains(strings.ToLower(conf.Server.ArtistArtPriority), "image-folder") {
-		a.imgFolderImgPath = findImageInArtistFolder(conf.Server.ArtistImageFolder, ar.MbzArtistID, ar.Name)
-		if a.imgFolderImgPath != "" {
-			if info, err := os.Stat(a.imgFolderImgPath); err == nil && info.ModTime().After(a.cacheKey.lastUpdate) {
-				a.cacheKey.lastUpdate = info.ModTime()
-			}
-		}
-	}
-	a.cacheKey.artID = artID
-	return a, nil
-}
-
-func (a *artistReader) Key() string {
-	hash := md5.Sum([]byte(conf.Server.Agents))
-	return fmt.Sprintf(
-		"%s.%t.%x",
-		a.cacheKey.Key(),
-		conf.Server.EnableExternalServices,
-		hash,
-	)
-}
-
-func (a *artistReader) LastUpdated() time.Time {
-	return a.lastUpdate
-}
-
-func (a *artistReader) Reader(ctx context.Context) (io.ReadCloser, string, error) {
-	ff := []sourceFunc{a.fromArtistUploadedImage()}
-	ff = append(ff, a.fromArtistArtPriority(ctx, conf.Server.ArtistArtPriority)...)
-	return selectImageReader(ctx, a.artID, ff...)
-}
-
-func (a *artistReader) fromArtistUploadedImage() sourceFunc {
-	return fromLocalFile(a.artist.UploadedImagePath())
-}
-
-func (a *artistReader) fromArtistArtPriority(ctx context.Context, priority string) []sourceFunc {
-	var ff []sourceFunc
-	for pattern := range strings.SplitSeq(strings.ToLower(priority), ",") {
-		pattern = strings.TrimSpace(pattern)
-		switch {
-		case pattern == "external":
-			ff = append(ff, fromArtistExternalSource(ctx, a.artist, a.provider))
-		case pattern == "image-folder":
-			ff = append(ff, a.fromArtistImageFolder(ctx))
-		case strings.HasPrefix(pattern, "album/"):
-			if a.lib.FS != nil {
-				ff = append(ff, fromExternalFile(ctx, a.lib.FS, a.imgFiles, strings.TrimPrefix(pattern, "album/")))
-			}
-		default:
-			ff = append(ff, fromArtistFolder(ctx, a.lib.FS, a.lib.absRoot, a.artistFolder, pattern))
-		}
-	}
-	return ff
-}
-
-// fromArtistFolder walks up from artistFolder toward libPath looking for a
-// file matching pattern. Traversal is bounded by both maxArtistFolderTraversalDepth
-// and the library root: once we reach libPath (or if artistFolder is outside
-// libPath), the walk stops. All reads go through libFS, which keeps artwork
-// resolution scoped to the configured library.
-func fromArtistFolder(ctx context.Context, libFS fs.FS, libPath, artistFolder, pattern string) sourceFunc {
-	return func() (io.ReadCloser, string, error) {
-		if libFS == nil {
-			return nil, "", fmt.Errorf("artist folder lookup unavailable")
-		}
-		rel, err := filepath.Rel(libPath, artistFolder)
-		if err != nil || rel == ".." || strings.HasPrefix(rel, ".."+string(filepath.Separator)) {
-			return nil, "", fmt.Errorf(`artist folder '%s' is outside library '%s'`, artistFolder, libPath)
-		}
-		// fs.Glob / path.Join below expect forward-slash paths; filepath.Rel may
-		// return backslash separators on Windows.
-		rel = filepath.ToSlash(rel)
-		current := artistFolder
-		for range maxArtistFolderTraversalDepth {
-			reader, hit, err := findImageInFolder(ctx, libFS, rel, current, pattern)
-			if err == nil {
-				return reader, hit, nil
-			}
-			if rel == "." {
-				break // reached library root; don't traverse above it
-			}
-			rel = path.Dir(rel)
-			current = filepath.Dir(current)
-		}
-		return nil, "", fmt.Errorf(`no matches for '%s' in '%s' or its parent directories (within library)`, pattern, artistFolder)
-	}
-}
-
-// findImageInFolder globs libFS at relFolder for pattern and returns the first
-// matching image. absFolder is used only for the returned display path and log
-// messages so callers see absolute-looking paths consistent with the rest of
-// the artwork pipeline.
-func findImageInFolder(ctx context.Context, libFS fs.FS, relFolder, absFolder, pattern string) (io.ReadCloser, string, error) {
-	log.Trace(ctx, "looking for artist image", "pattern", pattern, "folder", absFolder)
-	globPattern := pattern
-	if relFolder != "." {
-		globPattern = path.Join(escapeGlobLiteral(relFolder), pattern)
-	}
-	matches, err := fs.Glob(libFS, globPattern)
-	if err != nil {
-		log.Warn(ctx, "Error matching artist image pattern", "pattern", pattern, "folder", absFolder, err)
-		return nil, "", err
-	}
-
-	// Filter to valid image files
-	var imagePaths []string
-	for _, m := range matches {
-		if !model.IsImageFile(m) {
-			continue
-		}
-		imagePaths = append(imagePaths, m)
-	}
-
-	// Sort image files by prioritizing base filenames without numeric
-	// suffixes (e.g., artist.jpg before artist.1.jpg)
-	slices.SortFunc(imagePaths, compareImageFiles)
-
-	for _, p := range imagePaths {
-		f, err := libFS.Open(p)
-		if err != nil {
-			log.Warn(ctx, "Could not open cover art file", "file", p, err)
-			continue
-		}
-		_, name := path.Split(p)
-		return f, filepath.Join(absFolder, name), nil
-	}
-
-	return nil, "", fmt.Errorf(`no matches for '%s' in '%s'`, pattern, absFolder)
-}
-
-func escapeGlobLiteral(s string) string {
-	var b strings.Builder
-	b.Grow(len(s))
-	for _, r := range s {
-		switch r {
-		case '\\', '*', '?', '[', ']':
-			b.WriteByte('\\')
-		}
-		b.WriteRune(r)
-	}
-	return b.String()
-}
-
-// loadArtistAlbumRoots returns one path per album — the deepest folder holding
-// all of that album's tracks — so an album split into disc subfolders can't
-// pull the artist folder's common prefix below the artist level.
-func loadArtistAlbumRoots(ctx context.Context, ds model.DataStore, albums model.Albums) ([]string, []string, *time.Time, error) {
-	var folderIDs []string
-	for _, album := range albums {
-		folderIDs = append(folderIDs, album.FolderIDs...)
-	}
-	folders, err := loadFolders(ctx, ds, folderIDs)
-	if err != nil {
-		return nil, nil, nil, err
-	}
-
-	pathByID := slice.ToMap(folders, func(f model.Folder) (string, string) {
-		return f.ID, f.AbsolutePath()
-	})
-	var roots []string
-	for _, album := range albums {
-		var albumPaths []string
-		for _, fid := range album.FolderIDs {
-			if p, ok := pathByID[fid]; ok {
-				albumPaths = append(albumPaths, p)
-			}
-		}
-		if len(albumPaths) > 0 {
-			roots = append(roots, commonDir(albumPaths))
-		}
-	}
-
-	imgFiles, updatedAt := folderImages(folders)
-	return roots, imgFiles, &updatedAt, nil
-}
-
-// commonDir returns the deepest directory containing all paths. Trailing
-// separators keep the comparison on segment boundaries, so a shared name
-// fragment (".../Album" and ".../Album2") is never read as a shared directory.
-func commonDir(paths []string) string {
-	sep := string(filepath.Separator)
-	common := str.LongestCommonPrefix(slice.Map(paths, func(p string) string { return p + sep }))
-	if !strings.HasSuffix(common, sep) {
-		common, _ = filepath.Split(common)
-	}
-	return filepath.Clean(common)
-}
-
-func loadArtistFolder(ctx context.Context, ds model.DataStore, albums model.Albums, paths []string) (string, time.Time, error) {
-	if len(albums) == 0 {
-		return "", time.Time{}, nil
-	}
-	libID := albums[0].LibraryID // Just need one of the albums, as they should all be in the same Library - for now! TODO: Support multiple libraries
-
-	// paths holds one root per album: two or more distinct roots already meet at
-	// the artist folder, while a single root is an album folder needing a climb.
-	roots := slices.Compact(slices.Sorted(slices.Values(paths)))
-	folderPath := commonDir(roots)
-	if len(roots) < 2 {
-		folderPath = filepath.Dir(folderPath)
-	}
-
-	// Manipulate the path to get the folder ID
-	// TODO: This is a bit hacky, but it's the easiest way to get the folder ID, ATM
-	libPath := core.AbsolutePath(ctx, ds, libID, "")
-	folderID := model.FolderID(model.Library{ID: libID, Path: libPath}, folderPath)
-
-	log.Trace(ctx, "Calculating artist folder details", "folderPath", folderPath, "folderID", folderID,
-		"libPath", libPath, "libID", libID, "albumPaths", paths)
-
-	// Get the last update time for the folder
-	folders, err := ds.Folder(ctx).GetAll(model.QueryOptions{Filters: squirrel.Eq{"folder.id": folderID, "missing": false}})
-	if err != nil || len(folders) == 0 {
-		log.Warn(ctx, "Could not find folder for artist", "folderPath", folderPath, "id", folderID,
-			"libPath", libPath, "libID", libID, err)
-		return "", time.Time{}, err
-	}
-	return folderPath, folders[0].ImagesUpdatedAt, nil
-}
-
-func (a *artistReader) fromArtistImageFolder(ctx context.Context) sourceFunc {
-	return func() (io.ReadCloser, string, error) {
-		folder := conf.Server.ArtistImageFolder
-		if folder == "" {
-			return nil, "", nil
-		}
-		// Use cached path from newArtistArtworkReader if available,
-		// avoiding a second directory scan.
-		path := a.imgFolderImgPath
-		if path == "" {
-			path = findImageInArtistFolder(folder, a.artist.MbzArtistID, a.artist.Name)
-		}
-		if path == "" {
-			return nil, "", fmt.Errorf("no image found for artist %q in %s", a.artist.Name, folder)
-		}
-		f, err := os.Open(path)
-		if err != nil {
-			return nil, "", err
-		}
-		return f, path, nil
-	}
-}
-
-// findImageInArtistFolder scans a folder for an image file matching the artist's MBID or name
-// (case-insensitive). Returns the full path, or empty string if not found.
-func findImageInArtistFolder(folder, mbzArtistID, artistName string) string {
-	entries, err := os.ReadDir(folder)
-	if err != nil {
-		return ""
-	}
-	for _, candidate := range []string{mbzArtistID, artistName} {
-		if candidate == "" {
-			continue
-		}
-		for _, entry := range entries {
-			if entry.IsDir() {
-				continue
-			}
-			name := entry.Name()
-			base := strings.TrimSuffix(name, filepath.Ext(name))
-			if strings.EqualFold(base, candidate) && model.IsImageFile(name) {
-				return filepath.Join(folder, name)
-			}
-		}
-	}
-	return ""
-}

core/artwork/reader_artist_test.go

@@ -1,761 +0,0 @@
-package artwork
-
-import (
-	"context"
-	"errors"
-	"io"
-	"io/fs"
-	"os"
-	"path/filepath"
-	"time"
-
-	"github.com/navidrome/navidrome/conf"
-	"github.com/navidrome/navidrome/conf/configtest"
-	"github.com/navidrome/navidrome/core"
-	"github.com/navidrome/navidrome/model"
-	. "github.com/onsi/ginkgo/v2"
-	. "github.com/onsi/gomega"
-)
-
-var _ = Describe("artistArtworkReader", func() {
-	var _ = Describe("loadArtistFolder", func() {
-		var (
-			ctx             context.Context
-			fds             *fakeDataStore
-			repo            *fakeFolderRepo
-			albums          model.Albums
-			paths           []string
-			now             time.Time
-			expectedUpdTime time.Time
-		)
-
-		BeforeEach(func() {
-			ctx = context.Background()
-			DeferCleanup(stubCoreAbsolutePath())
-
-			now = time.Now().Truncate(time.Second)
-			expectedUpdTime = now.Add(5 * time.Minute)
-			repo = &fakeFolderRepo{
-				result: []model.Folder{
-					{
-						ImagesUpdatedAt: expectedUpdTime,
-					},
-				},
-				err: nil,
-			}
-			fds = &fakeDataStore{
-				folderRepo: repo,
-			}
-			albums = model.Albums{
-				{LibraryID: 1, ID: "album1", Name: "Album 1"},
-			}
-		})
-
-		When("no albums provided", func() {
-			It("returns empty and zero time", func() {
-				folder, upd, err := loadArtistFolder(ctx, fds, model.Albums{}, []string{"/dummy/path"})
-				Expect(err).ToNot(HaveOccurred())
-				Expect(folder).To(BeEmpty())
-				Expect(upd).To(BeZero())
-			})
-		})
-
-		When("artist has only one album", func() {
-			It("returns the parent folder", func() {
-				paths = []string{
-					filepath.FromSlash("/music/artist/album1"),
-				}
-				folder, upd, err := loadArtistFolder(ctx, fds, albums, paths)
-				Expect(err).ToNot(HaveOccurred())
-				Expect(folder).To(Equal(filepath.FromSlash("/music/artist")))
-				Expect(upd).To(Equal(expectedUpdTime))
-			})
-		})
-
-		When("the artist have multiple albums", func() {
-			It("returns the common prefix for the albums paths", func() {
-				paths = []string{
-					filepath.FromSlash("/music/library/artist/one"),
-					filepath.FromSlash("/music/library/artist/two"),
-				}
-				folder, upd, err := loadArtistFolder(ctx, fds, albums, paths)
-				Expect(err).ToNot(HaveOccurred())
-				Expect(folder).To(Equal(filepath.FromSlash("/music/library/artist")))
-				Expect(upd).To(Equal(expectedUpdTime))
-			})
-		})
-
-		When("two albums share the same folder", func() {
-			It("climbs above the shared album folder", func() {
-				paths = []string{
-					filepath.FromSlash("/music/artist/split"),
-					filepath.FromSlash("/music/artist/split"),
-				}
-				folder, upd, err := loadArtistFolder(ctx, fds, albums, paths)
-				Expect(err).ToNot(HaveOccurred())
-				Expect(folder).To(Equal(filepath.FromSlash("/music/artist")))
-				Expect(upd).To(Equal(expectedUpdTime))
-			})
-		})
-
-		When("the album paths contain same prefix", func() {
-			It("returns the common prefix", func() {
-				paths = []string{
-					filepath.FromSlash("/music/artist/album1"),
-					filepath.FromSlash("/music/artist/album2"),
-				}
-				folder, upd, err := loadArtistFolder(ctx, fds, albums, paths)
-				Expect(err).ToNot(HaveOccurred())
-				Expect(folder).To(Equal(filepath.FromSlash("/music/artist")))
-				Expect(upd).To(Equal(expectedUpdTime))
-			})
-		})
-
-		When("ds.Folder().GetAll returns an error", func() {
-			It("returns an error", func() {
-				paths = []string{
-					filepath.FromSlash("/music/artist/album1"),
-					filepath.FromSlash("/music/artist/album2"),
-				}
-				repo.err = errors.New("fake error")
-				folder, upd, err := loadArtistFolder(ctx, fds, albums, paths)
-				Expect(err).To(MatchError(ContainSubstring("fake error")))
-				// Folder and time are empty on error.
-				Expect(folder).To(BeEmpty())
-				Expect(upd).To(BeZero())
-			})
-		})
-	})
-
-	var _ = Describe("fromArtistFolder", func() {
-		var (
-			ctx      context.Context
-			tempDir  string
-			libFS    fs.FS
-			testFunc sourceFunc
-		)
-
-		BeforeEach(func() {
-			ctx = context.Background()
-			tempDir = GinkgoT().TempDir()
-			libFS = os.DirFS(tempDir)
-		})
-
-		When("artist folder contains matching image", func() {
-			BeforeEach(func() {
-				// Create test structure: /temp/artist/artist.jpg
-				artistDir := filepath.Join(tempDir, "artist")
-				Expect(os.MkdirAll(artistDir, 0755)).To(Succeed())
-
-				artistImagePath := filepath.Join(artistDir, "artist.jpg")
-				Expect(os.WriteFile(artistImagePath, []byte("fake image data"), 0600)).To(Succeed())
-
-				testFunc = fromArtistFolder(ctx, libFS, tempDir, artistDir, "artist.*")
-			})
-
-			It("finds and returns the image", func() {
-				reader, path, err := testFunc()
-				Expect(err).ToNot(HaveOccurred())
-				Expect(reader).ToNot(BeNil())
-				Expect(path).To(ContainSubstring("artist.jpg"))
-
-				// Verify we can read the content
-				data, err := io.ReadAll(reader)
-				Expect(err).ToNot(HaveOccurred())
-				Expect(string(data)).To(Equal("fake image data"))
-				reader.Close()
-			})
-		})
-
-		When("artist folder name contains glob metacharacters", func() {
-			BeforeEach(func() {
-				artistDir := filepath.Join(tempDir, "Artist [Live]")
-				Expect(os.MkdirAll(artistDir, 0755)).To(Succeed())
-
-				artistImagePath := filepath.Join(artistDir, "artist.jpg")
-				Expect(os.WriteFile(artistImagePath, []byte("bracketed artist image"), 0600)).To(Succeed())
-
-				testFunc = fromArtistFolder(ctx, libFS, tempDir, artistDir, "artist.*")
-			})
-
-			It("treats the folder path literally when globbing through the library fs", func() {
-				reader, path, err := testFunc()
-				Expect(err).ToNot(HaveOccurred())
-				Expect(reader).ToNot(BeNil())
-				Expect(path).To(ContainSubstring("Artist [Live]" + string(filepath.Separator) + "artist.jpg"))
-
-				data, err := io.ReadAll(reader)
-				Expect(err).ToNot(HaveOccurred())
-				Expect(string(data)).To(Equal("bracketed artist image"))
-				reader.Close()
-			})
-		})
-
-		When("artist folder is empty but parent contains image", func() {
-			BeforeEach(func() {
-				// Create test structure: /temp/parent/artist.jpg and /temp/parent/artist/album/
-				parentDir := filepath.Join(tempDir, "parent")
-				artistDir := filepath.Join(parentDir, "artist")
-				albumDir := filepath.Join(artistDir, "album")
-				Expect(os.MkdirAll(albumDir, 0755)).To(Succeed())
-
-				// Put artist image in parent directory
-				artistImagePath := filepath.Join(parentDir, "artist.jpg")
-				Expect(os.WriteFile(artistImagePath, []byte("parent image"), 0600)).To(Succeed())
-
-				testFunc = fromArtistFolder(ctx, libFS, tempDir, artistDir, "artist.*")
-			})
-
-			It("finds image in parent directory", func() {
-				reader, path, err := testFunc()
-				Expect(err).ToNot(HaveOccurred())
-				Expect(reader).ToNot(BeNil())
-				Expect(path).To(ContainSubstring("parent" + string(filepath.Separator) + "artist.jpg"))
-
-				data, err := io.ReadAll(reader)
-				Expect(err).ToNot(HaveOccurred())
-				Expect(string(data)).To(Equal("parent image"))
-				reader.Close()
-			})
-		})
-
-		When("image is two levels up", func() {
-			BeforeEach(func() {
-				// Create test structure: /temp/grandparent/artist.jpg and /temp/grandparent/parent/artist/
-				grandparentDir := filepath.Join(tempDir, "grandparent")
-				parentDir := filepath.Join(grandparentDir, "parent")
-				artistDir := filepath.Join(parentDir, "artist")
-				Expect(os.MkdirAll(artistDir, 0755)).To(Succeed())
-
-				// Put artist image in grandparent directory
-				artistImagePath := filepath.Join(grandparentDir, "artist.jpg")
-				Expect(os.WriteFile(artistImagePath, []byte("grandparent image"), 0600)).To(Succeed())
-
-				testFunc = fromArtistFolder(ctx, libFS, tempDir, artistDir, "artist.*")
-			})
-
-			It("finds image in grandparent directory", func() {
-				reader, path, err := testFunc()
-				Expect(err).ToNot(HaveOccurred())
-				Expect(reader).ToNot(BeNil())
-				Expect(path).To(ContainSubstring("grandparent" + string(filepath.Separator) + "artist.jpg"))
-
-				data, err := io.ReadAll(reader)
-				Expect(err).ToNot(HaveOccurred())
-				Expect(string(data)).To(Equal("grandparent image"))
-				reader.Close()
-			})
-		})
-
-		When("images exist at multiple levels", func() {
-			BeforeEach(func() {
-				// Create test structure with images at multiple levels
-				grandparentDir := filepath.Join(tempDir, "grandparent")
-				parentDir := filepath.Join(grandparentDir, "parent")
-				artistDir := filepath.Join(parentDir, "artist")
-				Expect(os.MkdirAll(artistDir, 0755)).To(Succeed())
-
-				// Put artist images at all levels
-				Expect(os.WriteFile(filepath.Join(artistDir, "artist.jpg"), []byte("artist level"), 0600)).To(Succeed())
-				Expect(os.WriteFile(filepath.Join(parentDir, "artist.jpg"), []byte("parent level"), 0600)).To(Succeed())
-				Expect(os.WriteFile(filepath.Join(grandparentDir, "artist.jpg"), []byte("grandparent level"), 0600)).To(Succeed())
-
-				testFunc = fromArtistFolder(ctx, libFS, tempDir, artistDir, "artist.*")
-			})
-
-			It("prioritizes the closest (artist folder) image", func() {
-				reader, path, err := testFunc()
-				Expect(err).ToNot(HaveOccurred())
-				Expect(reader).ToNot(BeNil())
-				Expect(path).To(ContainSubstring("artist" + string(filepath.Separator) + "artist.jpg"))
-
-				data, err := io.ReadAll(reader)
-				Expect(err).ToNot(HaveOccurred())
-				Expect(string(data)).To(Equal("artist level"))
-				reader.Close()
-			})
-		})
-
-		When("pattern matches multiple files", func() {
-			BeforeEach(func() {
-				artistDir := filepath.Join(tempDir, "artist")
-				Expect(os.MkdirAll(artistDir, 0755)).To(Succeed())
-
-				// Create multiple matching files
-				Expect(os.WriteFile(filepath.Join(artistDir, "artist.abc"), []byte("text file"), 0600)).To(Succeed())
-				Expect(os.WriteFile(filepath.Join(artistDir, "artist.png"), []byte("png image"), 0600)).To(Succeed())
-				Expect(os.WriteFile(filepath.Join(artistDir, "artist.jpg"), []byte("jpg image"), 0600)).To(Succeed())
-
-				testFunc = fromArtistFolder(ctx, libFS, tempDir, artistDir, "artist.*")
-			})
-
-			It("returns the first valid image file in sorted order", func() {
-				reader, path, err := testFunc()
-				Expect(err).ToNot(HaveOccurred())
-				Expect(reader).ToNot(BeNil())
-
-				// Should return an image file,
-				// Files are sorted: jpg comes before png alphabetically.
-				// .abc comes first, but it's not an image.
-				Expect(path).To(ContainSubstring("artist.jpg"))
-				reader.Close()
-			})
-		})
-
-		When("prioritizing files without numeric suffixes", func() {
-			BeforeEach(func() {
-				// Test case for issue #4683: artist.jpg should come before artist.1.jpg
-				artistDir := filepath.Join(tempDir, "artist")
-				Expect(os.MkdirAll(artistDir, 0755)).To(Succeed())
-
-				// Create multiple matches with and without numeric suffixes
-				Expect(os.WriteFile(filepath.Join(artistDir, "artist.1.jpg"), []byte("artist 1"), 0600)).To(Succeed())
-				Expect(os.WriteFile(filepath.Join(artistDir, "artist.jpg"), []byte("artist main"), 0600)).To(Succeed())
-				Expect(os.WriteFile(filepath.Join(artistDir, "artist.2.jpg"), []byte("artist 2"), 0600)).To(Succeed())
-
-				testFunc = fromArtistFolder(ctx, libFS, tempDir, artistDir, "artist.*")
-			})
-
-			It("returns artist.jpg before artist.1.jpg and artist.2.jpg", func() {
-				reader, path, err := testFunc()
-				Expect(err).ToNot(HaveOccurred())
-				Expect(reader).ToNot(BeNil())
-				Expect(path).To(ContainSubstring("artist.jpg"))
-
-				// Verify it's the main file, not a numbered variant
-				data, err := io.ReadAll(reader)
-				Expect(err).ToNot(HaveOccurred())
-				Expect(string(data)).To(Equal("artist main"))
-				reader.Close()
-			})
-		})
-
-		When("handling case-insensitive sorting", func() {
-			BeforeEach(func() {
-				// Test case to ensure case-insensitive natural sorting
-				artistDir := filepath.Join(tempDir, "artist")
-				Expect(os.MkdirAll(artistDir, 0755)).To(Succeed())
-
-				// Create files with mixed case names
-				Expect(os.WriteFile(filepath.Join(artistDir, "Folder.jpg"), []byte("folder"), 0600)).To(Succeed())
-				Expect(os.WriteFile(filepath.Join(artistDir, "artist.jpg"), []byte("artist"), 0600)).To(Succeed())
-				Expect(os.WriteFile(filepath.Join(artistDir, "BACK.jpg"), []byte("back"), 0600)).To(Succeed())
-
-				testFunc = fromArtistFolder(ctx, libFS, tempDir, artistDir, "*.*")
-			})
-
-			It("sorts case-insensitively", func() {
-				reader, path, err := testFunc()
-				Expect(err).ToNot(HaveOccurred())
-				Expect(reader).ToNot(BeNil())
-
-				// Should return artist.jpg first (case-insensitive: "artist" < "back" < "folder")
-				Expect(path).To(ContainSubstring("artist.jpg"))
-
-				data, err := io.ReadAll(reader)
-				Expect(err).ToNot(HaveOccurred())
-				Expect(string(data)).To(Equal("artist"))
-				reader.Close()
-			})
-		})
-
-		When("no matching files exist anywhere", func() {
-			BeforeEach(func() {
-				artistDir := filepath.Join(tempDir, "artist")
-				Expect(os.MkdirAll(artistDir, 0755)).To(Succeed())
-
-				// Create non-matching files
-				Expect(os.WriteFile(filepath.Join(artistDir, "cover.jpg"), []byte("cover image"), 0600)).To(Succeed())
-
-				testFunc = fromArtistFolder(ctx, libFS, tempDir, artistDir, "artist.*")
-			})
-
-			It("returns an error", func() {
-				reader, path, err := testFunc()
-				Expect(err).To(HaveOccurred())
-				Expect(reader).To(BeNil())
-				Expect(path).To(BeEmpty())
-				Expect(err.Error()).To(ContainSubstring("no matches for 'artist.*'"))
-				Expect(err.Error()).To(ContainSubstring("parent directories"))
-			})
-		})
-
-		When("directory traversal reaches filesystem root", func() {
-			BeforeEach(func() {
-				// Start from a shallow directory to test root boundary
-				artistDir := filepath.Join(tempDir, "artist")
-				Expect(os.MkdirAll(artistDir, 0755)).To(Succeed())
-
-				testFunc = fromArtistFolder(ctx, libFS, tempDir, artistDir, "artist.*")
-			})
-
-			It("handles root boundary gracefully", func() {
-				reader, path, err := testFunc()
-				Expect(err).To(HaveOccurred())
-				Expect(reader).To(BeNil())
-				Expect(path).To(BeEmpty())
-				// Should not panic or cause infinite loop
-			})
-		})
-
-		When("file exists but cannot be opened", func() {
-			BeforeEach(func() {
-				artistDir := filepath.Join(tempDir, "artist")
-				Expect(os.MkdirAll(artistDir, 0755)).To(Succeed())
-
-				// Create a file that cannot be opened (permission denied)
-				restrictedFile := filepath.Join(artistDir, "artist.jpg")
-				Expect(os.WriteFile(restrictedFile, []byte("restricted"), 0600)).To(Succeed())
-
-				testFunc = fromArtistFolder(ctx, libFS, tempDir, artistDir, "artist.*")
-			})
-
-			It("logs warning and continues searching", func() {
-				// This test depends on the ability to restrict file permissions
-				// For now, we'll just ensure it doesn't panic and returns appropriate error
-				reader, _, err := testFunc()
-				// The file should be readable in test environment, so this will succeed
-				// In a real scenario with permission issues, it would continue searching
-				if err == nil {
-					Expect(reader).ToNot(BeNil())
-					reader.Close()
-				}
-			})
-		})
-
-		When("single album artist scenario (original issue)", func() {
-			BeforeEach(func() {
-				// Simulate the exact folder structure from the issue:
-				// /music/artist/album1/ (single album)
-				// /music/artist/artist.jpg (artist image that should be found)
-				artistDir := filepath.Join(tempDir, "music", "artist")
-				albumDir := filepath.Join(artistDir, "album1")
-				Expect(os.MkdirAll(albumDir, 0755)).To(Succeed())
-
-				// Create artist.jpg in the artist folder (this was not being found before)
-				artistImagePath := filepath.Join(artistDir, "artist.jpg")
-				Expect(os.WriteFile(artistImagePath, []byte("single album artist image"), 0600)).To(Succeed())
-
-				// The fromArtistFolder is called with the artist folder path
-				testFunc = fromArtistFolder(ctx, libFS, tempDir, artistDir, "artist.*")
-			})
-
-			It("finds artist.jpg in artist folder for single album artist", func() {
-				reader, path, err := testFunc()
-				Expect(err).ToNot(HaveOccurred())
-				Expect(reader).ToNot(BeNil())
-				Expect(path).To(ContainSubstring("artist.jpg"))
-				Expect(path).To(ContainSubstring("artist"))
-
-				// Verify the content
-				data, err := io.ReadAll(reader)
-				Expect(err).ToNot(HaveOccurred())
-				Expect(string(data)).To(Equal("single album artist image"))
-				reader.Close()
-			})
-		})
-	})
-
-	Describe("fromArtistUploadedImage", func() {
-		var (
-			tempDir string
-			reader  *artistReader
-		)
-
-		BeforeEach(func() {
-			DeferCleanup(configtest.SetupConfig())
-			tempDir = GinkgoT().TempDir()
-			conf.Server.DataFolder = conf.NewDir(tempDir)
-
-			// Create the artwork/artist directory
-			Expect(os.MkdirAll(filepath.Join(tempDir, "artwork", "artist"), 0755)).To(Succeed())
-
-			reader = &artistReader{}
-		})
-
-		When("artist has an uploaded image", func() {
-			It("returns the uploaded image", func() {
-				imgPath := filepath.Join(tempDir, "artwork", "artist", "ar-1_test.jpg")
-				Expect(os.WriteFile(imgPath, []byte("uploaded artist image"), 0600)).To(Succeed())
-
-				reader.artist = model.Artist{ID: "ar-1", UploadedImage: "ar-1_test.jpg"}
-				sf := reader.fromArtistUploadedImage()
-				r, path, err := sf()
-				Expect(err).ToNot(HaveOccurred())
-				Expect(r).ToNot(BeNil())
-				Expect(path).To(Equal(imgPath))
-
-				data, err := io.ReadAll(r)
-				Expect(err).ToNot(HaveOccurred())
-				Expect(string(data)).To(Equal("uploaded artist image"))
-				r.Close()
-			})
-		})
-
-		When("artist has no uploaded image", func() {
-			It("returns nil reader (falls through)", func() {
-				reader.artist = model.Artist{ID: "ar-1"}
-				sf := reader.fromArtistUploadedImage()
-				r, path, err := sf()
-				Expect(err).ToNot(HaveOccurred())
-				Expect(r).To(BeNil())
-				Expect(path).To(BeEmpty())
-			})
-		})
-	})
-
-	Describe("fromArtistImageFolder", func() {
-		var (
-			ctx     context.Context
-			tempDir string
-			ar      *artistReader
-		)
-
-		BeforeEach(func() {
-			ctx = context.Background()
-			DeferCleanup(configtest.SetupConfig())
-			tempDir = GinkgoT().TempDir()
-			ar = &artistReader{}
-		})
-
-		When("ArtistImageFolder is not configured", func() {
-			It("returns nil (skips)", func() {
-				conf.Server.ArtistImageFolder = ""
-				ar.artist = model.Artist{Name: "Test Artist"}
-				sf := ar.fromArtistImageFolder(ctx)
-				r, path, err := sf()
-				Expect(err).ToNot(HaveOccurred())
-				Expect(r).To(BeNil())
-				Expect(path).To(BeEmpty())
-			})
-		})
-
-		When("image exists matching MBID", func() {
-			It("finds the image by MBID", func() {
-				conf.Server.ArtistImageFolder = tempDir
-				mbid := "f27ec8db-af05-4f36-916e-3d57f91ecf5e"
-				imgPath := filepath.Join(tempDir, mbid+".jpg")
-				Expect(os.WriteFile(imgPath, []byte("mbid image"), 0600)).To(Succeed())
-
-				ar.artist = model.Artist{Name: "Test Artist", MbzArtistID: mbid}
-				sf := ar.fromArtistImageFolder(ctx)
-				r, path, err := sf()
-				Expect(err).ToNot(HaveOccurred())
-				Expect(r).ToNot(BeNil())
-				Expect(path).To(Equal(imgPath))
-
-				data, err := io.ReadAll(r)
-				Expect(err).ToNot(HaveOccurred())
-				Expect(string(data)).To(Equal("mbid image"))
-				r.Close()
-			})
-		})
-
-		When("MBID match is case-insensitive", func() {
-			It("finds the image regardless of case", func() {
-				conf.Server.ArtistImageFolder = tempDir
-				mbid := "F27EC8DB-AF05-4F36-916E-3D57F91ECF5E"
-				imgPath := filepath.Join(tempDir, "f27ec8db-af05-4f36-916e-3d57f91ecf5e.png")
-				Expect(os.WriteFile(imgPath, []byte("mbid case image"), 0600)).To(Succeed())
-
-				ar.artist = model.Artist{Name: "Test Artist", MbzArtistID: mbid}
-				sf := ar.fromArtistImageFolder(ctx)
-				r, path, err := sf()
-				Expect(err).ToNot(HaveOccurred())
-				Expect(r).ToNot(BeNil())
-				Expect(path).To(Equal(imgPath))
-				r.Close()
-			})
-		})
-
-		When("no MBID file exists but artist name file does", func() {
-			It("falls back to artist name match", func() {
-				conf.Server.ArtistImageFolder = tempDir
-				imgPath := filepath.Join(tempDir, "Test Artist.jpg")
-				Expect(os.WriteFile(imgPath, []byte("name image"), 0600)).To(Succeed())
-
-				ar.artist = model.Artist{Name: "Test Artist", MbzArtistID: "nonexistent-mbid"}
-				sf := ar.fromArtistImageFolder(ctx)
-				r, path, err := sf()
-				Expect(err).ToNot(HaveOccurred())
-				Expect(r).ToNot(BeNil())
-				Expect(path).To(Equal(imgPath))
-
-				data, err := io.ReadAll(r)
-				Expect(err).ToNot(HaveOccurred())
-				Expect(string(data)).To(Equal("name image"))
-				r.Close()
-			})
-		})
-
-		When("artist name match is case-insensitive", func() {
-			It("matches regardless of case", func() {
-				conf.Server.ArtistImageFolder = tempDir
-				imgPath := filepath.Join(tempDir, "test artist.jpg")
-				Expect(os.WriteFile(imgPath, []byte("case insensitive"), 0600)).To(Succeed())
-
-				ar.artist = model.Artist{Name: "Test Artist"}
-				sf := ar.fromArtistImageFolder(ctx)
-				r, path, err := sf()
-				Expect(err).ToNot(HaveOccurred())
-				Expect(r).ToNot(BeNil())
-				Expect(path).To(Equal(imgPath))
-				r.Close()
-			})
-		})
-
-		When("both MBID and name files exist", func() {
-			It("prefers MBID over name match", func() {
-				conf.Server.ArtistImageFolder = tempDir
-				mbid := "f27ec8db-af05-4f36-916e-3d57f91ecf5e"
-				mbidPath := filepath.Join(tempDir, mbid+".jpg")
-				namePath := filepath.Join(tempDir, "Test Artist.jpg")
-				Expect(os.WriteFile(mbidPath, []byte("mbid image"), 0600)).To(Succeed())
-				Expect(os.WriteFile(namePath, []byte("name image"), 0600)).To(Succeed())
-
-				ar.artist = model.Artist{Name: "Test Artist", MbzArtistID: mbid}
-				sf := ar.fromArtistImageFolder(ctx)
-				r, path, err := sf()
-				Expect(err).ToNot(HaveOccurred())
-				Expect(r).ToNot(BeNil())
-				Expect(path).To(Equal(mbidPath))
-
-				data, err := io.ReadAll(r)
-				Expect(err).ToNot(HaveOccurred())
-				Expect(string(data)).To(Equal("mbid image"))
-				r.Close()
-			})
-		})
-
-		When("no matching image found", func() {
-			It("returns an error", func() {
-				conf.Server.ArtistImageFolder = tempDir
-				// Create an unrelated file
-				Expect(os.WriteFile(filepath.Join(tempDir, "other.jpg"), []byte("other"), 0600)).To(Succeed())
-
-				ar.artist = model.Artist{Name: "Test Artist"}
-				sf := ar.fromArtistImageFolder(ctx)
-				r, _, err := sf()
-				Expect(err).To(HaveOccurred())
-				Expect(r).To(BeNil())
-				Expect(err.Error()).To(ContainSubstring("no image found"))
-			})
-		})
-
-		When("cached imgFolderImgPath is set", func() {
-			It("uses cached path instead of scanning", func() {
-				conf.Server.ArtistImageFolder = tempDir
-				imgPath := filepath.Join(tempDir, "cached.jpg")
-				Expect(os.WriteFile(imgPath, []byte("cached image"), 0600)).To(Succeed())
-
-				ar.artist = model.Artist{Name: "Test Artist"}
-				ar.imgFolderImgPath = imgPath
-				sf := ar.fromArtistImageFolder(ctx)
-				r, path, err := sf()
-				Expect(err).ToNot(HaveOccurred())
-				Expect(r).ToNot(BeNil())
-				Expect(path).To(Equal(imgPath))
-
-				data, err := io.ReadAll(r)
-				Expect(err).ToNot(HaveOccurred())
-				Expect(string(data)).To(Equal("cached image"))
-				r.Close()
-			})
-		})
-	})
-
-	Describe("findImageInArtistFolder", func() {
-		var tempDir string
-
-		BeforeEach(func() {
-			tempDir = GinkgoT().TempDir()
-		})
-
-		When("matching file exists by MBID", func() {
-			It("returns the file path", func() {
-				mbid := "f27ec8db-af05-4f36-916e-3d57f91ecf5e"
-				imgPath := filepath.Join(tempDir, mbid+".jpg")
-				Expect(os.WriteFile(imgPath, []byte("image"), 0600)).To(Succeed())
-
-				path := findImageInArtistFolder(tempDir, mbid, "Test")
-				Expect(path).To(Equal(imgPath))
-			})
-		})
-
-		When("matching file exists by name", func() {
-			It("returns the file path", func() {
-				imgPath := filepath.Join(tempDir, "Test Artist.png")
-				Expect(os.WriteFile(imgPath, []byte("image"), 0600)).To(Succeed())
-
-				path := findImageInArtistFolder(tempDir, "", "Test Artist")
-				Expect(path).To(Equal(imgPath))
-			})
-		})
-
-		When("no matching file exists", func() {
-			It("returns empty string", func() {
-				path := findImageInArtistFolder(tempDir, "", "Unknown Artist")
-				Expect(path).To(BeEmpty())
-			})
-		})
-
-		When("folder does not exist", func() {
-			It("returns empty string", func() {
-				path := findImageInArtistFolder("/nonexistent/path", "", "Test")
-				Expect(path).To(BeEmpty())
-			})
-		})
-	})
-})
-
-type fakeFolderRepo struct {
-	model.FolderRepository
-	result       []model.Folder
-	parentResult *model.Folder
-	getErr       error
-	getCallCount int
-	err          error
-	// hasOtherAudio is returned by HasAudioOutsideFolders (the album-root
-	// check). False means the parent qualifies as an album root.
-	hasOtherAudio bool
-	otherAudioErr error
-}
-
-func (f *fakeFolderRepo) GetAll(...model.QueryOptions) ([]model.Folder, error) {
-	return f.result, f.err
-}
-
-func (f *fakeFolderRepo) HasAudioOutsideFolders(model.Folder, []string) (bool, error) {
-	return f.hasOtherAudio, f.otherAudioErr
-}
-
-func (f *fakeFolderRepo) Get(id string) (*model.Folder, error) {
-	f.getCallCount++
-	if f.getErr != nil {
-		return nil, f.getErr
-	}
-	if f.parentResult != nil {
-		return f.parentResult, nil
-	}
-	return nil, model.ErrNotFound
-}
-
-type fakeDataStore struct {
-	model.DataStore
-	folderRepo *fakeFolderRepo
-}
-
-func (fds *fakeDataStore) Folder(_ context.Context) model.FolderRepository {
-	return fds.folderRepo
-}
-
-func stubCoreAbsolutePath() func() {
-	// Override core.AbsolutePath to return a fixed string during tests.
-	original := core.AbsolutePath
-	core.AbsolutePath = func(_ context.Context, ds model.DataStore, libID int, p string) string {
-		return filepath.FromSlash("/music")
-	}
-	return func() {
-		core.AbsolutePath = original
-	}
-}

core/artwork/reader_mediafile.go

@@ -1,82 +0,0 @@
-package artwork
-
-import (
-	"context"
-	"fmt"
-	"io"
-	"time"
-
-	"github.com/navidrome/navidrome/conf"
-	"github.com/navidrome/navidrome/model"
-)
-
-type mediafileArtworkReader struct {
-	cacheKey
-	a         *artwork
-	mediafile model.MediaFile
-	album     model.Album
-	lib       libraryView
-}
-
-func newMediafileArtworkReader(ctx context.Context, artwork *artwork, artID model.ArtworkID) (*mediafileArtworkReader, error) {
-	mf, err := artwork.ds.MediaFile(ctx).Get(artID.ID)
-	if err != nil {
-		return nil, err
-	}
-	al, err := artwork.ds.Album(ctx).Get(mf.AlbumID)
-	if err != nil {
-		return nil, err
-	}
-	_, _, imagesUpdatedAt, err := loadAlbumFoldersPaths(ctx, artwork.ds, *al)
-	if err != nil {
-		return nil, err
-	}
-	lib, err := loadLibraryView(ctx, artwork.ds, mf.LibraryID)
-	if err != nil {
-		return nil, err
-	}
-	a := &mediafileArtworkReader{
-		a:         artwork,
-		mediafile: *mf,
-		album:     *al,
-		lib:       lib,
-	}
-	a.cacheKey.artID = artID
-	a.cacheKey.lastUpdate = mf.UpdatedAt
-	if al.UpdatedAt.After(a.cacheKey.lastUpdate) {
-		a.cacheKey.lastUpdate = al.UpdatedAt
-	}
-	if imagesUpdatedAt != nil && imagesUpdatedAt.After(a.cacheKey.lastUpdate) {
-		a.cacheKey.lastUpdate = *imagesUpdatedAt
-	}
-	return a, nil
-}
-
-func (a *mediafileArtworkReader) Key() string {
-	return fmt.Sprintf(
-		"%s.%t",
-		a.cacheKey.Key(),
-		conf.Server.EnableMediaFileCoverArt,
-	)
-}
-func (a *mediafileArtworkReader) LastUpdated() time.Time {
-	return a.lastUpdate
-}
-
-func (a *mediafileArtworkReader) Reader(ctx context.Context) (io.ReadCloser, string, error) {
-	var ff []sourceFunc
-	if a.mediafile.CoverArtID().Kind == model.KindMediaFileArtwork {
-		ff = []sourceFunc{
-			fromTag(ctx, a.lib.FS, a.mediafile.Path),
-			fromFFmpegTag(ctx, a.a.ffmpeg, a.lib.Abs(a.mediafile.Path)),
-		}
-	}
-	// For multi-disc albums, fall back to disc artwork first; for single-disc albums,
-	// skip disc resolution (it would just fall through to album art anyway).
-	if len(a.album.Discs) > 1 {
-		ff = append(ff, fromAlbum(ctx, a.a, a.mediafile.DiscCoverArtID()))
-	} else {
-		ff = append(ff, fromAlbum(ctx, a.a, a.mediafile.AlbumCoverArtID()))
-	}
-	return selectImageReader(ctx, a.artID, ff...)
-}

core/artwork/reader_playlist.go

@@ -1,269 +0,0 @@
-package artwork
-
-import (
-	"bytes"
-	"context"
-	"errors"
-	"image"
-	"image/draw"
-	"image/png"
-	"io"
-	"net/url"
-	"os"
-	"path/filepath"
-	"strings"
-	"time"
-
-	"github.com/navidrome/navidrome/conf"
-	"github.com/navidrome/navidrome/log"
-	"github.com/navidrome/navidrome/model"
-	"github.com/navidrome/navidrome/utils/slice"
-	xdraw "golang.org/x/image/draw"
-)
-
-type playlistArtworkReader struct {
-	cacheKey
-	a  *artwork
-	pl model.Playlist
-}
-
-const tileSize = 600
-
-func newPlaylistArtworkReader(ctx context.Context, artwork *artwork, artID model.ArtworkID) (*playlistArtworkReader, error) {
-	pl, err := artwork.ds.Playlist(ctx).Get(artID.ID)
-	if err != nil {
-		return nil, err
-	}
-	a := &playlistArtworkReader{
-		a:  artwork,
-		pl: *pl,
-	}
-	a.cacheKey.artID = artID
-	a.cacheKey.lastUpdate = pl.UpdatedAt
-
-	// Check sidecar and ExternalImageURL local file ModTimes for cache invalidation.
-	// If either is newer than the playlist's UpdatedAt, use that instead so the
-	// cache is busted when a user replaces a sidecar image or local file reference.
-	for _, path := range []string{
-		findPlaylistSidecarPath(ctx, pl.Path),
-		pl.ExternalImageURL,
-	} {
-		if path == "" || strings.HasPrefix(path, "http://") || strings.HasPrefix(path, "https://") {
-			continue
-		}
-		if info, err := os.Stat(path); err == nil {
-			if info.ModTime().After(a.cacheKey.lastUpdate) {
-				a.cacheKey.lastUpdate = info.ModTime()
-			}
-		}
-	}
-
-	return a, nil
-}
-
-func (a *playlistArtworkReader) LastUpdated() time.Time {
-	return a.lastUpdate
-}
-
-func (a *playlistArtworkReader) Reader(ctx context.Context) (io.ReadCloser, string, error) {
-	return selectImageReader(ctx, a.artID,
-		a.fromPlaylistUploadedImage(),
-		a.fromPlaylistSidecar(ctx),
-		a.fromPlaylistExternalImage(ctx),
-		a.fromGeneratedTiledCover(ctx),
-		fromAlbumPlaceholder(),
-	)
-}
-
-func (a *playlistArtworkReader) fromPlaylistUploadedImage() sourceFunc {
-	return fromLocalFile(a.pl.UploadedImagePath())
-}
-
-func (a *playlistArtworkReader) fromPlaylistSidecar(ctx context.Context) sourceFunc {
-	return fromLocalFile(findPlaylistSidecarPath(ctx, a.pl.Path))
-}
-
-func (a *playlistArtworkReader) fromPlaylistExternalImage(ctx context.Context) sourceFunc {
-	return func() (io.ReadCloser, string, error) {
-		imgURL := a.pl.ExternalImageURL
-		if imgURL == "" {
-			return nil, "", nil
-		}
-		parsed, err := url.Parse(imgURL)
-		if err != nil {
-			return nil, "", err
-		}
-		if parsed.Scheme == "http" || parsed.Scheme == "https" {
-			if !conf.Server.EnableM3UExternalAlbumArt {
-				return nil, "", nil
-			}
-			return fromURL(ctx, parsed)
-		}
-		return fromLocalFile(imgURL)()
-	}
-}
-
-// fromLocalFile returns a sourceFunc that opens the given local path.
-// Returns (nil, "", nil) if path is empty — signalling "not found, try next source".
-func fromLocalFile(path string) sourceFunc {
-	return func() (io.ReadCloser, string, error) {
-		if path == "" {
-			return nil, "", nil
-		}
-		f, err := os.Open(path)
-		if err != nil {
-			return nil, "", err
-		}
-		return f, path, nil
-	}
-}
-
-// findPlaylistSidecarPath scans the directory of the playlist file for a sidecar
-// image file with the same base name (case-insensitive). Returns empty string if
-// no matching image is found or if plsPath is empty.
-func findPlaylistSidecarPath(ctx context.Context, plsPath string) string {
-	if plsPath == "" {
-		return ""
-	}
-	dir := filepath.Dir(plsPath)
-	base := strings.TrimSuffix(filepath.Base(plsPath), filepath.Ext(plsPath))
-
-	entries, err := os.ReadDir(dir)
-	if err != nil {
-		log.Warn(ctx, "Could not read directory for playlist sidecar", "dir", dir, err)
-		return ""
-	}
-	for _, entry := range entries {
-		name := entry.Name()
-		nameBase := strings.TrimSuffix(name, filepath.Ext(name))
-		if !entry.IsDir() && strings.EqualFold(nameBase, base) && model.IsImageFile(name) {
-			return filepath.Join(dir, name)
-		}
-	}
-	return ""
-}
-
-func (a *playlistArtworkReader) fromGeneratedTiledCover(ctx context.Context) sourceFunc {
-	return func() (io.ReadCloser, string, error) {
-		tiles, err := a.loadTiles(ctx)
-		if err != nil {
-			return nil, "", err
-		}
-		r, err := a.createTiledImage(ctx, tiles)
-		return r, "", err
-	}
-}
-
-func toAlbumArtworkIDs(albumIDs []string) []model.ArtworkID {
-	return slice.Map(albumIDs, func(id string) model.ArtworkID {
-		al := model.Album{ID: id}
-		return al.CoverArtID()
-	})
-}
-
-func (a *playlistArtworkReader) loadTiles(ctx context.Context) ([]image.Image, error) {
-	tracksRepo := a.a.ds.Playlist(ctx).Tracks(a.pl.ID, false)
-	albumIds, err := tracksRepo.GetAlbumIDs(model.QueryOptions{Max: 4, Sort: "random()"})
-	if err != nil {
-		log.Error(ctx, "Error getting album IDs for playlist", "id", a.pl.ID, "name", a.pl.Name, err)
-		return nil, err
-	}
-	ids := toAlbumArtworkIDs(albumIds)
-
-	var tiles []image.Image
-	for _, id := range ids {
-		r, _, err := fromAlbum(ctx, a.a, id)()
-		if err == nil {
-			tile, err := a.createTile(ctx, r)
-			if err == nil {
-				tiles = append(tiles, tile)
-			}
-			_ = r.Close()
-		}
-		if len(tiles) == 4 {
-			break
-		}
-	}
-	switch len(tiles) {
-	case 0:
-		return nil, errors.New("could not find any eligible cover")
-	case 2:
-		tiles = append(tiles, tiles[1], tiles[0])
-	case 3:
-		tiles = append(tiles, tiles[0])
-	}
-	return tiles, nil
-}
-
-func (a *playlistArtworkReader) createTile(_ context.Context, r io.ReadCloser) (image.Image, error) {
-	img, _, err := image.Decode(r)
-	if err != nil {
-		return nil, err
-	}
-	return fillCenter(img, tileSize/2, tileSize/2), nil
-}
-
-func (a *playlistArtworkReader) createTiledImage(_ context.Context, tiles []image.Image) (io.ReadCloser, error) {
-	buf := new(bytes.Buffer)
-	var rgba draw.Image
-	var err error
-	if len(tiles) == 4 {
-		rgba = image.NewRGBA(image.Rectangle{Max: image.Point{X: tileSize - 1, Y: tileSize - 1}})
-		draw.Draw(rgba, rect(0), tiles[0], image.Point{}, draw.Src)
-		draw.Draw(rgba, rect(1), tiles[1], image.Point{}, draw.Src)
-		draw.Draw(rgba, rect(2), tiles[2], image.Point{}, draw.Src)
-		draw.Draw(rgba, rect(3), tiles[3], image.Point{}, draw.Src)
-		err = png.Encode(buf, rgba)
-	} else {
-		err = png.Encode(buf, tiles[0])
-	}
-	if err != nil {
-		return nil, err
-	}
-	return io.NopCloser(buf), nil
-}
-
-func rect(pos int) image.Rectangle {
-	r := image.Rectangle{}
-	switch pos {
-	case 1:
-		r.Min.X = tileSize / 2
-	case 2:
-		r.Min.Y = tileSize / 2
-	case 3:
-		r.Min.X = tileSize / 2
-		r.Min.Y = tileSize / 2
-	}
-	r.Max.X = r.Min.X + tileSize/2
-	r.Max.Y = r.Min.Y + tileSize/2
-	return r
-}
-
-// fillCenter crops the source image from the center and scales it to fill dstW x dstH exactly,
-// equivalent to imaging.Fill with Center anchor.
-func fillCenter(src image.Image, dstW, dstH int) image.Image {
-	srcBounds := src.Bounds()
-	srcW := srcBounds.Dx()
-	srcH := srcBounds.Dy()
-
-	// Calculate crop rectangle (center crop to match destination aspect ratio)
-	srcAspect := float64(srcW) / float64(srcH)
-	dstAspect := float64(dstW) / float64(dstH)
-
-	var cropRect image.Rectangle
-	if srcAspect > dstAspect {
-		// Source is wider — crop horizontally
-		cropW := int(float64(srcH) * dstAspect)
-		cropX := (srcW - cropW) / 2
-		cropRect = image.Rect(srcBounds.Min.X+cropX, srcBounds.Min.Y, srcBounds.Min.X+cropX+cropW, srcBounds.Max.Y)
-	} else {
-		// Source is taller — crop vertically
-		cropH := int(float64(srcW) / dstAspect)
-		cropY := (srcH - cropH) / 2
-		cropRect = image.Rect(srcBounds.Min.X, srcBounds.Min.Y+cropY, srcBounds.Max.X, srcBounds.Min.Y+cropY+cropH)
-	}
-
-	dst := image.NewNRGBA(image.Rect(0, 0, dstW, dstH))
-	xdraw.CatmullRom.Scale(dst, dst.Bounds(), src, cropRect, draw.Src, nil)
-	return dst
-}

core/artwork/reader_radio.go

@@ -1,40 +0,0 @@
-package artwork
-
-import (
-	"context"
-	"io"
-	"time"
-
-	"github.com/navidrome/navidrome/model"
-)
-
-type radioArtworkReader struct {
-	cacheKey
-	a     *artwork
-	radio model.Radio
-}
-
-func newRadioArtworkReader(ctx context.Context, artwork *artwork, artID model.ArtworkID) (*radioArtworkReader, error) {
-	r, err := artwork.ds.Radio(ctx).Get(artID.ID)
-	if err != nil {
-		return nil, err
-	}
-	a := &radioArtworkReader{a: artwork, radio: *r}
-	a.cacheKey.artID = artID
-	a.cacheKey.lastUpdate = r.UpdatedAt
-	return a, nil
-}
-
-func (a *radioArtworkReader) LastUpdated() time.Time {
-	return a.lastUpdate
-}
-
-func (a *radioArtworkReader) Reader(ctx context.Context) (io.ReadCloser, string, error) {
-	return selectImageReader(ctx, a.artID,
-		a.fromRadioUploadedImage(),
-	)
-}
-
-func (a *radioArtworkReader) fromRadioUploadedImage() sourceFunc {
-	return fromLocalFile(a.radio.UploadedImagePath())
-}

core/artwork/reader_radio_test.go

@@ -1,84 +0,0 @@
-package artwork
-
-import (
-	"context"
-	"os"
-	"path/filepath"
-
-	"github.com/navidrome/navidrome/conf"
-	"github.com/navidrome/navidrome/conf/configtest"
-	"github.com/navidrome/navidrome/model"
-	. "github.com/onsi/ginkgo/v2"
-	. "github.com/onsi/gomega"
-)
-
-var _ = Describe("radioArtworkReader", func() {
-	var (
-		tempDir string
-		reader  *radioArtworkReader
-	)
-
-	BeforeEach(func() {
-		DeferCleanup(configtest.SetupConfig())
-		tempDir = GinkgoT().TempDir()
-		conf.Server.DataFolder = conf.NewDir(tempDir)
-
-		Expect(os.MkdirAll(filepath.Join(tempDir, "artwork", "radio"), 0755)).To(Succeed())
-
-		reader = &radioArtworkReader{}
-	})
-
-	Describe("fromRadioUploadedImage", func() {
-		When("radio has an uploaded image", func() {
-			It("returns the uploaded image", func() {
-				imgPath := filepath.Join(tempDir, "artwork", "radio", "rd-1_test.jpg")
-				Expect(os.WriteFile(imgPath, []byte("uploaded radio image"), 0600)).To(Succeed())
-
-				reader.radio = model.Radio{ID: "rd-1", UploadedImage: "rd-1_test.jpg"}
-				sf := reader.fromRadioUploadedImage()
-				r, path, err := sf()
-				Expect(err).ToNot(HaveOccurred())
-				Expect(r).ToNot(BeNil())
-				Expect(path).To(Equal(imgPath))
-				r.Close()
-			})
-		})
-
-		When("radio has no uploaded image", func() {
-			It("returns nil reader (falls through)", func() {
-				reader.radio = model.Radio{ID: "rd-1"}
-				sf := reader.fromRadioUploadedImage()
-				r, path, err := sf()
-				Expect(err).ToNot(HaveOccurred())
-				Expect(r).To(BeNil())
-				Expect(path).To(BeEmpty())
-			})
-		})
-	})
-
-	Describe("Reader", func() {
-		When("radio has an uploaded image", func() {
-			It("returns the image reader", func() {
-				imgPath := filepath.Join(tempDir, "artwork", "radio", "rd-1_test.jpg")
-				Expect(os.WriteFile(imgPath, []byte("uploaded radio image"), 0600)).To(Succeed())
-
-				reader.radio = model.Radio{ID: "rd-1", UploadedImage: "rd-1_test.jpg"}
-				reader.cacheKey.artID = model.ArtworkID{Kind: model.KindRadioArtwork, ID: "rd-1"}
-				r, _, err := reader.Reader(context.Background())
-				Expect(err).ToNot(HaveOccurred())
-				Expect(r).ToNot(BeNil())
-				r.Close()
-			})
-		})
-
-		When("radio has no uploaded image", func() {
-			It("returns ErrUnavailable", func() {
-				reader.radio = model.Radio{ID: "rd-1"}
-				reader.cacheKey.artID = model.ArtworkID{Kind: model.KindRadioArtwork, ID: "rd-1"}
-				r, _, err := reader.Reader(context.Background())
-				Expect(err).To(MatchError(ErrUnavailable))
-				Expect(r).To(BeNil())
-			})
-		})
-	})
-})

core/artwork/reader_resized.go

@@ -1,209 +0,0 @@
-package artwork
-
-import (
-	"bytes"
-	"context"
-	"fmt"
-	"image"
-	"image/draw"
-	"image/jpeg"
-	"image/png"
-	"io"
-	"sync"
-	"time"
-
-	"github.com/gen2brain/webp"
-	"github.com/navidrome/navidrome/conf"
-	"github.com/navidrome/navidrome/log"
-	"github.com/navidrome/navidrome/model"
-	xdraw "golang.org/x/image/draw"
-)
-
-func init() {
-	conf.AddHook(func() {
-		// gen2brain/webp selects native (purego/libwebp) vs WASM in its own
-		// package init() and exposes the result only via webp.Dynamic(); there is
-		// no runtime way to switch back. On 32-bit ARM/x86 the purego callback path
-		// crashes (issue #5597), so those builds must be compiled with the
-		// "nodynamic" tag (see Dockerfile), which makes webp.Dynamic() report an
-		// error here and forces the safe WASM path.
-		if err := webp.Dynamic(); err != nil {
-			log.Debug("Using WASM WebP encoder/decoder", "reason", err)
-		} else {
-			log.Debug("Using native libwebp for WebP encoding/decoding")
-		}
-	})
-}
-
-var bufPool = sync.Pool{
-	New: func() any {
-		return new(bytes.Buffer)
-	},
-}
-
-type resizedArtworkReader struct {
-	artID      model.ArtworkID
-	cacheKey   string
-	lastUpdate time.Time
-	size       int
-	square     bool
-	a          *artwork
-}
-
-func resizedFromOriginal(ctx context.Context, a *artwork, artID model.ArtworkID, size int, square bool) (*resizedArtworkReader, error) {
-	r := &resizedArtworkReader{a: a}
-	r.artID = artID
-	r.size = size
-	r.square = square
-
-	// Get lastUpdated and cacheKey from original artwork
-	original, err := a.getArtworkReader(ctx, artID, 0, false)
-	if err != nil {
-		return nil, err
-	}
-	r.cacheKey = original.Key()
-	r.lastUpdate = original.LastUpdated()
-	return r, nil
-}
-
-func (a *resizedArtworkReader) Key() string {
-	baseKey := fmt.Sprintf("%s.%d", a.cacheKey, a.size)
-	if a.square {
-		return baseKey + ".square"
-	}
-	return fmt.Sprintf("%s.%d", baseKey, conf.Server.CoverArtQuality)
-}
-
-func (a *resizedArtworkReader) LastUpdated() time.Time {
-	return a.lastUpdate
-}
-
-func (a *resizedArtworkReader) Reader(ctx context.Context) (io.ReadCloser, string, error) {
-	// Get artwork in original size, possibly from cache
-	orig, _, err := a.a.Get(ctx, a.artID, 0, false)
-	if err != nil {
-		return nil, "", err
-	}
-	defer orig.Close()
-
-	resized, origSize, err := a.resizeImage(ctx, orig)
-	if resized == nil {
-		log.Trace(ctx, "Image smaller than requested size", "artID", a.artID, "original", origSize, "resized", a.size, "square", a.square)
-	} else {
-		log.Trace(ctx, "Resizing artwork", "artID", a.artID, "original", origSize, "resized", a.size, "square", a.square)
-	}
-	if err != nil {
-		log.Warn(ctx, "Could not resize image. Will return image as is", "artID", a.artID, "size", a.size, "square", a.square, err)
-	}
-	if err != nil || resized == nil {
-		// if we couldn't resize the image, return the original
-		orig, _, err = a.a.Get(ctx, a.artID, 0, false)
-		return orig, "", err
-	}
-	// Preserve ReadCloser semantics if the resized reader already supports Close
-	// (e.g., ffmpeg pipe), otherwise wrap with NopCloser
-	if rc, ok := resized.(io.ReadCloser); ok {
-		return rc, fmt.Sprintf("%s@%d", a.artID, a.size), nil
-	}
-	return io.NopCloser(resized), fmt.Sprintf("%s@%d", a.artID, a.size), nil
-}
-
-func (a *resizedArtworkReader) resizeImage(ctx context.Context, reader io.Reader) (io.Reader, int, error) {
-	data, err := io.ReadAll(reader)
-	if err != nil {
-		return nil, 0, fmt.Errorf("reading image data: %w", err)
-	}
-
-	// Preserve animation for animated images
-	if isAnimatedGIF(data) {
-		if a.a.ffmpeg.IsAvailable() {
-			// Animated GIF: convert to animated WebP via ffmpeg (with optional resize)
-			r, err := a.a.ffmpeg.ConvertAnimatedImage(ctx, bytes.NewReader(data), a.size, conf.Server.CoverArtQuality)
-			if err == nil {
-				return r, 0, nil
-			}
-			log.Warn(ctx, "Could not convert animated GIF, falling back to static", err)
-		}
-	} else if isAnimatedWebP(data) || isAnimatedPNG(data) {
-		// Animated WebP/APNG: return original as-is (ffmpeg can't re-encode these)
-		return bytes.NewReader(data), 0, nil
-	}
-
-	return resizeStaticImage(data, a.size, a.square)
-}
-
-// toFastScaleType converts images whose concrete type has no optimized scaler
-// in x/image/draw (e.g. *image.NYCbCrA from WebP, *image.Paletted from indexed
-// PNGs) into *image.RGBA, which has a fast path. Without this, CatmullRom.Scale
-// falls back to a generic per-pixel At()/RGBA() loop that is several times
-// slower. Fast-path types are returned unchanged.
-func toFastScaleType(img image.Image) image.Image {
-	switch img.(type) {
-	case *image.RGBA, *image.NRGBA, *image.Gray, *image.YCbCr:
-		return img
-	default:
-		rgba := image.NewRGBA(img.Bounds())
-		draw.Draw(rgba, rgba.Bounds(), img, img.Bounds().Min, draw.Src)
-		return rgba
-	}
-}
-
-func resizeStaticImage(data []byte, size int, square bool) (io.Reader, int, error) {
-	original, format, err := image.Decode(bytes.NewReader(data))
-	if err != nil {
-		return nil, 0, err
-	}
-
-	bounds := original.Bounds()
-	originalSize := max(bounds.Max.X, bounds.Max.Y)
-
-	// Clamp size to original dimensions - upscaling wastes resources and adds no information
-	if size > originalSize {
-		size = originalSize
-	}
-
-	if originalSize <= size && !square {
-		return nil, originalSize, nil
-	}
-
-	// Calculate aspect-fit dimensions
-	srcW, srcH := bounds.Dx(), bounds.Dy()
-	scale := float64(size) / float64(max(srcW, srcH))
-	dstW := int(float64(srcW) * scale)
-	dstH := int(float64(srcH) * scale)
-
-	var dst *image.NRGBA
-	var dstRect image.Rectangle
-	if square {
-		// Square canvas with image centered (transparent padding via zero-initialized NRGBA)
-		dst = image.NewNRGBA(image.Rect(0, 0, size, size))
-		offsetX := (size - dstW) / 2
-		offsetY := (size - dstH) / 2
-		dstRect = image.Rect(offsetX, offsetY, offsetX+dstW, offsetY+dstH)
-	} else {
-		// Tight-fit canvas
-		dst = image.NewNRGBA(image.Rect(0, 0, dstW, dstH))
-		dstRect = dst.Bounds()
-	}
-	original = toFastScaleType(original)
-	xdraw.CatmullRom.Scale(dst, dstRect, original, bounds, draw.Src, nil)
-
-	buf := bufPool.Get().(*bytes.Buffer)
-	buf.Reset()
-	if conf.Server.EnableWebPEncoding {
-		err = webp.Encode(buf, dst, webp.Options{Quality: conf.Server.CoverArtQuality})
-	} else if format == "png" || square {
-		err = png.Encode(buf, dst)
-	} else {
-		err = jpeg.Encode(buf, dst, &jpeg.Options{Quality: conf.Server.CoverArtQuality})
-	}
-	if err != nil {
-		bufPool.Put(buf)
-		return nil, originalSize, err
-	}
-	// Copy bytes before returning buffer to pool (pool may reuse the buffer)
-	encoded := make([]byte, buf.Len())
-	copy(encoded, buf.Bytes())
-	bufPool.Put(buf)
-	return bytes.NewReader(encoded), originalSize, nil
-}

core/artwork/reader_resized_test.go

@@ -1,176 +0,0 @@
-package artwork
-
-import (
-	"bytes"
-	"context"
-	"errors"
-	"io"
-
-	"github.com/navidrome/navidrome/core/ffmpeg"
-	"github.com/navidrome/navidrome/tests"
-	. "github.com/onsi/ginkgo/v2"
-	. "github.com/onsi/gomega"
-)
-
-var _ = Describe("resizeImage", func() {
-	var mockFF *tests.MockFFmpeg
-	var r *resizedArtworkReader
-
-	BeforeEach(func() {
-		mockFF = tests.NewMockFFmpeg("converted-animated-data")
-		r = &resizedArtworkReader{
-			size:   300,
-			square: false,
-			a:      &artwork{ffmpeg: mockFF},
-		}
-	})
-
-	Describe("animated GIF handling", func() {
-		It("converts animated GIF via ffmpeg when available", func() {
-			data := createAnimatedGIF(3)
-			result, _, err := r.resizeImage(context.Background(), bytes.NewReader(data))
-			Expect(err).ToNot(HaveOccurred())
-			Expect(result).ToNot(BeNil())
-
-			// Should have been processed by ffmpeg (mock returns "converted-animated-data")
-			output, err := io.ReadAll(result)
-			Expect(err).ToNot(HaveOccurred())
-			Expect(output).To(Equal(data)) // MockFFmpeg echoes input back
-		})
-
-		It("falls back to static resize when ffmpeg fails for animated GIF", func() {
-			mockFF.Error = errors.New("ffmpeg failed")
-			// Use size smaller than image so static resize actually produces output
-			r.size = 1
-			data := createAnimatedGIF(3)
-			result, _, err := r.resizeImage(context.Background(), bytes.NewReader(data))
-			// Should fall through to static resize successfully (no ffmpeg error propagated)
-			Expect(err).ToNot(HaveOccurred())
-			Expect(result).ToNot(BeNil())
-
-			// Verify it's a static image (WebP encoded), not the ffmpeg error
-			output, err := io.ReadAll(result)
-			Expect(err).ToNot(HaveOccurred())
-			Expect(len(output)).To(BeNumerically(">", 0))
-		})
-
-		It("preserves animation for square thumbnails with animated GIF", func() {
-			r.square = true
-			data := createAnimatedGIF(3)
-			result, _, err := r.resizeImage(context.Background(), bytes.NewReader(data))
-			Expect(err).ToNot(HaveOccurred())
-			Expect(result).ToNot(BeNil())
-
-			// Should have been processed by ffmpeg (mock returns input data)
-			output, err := io.ReadAll(result)
-			Expect(err).ToNot(HaveOccurred())
-			Expect(output).To(Equal(data))
-		})
-	})
-
-	Describe("animated WebP handling", func() {
-		It("returns animated WebP data as-is when not square", func() {
-			data := createAnimatedWebPBytes()
-			result, _, err := r.resizeImage(context.Background(), bytes.NewReader(data))
-			Expect(err).ToNot(HaveOccurred())
-			Expect(result).ToNot(BeNil())
-
-			// Should return original data unchanged
-			output, err := io.ReadAll(result)
-			Expect(err).ToNot(HaveOccurred())
-			Expect(output).To(Equal(data))
-		})
-
-		It("preserves animated WebP for square thumbnails", func() {
-			r.square = true
-			data := createAnimatedWebPBytes()
-			result, _, err := r.resizeImage(context.Background(), bytes.NewReader(data))
-			Expect(err).ToNot(HaveOccurred())
-			Expect(result).ToNot(BeNil())
-
-			// Should return original data unchanged
-			output, err := io.ReadAll(result)
-			Expect(err).ToNot(HaveOccurred())
-			Expect(output).To(Equal(data))
-		})
-	})
-
-	Describe("animated PNG handling", func() {
-		It("returns animated PNG data as-is when not square", func() {
-			data := createAPNGBytes()
-			result, _, err := r.resizeImage(context.Background(), bytes.NewReader(data))
-			Expect(err).ToNot(HaveOccurred())
-			Expect(result).ToNot(BeNil())
-
-			// Should return original data unchanged
-			output, err := io.ReadAll(result)
-			Expect(err).ToNot(HaveOccurred())
-			Expect(output).To(Equal(data))
-		})
-
-		It("preserves animated PNG for square thumbnails", func() {
-			r.square = true
-			data := createAPNGBytes()
-			result, _, err := r.resizeImage(context.Background(), bytes.NewReader(data))
-			Expect(err).ToNot(HaveOccurred())
-			Expect(result).ToNot(BeNil())
-
-			// Should return original data unchanged
-			output, err := io.ReadAll(result)
-			Expect(err).ToNot(HaveOccurred())
-			Expect(output).To(Equal(data))
-		})
-	})
-
-	Describe("static image handling", func() {
-		It("resizes a static PNG normally", func() {
-			data := createStaticPNGBytes()
-			result, _, err := r.resizeImage(context.Background(), bytes.NewReader(data))
-			// Static PNG is 2x2, size 300 is larger, so should return nil (no upscale)
-			Expect(err).ToNot(HaveOccurred())
-			Expect(result).To(BeNil())
-		})
-	})
-
-	Describe("ReadCloser preservation", func() {
-		It("preserves Close semantics from ffmpeg ReadCloser", func() {
-			// Create a trackable ReadCloser
-			tracker := &closeTracker{Reader: bytes.NewReader([]byte("test data"))}
-			mockFF2 := &mockFFmpegWithCloser{tracker: tracker}
-			r.a = &artwork{ffmpeg: mockFF2}
-
-			data := createAnimatedGIF(3)
-			result, _, err := r.resizeImage(context.Background(), bytes.NewReader(data))
-			Expect(err).ToNot(HaveOccurred())
-
-			// The result should be an io.ReadCloser (the tracker)
-			rc, ok := result.(io.ReadCloser)
-			Expect(ok).To(BeTrue())
-			Expect(rc.Close()).ToNot(HaveOccurred())
-			Expect(tracker.closed).To(BeTrue())
-		})
-	})
-})
-
-// closeTracker is an io.ReadCloser that tracks whether Close was called.
-type closeTracker struct {
-	io.Reader
-	closed bool
-}
-
-func (c *closeTracker) Close() error {
-	c.closed = true
-	return nil
-}
-
-// mockFFmpegWithCloser is a minimal FFmpeg mock that returns a specific ReadCloser
-// for ConvertAnimatedImage, allowing us to verify Close propagation.
-type mockFFmpegWithCloser struct {
-	ffmpeg.FFmpeg
-	tracker *closeTracker
-}
-
-func (m *mockFFmpegWithCloser) IsAvailable() bool { return true }
-func (m *mockFFmpegWithCloser) ConvertAnimatedImage(_ context.Context, _ io.Reader, _ int, _ int) (io.ReadCloser, error) {
-	return m.tracker, nil
-}

core/artwork/resize.go

@@ -0,0 +1,144 @@
+package artwork
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"image"
+	"image/draw"
+	"image/jpeg"
+	"image/png"
+	"io"
+	"sync"
+	"time"
+
+	"github.com/gen2brain/webp"
+	"github.com/navidrome/navidrome/conf"
+	"github.com/navidrome/navidrome/core/ffmpeg"
+	"github.com/navidrome/navidrome/log"
+	xdraw "golang.org/x/image/draw"
+)
+
+func init() {
+	conf.AddHook(func() {
+		// gen2brain/webp picks native vs WASM in its own init(), with no way to switch at
+		// runtime: 32-bit builds need the "nodynamic" tag (see Dockerfile) to force WASM.
+		if err := webp.Dynamic(); err != nil {
+			log.Debug("Artwork: Using WASM WebP encoder/decoder", "reason", err)
+		} else {
+			log.Debug("Artwork: Using native libwebp for WebP encoding/decoding")
+		}
+	})
+}
+
+var bufPool = sync.Pool{
+	New: func() any {
+		return new(bytes.Buffer)
+	},
+}
+
+// resizeImageData resizes raw image bytes to fit size, preserving animation where
+// possible. A nil reader means the image was already within bounds (no resize needed).
+func resizeImageData(ctx context.Context, ffm ffmpeg.FFmpeg, data []byte, size int, square bool) (io.Reader, int, error) {
+	start := time.Now()
+	defer func() {
+		log.Trace(ctx, "Artwork: Resized image", "bytes", len(data), "size", size, "square", square,
+			"elapsed", time.Since(start))
+	}()
+	if isAnimatedGIF(data) {
+		if ffm.IsAvailable() {
+			// Animated GIF: convert to animated WebP via ffmpeg (with optional resize)
+			r, err := ffm.ConvertAnimatedImage(ctx, bytes.NewReader(data), size, conf.Server.CoverArtQuality)
+			if err == nil {
+				return r, 0, nil
+			}
+			log.Warn(ctx, "Artwork: Could not convert animated GIF, falling back to static", err)
+		}
+	} else if isAnimatedWebP(data) || isAnimatedPNG(data) {
+		// Animated WebP/APNG: return original as-is (ffmpeg can't re-encode these)
+		return bytes.NewReader(data), 0, nil
+	}
+
+	return resizeStaticImage(data, size, square)
+}
+
+// toFastScaleType converts types x/image/draw has no optimized scaler for (e.g. *image.NYCbCrA,
+// *image.Paletted) to *image.RGBA, avoiding CatmullRom.Scale's generic per-pixel fallback.
+func toFastScaleType(img image.Image) image.Image {
+	switch img.(type) {
+	case *image.RGBA, *image.NRGBA, *image.Gray, *image.YCbCr:
+		return img
+	default:
+		rgba := image.NewRGBA(img.Bounds())
+		draw.Draw(rgba, rgba.Bounds(), img, img.Bounds().Min, draw.Src)
+		return rgba
+	}
+}
+
+func resizeStaticImage(data []byte, size int, square bool) (io.Reader, int, error) {
+	original, format, err := image.Decode(bytes.NewReader(data))
+	if err != nil {
+		return nil, 0, err
+	}
+
+	bounds := original.Bounds()
+	originalSize := max(bounds.Max.X, bounds.Max.Y)
+
+	// Clamp size to original dimensions - upscaling wastes resources and adds no information
+	if size > originalSize {
+		size = originalSize
+	}
+
+	if originalSize <= size && !square {
+		return nil, originalSize, nil
+	}
+
+	// Calculate aspect-fit dimensions
+	srcW, srcH := bounds.Dx(), bounds.Dy()
+	scale := float64(size) / float64(max(srcW, srcH))
+	dstW := int(float64(srcW) * scale)
+	dstH := int(float64(srcH) * scale)
+
+	var dst *image.NRGBA
+	var dstRect image.Rectangle
+	if square {
+		// Square canvas with image centered (transparent padding via zero-initialized NRGBA)
+		dst = image.NewNRGBA(image.Rect(0, 0, size, size))
+		offsetX := (size - dstW) / 2
+		offsetY := (size - dstH) / 2
+		dstRect = image.Rect(offsetX, offsetY, offsetX+dstW, offsetY+dstH)
+	} else {
+		// Tight-fit canvas
+		dst = image.NewNRGBA(image.Rect(0, 0, dstW, dstH))
+		dstRect = dst.Bounds()
+	}
+	original = toFastScaleType(original)
+	xdraw.CatmullRom.Scale(dst, dstRect, original, bounds, draw.Src, nil)
+
+	buf := bufPool.Get().(*bytes.Buffer)
+	buf.Reset()
+	if conf.Server.EnableWebPEncoding {
+		err = webp.Encode(buf, dst, webp.Options{Quality: conf.Server.CoverArtQuality})
+	} else if format == "png" || square {
+		err = png.Encode(buf, dst)
+	} else {
+		err = jpeg.Encode(buf, dst, &jpeg.Options{Quality: conf.Server.CoverArtQuality})
+	}
+	if err != nil {
+		bufPool.Put(buf)
+		return nil, originalSize, err
+	}
+	// Copy bytes before returning buffer to pool (pool may reuse the buffer)
+	encoded := bytes.Clone(buf.Bytes())
+	bufPool.Put(buf)
+	return bytes.NewReader(encoded), originalSize, nil
+}
+
+// formatQualityTag folds the encoder config (WebP toggle + quality) into a cache-key
+// fragment, so flipping either setting invalidates previously-encoded sized artwork.
+func formatQualityTag() string {
+	if conf.Server.EnableWebPEncoding {
+		return fmt.Sprintf("webp%d", conf.Server.CoverArtQuality)
+	}
+	return fmt.Sprintf("q%d", conf.Server.CoverArtQuality)
+}

core/artwork/resolve.go

@@ -0,0 +1,452 @@
+package artwork
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"image"
+	"io"
+	"io/fs"
+	"net/url"
+	"os"
+	"strings"
+
+	"github.com/Masterminds/squirrel"
+	"github.com/navidrome/navidrome/conf"
+	"github.com/navidrome/navidrome/core/agents"
+	"github.com/navidrome/navidrome/core/ffmpeg"
+	"github.com/navidrome/navidrome/model"
+)
+
+// resolution is one attempted acquisition outcome for an entity.
+type resolution struct {
+	reader     io.ReadCloser // nil when no source yielded an image
+	source     string        // model.ItemArtwork.Source value: "folder", "embedded", "external", "upload", "generated"
+	sourcePath string        // backing library/upload file (folder/upload: the image; embedded: the audio file); "" otherwise
+	refMtime   int64         // sourcePath mtime (unix-nanoseconds) at resolution; 0 when no sourcePath
+	// external source errored/timed out. With no reader it forces failed (never absent);
+	// on a hit a higher-priority external step failed—serve this, but retry later.
+	extError bool
+	// a local source that should have been readable wasn't. With no reader it forces failed,
+	// so a transient I/O fault never records absent.
+	localError bool
+}
+
+// chainState carries what a priority walk has seen so far. A hit takes extErr with it so a
+// transient external failure still retries; localErr is dropped, as the scanner re-lists changes.
+type chainState struct{ extErr, localErr bool }
+
+// try stamps the accumulated external failure onto a hit, and records the miss otherwise.
+func (c *chainState) try(res resolution, ok bool) (resolution, bool) {
+	if ok {
+		res.extError = c.extErr
+		return res, true
+	}
+	c.localErr = c.localErr || res.localError
+	return resolution{}, false
+}
+
+// exhausted is the outcome when no source in the chain yielded an image.
+func (c *chainState) exhausted() resolution {
+	return resolution{extError: c.extErr, localError: c.localErr}
+}
+
+// externalSource holds the agents to ask and the rate limiter/circuit breaker to ask them through.
+type externalSource struct {
+	agents *agents.Agents
+	gate   gateFunc
+}
+
+// resolver walks a kind's priority chain and returns the first hit; a nil ext means local-only.
+type resolver struct {
+	ds     model.DataStore
+	ffmpeg ffmpeg.FFmpeg
+	ext    *externalSource
+}
+
+func newResolver(ds model.DataStore, ag *agents.Agents, ffm ffmpeg.FFmpeg, gate gateFunc) *resolver {
+	if gate == nil {
+		gate = passthroughGate
+	}
+	return &resolver{ds: ds, ffmpeg: ffm, ext: &externalSource{agents: ag, gate: gate}}
+}
+
+// newLocalResolver builds a resolver that can neither reach the network nor sample album art
+// for the worker-built grid.
+func newLocalResolver(ds model.DataStore, ffm ffmpeg.FFmpeg) *resolver {
+	return &resolver{ds: ds, ffmpeg: ffm}
+}
+
+func (r *resolver) resolve(ctx context.Context, item model.ArtworkQueueItem) (resolution, error) {
+	kind, _ := model.ParseKind(item.ItemKind)
+	switch kind {
+	case model.KindAlbumArtwork:
+		return r.resolveAlbum(ctx, item.ItemID)
+	case model.KindArtistArtwork:
+		return r.resolveArtist(ctx, item.ItemID)
+	case model.KindPlaylistArtwork:
+		return r.resolvePlaylist(ctx, item.ItemID)
+	case model.KindRadioArtwork:
+		return r.resolveRadio(ctx, item.ItemID)
+	case model.KindMediaFileArtwork:
+		return r.resolveMediaFile(ctx, item.ItemID)
+	default:
+		return resolution{}, fmt.Errorf("artwork: kind %q is not resolvable by the worker", item.ItemKind)
+	}
+}
+
+// fetchExternalAlbum and fetchExternalArtist are the only places resolution touches the network,
+// so a local-only resolver is stopped here rather than at each point in the chain walk.
+func (r *resolver) fetchExternalAlbum(ctx context.Context, al model.Album) (io.ReadCloser, string, bool) {
+	if r.ext == nil {
+		return nil, "", false
+	}
+	return fetchAlbumImage(ctx, r.ext.agents, r.ext.gate, al)
+}
+
+func (r *resolver) fetchExternalArtist(ctx context.Context, ar model.Artist) (io.ReadCloser, string, bool) {
+	if r.ext == nil {
+		return nil, "", false
+	}
+	return fetchArtistImage(ctx, r.ext.agents, r.ext.gate, ar)
+}
+
+// resolveAlbum walks conf.Server.CoverArtPriority over the folder, embedded and external sources.
+func (r *resolver) resolveAlbum(ctx context.Context, albumID string) (resolution, error) {
+	al, err := r.ds.Album(ctx).Get(albumID)
+	if err != nil {
+		return resolution{}, err
+	}
+	_, imgFiles, _, err := loadAlbumFoldersPaths(ctx, r.ds, *al)
+	if err != nil {
+		return resolution{}, err
+	}
+	lib, err := loadLibraryView(ctx, r.ds, al.LibraryID)
+	if err != nil {
+		return resolution{}, err
+	}
+
+	var chain chainState
+	for pattern := range strings.SplitSeq(strings.ToLower(conf.Server.CoverArtPriority), ",") {
+		pattern = strings.TrimSpace(pattern)
+		switch {
+		case pattern == "embedded":
+			if res, ok := chain.try(resolveEmbedded(ctx, lib, r.ffmpeg, al.EmbedArtPath)); ok {
+				return res, nil
+			}
+		case pattern == "external":
+			if rd, name, isErr := r.fetchExternalAlbum(ctx, *al); rd != nil {
+				return resolution{reader: rd, source: "external:" + name}, nil
+			} else if isErr {
+				chain.extErr = true
+			}
+		case len(imgFiles) > 0:
+			if res, ok := chain.try(resolveFolderFile(ctx, lib, imgFiles, pattern)); ok {
+				return res, nil
+			}
+		}
+	}
+	return chain.exhausted(), nil
+}
+
+// resolveArtist tries the uploaded image first, then walks conf.Server.ArtistArtPriority.
+func (r *resolver) resolveArtist(ctx context.Context, artistID string) (resolution, error) {
+	ar, err := r.ds.Artist(ctx).Get(artistID)
+	if err != nil {
+		return resolution{}, err
+	}
+	upload, ok := resolveLocalFile(ar.UploadedImagePath(), "upload")
+	if ok {
+		return upload, nil
+	}
+	if upload.localError {
+		// The upload outranks every other source; falling through would persist a lower-priority
+		// image as if the upload were gone.
+		return upload, nil
+	}
+
+	// Only consider albums where the artist is the sole album artist.
+	als, err := r.ds.Album(ctx).GetAll(model.QueryOptions{
+		Filters: squirrel.And{
+			squirrel.Eq{"album_artist_id": artistID},
+			squirrel.Eq{"json_array_length(participants, '$.albumartist')": 1},
+		},
+	})
+	if err != nil {
+		return resolution{}, err
+	}
+	albumPaths, imgFiles, _, err := loadArtistAlbumRoots(ctx, r.ds, als)
+	if err != nil {
+		return resolution{}, err
+	}
+	artistFolder, _, err := loadArtistFolder(ctx, r.ds, als, albumPaths)
+	if err != nil {
+		return resolution{}, err
+	}
+	var lib libraryView
+	if len(als) > 0 {
+		lib, err = loadLibraryView(ctx, r.ds, als[0].LibraryID)
+		if err != nil {
+			return resolution{}, err
+		}
+	}
+
+	var chain chainState
+	for pattern := range strings.SplitSeq(strings.ToLower(conf.Server.ArtistArtPriority), ",") {
+		pattern = strings.TrimSpace(pattern)
+		switch {
+		case pattern == "external":
+			if rd, name, isErr := r.fetchExternalArtist(ctx, *ar); rd != nil {
+				return resolution{reader: rd, source: "external:" + name}, nil
+			} else if isErr {
+				chain.extErr = true
+			}
+		case pattern == "image-folder":
+			if res, ok := chain.try(resolveArtistImageFolder(ar)); ok {
+				return res, nil
+			}
+		case strings.HasPrefix(pattern, "album/"):
+			if lib.FS == nil {
+				continue
+			}
+			if res, ok := chain.try(resolveFolderFile(ctx, lib, imgFiles, strings.TrimPrefix(pattern, "album/"))); ok {
+				return res, nil
+			}
+		default:
+			if lib.FS == nil || artistFolder == "" {
+				continue
+			}
+			if res, ok := chain.try(resolveArtistFolderPattern(ctx, lib, artistFolder, pattern)); ok {
+				return res, nil
+			}
+		}
+	}
+	return chain.exhausted(), nil
+}
+
+// resolvePlaylist tries the uploaded image, the sidecar and ExternalImageURL, then a generated grid.
+func (r *resolver) resolvePlaylist(ctx context.Context, playlistID string) (resolution, error) {
+	pl, err := r.ds.Playlist(ctx).Get(playlistID)
+	if err != nil {
+		return resolution{}, err
+	}
+
+	var extErr bool
+	for _, src := range []struct{ path, source string }{
+		{pl.UploadedImagePath(), "upload"},
+		{findPlaylistSidecarPath(ctx, pl.Path), "folder"},
+	} {
+		res, ok := resolveLocalFile(src.path, src.source)
+		if ok {
+			return res, nil
+		}
+		if res.localError {
+			// These outrank the generated grid; falling through would replace them with it.
+			return res, nil
+		}
+	}
+	// A local ExternalImageURL is file-backed and served in place; only http(s) needs the gated fetch.
+	localImg, remoteImg := classifyPlaylistImage(pl.ExternalImageURL)
+	if localImg != "" {
+		res, ok := resolveLocalFile(localImg, "folder")
+		if ok {
+			return res, nil
+		}
+		if res.localError {
+			return res, nil
+		}
+	}
+	if r.ext == nil {
+		// The remote fetch and the generated grid are worker-only; a request must do neither.
+		return resolution{}, nil
+	}
+	if remoteImg != nil && conf.Server.EnableM3UExternalAlbumArt {
+		sf := func() (io.ReadCloser, string, error) { return fromURL(ctx, remoteImg) }
+		if res, ok, isErr := resolveExternalStep(r.ext.gate, "m3u", sf); ok {
+			return res, nil
+		} else if isErr {
+			extErr = true
+		}
+	}
+
+	albumIDs, err := r.ds.Playlist(ctx).Tracks(pl.ID, false).GetAlbumIDs(model.QueryOptions{Max: 4, Sort: "random()"})
+	if err != nil {
+		return resolution{}, err
+	}
+
+	var tiles []image.Image
+	var tileErr error // first internal (non-external) tile failure, e.g. album deleted mid-flight
+	for _, albumID := range albumIDs {
+		res, err := r.resolveAlbum(ctx, albumID)
+		if err != nil {
+			if tileErr == nil {
+				tileErr = err
+			}
+			continue
+		}
+		if res.extError {
+			extErr = true
+		}
+		if res.reader == nil {
+			continue
+		}
+		tile, decErr := decodeTile(res.reader)
+		res.reader.Close()
+		if decErr == nil {
+			tiles = append(tiles, tile)
+		}
+		if len(tiles) == 4 {
+			break
+		}
+	}
+	if len(tiles) == 0 {
+		// A tile-level failure must never resolve as a clean absent.
+		if tileErr != nil {
+			return resolution{}, fmt.Errorf("resolvePlaylist: sampled album art failed: %w", tileErr)
+		}
+		return resolution{extError: extErr}, nil
+	}
+	// Grow to 4 tiles by repeating what we have.
+	switch len(tiles) {
+	case 2:
+		tiles = append(tiles, tiles[1], tiles[0])
+	case 3:
+		tiles = append(tiles, tiles[0])
+	}
+	grid, err := assembleTiles(tiles)
+	if err != nil {
+		return resolution{extError: extErr}, nil //nolint:nilerr // encode failure is a soft "no image", not a resolution error
+	}
+	return resolution{reader: grid, source: "generated", extError: extErr}, nil
+}
+
+// resolveRadio serves only an uploaded image; there is no fallback.
+func (r *resolver) resolveRadio(ctx context.Context, radioID string) (resolution, error) {
+	radio, err := r.ds.Radio(ctx).Get(radioID)
+	if err != nil {
+		return resolution{}, err
+	}
+	res, _ := resolveLocalFile(radio.UploadedImagePath(), "upload")
+	return res, nil
+}
+
+// resolveMediaFile resolves a track's own embedded art only, so disabled or missing cover art
+// is a definitive absent.
+func (r *resolver) resolveMediaFile(ctx context.Context, id string) (resolution, error) {
+	mf, err := r.ds.MediaFile(ctx).Get(id)
+	if err != nil {
+		return resolution{}, err
+	}
+	if !conf.Server.EnableMediaFileCoverArt || !mf.HasCoverArt {
+		return resolution{}, nil
+	}
+	lib, err := loadLibraryView(ctx, r.ds, mf.LibraryID)
+	if err != nil {
+		return resolution{}, err
+	}
+	res, _ := resolveEmbedded(ctx, lib, r.ffmpeg, mf.Path)
+	return res, nil
+}
+
+// resolveExternalStep runs a single external sourceFunc through the named gate. extErr excludes
+// a not-found, which is a definitive "no" rather than a failure.
+func resolveExternalStep(gate gateFunc, name string, sf sourceFunc) (res resolution, ok bool, extErr bool) {
+	r, path, err := gate(name, sf)
+	if r != nil {
+		return resolution{reader: r, source: "external", sourcePath: path}, true, false
+	}
+	return resolution{}, false, err != nil && !errors.Is(err, model.ErrNotFound)
+}
+
+// classifyPlaylistImage splits a playlist ExternalImageURL into a local filesystem path or a
+// remote http(s) URL; at most one is set.
+func classifyPlaylistImage(imageURL string) (localPath string, remote *url.URL) {
+	if imageURL == "" {
+		return "", nil
+	}
+	u, err := url.Parse(imageURL)
+	if err != nil {
+		return imageURL, nil // unparseable → treat as a local path
+	}
+	switch u.Scheme {
+	case "http", "https":
+		return "", u
+	case "file":
+		return u.Path, nil
+	default:
+		return imageURL, nil
+	}
+}
+
+func resolveEmbedded(ctx context.Context, lib libraryView, ffm ffmpeg.FFmpeg, embedRel string) (resolution, bool) {
+	if embedRel == "" {
+		return resolution{}, false
+	}
+	abs := lib.Abs(embedRel)
+	var unreadable bool
+	for _, sf := range []sourceFunc{fromTag(ctx, lib.FS, embedRel), fromFFmpegTag(ctx, ffm, abs)} {
+		r, _, err := sf()
+		if r != nil {
+			return resolution{reader: r, source: "embedded", sourcePath: abs, refMtime: mtimeViaFS(lib.FS, embedRel)}, true
+		}
+		unreadable = unreadable || errors.Is(err, errSourceUnreadable)
+	}
+	return resolution{localError: unreadable}, false
+}
+
+func resolveFolderFile(ctx context.Context, lib libraryView, imgFiles []string, pattern string) (resolution, bool) {
+	r, path, err := fromExternalFile(ctx, lib.FS, imgFiles, pattern)()
+	if r == nil {
+		return resolution{localError: errors.Is(err, errSourceUnreadable)}, false
+	}
+	return resolution{reader: r, source: "folder", sourcePath: lib.Abs(path), refMtime: mtimeViaFS(lib.FS, path)}, true
+}
+
+func resolveArtistImageFolder(ar *model.Artist) (resolution, bool) {
+	folder := conf.Server.ArtistImageFolder
+	if folder == "" {
+		return resolution{}, false
+	}
+	return resolveLocalFile(findImageInArtistFolder(folder, ar.MbzArtistID, ar.Name), "folder")
+}
+
+func resolveArtistFolderPattern(ctx context.Context, lib libraryView, artistFolder, pattern string) (resolution, bool) {
+	r, path, err := fromArtistFolder(ctx, lib.FS, lib.absRoot, artistFolder, pattern)()
+	if r == nil {
+		return resolution{localError: errors.Is(err, errSourceUnreadable)}, false
+	}
+	return resolution{reader: r, source: "folder", sourcePath: path, refMtime: mtimeOf(path)}, true
+}
+
+// resolveLocalFile opens an absolute path directly. A missing path is "no source"; any other
+// open failure says nothing about whether the image exists.
+func resolveLocalFile(path, source string) (resolution, bool) {
+	if path == "" {
+		return resolution{}, false
+	}
+	f, err := os.Open(path)
+	if err != nil {
+		return resolution{localError: !errors.Is(err, fs.ErrNotExist)}, false
+	}
+	return resolution{reader: f, source: source, sourcePath: path, refMtime: mtimeOf(path)}, true
+}
+
+func mtimeOf(path string) int64 {
+	info, err := os.Stat(path)
+	if err != nil {
+		return 0
+	}
+	return info.ModTime().UnixNano()
+}
+
+// mtimeViaFS stats through the library FS, since library roots in tests may not be real OS paths.
+func mtimeViaFS(fsys fs.FS, name string) int64 {
+	if fsys == nil || name == "" {
+		return 0
+	}
+	info, err := fs.Stat(fsys, name)
+	if err != nil {
+		return 0
+	}
+	return info.ModTime().UnixNano()
+}

core/artwork/resolve_test.go

@@ -0,0 +1,632 @@
+package artwork
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"image"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"path/filepath"
+	"sync/atomic"
+
+	"github.com/navidrome/navidrome/conf"
+	"github.com/navidrome/navidrome/conf/configtest"
+	"github.com/navidrome/navidrome/core/agents"
+	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/tests"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("resolveItem", func() {
+	var (
+		ctx        context.Context
+		ds         *tests.MockDataStore
+		folderRepo *fakeFolderRepo
+		libRepo    *tests.MockLibraryRepo
+		ffm        *tests.MockFFmpeg
+		ag         *agents.Agents
+		repoRoot   string
+	)
+
+	BeforeEach(func() {
+		DeferCleanup(configtest.SetupConfig())
+		ctx = context.Background()
+		var err error
+		repoRoot, err = os.Getwd()
+		Expect(err).ToNot(HaveOccurred())
+
+		folderRepo = &fakeFolderRepo{}
+		libRepo = &tests.MockLibraryRepo{}
+		libRepo.SetData(model.Libraries{{ID: 0, Path: testFileLibPath(repoRoot)}})
+		ffm = tests.NewMockFFmpeg("")
+		ag = agents.GetAgents(&tests.MockDataStore{}, nil)
+		ds = &tests.MockDataStore{
+			MockedFolder:  folderRepo,
+			MockedLibrary: libRepo,
+		}
+	})
+
+	Describe("kind dispatch", func() {
+		It("returns an error for kinds the worker never enqueues", func() {
+			_, err := newResolver(ds, ag, ffm, nil).resolve(ctx, model.ArtworkQueueItem{ItemKind: "zz", ItemID: "x"})
+			Expect(err).To(HaveOccurred())
+		})
+	})
+
+	Describe("media file", func() {
+		BeforeEach(func() {
+			conf.Server.EnableMediaFileCoverArt = true
+			ds.MockedMediaFile = tests.CreateMockMediaFileRepo()
+		})
+
+		It("resolves embedded art from the track file", func() {
+			ds.MockedMediaFile.(*tests.MockMediaFileRepo).SetData(model.MediaFiles{
+				{ID: "mf1", LibraryID: 0, Path: "tests/fixtures/artist/an-album/test.mp3", HasCoverArt: true},
+			})
+
+			res, err := newResolver(ds, ag, ffm, nil).resolve(ctx, model.ArtworkQueueItem{ItemKind: "mf", ItemID: "mf1"})
+			Expect(err).ToNot(HaveOccurred())
+			Expect(res.reader).ToNot(BeNil())
+			defer res.reader.Close()
+			Expect(res.source).To(Equal("embedded"))
+			Expect(filepath.ToSlash(res.sourcePath)).To(HaveSuffix("tests/fixtures/artist/an-album/test.mp3"))
+			Expect(res.refMtime).To(BeNumerically(">", 0))
+			Expect(res.extError).To(BeFalse())
+		})
+
+		It("resolves absent when the track has no cover art", func() {
+			ds.MockedMediaFile.(*tests.MockMediaFileRepo).SetData(model.MediaFiles{
+				{ID: "mf2", LibraryID: 0, Path: "tests/fixtures/artist/an-album/test.mp3", HasCoverArt: false},
+			})
+
+			res, err := newResolver(ds, ag, ffm, nil).resolve(ctx, model.ArtworkQueueItem{ItemKind: "mf", ItemID: "mf2"})
+			Expect(err).ToNot(HaveOccurred())
+			Expect(res.reader).To(BeNil())
+			Expect(res.extError).To(BeFalse())
+		})
+
+		It("resolves absent when media file cover art is disabled", func() {
+			conf.Server.EnableMediaFileCoverArt = false
+			ds.MockedMediaFile.(*tests.MockMediaFileRepo).SetData(model.MediaFiles{
+				{ID: "mf3", LibraryID: 0, Path: "tests/fixtures/artist/an-album/test.mp3", HasCoverArt: true},
+			})
+
+			res, err := newResolver(ds, ag, ffm, nil).resolve(ctx, model.ArtworkQueueItem{ItemKind: "mf", ItemID: "mf3"})
+			Expect(err).ToNot(HaveOccurred())
+			Expect(res.reader).To(BeNil())
+		})
+
+		It("returns the error when the track is not in the DB", func() {
+			res, err := newResolver(ds, ag, ffm, nil).resolve(ctx, model.ArtworkQueueItem{ItemKind: "mf", ItemID: "missing"})
+			Expect(err).To(MatchError(model.ErrNotFound))
+			Expect(res.reader).To(BeNil())
+		})
+	})
+
+	Describe("album", func() {
+		BeforeEach(func() {
+			conf.Server.CoverArtPriority = "cover.jpg, embedded"
+			ds.MockedAlbum = tests.CreateMockAlbumRepo()
+		})
+
+		It("resolves folder art from the library FS", func() {
+			folderRepo.result = []model.Folder{{
+				Path:       "tests/fixtures/artist/an-album",
+				ImageFiles: []string{"cover.jpg"},
+			}}
+			ds.MockedAlbum.(*tests.MockAlbumRepo).SetData(model.Albums{
+				{ID: "al1", Name: "Album", FolderIDs: []string{"f1"}},
+			})
+
+			res, err := newResolver(ds, ag, ffm, nil).resolve(ctx, model.ArtworkQueueItem{ItemKind: "al", ItemID: "al1"})
+			Expect(err).ToNot(HaveOccurred())
+			Expect(res.reader).ToNot(BeNil())
+			defer res.reader.Close()
+			Expect(res.source).To(Equal("folder"))
+			Expect(filepath.ToSlash(res.sourcePath)).To(HaveSuffix("tests/fixtures/artist/an-album/cover.jpg"))
+			Expect(res.refMtime).To(BeNumerically(">", 0))
+			Expect(res.extError).To(BeFalse())
+		})
+
+		It("falls back to embedded art when no folder image matches", func() {
+			folderRepo.result = nil
+			ds.MockedAlbum.(*tests.MockAlbumRepo).SetData(model.Albums{
+				{ID: "al2", Name: "Album", EmbedArtPath: "tests/fixtures/artist/an-album/test.mp3", FolderIDs: []string{"f1"}},
+			})
+
+			res, err := newResolver(ds, ag, ffm, nil).resolve(ctx, model.ArtworkQueueItem{ItemKind: "al", ItemID: "al2"})
+			Expect(err).ToNot(HaveOccurred())
+			Expect(res.reader).ToNot(BeNil())
+			defer res.reader.Close()
+			Expect(res.source).To(Equal("embedded"))
+			Expect(filepath.ToSlash(res.sourcePath)).To(HaveSuffix("tests/fixtures/artist/an-album/test.mp3"))
+			Expect(res.refMtime).To(BeNumerically(">", 0))
+		})
+
+		It("sets extError when the external source errors without being not-found", func() {
+			conf.Server.CoverArtPriority = "external"
+			ds.MockedAlbum.(*tests.MockAlbumRepo).SetData(model.Albums{
+				{ID: "al3", Name: "Album"},
+			})
+			imageAgents(&fakeImageAgent{name: "failAgent", err: errors.New("agent timed out")})
+
+			res, err := newResolver(ds, ag, ffm, nil).resolve(ctx, model.ArtworkQueueItem{ItemKind: "al", ItemID: "al3"})
+			Expect(err).ToNot(HaveOccurred())
+			Expect(res.reader).To(BeNil())
+			Expect(res.extError).To(BeTrue())
+		})
+
+		It("does not set extError when the external source reports not-found", func() {
+			conf.Server.CoverArtPriority = "external"
+			ds.MockedAlbum.(*tests.MockAlbumRepo).SetData(model.Albums{
+				{ID: "al4", Name: "Album"},
+			})
+			// no image agents enabled -> the external step is a definitive not-found
+
+			res, err := newResolver(ds, ag, ffm, nil).resolve(ctx, model.ArtworkQueueItem{ItemKind: "al", ItemID: "al4"})
+			Expect(err).ToNot(HaveOccurred())
+			Expect(res.reader).To(BeNil())
+			Expect(res.extError).To(BeFalse())
+		})
+
+		It("carries extError onto a fallback folder hit after a transient external failure", func() {
+			conf.Server.CoverArtPriority = "external, cover.jpg"
+			folderRepo.result = []model.Folder{{
+				Path:       "tests/fixtures/artist/an-album",
+				ImageFiles: []string{"cover.jpg"},
+			}}
+			ds.MockedAlbum.(*tests.MockAlbumRepo).SetData(model.Albums{
+				{ID: "al6", Name: "Album", FolderIDs: []string{"f1"}},
+			})
+			imageAgents(&fakeImageAgent{name: "failAgent", err: errors.New("agent timed out")})
+
+			res, err := newResolver(ds, ag, ffm, nil).resolve(ctx, model.ArtworkQueueItem{ItemKind: "al", ItemID: "al6"})
+			Expect(err).ToNot(HaveOccurred())
+			Expect(res.reader).ToNot(BeNil())
+			defer res.reader.Close()
+			Expect(res.source).To(Equal("folder"))
+			Expect(res.extError).To(BeTrue())
+		})
+
+		It("does not carry extError onto a fallback folder hit after a definitive external not-found", func() {
+			conf.Server.CoverArtPriority = "external, cover.jpg"
+			folderRepo.result = []model.Folder{{
+				Path:       "tests/fixtures/artist/an-album",
+				ImageFiles: []string{"cover.jpg"},
+			}}
+			ds.MockedAlbum.(*tests.MockAlbumRepo).SetData(model.Albums{
+				{ID: "al7", Name: "Album", FolderIDs: []string{"f1"}},
+			})
+			// no image agents enabled -> the external step is a definitive not-found
+
+			res, err := newResolver(ds, ag, ffm, nil).resolve(ctx, model.ArtworkQueueItem{ItemKind: "al", ItemID: "al7"})
+			Expect(err).ToNot(HaveOccurred())
+			Expect(res.reader).ToNot(BeNil())
+			defer res.reader.Close()
+			Expect(res.source).To(Equal("folder"))
+			Expect(res.extError).To(BeFalse())
+		})
+
+		It("routes the external step through the injected gate, keyed by agent name", func() {
+			conf.Server.CoverArtPriority = "external"
+			ds.MockedAlbum.(*tests.MockAlbumRepo).SetData(model.Albums{
+				{ID: "al5", Name: "Album"},
+			})
+			imageAgents(&fakeImageAgent{name: "failAgent", err: errors.New("boom")})
+			var gatedNames []string
+			gate := func(name string, f func() (io.ReadCloser, string, error)) (io.ReadCloser, string, error) {
+				gatedNames = append(gatedNames, name)
+				return f()
+			}
+
+			res, err := newResolver(ds, ag, ffm, gate).resolve(ctx, model.ArtworkQueueItem{ItemKind: "al", ItemID: "al5"})
+			Expect(err).ToNot(HaveOccurred())
+			Expect(res.extError).To(BeTrue())
+			Expect(gatedNames).To(Equal([]string{"failAgent"}))
+		})
+	})
+
+	Describe("artist", func() {
+		It("resolves the uploaded image before any priority chain lookup", func() {
+			tmpDir := GinkgoT().TempDir()
+			conf.Server.DataFolder = conf.NewDir(tmpDir)
+			Expect(os.MkdirAll(filepath.Join(tmpDir, "artwork", "artist"), 0755)).To(Succeed())
+			imgPath := filepath.Join(tmpDir, "artwork", "artist", "ar1_test.jpg")
+			Expect(os.WriteFile(imgPath, []byte("uploaded artist image"), 0600)).To(Succeed())
+
+			artistRepo := tests.CreateMockArtistRepo()
+			artistRepo.SetData(model.Artists{{ID: "ar1", Name: "Artist", UploadedImage: "ar1_test.jpg"}})
+			ds.MockedArtist = artistRepo
+
+			res, err := newResolver(ds, ag, ffm, nil).resolve(ctx, model.ArtworkQueueItem{ItemKind: "ar", ItemID: "ar1"})
+			Expect(err).ToNot(HaveOccurred())
+			Expect(res.reader).ToNot(BeNil())
+			defer res.reader.Close()
+			Expect(res.source).To(Equal("upload"))
+			Expect(res.sourcePath).To(Equal(imgPath))
+		})
+
+		It("falls through to the ArtistArtPriority chain when there is no upload", func() {
+			conf.Server.ArtistArtPriority = "album/artist.*"
+			folderRepo.result = []model.Folder{{
+				LibraryPath: testFileLibPath(repoRoot),
+				Path:        "tests/fixtures/artist/an-album",
+				ImageFiles:  []string{"artist.png"},
+			}}
+			artistRepo := tests.CreateMockArtistRepo()
+			artistRepo.SetData(model.Artists{{ID: "ar2", Name: "Artist"}})
+			ds.MockedArtist = artistRepo
+			ds.MockedAlbum = tests.CreateMockAlbumRepo()
+			ds.MockedAlbum.(*tests.MockAlbumRepo).All = model.Albums{
+				{ID: "al9", Name: "Album", LibraryID: 0, FolderIDs: []string{"f1"}},
+			}
+
+			res, err := newResolver(ds, ag, ffm, nil).resolve(ctx, model.ArtworkQueueItem{ItemKind: "ar", ItemID: "ar2"})
+			Expect(err).ToNot(HaveOccurred())
+			Expect(res.reader).ToNot(BeNil())
+			defer res.reader.Close()
+			Expect(res.source).To(Equal("folder"))
+			Expect(filepath.ToSlash(res.sourcePath)).To(HaveSuffix("tests/fixtures/artist/an-album/artist.png"))
+		})
+
+		It("sets extError when the external source errors without being not-found", func() {
+			conf.Server.ArtistArtPriority = "external"
+			artistRepo := tests.CreateMockArtistRepo()
+			artistRepo.SetData(model.Artists{{ID: "ar3", Name: "Artist"}})
+			ds.MockedArtist = artistRepo
+			imageAgents(&fakeImageAgent{name: "failAgent", err: errors.New("agent timed out")})
+
+			res, err := newResolver(ds, ag, ffm, nil).resolve(ctx, model.ArtworkQueueItem{ItemKind: "ar", ItemID: "ar3"})
+			Expect(err).ToNot(HaveOccurred())
+			Expect(res.reader).To(BeNil())
+			Expect(res.extError).To(BeTrue())
+		})
+
+		It("does not set extError when the external source reports not-found", func() {
+			conf.Server.ArtistArtPriority = "external"
+			artistRepo := tests.CreateMockArtistRepo()
+			artistRepo.SetData(model.Artists{{ID: "ar4", Name: "Artist"}})
+			ds.MockedArtist = artistRepo
+			// no image agents enabled -> the external step is a definitive not-found
+
+			res, err := newResolver(ds, ag, ffm, nil).resolve(ctx, model.ArtworkQueueItem{ItemKind: "ar", ItemID: "ar4"})
+			Expect(err).ToNot(HaveOccurred())
+			Expect(res.reader).To(BeNil())
+			Expect(res.extError).To(BeFalse())
+		})
+
+		It("routes the external step through the injected gate, keyed by agent name", func() {
+			conf.Server.ArtistArtPriority = "external"
+			artistRepo := tests.CreateMockArtistRepo()
+			artistRepo.SetData(model.Artists{{ID: "ar5", Name: "Artist"}})
+			ds.MockedArtist = artistRepo
+			imageAgents(&fakeImageAgent{name: "failAgent", err: errors.New("boom")})
+			var gatedNames []string
+			gate := func(name string, f func() (io.ReadCloser, string, error)) (io.ReadCloser, string, error) {
+				gatedNames = append(gatedNames, name)
+				return f()
+			}
+
+			res, err := newResolver(ds, ag, ffm, gate).resolve(ctx, model.ArtworkQueueItem{ItemKind: "ar", ItemID: "ar5"})
+			Expect(err).ToNot(HaveOccurred())
+			Expect(res.extError).To(BeTrue())
+			Expect(gatedNames).To(Equal([]string{"failAgent"}))
+		})
+	})
+
+	Describe("radio", func() {
+		It("yields an empty resolution when there is no uploaded image", func() {
+			tmpDir := GinkgoT().TempDir()
+			conf.Server.DataFolder = conf.NewDir(tmpDir)
+
+			radioRepo := tests.CreateMockedRadioRepo()
+			radioRepo.Data = map[string]*model.Radio{"ra1": {ID: "ra1", Name: "Radio"}}
+			ds.MockedRadio = radioRepo
+
+			res, err := newResolver(ds, ag, ffm, nil).resolve(ctx, model.ArtworkQueueItem{ItemKind: "ra", ItemID: "ra1"})
+			Expect(err).ToNot(HaveOccurred())
+			Expect(res).To(Equal(resolution{}))
+		})
+
+		It("resolves the uploaded image when set", func() {
+			tmpDir := GinkgoT().TempDir()
+			conf.Server.DataFolder = conf.NewDir(tmpDir)
+			Expect(os.MkdirAll(filepath.Join(tmpDir, "artwork", "radio"), 0755)).To(Succeed())
+			imgPath := filepath.Join(tmpDir, "artwork", "radio", "ra2_test.jpg")
+			Expect(os.WriteFile(imgPath, []byte("uploaded radio image"), 0600)).To(Succeed())
+
+			radioRepo := tests.CreateMockedRadioRepo()
+			radioRepo.Data = map[string]*model.Radio{"ra2": {ID: "ra2", Name: "Radio", UploadedImage: "ra2_test.jpg"}}
+			ds.MockedRadio = radioRepo
+
+			res, err := newResolver(ds, ag, ffm, nil).resolve(ctx, model.ArtworkQueueItem{ItemKind: "ra", ItemID: "ra2"})
+			Expect(err).ToNot(HaveOccurred())
+			Expect(res.reader).ToNot(BeNil())
+			defer res.reader.Close()
+			Expect(res.source).To(Equal("upload"))
+			Expect(res.sourcePath).To(Equal(imgPath))
+		})
+	})
+
+	Describe("playlist", func() {
+		BeforeEach(func() {
+			conf.Server.CoverArtPriority = "cover.jpg"
+			folderRepo.result = []model.Folder{{
+				Path:       "tests/fixtures/artist/an-album",
+				ImageFiles: []string{"cover.jpg"},
+			}}
+			ds.MockedAlbum = tests.CreateMockAlbumRepo()
+			ds.MockedAlbum.(*tests.MockAlbumRepo).SetData(model.Albums{
+				{ID: "t1", Name: "T1", FolderIDs: []string{"f1"}},
+				{ID: "t2", Name: "T2", FolderIDs: []string{"f1"}},
+				{ID: "t3", Name: "T3", FolderIDs: []string{"f1"}},
+				{ID: "t4", Name: "T4", FolderIDs: []string{"f1"}},
+			})
+		})
+
+		DescribeTable("yields a generated grid from up to 4 album tiles",
+			func(albumIDs []string, expectedSize int) {
+				plRepo := tests.CreateMockPlaylistRepo()
+				plRepo.SetData(model.Playlists{{ID: "pl1", Name: "Playlist"}})
+				plRepo.TracksRepo = &tests.MockPlaylistTrackRepo{AlbumIDs: albumIDs}
+				ds.MockedPlaylist = plRepo
+
+				res, err := newResolver(ds, ag, ffm, nil).resolve(ctx, model.ArtworkQueueItem{ItemKind: "pl", ItemID: "pl1"})
+				Expect(err).ToNot(HaveOccurred())
+				Expect(res.reader).ToNot(BeNil())
+				defer res.reader.Close()
+				Expect(res.source).To(Equal("generated"))
+
+				img, format, err := image.Decode(res.reader)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(format).To(Equal("png"))
+				Expect(img.Bounds().Dx()).To(Equal(expectedSize))
+				Expect(img.Bounds().Dy()).To(Equal(expectedSize))
+			},
+			// tileSize-1: the 4-tile canvas is built as [0, tileSize-1].
+			Entry("1 album -> single tile", []string{"t1"}, tileSize/2),
+			Entry("2 albums -> duplicated to 4 tiles", []string{"t1", "t2"}, tileSize-1),
+			Entry("3 albums -> duplicated to 4 tiles", []string{"t1", "t2", "t3"}, tileSize-1),
+			Entry("4 albums -> full grid", []string{"t1", "t2", "t3", "t4"}, tileSize-1),
+		)
+
+		It("resolves the uploaded image before the generated grid", func() {
+			tmpDir := GinkgoT().TempDir()
+			conf.Server.DataFolder = conf.NewDir(tmpDir)
+			Expect(os.MkdirAll(filepath.Join(tmpDir, "artwork", "playlist"), 0755)).To(Succeed())
+			imgPath := filepath.Join(tmpDir, "artwork", "playlist", "plu_test.jpg")
+			Expect(os.WriteFile(imgPath, []byte("uploaded playlist image"), 0600)).To(Succeed())
+
+			plRepo := tests.CreateMockPlaylistRepo()
+			plRepo.SetData(model.Playlists{{ID: "plu", Name: "Playlist", UploadedImage: "plu_test.jpg"}})
+			plRepo.TracksRepo = &tests.MockPlaylistTrackRepo{AlbumIDs: []string{"t1", "t2"}}
+			ds.MockedPlaylist = plRepo
+
+			res, err := newResolver(ds, ag, ffm, nil).resolve(ctx, model.ArtworkQueueItem{ItemKind: "pl", ItemID: "plu"})
+			Expect(err).ToNot(HaveOccurred())
+			Expect(res.reader).ToNot(BeNil())
+			defer res.reader.Close()
+			Expect(res.source).To(Equal("upload"))
+			Expect(res.sourcePath).To(Equal(imgPath))
+		})
+
+		It("resolves a sidecar image next to the playlist file before the grid", func() {
+			plDir := GinkgoT().TempDir()
+			Expect(os.WriteFile(filepath.Join(plDir, "list.m3u"), []byte("#EXTM3U"), 0600)).To(Succeed())
+			Expect(os.WriteFile(filepath.Join(plDir, "list.jpg"), []byte("sidecar image"), 0600)).To(Succeed())
+
+			plRepo := tests.CreateMockPlaylistRepo()
+			plRepo.SetData(model.Playlists{{ID: "pls", Name: "Playlist", Path: filepath.Join(plDir, "list.m3u")}})
+			plRepo.TracksRepo = &tests.MockPlaylistTrackRepo{AlbumIDs: []string{"t1", "t2"}}
+			ds.MockedPlaylist = plRepo
+
+			res, err := newResolver(ds, ag, ffm, nil).resolve(ctx, model.ArtworkQueueItem{ItemKind: "pl", ItemID: "pls"})
+			Expect(err).ToNot(HaveOccurred())
+			Expect(res.reader).ToNot(BeNil())
+			defer res.reader.Close()
+			Expect(res.source).To(Equal("folder"))
+			Expect(filepath.ToSlash(res.sourcePath)).To(HaveSuffix("list.jpg"))
+		})
+
+		It("serves a local ExternalImageURL as a file-backed reference (staleness-checked)", func() {
+			dir := GinkgoT().TempDir()
+			imgPath := filepath.Join(dir, "cover.png")
+			Expect(os.WriteFile(imgPath, []byte("local external image"), 0600)).To(Succeed())
+
+			plRepo := tests.CreateMockPlaylistRepo()
+			plRepo.SetData(model.Playlists{{ID: "pll", Name: "Playlist", ExternalImageURL: imgPath}})
+			plRepo.TracksRepo = &tests.MockPlaylistTrackRepo{AlbumIDs: []string{"t1"}}
+			ds.MockedPlaylist = plRepo
+
+			res, err := newResolver(ds, ag, ffm, nil).resolve(ctx, model.ArtworkQueueItem{ItemKind: "pl", ItemID: "pll"})
+			Expect(err).ToNot(HaveOccurred())
+			Expect(res.reader).ToNot(BeNil())
+			defer res.reader.Close()
+			Expect(res.source).To(Equal("folder"))
+			Expect(res.sourcePath).To(Equal(imgPath))
+			Expect(res.refMtime).To(BeNumerically(">", 0))
+		})
+
+		It("routes ExternalImageURL through extGate and sets extError on transient failure", func() {
+			conf.Server.EnableM3UExternalAlbumArt = true
+			folderRepo.result = nil // no grid tiles, so the external failure is what surfaces
+
+			plRepo := tests.CreateMockPlaylistRepo()
+			plRepo.SetData(model.Playlists{{ID: "ple", Name: "Playlist", ExternalImageURL: "http://example.com/cover.jpg"}})
+			plRepo.TracksRepo = &tests.MockPlaylistTrackRepo{AlbumIDs: []string{"t1"}}
+			ds.MockedPlaylist = plRepo
+
+			var gatedNames []string
+			gate := func(name string, _ func() (io.ReadCloser, string, error)) (io.ReadCloser, string, error) {
+				gatedNames = append(gatedNames, name)
+				return nil, "", errors.New("network down")
+			}
+
+			res, err := newResolver(ds, ag, ffm, gate).resolve(ctx, model.ArtworkQueueItem{ItemKind: "pl", ItemID: "ple"})
+			Expect(err).ToNot(HaveOccurred())
+			Expect(res.reader).To(BeNil())
+			Expect(res.extError).To(BeTrue())
+			Expect(gatedNames).To(Equal([]string{"m3u"}), "the playlist URL fetch is gated under \"m3u\"")
+		})
+
+		It("treats a missing local ExternalImageURL as a definitive miss, not extError", func() {
+			folderRepo.result = nil // no grid tiles, so the local-file miss is what surfaces
+
+			plRepo := tests.CreateMockPlaylistRepo()
+			plRepo.SetData(model.Playlists{{ID: "plm", Name: "Playlist", ExternalImageURL: "/nonexistent/path/cover.jpg"}})
+			plRepo.TracksRepo = &tests.MockPlaylistTrackRepo{AlbumIDs: []string{"t1"}}
+			ds.MockedPlaylist = plRepo
+
+			res, err := newResolver(ds, ag, ffm, nil).resolve(ctx, model.ArtworkQueueItem{ItemKind: "pl", ItemID: "plm"})
+			Expect(err).ToNot(HaveOccurred())
+			Expect(res.reader).To(BeNil())
+			Expect(res.extError).To(BeFalse())
+		})
+
+		It("treats an ExternalImageURL 404 as a definitive miss and falls through to the grid", func() {
+			conf.Server.EnableM3UExternalAlbumArt = true
+			srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+				w.WriteHeader(http.StatusNotFound)
+			}))
+			defer srv.Close()
+
+			plRepo := tests.CreateMockPlaylistRepo()
+			plRepo.SetData(model.Playlists{{ID: "pl404", Name: "Playlist", ExternalImageURL: srv.URL}})
+			plRepo.TracksRepo = &tests.MockPlaylistTrackRepo{AlbumIDs: []string{"t1"}}
+			ds.MockedPlaylist = plRepo
+
+			res, err := newResolver(ds, ag, ffm, nil).resolve(ctx, model.ArtworkQueueItem{ItemKind: "pl", ItemID: "pl404"})
+			Expect(err).ToNot(HaveOccurred())
+			Expect(res.reader).ToNot(BeNil())
+			defer res.reader.Close()
+			Expect(res.source).To(Equal("generated"))
+			Expect(res.extError).To(BeFalse())
+		})
+
+		// A local resolver holds no agents: reaching the external branch would panic, not degrade.
+		It("skips the external step instead of dereferencing absent agents", func() {
+			conf.Server.CoverArtPriority = "external"
+			ds.MockedAlbum = tests.CreateMockAlbumRepo()
+			ds.MockedAlbum.(*tests.MockAlbumRepo).SetData(model.Albums{{ID: "alx", Name: "Album"}})
+
+			res, err := newLocalResolver(ds, ffm).resolve(ctx, model.ArtworkQueueItem{ItemKind: "al", ItemID: "alx"})
+			Expect(err).ToNot(HaveOccurred())
+			Expect(res.reader).To(BeNil())
+			Expect(res.extError).To(BeFalse(), "a skipped step is not a failed one")
+		})
+
+		// The worker resolving the same playlist is asserted alongside, so this cannot pass vacuously.
+		It("resolves a playlist locally without fetching remotely or building the grid", func() {
+			conf.Server.EnableM3UExternalAlbumArt = true
+			var hits atomic.Int32
+			srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+				hits.Add(1)
+				w.WriteHeader(http.StatusNotFound)
+			}))
+			defer srv.Close()
+
+			plRepo := tests.CreateMockPlaylistRepo()
+			plRepo.SetData(model.Playlists{{ID: "pllocal", Name: "Playlist", ExternalImageURL: srv.URL}})
+			plRepo.TracksRepo = &tests.MockPlaylistTrackRepo{AlbumIDs: []string{"t1"}}
+			ds.MockedPlaylist = plRepo
+			item := model.ArtworkQueueItem{ItemKind: "pl", ItemID: "pllocal"}
+
+			res, err := newLocalResolver(ds, ffm).resolve(ctx, item)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(res.reader).To(BeNil(), "no local source, and the grid is worker-only")
+			Expect(hits.Load()).To(BeZero(), "a request must never reach the network")
+
+			worker, err := newResolver(ds, ag, ffm, nil).resolve(ctx, item)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(worker.reader).ToNot(BeNil())
+			defer worker.reader.Close()
+			Expect(worker.source).To(Equal("generated"), "the worker does build the grid")
+			Expect(hits.Load()).To(Equal(int32(1)), "and the worker does fetch")
+		})
+
+		It("treats an ExternalImageURL 500 as a transient failure and sets extError", func() {
+			conf.Server.EnableM3UExternalAlbumArt = true
+			folderRepo.result = nil // no grid tiles, so the external failure is what surfaces
+			srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+				w.WriteHeader(http.StatusInternalServerError)
+			}))
+			defer srv.Close()
+
+			plRepo := tests.CreateMockPlaylistRepo()
+			plRepo.SetData(model.Playlists{{ID: "pl500", Name: "Playlist", ExternalImageURL: srv.URL}})
+			plRepo.TracksRepo = &tests.MockPlaylistTrackRepo{AlbumIDs: []string{"t1"}}
+			ds.MockedPlaylist = plRepo
+
+			res, err := newResolver(ds, ag, ffm, nil).resolve(ctx, model.ArtworkQueueItem{ItemKind: "pl", ItemID: "pl500"})
+			Expect(err).ToNot(HaveOccurred())
+			Expect(res.reader).To(BeNil())
+			Expect(res.extError).To(BeTrue())
+		})
+
+		It("yields an empty resolution when no album has art", func() {
+			ds.MockedAlbum.(*tests.MockAlbumRepo).SetData(model.Albums{
+				{ID: "empty1", Name: "Empty"},
+			})
+			plRepo := tests.CreateMockPlaylistRepo()
+			plRepo.SetData(model.Playlists{{ID: "pl2", Name: "Playlist"}})
+			plRepo.TracksRepo = &tests.MockPlaylistTrackRepo{AlbumIDs: []string{"empty1"}}
+			ds.MockedPlaylist = plRepo
+			folderRepo.result = nil
+
+			res, err := newResolver(ds, ag, ffm, nil).resolve(ctx, model.ArtworkQueueItem{ItemKind: "pl", ItemID: "pl2"})
+			Expect(err).ToNot(HaveOccurred())
+			Expect(res.reader).To(BeNil())
+			Expect(res.source).To(BeEmpty())
+		})
+
+		It("skips a grid tile whose declared dimensions are a decompression bomb", func() {
+			libRoot := GinkgoT().TempDir()
+			Expect(os.MkdirAll(filepath.Join(libRoot, "bomb"), 0755)).To(Succeed())
+			Expect(os.WriteFile(filepath.Join(libRoot, "bomb", "cover.jpg"), pngHeaderWithDims(50000, 50000), 0600)).To(Succeed())
+			libRepo.SetData(model.Libraries{{ID: 0, Path: testFileLibPath(libRoot)}})
+			folderRepo.result = []model.Folder{{Path: "bomb", ImageFiles: []string{"cover.jpg"}}}
+
+			plRepo := tests.CreateMockPlaylistRepo()
+			plRepo.SetData(model.Playlists{{ID: "plbomb", Name: "Playlist"}})
+			plRepo.TracksRepo = &tests.MockPlaylistTrackRepo{AlbumIDs: []string{"t1"}}
+			ds.MockedPlaylist = plRepo
+
+			res, err := newResolver(ds, ag, ffm, nil).resolve(ctx, model.ArtworkQueueItem{ItemKind: "pl", ItemID: "plbomb"})
+			Expect(err).ToNot(HaveOccurred())
+			Expect(res.reader).To(BeNil())
+			Expect(res.source).To(BeEmpty())
+		})
+
+		It("does not resolve as absent when every sampled album fails to resolve", func() {
+			// The album ids are absent from MockAlbumRepo, so every tile fails non-externally.
+			plRepo := tests.CreateMockPlaylistRepo()
+			plRepo.SetData(model.Playlists{{ID: "pl3", Name: "Playlist"}})
+			plRepo.TracksRepo = &tests.MockPlaylistTrackRepo{AlbumIDs: []string{"missing1", "missing2"}}
+			ds.MockedPlaylist = plRepo
+
+			res, err := newResolver(ds, ag, ffm, nil).resolve(ctx, model.ArtworkQueueItem{ItemKind: "pl", ItemID: "pl3"})
+			Expect(err).To(HaveOccurred())
+			Expect(res).To(Equal(resolution{}))
+		})
+	})
+})
+
+// decodeTile runs before the processor's own guards, so it must enforce the caps itself.
+var _ = Describe("decodeTile", func() {
+	It("rejects a decompression bomb before the full decode", func() {
+		data := pngHeaderWithDims(50000, 50000) // 2.5 gigapixels, far above the cap
+		_, err := decodeTile(io.NopCloser(bytes.NewReader(data)))
+		Expect(err).To(HaveOccurred())
+		Expect(err.Error()).To(ContainSubstring("dimensions"))
+	})
+
+	It("rejects a tile larger than the size cap", func() {
+		data := bytes.Repeat([]byte{0}, maxImageBytes+1)
+		_, err := decodeTile(io.NopCloser(bytes.NewReader(data)))
+		Expect(err).To(HaveOccurred())
+	})
+})

core/artwork/sources.go

@@ -3,6 +3,7 @@ package artwork
 import (
 	"bytes"
 	"context"
+	"errors"
 	"fmt"
 	"io"
 	"io/fs"
@@ -16,14 +17,16 @@ import (
 	"time"
 
 	"github.com/navidrome/navidrome/consts"
-	"github.com/navidrome/navidrome/core/external"
 	"github.com/navidrome/navidrome/core/ffmpeg"
 	"github.com/navidrome/navidrome/log"
 	"github.com/navidrome/navidrome/model"
-	"github.com/navidrome/navidrome/resources"
 	"go.senan.xyz/taglib"
 )
 
+// errSourceUnreadable marks a candidate the resolver knows exists but could not read. Failing
+// to open it is not evidence the entity has no artwork, so callers must not settle on absent.
+var errSourceUnreadable = errors.New("artwork source unreadable")
+
 func selectImageReader(ctx context.Context, artID model.ArtworkID, extractFuncs ...sourceFunc) (io.ReadCloser, string, error) {
 	for _, f := range extractFuncs {
 		if ctx.Err() != nil {
@@ -32,11 +35,11 @@ func selectImageReader(ctx context.Context, artID model.ArtworkID, extractFuncs
 		start := time.Now()
 		r, path, err := f()
 		if r != nil {
-			msg := fmt.Sprintf("Found %s artwork", artID.Kind)
+			msg := fmt.Sprintf("Artwork: Found %s artwork", artID.Kind)
 			log.Debug(ctx, msg, "artID", artID, "path", path, "source", f, "elapsed", time.Since(start))
 			return r, path, nil
 		}
-		log.Trace(ctx, "Failed trying to extract artwork", "artID", artID, "source", f, "elapsed", time.Since(start), err)
+		log.Trace(ctx, "Artwork: Failed trying to extract artwork", "artID", artID, "source", f, "elapsed", time.Since(start), err)
 	}
 	return nil, "", fmt.Errorf("could not get `%s` cover art for %s: %w", artID.Kind, artID, ErrUnavailable)
 }
@@ -55,11 +58,12 @@ func (f sourceFunc) String() string {
 
 func fromExternalFile(ctx context.Context, libFS fs.FS, files []string, pattern string) sourceFunc {
 	return func() (io.ReadCloser, string, error) {
+		var openErr error
 		for _, file := range files {
 			_, name := filepath.Split(file)
 			match, err := filepath.Match(pattern, strings.ToLower(name))
 			if err != nil {
-				log.Warn(ctx, "Error matching cover art file to pattern", "pattern", pattern, "file", file)
+				log.Warn(ctx, "Artwork: Error matching cover art file to pattern", "pattern", pattern, "file", file)
 				continue
 			}
 			if !match {
@@ -67,11 +71,15 @@ func fromExternalFile(ctx context.Context, libFS fs.FS, files []string, pattern
 			}
 			f, err := libFS.Open(file)
 			if err != nil {
-				log.Warn(ctx, "Could not open cover art file", "file", file, err)
+				log.Warn(ctx, "Artwork: Could not open cover art file", "file", file, err)
+				openErr = fmt.Errorf("%w: %s: %w", errSourceUnreadable, file, err)
 				continue
 			}
 			return f, file, nil
 		}
+		if openErr != nil {
+			return nil, "", openErr
+		}
 		return nil, "", fmt.Errorf("pattern '%s' not matched by files %v", pattern, files)
 	}
 }
@@ -90,7 +98,7 @@ func fromTag(ctx context.Context, libFS fs.FS, relPath string) sourceFunc {
 		}
 		f, err := libFS.Open(relPath)
 		if err != nil {
-			return nil, "", err
+			return nil, "", fmt.Errorf("%w: %s: %w", errSourceUnreadable, relPath, err)
 		}
 		rs, ok := f.(io.ReadSeeker)
 		if !ok {
@@ -103,7 +111,7 @@ func fromTag(ctx context.Context, libFS fs.FS, relPath string) sourceFunc {
 		)
 		if err != nil {
 			f.Close()
-			return nil, "", err
+			return nil, "", fmt.Errorf("%w: %s: %w", errSourceUnreadable, relPath, err)
 		}
 		// Close in LIFO order: tf first (it holds rs internally), then f.
 		defer f.Close()
@@ -127,12 +135,12 @@ func findBestImageIndex(ctx context.Context, images []taglib.ImageDesc, path str
 	for _, regex := range picTypeRegexes {
 		for i, img := range images {
 			if regex.MatchString(img.Type) {
-				log.Trace(ctx, "Found embedded image", "type", img.Type, "path", path)
+				log.Trace(ctx, "Artwork: Found embedded image", "type", img.Type, "path", path)
 				return i
 			}
 		}
 	}
-	log.Trace(ctx, "Could not find a front image. Getting the first one", "type", images[0].Type, "path", path)
+	log.Trace(ctx, "Artwork: Could not find a front image. Getting the first one", "type", images[0].Type, "path", path)
 	return 0
 }
 
@@ -171,44 +179,6 @@ type readCloser struct {
 	io.Closer
 }
 
-func fromAlbum(ctx context.Context, a *artwork, id model.ArtworkID) sourceFunc {
-	return func() (io.ReadCloser, string, error) {
-		r, _, err := a.Get(ctx, id, 0, false)
-		if err != nil {
-			return nil, "", err
-		}
-		return r, id.String(), nil
-	}
-}
-
-func fromAlbumPlaceholder() sourceFunc {
-	return func() (io.ReadCloser, string, error) {
-		r, _ := resources.FS().Open(consts.PlaceholderAlbumArt)
-		return r, consts.PlaceholderAlbumArt, nil
-	}
-}
-func fromArtistExternalSource(ctx context.Context, ar model.Artist, provider external.Provider) sourceFunc {
-	return func() (io.ReadCloser, string, error) {
-		imageUrl, err := provider.ArtistImage(ctx, ar.ID)
-		if err != nil {
-			return nil, "", err
-		}
-
-		return fromURL(ctx, imageUrl)
-	}
-}
-
-func fromAlbumExternalSource(ctx context.Context, al model.Album, provider external.Provider) sourceFunc {
-	return func() (io.ReadCloser, string, error) {
-		imageUrl, err := provider.AlbumImage(ctx, al.ID)
-		if err != nil {
-			return nil, "", err
-		}
-
-		return fromURL(ctx, imageUrl)
-	}
-}
-
 func fromURL(ctx context.Context, imageUrl *url.URL) (io.ReadCloser, string, error) {
 	hc := http.Client{Timeout: 5 * time.Second}
 	req, _ := http.NewRequestWithContext(ctx, http.MethodGet, imageUrl.String(), nil)
@@ -217,6 +187,12 @@ func fromURL(ctx context.Context, imageUrl *url.URL) (io.ReadCloser, string, err
 	if err != nil {
 		return nil, "", err
 	}
+	// An agent-advertised URL that 404s is a definitive miss, not a fault: settle absent
+	// instead of retrying forever and tripping the artwork breaker.
+	if resp.StatusCode == http.StatusNotFound || resp.StatusCode == http.StatusGone {
+		resp.Body.Close()
+		return nil, "", model.ErrNotFound
+	}
 	if resp.StatusCode != http.StatusOK {
 		resp.Body.Close()
 		return nil, "", fmt.Errorf("error retrieving artwork from %s: %s", imageUrl, resp.Status)

core/artwork/thumbhash/testdata/gen_fixtures.mjs

@@ -0,0 +1,90 @@
+// Generates lossless PNG fixtures <=100px. Run: node gen_fixtures.mjs
+import { writeFileSync } from 'fs'
+import { deflateSync } from 'zlib'
+
+const crcTable = Array.from({ length: 256 }, (_, n) => {
+  let c = n
+  for (let k = 0; k < 8; k++) c = c & 1 ? 0xedb88320 ^ (c >>> 1) : c >>> 1
+  return c >>> 0
+})
+const crc32 = (buf) => {
+  let c = 0xffffffff
+  for (const b of buf) c = crcTable[(c ^ b) & 0xff] ^ (c >>> 8)
+  return (c ^ 0xffffffff) >>> 0
+}
+const chunk = (type, data) => {
+  const len = Buffer.alloc(4)
+  len.writeUInt32BE(data.length)
+  const body = Buffer.concat([Buffer.from(type, 'ascii'), data])
+  const crc = Buffer.alloc(4)
+  crc.writeUInt32BE(crc32(body))
+  return Buffer.concat([len, body, crc])
+}
+const png = (w, h, rgba) => {
+  const ihdr = Buffer.alloc(13)
+  ihdr.writeUInt32BE(w, 0)
+  ihdr.writeUInt32BE(h, 4)
+  ihdr[8] = 8 // bit depth
+  ihdr[9] = 6 // truecolor + alpha
+  const raw = Buffer.alloc(h * (w * 4 + 1))
+  for (let y = 0; y < h; y++) {
+    raw[y * (w * 4 + 1)] = 0 // filter: none
+    for (let x = 0; x < w * 4; x++) raw[y * (w * 4 + 1) + 1 + x] = rgba[y * w * 4 + x]
+  }
+  return Buffer.concat([
+    Buffer.from([137, 80, 78, 71, 13, 10, 26, 10]),
+    chunk('IHDR', ihdr),
+    chunk('IDAT', deflateSync(raw)),
+    chunk('IEND', Buffer.alloc(0)),
+  ])
+}
+
+// A ramp has exactly-zero DCT coefficients, and a zero coefficient's nibble is decided by float
+// rounding noise, so no two summation orders agree on it. Dither gives every coefficient signal.
+let seed = 0
+const dither = () => {
+  seed ^= seed << 13
+  seed ^= seed >>> 17
+  seed ^= seed << 5
+  seed >>>= 0
+  return (seed % 9) - 4
+}
+const shade = (v) => Math.max(0, Math.min(255, v + dither()))
+
+const make = (w, h, fn) => {
+  seed = 0x9e3779b9
+  const rgba = new Uint8Array(w * h * 4)
+  for (let y = 0; y < h; y++)
+    for (let x = 0; x < w; x++) fn(rgba, (y * w + x) * 4, x, y, w, h)
+  return png(w, h, rgba)
+}
+
+const gradient = (rgba, i, x, y, w, h) => {
+  rgba[i] = shade(Math.floor((255 * x) / w))
+  rgba[i + 1] = shade(Math.floor((255 * y) / h))
+  rgba[i + 2] = shade(Math.floor((255 * (x + y)) / (w + h)))
+  rgba[i + 3] = 255
+}
+const solid = (rgba, i) => {
+  rgba[i] = 60
+  rgba[i + 1] = 120
+  rgba[i + 2] = 180
+  rgba[i + 3] = 255
+}
+// RGB must vary with position too: a constant color composited over its own average cancels to a
+// flat L/P/Q (the bug this fixture exists to catch), so pair a color gradient with the alpha ramp.
+const alphaRamp = (rgba, i, x, y, w, h) => {
+  rgba[i] = shade(Math.floor((255 * x) / w))
+  rgba[i + 1] = shade(Math.floor((255 * y) / h))
+  rgba[i + 2] = shade(Math.floor((255 * (x + y)) / (w + h)))
+  rgba[i + 3] = shade(Math.floor((255 * (x + 2 * y)) / (w + 2 * h)))
+}
+
+const out = new URL('.', import.meta.url).pathname
+writeFileSync(out + 'square.png', make(100, 100, gradient))
+writeFileSync(out + 'landscape.png', make(100, 60, gradient))
+writeFileSync(out + 'portrait.png', make(60, 100, gradient))
+writeFileSync(out + 'alpha.png', make(80, 80, alphaRamp))
+writeFileSync(out + 'solid.png', make(64, 64, solid))
+writeFileSync(out + 'tiny.png', make(1, 1, solid))
+console.log('fixtures written')

core/artwork/thumbhash/testdata/gen_generated.mjs

@@ -0,0 +1,28 @@
+// Produces generated.json: ThumbHashes of synthetic images, from the vendored reference.
+// The pixels are a pure function of their index, so Go rebuilds them byte-for-byte from the same
+// formula and only the hashes need committing. Run: node gen_generated.mjs
+import { writeFileSync } from 'fs'
+import { rgbaToThumbHash } from './thumbhash.js'
+
+const COUNT = 300
+
+// mix is a stateless 32-bit finaliser; Go's mix in thumbhash_test.go must match it exactly.
+const mix = (n) => {
+  n = Math.imul(n ^ (n >>> 16), 2246822507) >>> 0
+  n = Math.imul(n ^ (n >>> 13), 3266489909) >>> 0
+  return (n ^ (n >>> 16)) >>> 0
+}
+
+const out = []
+for (let i = 0; i < COUNT; i++) {
+  const w = 1 + (mix(i * 3 + 1) % 100)
+  const h = 1 + (mix(i * 3 + 2) % 100)
+  const rgba = new Uint8Array(w * h * 4)
+  for (let k = 0; k < rgba.length; k++) rgba[k] = mix(i * 1000003 + k) & 255
+  // Random alpha is opaque essentially never, so half are forced opaque to exercise the 7x7
+  // no-alpha layout as often as the 5x5-plus-alpha one.
+  if (i % 2 === 0) for (let k = 3; k < rgba.length; k += 4) rgba[k] = 255
+  out.push({ w, h, hash: Buffer.from(rgbaToThumbHash(w, h, rgba)).toString('base64') })
+}
+writeFileSync(new URL('.', import.meta.url).pathname + 'generated.json', JSON.stringify(out) + '\n')
+console.log(`${out.length} vectors; first ${out[0].w}x${out[0].h} ${out[0].hash}`)

core/artwork/thumbhash/testdata/gen_golden.mjs

@@ -0,0 +1,37 @@
+// Produces golden.json from the vendored reference. Run: node gen_golden.mjs
+import { readFileSync, writeFileSync, readdirSync } from 'fs'
+import { inflateSync } from 'zlib'
+import { rgbaToThumbHash } from './thumbhash.js'
+
+// Minimal reader for the exact PNGs gen_fixtures.mjs writes: 8-bit RGBA, filter 0, single IDAT.
+const readPNG = (buf) => {
+  let w = 0, h = 0
+  const idat = []
+  for (let off = 8; off < buf.length; ) {
+    const len = buf.readUInt32BE(off)
+    const type = buf.toString('ascii', off + 4, off + 8)
+    const data = buf.subarray(off + 8, off + 8 + len)
+    if (type === 'IHDR') {
+      w = data.readUInt32BE(0)
+      h = data.readUInt32BE(4)
+      if (data[8] !== 8 || data[9] !== 6) throw new Error('expected 8-bit RGBA')
+    } else if (type === 'IDAT') idat.push(data)
+    off += 12 + len
+  }
+  const raw = inflateSync(Buffer.concat(idat))
+  const rgba = new Uint8Array(w * h * 4)
+  for (let y = 0; y < h; y++) {
+    if (raw[y * (w * 4 + 1)] !== 0) throw new Error('expected filter 0')
+    for (let x = 0; x < w * 4; x++) rgba[y * w * 4 + x] = raw[y * (w * 4 + 1) + 1 + x]
+  }
+  return { w, h, rgba }
+}
+
+const dir = new URL('.', import.meta.url).pathname
+const golden = {}
+for (const name of readdirSync(dir).filter((f) => f.endsWith('.png')).sort()) {
+  const { w, h, rgba } = readPNG(readFileSync(dir + name))
+  golden[name] = Buffer.from(rgbaToThumbHash(w, h, rgba)).toString('base64')
+}
+writeFileSync(dir + 'golden.json', JSON.stringify(golden, null, 2) + '\n')
+console.log(golden)

core/artwork/thumbhash/testdata/golden.json

@@ -0,0 +1,8 @@
+{
+  "alpha.png": "JOiFBQ4nkIexh3p4iA8uB+lYhIeAh3d4dw==",
+  "landscape.png": "3wcOFJpwh4eBh3d4iIePgAj3hw==",
+  "portrait.png": "3/cNFBqBB4iId4d3d4iAjwj4hw==",
+  "solid.png": "HoUBBwB4eHeHd3hweId3h3h4B2+Ih4gA",
+  "square.png": "H/gNBxpwh4dwd3eIiHd3iHeHeJ+dcH8I",
+  "tiny.png": "HoU9tx4I9wiIh4hwj3CI+AiIcH/494cP"
+}

core/artwork/thumbhash/testdata/thumbhash.js

@@ -0,0 +1,288 @@
+/**
+ * Encodes an RGBA image to a ThumbHash. RGB should not be premultiplied by A.
+ *
+ * @param w The width of the input image. Must be ≤100px.
+ * @param h The height of the input image. Must be ≤100px.
+ * @param rgba The pixels in the input image, row-by-row. Must have w*h*4 elements.
+ * @returns The ThumbHash as a Uint8Array.
+ */
+export function rgbaToThumbHash(w, h, rgba) {
+  // Encoding an image larger than 100x100 is slow with no benefit
+  if (w > 100 || h > 100) throw new Error(`${w}x${h} doesn't fit in 100x100`)
+  let { PI, round, max, cos, abs } = Math
+
+  // Determine the average color
+  let avg_r = 0, avg_g = 0, avg_b = 0, avg_a = 0
+  for (let i = 0, j = 0; i < w * h; i++, j += 4) {
+    let alpha = rgba[j + 3] / 255
+    avg_r += alpha / 255 * rgba[j]
+    avg_g += alpha / 255 * rgba[j + 1]
+    avg_b += alpha / 255 * rgba[j + 2]
+    avg_a += alpha
+  }
+  if (avg_a) {
+    avg_r /= avg_a
+    avg_g /= avg_a
+    avg_b /= avg_a
+  }
+
+  let hasAlpha = avg_a < w * h
+  let l_limit = hasAlpha ? 5 : 7 // Use fewer luminance bits if there's alpha
+  let lx = max(1, round(l_limit * w / max(w, h)))
+  let ly = max(1, round(l_limit * h / max(w, h)))
+  let l = [] // luminance
+  let p = [] // yellow - blue
+  let q = [] // red - green
+  let a = [] // alpha
+
+  // Convert the image from RGBA to LPQA (composite atop the average color)
+  for (let i = 0, j = 0; i < w * h; i++, j += 4) {
+    let alpha = rgba[j + 3] / 255
+    let r = avg_r * (1 - alpha) + alpha / 255 * rgba[j]
+    let g = avg_g * (1 - alpha) + alpha / 255 * rgba[j + 1]
+    let b = avg_b * (1 - alpha) + alpha / 255 * rgba[j + 2]
+    l[i] = (r + g + b) / 3
+    p[i] = (r + g) / 2 - b
+    q[i] = r - g
+    a[i] = alpha
+  }
+
+  // Encode using the DCT into DC (constant) and normalized AC (varying) terms
+  let encodeChannel = (channel, nx, ny) => {
+    let dc = 0, ac = [], scale = 0, fx = []
+    for (let cy = 0; cy < ny; cy++) {
+      for (let cx = 0; cx * ny < nx * (ny - cy); cx++) {
+        let f = 0
+        for (let x = 0; x < w; x++)
+          fx[x] = cos(PI / w * cx * (x + 0.5))
+        for (let y = 0; y < h; y++)
+          for (let x = 0, fy = cos(PI / h * cy * (y + 0.5)); x < w; x++)
+            f += channel[x + y * w] * fx[x] * fy
+        f /= w * h
+        if (cx || cy) {
+          ac.push(f)
+          scale = max(scale, abs(f))
+        } else {
+          dc = f
+        }
+      }
+    }
+    if (scale)
+      for (let i = 0; i < ac.length; i++)
+        ac[i] = 0.5 + 0.5 / scale * ac[i]
+    return [dc, ac, scale]
+  }
+  let [l_dc, l_ac, l_scale] = encodeChannel(l, max(3, lx), max(3, ly))
+  let [p_dc, p_ac, p_scale] = encodeChannel(p, 3, 3)
+  let [q_dc, q_ac, q_scale] = encodeChannel(q, 3, 3)
+  let [a_dc, a_ac, a_scale] = hasAlpha ? encodeChannel(a, 5, 5) : []
+
+  // Write the constants
+  let isLandscape = w > h
+  let header24 = round(63 * l_dc) | (round(31.5 + 31.5 * p_dc) << 6) | (round(31.5 + 31.5 * q_dc) << 12) | (round(31 * l_scale) << 18) | (hasAlpha << 23)
+  let header16 = (isLandscape ? ly : lx) | (round(63 * p_scale) << 3) | (round(63 * q_scale) << 9) | (isLandscape << 15)
+  let hash = [header24 & 255, (header24 >> 8) & 255, header24 >> 16, header16 & 255, header16 >> 8]
+  let ac_start = hasAlpha ? 6 : 5
+  let ac_index = 0
+  if (hasAlpha) hash.push(round(15 * a_dc) | (round(15 * a_scale) << 4))
+
+  // Write the varying factors
+  for (let ac of hasAlpha ? [l_ac, p_ac, q_ac, a_ac] : [l_ac, p_ac, q_ac])
+    for (let f of ac)
+      hash[ac_start + (ac_index >> 1)] |= round(15 * f) << ((ac_index++ & 1) << 2)
+  return new Uint8Array(hash)
+}
+
+/**
+ * Decodes a ThumbHash to an RGBA image. RGB is not be premultiplied by A.
+ *
+ * @param hash The bytes of the ThumbHash.
+ * @returns The width, height, and pixels of the rendered placeholder image.
+ */
+export function thumbHashToRGBA(hash) {
+  let { PI, min, max, cos, round } = Math
+
+  // Read the constants
+  let header24 = hash[0] | (hash[1] << 8) | (hash[2] << 16)
+  let header16 = hash[3] | (hash[4] << 8)
+  let l_dc = (header24 & 63) / 63
+  let p_dc = ((header24 >> 6) & 63) / 31.5 - 1
+  let q_dc = ((header24 >> 12) & 63) / 31.5 - 1
+  let l_scale = ((header24 >> 18) & 31) / 31
+  let hasAlpha = header24 >> 23
+  let p_scale = ((header16 >> 3) & 63) / 63
+  let q_scale = ((header16 >> 9) & 63) / 63
+  let isLandscape = header16 >> 15
+  let lx = max(3, isLandscape ? hasAlpha ? 5 : 7 : header16 & 7)
+  let ly = max(3, isLandscape ? header16 & 7 : hasAlpha ? 5 : 7)
+  let a_dc = hasAlpha ? (hash[5] & 15) / 15 : 1
+  let a_scale = (hash[5] >> 4) / 15
+
+  // Read the varying factors (boost saturation by 1.25x to compensate for quantization)
+  let ac_start = hasAlpha ? 6 : 5
+  let ac_index = 0
+  let decodeChannel = (nx, ny, scale) => {
+    let ac = []
+    for (let cy = 0; cy < ny; cy++)
+      for (let cx = cy ? 0 : 1; cx * ny < nx * (ny - cy); cx++)
+        ac.push((((hash[ac_start + (ac_index >> 1)] >> ((ac_index++ & 1) << 2)) & 15) / 7.5 - 1) * scale)
+    return ac
+  }
+  let l_ac = decodeChannel(lx, ly, l_scale)
+  let p_ac = decodeChannel(3, 3, p_scale * 1.25)
+  let q_ac = decodeChannel(3, 3, q_scale * 1.25)
+  let a_ac = hasAlpha && decodeChannel(5, 5, a_scale)
+
+  // Decode using the DCT into RGB
+  let ratio = thumbHashToApproximateAspectRatio(hash)
+  let w = round(ratio > 1 ? 32 : 32 * ratio)
+  let h = round(ratio > 1 ? 32 / ratio : 32)
+  let rgba = new Uint8Array(w * h * 4), fx = [], fy = []
+  for (let y = 0, i = 0; y < h; y++) {
+    for (let x = 0; x < w; x++, i += 4) {
+      let l = l_dc, p = p_dc, q = q_dc, a = a_dc
+
+      // Precompute the coefficients
+      for (let cx = 0, n = max(lx, hasAlpha ? 5 : 3); cx < n; cx++)
+        fx[cx] = cos(PI / w * (x + 0.5) * cx)
+      for (let cy = 0, n = max(ly, hasAlpha ? 5 : 3); cy < n; cy++)
+        fy[cy] = cos(PI / h * (y + 0.5) * cy)
+
+      // Decode L
+      for (let cy = 0, j = 0; cy < ly; cy++)
+        for (let cx = cy ? 0 : 1, fy2 = fy[cy] * 2; cx * ly < lx * (ly - cy); cx++, j++)
+          l += l_ac[j] * fx[cx] * fy2
+
+      // Decode P and Q
+      for (let cy = 0, j = 0; cy < 3; cy++) {
+        for (let cx = cy ? 0 : 1, fy2 = fy[cy] * 2; cx < 3 - cy; cx++, j++) {
+          let f = fx[cx] * fy2
+          p += p_ac[j] * f
+          q += q_ac[j] * f
+        }
+      }
+
+      // Decode A
+      if (hasAlpha)
+        for (let cy = 0, j = 0; cy < 5; cy++)
+          for (let cx = cy ? 0 : 1, fy2 = fy[cy] * 2; cx < 5 - cy; cx++, j++)
+            a += a_ac[j] * fx[cx] * fy2
+
+      // Convert to RGB
+      let b = l - 2 / 3 * p
+      let r = (3 * l - b + q) / 2
+      let g = r - q
+      rgba[i] = max(0, 255 * min(1, r))
+      rgba[i + 1] = max(0, 255 * min(1, g))
+      rgba[i + 2] = max(0, 255 * min(1, b))
+      rgba[i + 3] = max(0, 255 * min(1, a))
+    }
+  }
+  return { w, h, rgba }
+}
+
+/**
+ * Extracts the average color from a ThumbHash. RGB is not be premultiplied by A.
+ *
+ * @param hash The bytes of the ThumbHash.
+ * @returns The RGBA values for the average color. Each value ranges from 0 to 1.
+ */
+export function thumbHashToAverageRGBA(hash) {
+  let { min, max } = Math
+  let header = hash[0] | (hash[1] << 8) | (hash[2] << 16)
+  let l = (header & 63) / 63
+  let p = ((header >> 6) & 63) / 31.5 - 1
+  let q = ((header >> 12) & 63) / 31.5 - 1
+  let hasAlpha = header >> 23
+  let a = hasAlpha ? (hash[5] & 15) / 15 : 1
+  let b = l - 2 / 3 * p
+  let r = (3 * l - b + q) / 2
+  let g = r - q
+  return {
+    r: max(0, min(1, r)),
+    g: max(0, min(1, g)),
+    b: max(0, min(1, b)),
+    a
+  }
+}
+
+/**
+ * Extracts the approximate aspect ratio of the original image.
+ *
+ * @param hash The bytes of the ThumbHash.
+ * @returns The approximate aspect ratio (i.e. width / height).
+ */
+export function thumbHashToApproximateAspectRatio(hash) {
+  let header = hash[3]
+  let hasAlpha = hash[2] & 0x80
+  let isLandscape = hash[4] & 0x80
+  let lx = isLandscape ? hasAlpha ? 5 : 7 : header & 7
+  let ly = isLandscape ? header & 7 : hasAlpha ? 5 : 7
+  return lx / ly
+}
+
+/**
+ * Encodes an RGBA image to a PNG data URL. RGB should not be premultiplied by
+ * A. This is optimized for speed and simplicity and does not optimize for size
+ * at all. This doesn't do any compression (all values are stored uncompressed).
+ *
+ * @param w The width of the input image. Must be ≤100px.
+ * @param h The height of the input image. Must be ≤100px.
+ * @param rgba The pixels in the input image, row-by-row. Must have w*h*4 elements.
+ * @returns A data URL containing a PNG for the input image.
+ */
+export function rgbaToDataURL(w, h, rgba) {
+  let row = w * 4 + 1
+  let idat = 6 + h * (5 + row)
+  let bytes = [
+    137, 80, 78, 71, 13, 10, 26, 10, 0, 0, 0, 13, 73, 72, 68, 82, 0, 0,
+    w >> 8, w & 255, 0, 0, h >> 8, h & 255, 8, 6, 0, 0, 0, 0, 0, 0, 0,
+    idat >>> 24, (idat >> 16) & 255, (idat >> 8) & 255, idat & 255,
+    73, 68, 65, 84, 120, 1
+  ]
+  let table = [
+    0, 498536548, 997073096, 651767980, 1994146192, 1802195444, 1303535960,
+    1342533948, -306674912, -267414716, -690576408, -882789492, -1687895376,
+    -2032938284, -1609899400, -1111625188
+  ]
+  let a = 1, b = 0
+  for (let y = 0, i = 0, end = row - 1; y < h; y++, end += row - 1) {
+    bytes.push(y + 1 < h ? 0 : 1, row & 255, row >> 8, ~row & 255, (row >> 8) ^ 255, 0)
+    for (b = (b + a) % 65521; i < end; i++) {
+      let u = rgba[i] & 255
+      bytes.push(u)
+      a = (a + u) % 65521
+      b = (b + a) % 65521
+    }
+  }
+  bytes.push(
+    b >> 8, b & 255, a >> 8, a & 255, 0, 0, 0, 0,
+    0, 0, 0, 0, 73, 69, 78, 68, 174, 66, 96, 130
+  )
+  for (let [start, end] of [[12, 29], [37, 41 + idat]]) {
+    let c = ~0
+    for (let i = start; i < end; i++) {
+      c ^= bytes[i]
+      c = (c >>> 4) ^ table[c & 15]
+      c = (c >>> 4) ^ table[c & 15]
+    }
+    c = ~c
+    bytes[end++] = c >>> 24
+    bytes[end++] = (c >> 16) & 255
+    bytes[end++] = (c >> 8) & 255
+    bytes[end++] = c & 255
+  }
+  return 'data:image/png;base64,' + btoa(String.fromCharCode(...bytes))
+}
+
+/**
+ * Decodes a ThumbHash to a PNG data URL. This is a convenience function that
+ * just calls "thumbHashToRGBA" followed by "rgbaToDataURL".
+ *
+ * @param hash The bytes of the ThumbHash.
+ * @returns A data URL containing a PNG for the rendered ThumbHash.
+ */
+export function thumbHashToDataURL(hash) {
+  let image = thumbHashToRGBA(hash)
+  return rgbaToDataURL(image.w, image.h, image.rgba)
+}

core/artwork/thumbhash/thumbhash.go

@@ -0,0 +1,257 @@
+// Package thumbhash implements the ThumbHash encoding algorithm (https://github.com/evanw/thumbhash).
+package thumbhash
+
+import (
+	"errors"
+	"image"
+	"image/draw"
+	"math"
+
+	xdraw "golang.org/x/image/draw"
+)
+
+// maxInputSize is the algorithm's hard limit: larger inputs are rejected by every implementation.
+const maxInputSize = 100
+
+// term is one DCT coefficient's frequency pair, in the reference's triangular scan order.
+type term struct{ cx, cy int }
+
+// Encode returns the ThumbHash of img: 24 bytes when opaque, 25 with alpha. Output matches
+// evanw/thumbhash except where a coefficient lands on a quantization tie, where a nibble may differ by 1.
+func Encode(img image.Image) ([]byte, error) {
+	rgba := toNRGBA(downscale(img))
+	b := rgba.Bounds()
+	w, h := b.Dx(), b.Dy()
+	if w == 0 || h == 0 {
+		return nil, errors.New("thumbhash: empty image")
+	}
+
+	avgR, avgG, avgB, avgA := averageColor(rgba, w, h)
+	hasAlpha := avgA < float64(w*h)
+	if avgA > 0 {
+		avgR /= avgA
+		avgG /= avgA
+		avgB /= avgA
+	}
+
+	lLimit := 7.0
+	if hasAlpha {
+		lLimit = 5.0
+	}
+	maxWH := float64(max(w, h))
+	lx := max(1, int(math.Round(lLimit*float64(w)/maxWH)))
+	ly := max(1, int(math.Round(lLimit*float64(h)/maxWH)))
+
+	lTerms := terms(max(3, lx), max(3, ly))
+	pTerms := terms(3, 3)
+	qTerms := terms(3, 3)
+	var aTerms []term
+	if hasAlpha {
+		aTerms = terms(5, 5)
+	}
+
+	// The widest coefficient region wins: 3x3 chroma, 5x5 alpha, and luma's own lx by ly.
+	chan5 := 3
+	if hasAlpha {
+		chan5 = 5
+	}
+	nx := max(max(3, lx), chan5)
+	cosX := cosTable(nx, w)
+	cosY := cosTable(max(max(3, ly), chan5), h)
+
+	lAcc := make([]float64, len(lTerms))
+	pAcc := make([]float64, len(pTerms))
+	qAcc := make([]float64, len(qTerms))
+	aAcc := make([]float64, len(aTerms))
+	rowL := make([]float64, nx)
+	rowP := make([]float64, nx)
+	rowQ := make([]float64, nx)
+	rowA := make([]float64, nx)
+
+	for y := range h {
+		clear(rowL)
+		clear(rowP)
+		clear(rowQ)
+		clear(rowA)
+		row := rgba.Pix[y*rgba.Stride:]
+		for x := range w {
+			j := x * 4
+			alpha := float64(row[j+3]) / 255
+			r := avgR*(1-alpha) + alpha/255*float64(row[j])
+			g := avgG*(1-alpha) + alpha/255*float64(row[j+1])
+			bl := avgB*(1-alpha) + alpha/255*float64(row[j+2])
+			lv := (r + g + bl) / 3
+			pv := (r+g)/2 - bl
+			qv := r - g
+			for cx := range nx {
+				f := cosX[cx][x]
+				rowL[cx] += lv * f
+				rowP[cx] += pv * f
+				rowQ[cx] += qv * f
+			}
+			// hasAlpha is loop-invariant, so this costs a predicted branch rather than a quarter
+			// of the inner loop that opaque images never need.
+			if hasAlpha {
+				for cx := range nx {
+					rowA[cx] += alpha * cosX[cx][x]
+				}
+			}
+		}
+		accumulate(lAcc, lTerms, rowL, cosY, y)
+		accumulate(pAcc, pTerms, rowP, cosY, y)
+		accumulate(qAcc, qTerms, rowQ, cosY, y)
+		accumulate(aAcc, aTerms, rowA, cosY, y)
+	}
+
+	n := float64(w * h)
+	lDC, lAC, lScale := normalize(lAcc, n)
+	pDC, pAC, pScale := normalize(pAcc, n)
+	qDC, qAC, qScale := normalize(qAcc, n)
+	aDC, aAC, aScale := normalize(aAcc, n)
+
+	return pack(w, h, hasAlpha, lx, ly,
+		lDC, pDC, qDC, aDC, lScale, pScale, qScale, aScale, lAC, pAC, qAC, aAC), nil
+}
+
+// terms lists the (cx, cy) pairs of the reference's triangular coefficient region, in write order.
+func terms(nx, ny int) []term {
+	var ts []term
+	for cy := range ny {
+		for cx := 0; cx*ny < nx*(ny-cy); cx++ {
+			ts = append(ts, term{cx, cy})
+		}
+	}
+	return ts
+}
+
+// cosTable precomputes cos(pi/size * c * (i+0.5)) with the reference's exact expression, so the
+// table values are bit-identical to recomputing them per coefficient.
+func cosTable(n, size int) [][]float64 {
+	t := make([][]float64, n)
+	for c := range n {
+		t[c] = make([]float64, size)
+		for i := range size {
+			t[c][i] = math.Cos(math.Pi / float64(size) * float64(c) * (float64(i) + 0.5))
+		}
+	}
+	return t
+}
+
+func averageColor(rgba *image.NRGBA, w, h int) (r, g, b, a float64) {
+	for y := range h {
+		row := rgba.Pix[y*rgba.Stride:]
+		for x := range w {
+			j := x * 4
+			alpha := float64(row[j+3]) / 255
+			r += alpha / 255 * float64(row[j])
+			g += alpha / 255 * float64(row[j+1])
+			b += alpha / 255 * float64(row[j+2])
+			a += alpha
+		}
+	}
+	return r, g, b, a
+}
+
+// accumulate folds one row's per-cx sums into the term accumulators, so the pixel loop costs
+// nx multiplies per pixel instead of one per coefficient.
+func accumulate(acc []float64, ts []term, row []float64, cosY [][]float64, y int) {
+	for k, t := range ts {
+		acc[k] += row[t.cx] * cosY[t.cy][y]
+	}
+}
+
+// normalize splits the accumulators into DC and scaled AC terms, matching the reference: a constant
+// image leaves scale at 0, which skips normalization rather than mapping the terms to the midpoint.
+func normalize(acc []float64, n float64) (dc float64, ac []float64, scale float64) {
+	if len(acc) == 0 {
+		return 0, nil, 0
+	}
+	dc = acc[0] / n
+	ac = make([]float64, len(acc)-1)
+	for i, v := range acc[1:] {
+		ac[i] = v / n
+		scale = max(scale, math.Abs(ac[i]))
+	}
+	if scale > 0 {
+		for i := range ac {
+			ac[i] = 0.5 + 0.5/scale*ac[i]
+		}
+	}
+	return dc, ac, scale
+}
+
+func pack(w, h int, hasAlpha bool, lx, ly int,
+	lDC, pDC, qDC, aDC, lScale, pScale, qScale, aScale float64,
+	lAC, pAC, qAC, aAC []float64,
+) []byte {
+	isLandscape := 0
+	if w > h {
+		isLandscape = 1
+	}
+	alphaBit := 0
+	if hasAlpha {
+		alphaBit = 1
+	}
+	header24 := int(math.Round(63*lDC)) | int(math.Round(31.5+31.5*pDC))<<6 |
+		int(math.Round(31.5+31.5*qDC))<<12 | int(math.Round(31*lScale))<<18 | alphaBit<<23
+	lead := lx
+	if isLandscape == 1 {
+		lead = ly
+	}
+	header16 := lead | int(math.Round(63*pScale))<<3 | int(math.Round(63*qScale))<<9 | isLandscape<<15
+
+	acs := [][]float64{lAC, pAC, qAC}
+	acStart := 5
+	if hasAlpha {
+		acs = append(acs, aAC)
+		acStart = 6
+	}
+	acCount := 0
+	for _, ac := range acs {
+		acCount += len(ac)
+	}
+
+	hash := make([]byte, acStart+(acCount+1)/2)
+	hash[0] = byte(header24 & 255)
+	hash[1] = byte((header24 >> 8) & 255)
+	hash[2] = byte(header24 >> 16)
+	hash[3] = byte(header16 & 255)
+	hash[4] = byte(header16 >> 8)
+	if hasAlpha {
+		hash[5] = byte(int(math.Round(15*aDC)) | int(math.Round(15*aScale))<<4)
+	}
+	acIndex := 0
+	for _, ac := range acs {
+		for _, f := range ac {
+			hash[acStart+(acIndex>>1)] |= byte(int(math.Round(15*f)) << ((acIndex & 1) << 2))
+			acIndex++
+		}
+	}
+	return hash
+}
+
+// NRGBA, not RGBA: ThumbHash requires non-premultiplied RGB and the pipeline hands us a
+// premultiplied *image.RGBA, which draw.Draw un-premultiplies on the way in.
+func toNRGBA(img image.Image) *image.NRGBA {
+	// Conservative: a sub-image re-slices Pix so the loops would read it correctly too, but the
+	// copy costs nothing on the origin-anchored images the pipeline actually produces.
+	if nrgba, ok := img.(*image.NRGBA); ok && nrgba.Rect.Min == (image.Point{}) {
+		return nrgba
+	}
+	b := img.Bounds()
+	dst := image.NewNRGBA(image.Rect(0, 0, b.Dx(), b.Dy()))
+	draw.Draw(dst, dst.Bounds(), img, b.Min, draw.Src)
+	return dst
+}
+
+func downscale(img image.Image) image.Image {
+	b := img.Bounds()
+	w, h := b.Dx(), b.Dy()
+	if w <= maxInputSize && h <= maxInputSize {
+		return img
+	}
+	scale := float64(maxInputSize) / float64(max(w, h))
+	dst := image.NewNRGBA(image.Rect(0, 0, max(1, int(float64(w)*scale)), max(1, int(float64(h)*scale))))
+	xdraw.ApproxBiLinear.Scale(dst, dst.Bounds(), img, b, draw.Src, nil)
+	return dst
+}

core/artwork/thumbhash/thumbhash_suite_test.go

@@ -0,0 +1,17 @@
+package thumbhash_test
+
+import (
+	"testing"
+
+	"github.com/navidrome/navidrome/log"
+	"github.com/navidrome/navidrome/tests"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+func TestThumbHash(t *testing.T) {
+	tests.Init(t, false)
+	log.SetLevel(log.LevelFatal)
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "ThumbHash Suite")
+}

core/artwork/thumbhash/thumbhash_test.go

@@ -0,0 +1,194 @@
+package thumbhash_test
+
+import (
+	"encoding/base64"
+	"encoding/json"
+	"image"
+	"image/color"
+	"image/draw"
+	_ "image/png"
+	"os"
+	"path/filepath"
+	"runtime"
+	"slices"
+
+	"github.com/navidrome/navidrome/core/artwork/thumbhash"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+// testdataDir is resolved via runtime.Caller because tests.Init (thumbhash_suite_test.go) chdirs
+// the process to the repo root, which would break a plain relative "testdata" path.
+var testdataDir = func() string {
+	_, file, _, _ := runtime.Caller(0)
+	return filepath.Join(filepath.Dir(file), "testdata")
+}()
+
+// fixtureImage decodes a testdata PNG. NRGBA, not RGBA: ThumbHash needs non-premultiplied pixels,
+// and RGBA would silently premultiply every fixture that has alpha.
+func fixtureImage(name string) *image.NRGBA {
+	GinkgoHelper()
+	f, err := os.Open(filepath.Join(testdataDir, name))
+	Expect(err).ToNot(HaveOccurred())
+	defer f.Close()
+	src, _, err := image.Decode(f)
+	Expect(err).ToNot(HaveOccurred())
+	b := src.Bounds()
+	dst := image.NewNRGBA(image.Rect(0, 0, b.Dx(), b.Dy()))
+	draw.Draw(dst, dst.Bounds(), src, b.Min, draw.Src)
+	return dst
+}
+
+// headerOnlyFixtures have mathematically-zero AC content, so every AC nibble is float rounding
+// noise sitting on a quantization tie; only the header bytes carry signal.
+var headerOnlyFixtures = []string{"solid.png", "tiny.png"}
+
+func loadJSON[T any](name string) T {
+	GinkgoHelper()
+	data, err := os.ReadFile(filepath.Join(testdataDir, name))
+	Expect(err).ToNot(HaveOccurred())
+	var out T
+	Expect(json.Unmarshal(data, &out)).To(Succeed())
+	return out
+}
+
+func loadGoldens() map[string]string {
+	GinkgoHelper()
+	golden := loadJSON[map[string]string]("golden.json")
+	Expect(golden).ToNot(BeEmpty())
+	return golden
+}
+
+// mix is a stateless 32-bit finaliser matching gen_generated.mjs, so both languages build the
+// same synthetic pixels and only the reference's hashes need committing.
+func mix(n uint32) uint32 {
+	n = (n ^ (n >> 16)) * 2246822507
+	n = (n ^ (n >> 13)) * 3266489909
+	return n ^ (n >> 16)
+}
+
+func generatedImage(i int) *image.NRGBA {
+	w := 1 + int(mix(uint32(i)*3+1)%100)
+	h := 1 + int(mix(uint32(i)*3+2)%100)
+	img := image.NewNRGBA(image.Rect(0, 0, w, h))
+	for k := range img.Pix {
+		img.Pix[k] = byte(mix(uint32(i)*1000003 + uint32(k)))
+	}
+	if i%2 == 0 {
+		for k := 3; k < len(img.Pix); k += 4 {
+			img.Pix[k] = 255
+		}
+	}
+	return img
+}
+
+var _ = Describe("Encode", func() {
+	It("matches every golden vector", func() {
+		for name, want := range loadGoldens() {
+			if slices.Contains(headerOnlyFixtures, name) {
+				continue // see the dedicated header-only spec below
+			}
+			got, err := thumbhash.Encode(fixtureImage(name))
+			Expect(err).ToNot(HaveOccurred(), "fixture %s", name)
+			Expect(base64.StdEncoding.EncodeToString(got)).To(Equal(want), "fixture %s", name)
+		}
+	})
+
+	It("reproduces the well-conditioned header of the ill-conditioned fixtures", func() {
+		for _, name := range headerOnlyFixtures {
+			want, err := base64.StdEncoding.DecodeString(loadGoldens()[name])
+			Expect(err).ToNot(HaveOccurred(), "fixture %s", name)
+			got, err := thumbhash.Encode(fixtureImage(name))
+			Expect(err).ToNot(HaveOccurred(), "fixture %s", name)
+			Expect(got[:5]).To(Equal(want[:5]), "fixture %s header bytes", name)
+		}
+	})
+
+	// The PNG fixtures cannot reach every layout; these sweep random sizes, aspects and both the
+	// 7x7 no-alpha and 5x5-plus-alpha coefficient regions against the same reference.
+	It("matches the reference on 300 generated images", func() {
+		vectors := loadJSON[[]struct {
+			W, H int
+			Hash string
+		}]("generated.json")
+		Expect(vectors).ToNot(BeEmpty())
+		for i, want := range vectors {
+			img := generatedImage(i)
+			Expect(img.Bounds().Dx()).To(Equal(want.W), "vector %d width", i)
+			Expect(img.Bounds().Dy()).To(Equal(want.H), "vector %d height", i)
+			got, err := thumbhash.Encode(img)
+			Expect(err).ToNot(HaveOccurred(), "vector %d", i)
+			Expect(base64.StdEncoding.EncodeToString(got)).To(Equal(want.Hash), "vector %d (%dx%d)", i, want.W, want.H)
+		}
+	})
+
+	It("quantizes a uniform image's scales to zero", func() {
+		got, err := thumbhash.Encode(fixtureImage("solid.png"))
+		Expect(err).ToNot(HaveOccurred())
+		header24 := int(got[0]) | int(got[1])<<8 | int(got[2])<<16
+		header16 := int(got[3]) | int(got[4])<<8
+		Expect((header24>>18)&31).To(Equal(0), "lScale")
+		Expect((header16>>3)&63).To(Equal(0), "pScale")
+		Expect((header16>>9)&63).To(Equal(0), "qScale")
+	})
+
+	It("produces 24 bytes for a square opaque image", func() {
+		got, err := thumbhash.Encode(fixtureImage("square.png"))
+		Expect(err).ToNot(HaveOccurred())
+		Expect(got).To(HaveLen(24))
+	})
+
+	It("produces 25 bytes when the image has alpha", func() {
+		got, err := thumbhash.Encode(fixtureImage("alpha.png"))
+		Expect(err).ToNot(HaveOccurred())
+		Expect(got).To(HaveLen(25))
+	})
+
+	It("downscales an oversized image rather than failing", func() {
+		img := image.NewNRGBA(image.Rect(0, 0, 500, 300))
+		for i := range img.Pix {
+			img.Pix[i] = byte(i)
+		}
+		got, err := thumbhash.Encode(img)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(len(got)).To(BeNumerically(">=", 5))
+	})
+
+	It("encodes a 1x1 image", func() {
+		img := image.NewNRGBA(image.Rect(0, 0, 1, 1))
+		img.Set(0, 0, color.NRGBA{R: 60, G: 120, B: 180, A: 255})
+		got, err := thumbhash.Encode(img)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(got).ToNot(BeEmpty())
+	})
+
+	It("encodes a sub-image like an origin-anchored copy of the same region", func() {
+		parent := image.NewNRGBA(image.Rect(0, 0, 60, 50))
+		for i := range parent.Pix {
+			parent.Pix[i] = byte(i * 7 % 251)
+		}
+		region := image.Rect(10, 7, 40, 30)
+		cropped := image.NewNRGBA(image.Rect(0, 0, region.Dx(), region.Dy()))
+		draw.Draw(cropped, cropped.Bounds(), parent, region.Min, draw.Src)
+
+		got, err := thumbhash.Encode(parent.SubImage(region))
+		Expect(err).ToNot(HaveOccurred())
+		want, err := thumbhash.Encode(cropped)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(got).To(Equal(want))
+	})
+
+	It("rejects an empty image", func() {
+		_, err := thumbhash.Encode(image.NewRGBA(image.Rect(0, 0, 0, 0)))
+		Expect(err).To(HaveOccurred())
+	})
+
+	It("is deterministic", func() {
+		img := fixtureImage("square.png")
+		first, err := thumbhash.Encode(img)
+		Expect(err).ToNot(HaveOccurred())
+		second, err := thumbhash.Encode(img)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(first).To(Equal(second))
+	})
+})

core/artwork/uploader.go

@@ -1,4 +1,4 @@
-package core
+package artwork
 
 import (
 	"context"
@@ -15,13 +15,7 @@ import (
 	"github.com/navidrome/navidrome/utils"
 )
 
-type ImageUploadService interface {
-	SetImage(ctx context.Context, entityType string, entityID string, name string, oldPath string, reader io.Reader, ext string) (filename string, err error)
-	RemoveImage(ctx context.Context, path string) error
-}
-
-// MaxImageUploadSize returns the configured MaxImageUploadSize in bytes, or the built-in default
-// when it's unset/invalid. Shared by every API that accepts image uploads.
+// MaxImageUploadSize returns the configured max upload size in bytes, or the built-in default.
 func MaxImageUploadSize() int64 {
 	if size, err := humanize.ParseBytes(conf.Server.MaxImageUploadSize); err == nil && size > 0 {
 		return int64(size)
@@ -30,13 +24,30 @@ func MaxImageUploadSize() int64 {
 	return int64(size)
 }
 
-type imageUploadService struct{}
-
-func NewImageUploadService() ImageUploadService {
-	return &imageUploadService{}
+// Uploader stores a user-uploaded entity image and invalidates that entity's artwork state.
+type Uploader interface {
+	SetImage(ctx context.Context, entityType string, entityID string, name string, oldPath string, reader io.Reader, ext string) (filename string, err error)
+	RemoveImage(ctx context.Context, path string) error
+	// EnqueueArtwork re-resolves the item's artwork. Call it AFTER persisting the new
+	// filename, or the worker resolves the old one.
+	EnqueueArtwork(ctx context.Context, entityType, entityID string)
 }
 
-func (s *imageUploadService) SetImage(ctx context.Context, entityType string, entityID string, name string, oldPath string, reader io.Reader, ext string) (string, error) {
+var uploadEntityKind = map[string]model.Kind{
+	consts.EntityArtist:   model.KindArtistArtwork,
+	consts.EntityPlaylist: model.KindPlaylistArtwork,
+	consts.EntityRadio:    model.KindRadioArtwork,
+}
+
+type uploader struct {
+	ds model.DataStore
+}
+
+func NewUploader(ds model.DataStore) Uploader {
+	return &uploader{ds: ds}
+}
+
+func (s *uploader) SetImage(ctx context.Context, entityType string, entityID string, name string, oldPath string, reader io.Reader, ext string) (string, error) {
 	filename := imageFilename(entityID, name, ext)
 	absPath := model.UploadedImagePath(entityType, filename)
 
@@ -44,14 +55,12 @@ func (s *imageUploadService) SetImage(ctx context.Context, entityType string, en
 		return "", fmt.Errorf("creating image directory: %w", err)
 	}
 
-	// Remove old image if it exists
 	if oldPath != "" {
 		if err := os.Remove(oldPath); err != nil && !os.IsNotExist(err) {
-			log.Warn(ctx, "Failed to remove old image", "path", oldPath, err)
+			log.Warn(ctx, "Artwork: Failed to remove old image", "path", oldPath, err)
 		}
 	}
 
-	// Save new image
 	f, err := os.Create(absPath)
 	if err != nil {
 		return "", fmt.Errorf("creating image file: %w", err)
@@ -61,11 +70,20 @@ func (s *imageUploadService) SetImage(ctx context.Context, entityType string, en
 	if _, err := io.Copy(f, reader); err != nil {
 		return "", fmt.Errorf("writing image file: %w", err)
 	}
-
 	return filename, nil
 }
 
-func (s *imageUploadService) RemoveImage(ctx context.Context, path string) error {
+func (s *uploader) EnqueueArtwork(ctx context.Context, entityType, id string) {
+	kind, ok := uploadEntityKind[entityType]
+	if !ok {
+		return
+	}
+	if err := Refresh(ctx, s.ds, kind, id); err != nil {
+		log.Warn(ctx, "Artwork: Could not refresh artwork after upload", "kind", kind, "id", id, err)
+	}
+}
+
+func (s *uploader) RemoveImage(ctx context.Context, path string) error {
 	if path == "" {
 		return nil
 	}

core/artwork/uploader_test.go

@@ -1,4 +1,4 @@
-package core_test
+package artwork
 
 import (
 	"context"
@@ -9,20 +9,26 @@ import (
 	"github.com/navidrome/navidrome/conf"
 	"github.com/navidrome/navidrome/conf/configtest"
 	"github.com/navidrome/navidrome/consts"
-	"github.com/navidrome/navidrome/core"
+	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/tests"
 	. "github.com/onsi/ginkgo/v2"
 	. "github.com/onsi/gomega"
 )
 
-var _ = Describe("ImageUploadService", func() {
-	var svc core.ImageUploadService
+var _ = Describe("Uploader", func() {
+	var svc Uploader
 	var tmpDir string
+	var artRepo *tests.MockArtworkRepo
+	var queueRepo *tests.MockArtworkQueueRepo
 
 	BeforeEach(func() {
 		DeferCleanup(configtest.SetupConfig())
 		tmpDir = GinkgoT().TempDir()
 		conf.Server.DataFolder = conf.NewDir(tmpDir)
-		svc = core.NewImageUploadService()
+		artRepo = tests.CreateMockArtworkRepo()
+		queueRepo = tests.CreateMockArtworkQueueRepo()
+		ds := &tests.MockDataStore{MockedArtwork: artRepo, MockedArtworkQueue: queueRepo}
+		svc = NewUploader(ds)
 	})
 
 	Describe("SetImage", func() {
@@ -69,6 +75,49 @@ var _ = Describe("ImageUploadService", func() {
 			_, err := svc.SetImage(ctx, consts.EntityArtist, "ar-1", "Name", "/nonexistent/path.jpg", reader, ".jpg")
 			Expect(err).ToNot(HaveOccurred())
 		})
+
+		It("does not touch artwork state or the queue (that is EnqueueArtwork's job, post-Put)", func() {
+			ctx := context.Background()
+			Expect(artRepo.PutItemArtwork(&model.ItemArtwork{
+				ItemKind: "ar", ItemID: "ar-1", Hash: "oldhash", Source: "external",
+			})).To(Succeed())
+
+			_, err := svc.SetImage(ctx, consts.EntityArtist, "ar-1", "Pink Floyd", "", strings.NewReader("img"), ".jpg")
+			Expect(err).ToNot(HaveOccurred())
+
+			// SetImage only writes the file; the state row survives and nothing is queued until
+			// the caller has persisted the new filename and called EnqueueArtwork.
+			_, err = artRepo.GetItemArtwork(model.KindArtistArtwork, "ar-1", model.ImageTypePrimary)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(queueRepo.DequeueBatch(1000)).To(BeEmpty())
+		})
+	})
+
+	Describe("EnqueueArtwork", func() {
+		It("clears artwork state and enqueues a Bump", func() {
+			ctx := context.Background()
+			Expect(artRepo.PutItemArtwork(&model.ItemArtwork{
+				ItemKind: "ar", ItemID: "ar-1", Hash: "oldhash", Source: "external",
+			})).To(Succeed())
+
+			svc.EnqueueArtwork(ctx, consts.EntityArtist, "ar-1")
+
+			_, err := artRepo.GetItemArtwork(model.KindArtistArtwork, "ar-1", model.ImageTypePrimary)
+			Expect(err).To(MatchError(model.ErrNotFound))
+
+			queued, err := queueRepo.DequeueBatch(1000)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(queued).To(ContainElement(SatisfyAll(
+				HaveField("ItemKind", "ar"),
+				HaveField("ItemID", "ar-1"),
+				HaveField("Priority", model.ArtworkPriorityBump),
+			)))
+		})
+
+		It("is a no-op for an unknown entity type", func() {
+			svc.EnqueueArtwork(context.Background(), "unknown", "x-1")
+			Expect(queueRepo.DequeueBatch(1000)).To(BeEmpty())
+		})
 	})
 
 	Describe("RemoveImage", func() {
@@ -105,21 +154,21 @@ var _ = Describe("MaxImageUploadSize", func() {
 
 	It("returns the configured size when valid", func() {
 		conf.Server.MaxImageUploadSize = "20MB"
-		Expect(core.MaxImageUploadSize()).To(Equal(int64(20_000_000)))
+		Expect(MaxImageUploadSize()).To(Equal(int64(20_000_000)))
 	})
 
 	It("returns the default size when config is empty", func() {
 		conf.Server.MaxImageUploadSize = ""
-		Expect(core.MaxImageUploadSize()).To(Equal(int64(10_000_000)))
+		Expect(MaxImageUploadSize()).To(Equal(int64(10_000_000)))
 	})
 
 	It("returns the default size when config is invalid", func() {
 		conf.Server.MaxImageUploadSize = "not-a-size"
-		Expect(core.MaxImageUploadSize()).To(Equal(int64(10_000_000)))
+		Expect(MaxImageUploadSize()).To(Equal(int64(10_000_000)))
 	})
 
 	It("parses raw byte values", func() {
 		conf.Server.MaxImageUploadSize = "52428800"
-		Expect(core.MaxImageUploadSize()).To(Equal(int64(52_428_800)))
+		Expect(MaxImageUploadSize()).To(Equal(int64(52_428_800)))
 	})
 })

core/artwork/wire_providers.go

@@ -7,5 +7,7 @@ import (
 var Set = wire.NewSet(
 	NewArtwork,
 	GetImageCache,
-	NewCacheWarmer,
+	NewWorker,
+	GetImageStore,
+	NewUploader,
 )

core/artwork/worker.go

@@ -0,0 +1,321 @@
+package artwork
+
+import (
+	"bytes"
+	"cmp"
+	"context"
+	"io"
+	"math"
+	"math/rand/v2"
+	"sync"
+	"time"
+
+	"github.com/navidrome/navidrome/conf"
+	"github.com/navidrome/navidrome/core/agents"
+	"github.com/navidrome/navidrome/core/auth"
+	"github.com/navidrome/navidrome/core/ffmpeg"
+	"github.com/navidrome/navidrome/log"
+	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/server/events"
+	"github.com/navidrome/navidrome/utils/cache"
+)
+
+const (
+	workerPollInterval = 5 * time.Second
+	backoffBase        = 5 * time.Second
+	// giveUpAfter bounds the retry budget from enqueue; past it the item falls to the
+	// periodic stale-absent recheck.
+	giveUpAfter = 12 * time.Hour
+)
+
+// drainPool drains one class of work with its own slot budget, so a blocking kind cannot
+// occupy slots another kind needs.
+type drainPool struct {
+	name        string
+	kinds       []string
+	concurrency int
+}
+
+// Worker drains the artwork queue: each external agent is rate-limited and circuit-broken
+// independently, and pruneMu serializes prune against the store-write window.
+type Worker struct {
+	proc    *processor
+	cache   cache.FileCache
+	ffmpeg  ffmpeg.FFmpeg
+	broker  events.Broker
+	pruneMu sync.RWMutex
+	pools   []*drainPool
+	runCtx  context.Context
+
+	gatesMu sync.Mutex
+	gates   map[string]*extGate
+}
+
+func NewWorker(ds model.DataStore, store *ImageStore, ag *agents.Agents, ffmpeg ffmpeg.FFmpeg, broker events.Broker, imgCache cache.FileCache) *Worker {
+	w := &Worker{
+		proc:   &processor{ds: ds, store: store},
+		cache:  imgCache,
+		ffmpeg: ffmpeg,
+		broker: broker,
+		pools:  newDrainPools(),
+		runCtx: context.Background(),
+		gates:  map[string]*extGate{},
+	}
+	w.proc.resolver = newResolver(ds, ag, ffmpeg, w.gate)
+	w.proc.pruneLock = w.pruneMu.RLocker()
+	return w
+}
+
+// newDrainPools splits the drain by what bounds it: gate() holds a slot while waiting for its
+// rate-limit permit, so a sleeping lookup would crowd out a cover sitting on disk.
+func newDrainPools() []*drainPool {
+	budget := conf.MaxOpenConns() // floored at 4, so both remainders below stay positive
+	local := min(max(1, conf.Server.DevArtworkWorkerConcurrency), budget-1)
+	// More external slots than the rate allows would only sleep in the limiter.
+	external := min(max(2, 2*conf.Server.DevArtworkExternalMaxRPS), budget-local)
+	return []*drainPool{
+		{name: "local", kinds: localDrainKinds, concurrency: local},
+		{name: "external", kinds: externalDrainKinds, concurrency: external},
+	}
+}
+
+// Kind is a proxy for cost: an album that reaches an external agent still costs a local slot.
+var (
+	externalDrainKinds = []string{model.KindArtistArtwork.Prefix()}
+	localDrainKinds    = []string{
+		model.KindAlbumArtwork.Prefix(),
+		model.KindPlaylistArtwork.Prefix(),
+		model.KindRadioArtwork.Prefix(),
+		model.KindMediaFileArtwork.Prefix(),
+	}
+)
+
+// Run blocks draining the queue until ctx is cancelled.
+func (w *Worker) Run(ctx context.Context) error {
+	w.runCtx = ctx
+	var wg sync.WaitGroup
+	for _, p := range w.pools {
+		wg.Go(func() { w.runPool(ctx, p) })
+	}
+	wg.Wait()
+	return nil
+}
+
+func (w *Worker) runPool(ctx context.Context, p *drainPool) {
+	ticker := time.NewTicker(workerPollInterval)
+	defer ticker.Stop()
+	for {
+		n, err := w.drain(ctx, p.concurrency, p.kinds...)
+		if err != nil && ctx.Err() == nil {
+			log.Warn(ctx, "Artwork: Worker drain failed", "pool", p.name, err)
+		}
+		if ctx.Err() != nil {
+			return
+		}
+		if n > 0 {
+			continue
+		}
+		select {
+		case <-ctx.Done():
+			return
+		case <-ticker.C:
+		}
+	}
+}
+
+// RunPrune runs prune under the worker's write lock, so no acquisition can place
+// a file while orphans are being reclaimed. This is the only sanctioned prune path.
+func (w *Worker) RunPrune(ctx context.Context) error {
+	w.pruneMu.Lock()
+	defer w.pruneMu.Unlock()
+	return prune(ctx, w.proc.ds, w.proc.store)
+}
+
+// Backfill enqueues every entity for re-resolution when the artwork config fingerprint changed,
+// artists first. It reports whether anything was enqueued.
+func (w *Worker) Backfill(ctx context.Context) (bool, error) {
+	return backfill(ctx, w.proc.ds)
+}
+
+// EnqueueStaleAbsentAll requeues known-absent entries older than staleAbsentAge.
+func (w *Worker) EnqueueStaleAbsentAll(ctx context.Context) error {
+	return enqueueStaleAbsentAll(ctx, w.proc.ds)
+}
+
+// EnqueueMissingAll requeues entities with no artwork state row: the safety net for anything
+// a scan never enqueued.
+func (w *Worker) EnqueueMissingAll(ctx context.Context) error {
+	return enqueueMissingAll(ctx, w.proc.ds)
+}
+
+func (w *Worker) drain(ctx context.Context, concurrency int, kinds ...string) (int, error) {
+	// Dequeue well past the pool size so a slow external lookup never idles the other slots.
+	// DequeueBatch does not mark rows taken, so this is one query per pass, not per slot.
+	items, err := w.proc.ds.ArtworkQueue(ctx).DequeueBatch(max(16, 4*concurrency), kinds...)
+	if err != nil {
+		return 0, err
+	}
+	if len(items) == 0 {
+		return 0, nil
+	}
+	drainStart := time.Now()
+	// Private playlists need an admin identity; resolved per drain because the worker can
+	// start before any admin exists.
+	ctx = auth.WithAdminUser(ctx, w.proc.ds)
+	sem := make(chan struct{}, concurrency)
+	var wg sync.WaitGroup
+	var refreshMu sync.Mutex
+	var refresh []model.ArtworkQueueItem
+	for _, item := range items {
+		select {
+		case sem <- struct{}{}:
+		case <-ctx.Done():
+		}
+		// select picks randomly when both cases are ready, so re-check to never dispatch after cancellation.
+		if ctx.Err() != nil {
+			wg.Wait()
+			return len(items), nil //nolint:nilerr // a cancelled drain is a clean stop, not an error
+		}
+		wg.Go(func() {
+			defer func() { <-sem }()
+			out, got := w.process(ctx, item)
+			// Absent counts as a visible change too: clients must drop a previously-served
+			// immutable cover.
+			if out == outcomeFound || out == outcomeFoundStale || out == outcomeAbsent {
+				refreshMu.Lock()
+				refresh = append(refresh, item)
+				refreshMu.Unlock()
+			}
+			// Post-outcome: the queue row is already settled, so warming the cache can't
+			// block or alter queue ops.
+			if got != nil {
+				w.precache(ctx, got)
+			}
+		})
+	}
+	wg.Wait()
+	w.broadcastRefresh(ctx, refresh)
+	log.Debug(ctx, "Artwork: Drained a batch", "kinds", kinds, "items", len(items),
+		"refreshed", len(refresh), "concurrency", concurrency, "elapsed", time.Since(drainStart))
+	return len(items), nil
+}
+
+// artworkKindToResource maps a kind to its UI resource name; media_file maps to "song", so
+// this can't derive from Kind.String().
+var artworkKindToResource = map[model.Kind]string{
+	model.KindAlbumArtwork:     "album",
+	model.KindArtistArtwork:    "artist",
+	model.KindPlaylistArtwork:  "playlist",
+	model.KindRadioArtwork:     "radio",
+	model.KindMediaFileArtwork: "song",
+}
+
+// broadcastRefresh emits one coalesced RefreshResource for the batch, so UIs re-fetch the
+// affected records and pick up the new coverArt id.
+func (w *Worker) broadcastRefresh(ctx context.Context, found []model.ArtworkQueueItem) {
+	if len(found) == 0 {
+		return
+	}
+	event := &events.RefreshResource{}
+	byResource := map[string][]string{}
+	for _, it := range found {
+		kind, _ := model.ParseKind(it.ItemKind)
+		if res, ok := artworkKindToResource[kind]; ok {
+			byResource[res] = append(byResource[res], it.ItemID)
+		}
+	}
+	if len(byResource) == 0 {
+		return
+	}
+	for res, ids := range byResource {
+		event = event.With(res, ids...)
+	}
+	w.broker.SendBroadcastMessage(ctx, event)
+}
+
+func (w *Worker) process(ctx context.Context, item model.ArtworkQueueItem) (outcome, *acquired) {
+	item.ImageType = cmp.Or(item.ImageType, model.ImageTypePrimary)
+	out, got := w.proc.acquire(ctx, item)
+
+	queue := w.proc.ds.ArtworkQueue(ctx)
+	switch out {
+	case outcomeFound, outcomeAbsent:
+		// A scan that re-enqueued this row mid-flight reset its retry_at, so the row survives
+		// here and the next drain re-resolves it.
+		if err := queue.DeleteIfUnchanged(item.ItemKind, item.ItemID, item.ImageType, item.RetryAt); err != nil {
+			log.Warn(ctx, "Artwork: Could not delete processed queue item", "kind", item.ItemKind, "id", item.ItemID, err)
+		}
+	case outcomeFoundStale, outcomeFailed:
+		retryAt := time.Now().Add(backoff(item.Attempts))
+		if retryAt.Before(item.EnqueuedAt.Add(giveUpAfter)) {
+			// A mid-flight re-enqueue reset retry_at; stale backoff must not stomp its
+			// fresh, immediate eligibility.
+			if err := queue.MarkFailedIfUnchanged(item.ItemKind, item.ItemID, item.ImageType, item.RetryAt, retryAt); err != nil {
+				log.Warn(ctx, "Artwork: Could not reschedule failed queue item", "kind", item.ItemKind, "id", item.ItemID, err)
+			}
+			log.Debug(ctx, "Artwork: Rescheduled item", "kind", item.ItemKind, "id", item.ItemID,
+				"outcome", out, "attempts", item.Attempts+1, "retryIn", time.Until(retryAt),
+				"budgetLeft", time.Until(item.EnqueuedAt.Add(giveUpAfter)))
+			break
+		}
+		// Absent is only recoverable where a periodic recheck revisits it, so other kinds keep
+		// no row; art already being served is kept, as exhaustion means unreachable, not removed.
+		settled := "kept previous state"
+		if out == outcomeFailed && hasRecheckPath(item.ItemKind) && !w.hasResolvedArtwork(ctx, item) {
+			writeAbsent(ctx, w.proc.ds.Artwork(ctx), item)
+			settled = "recorded absent"
+		}
+		log.Info(ctx, "Artwork: Retry budget exhausted, giving up", "kind", item.ItemKind, "id", item.ItemID,
+			"outcome", out, "attempts", item.Attempts+1, "budget", giveUpAfter, "settled", settled)
+		if err := queue.DeleteIfUnchanged(item.ItemKind, item.ItemID, item.ImageType, item.RetryAt); err != nil {
+			log.Warn(ctx, "Artwork: Could not remove exhausted queue item", "kind", item.ItemKind, "id", item.ItemID, err)
+		}
+	}
+	return out, got
+}
+
+func (w *Worker) hasResolvedArtwork(ctx context.Context, item model.ArtworkQueueItem) bool {
+	kind, ok := model.ParseKind(item.ItemKind)
+	if !ok {
+		return false
+	}
+	ia, err := w.proc.ds.Artwork(ctx).GetItemArtwork(kind, item.ItemID, item.ImageType)
+	return err == nil && ia.Hash != ""
+}
+
+// precache warms the resize cache at the UI cover size from the bytes just acquired, so the
+// first UI request hits without re-reading the rows or the file.
+func (w *Worker) precache(ctx context.Context, got *acquired) {
+	if !conf.Server.EnableArtworkPrecache || w.cache == nil || w.cache.Disabled(ctx) {
+		return
+	}
+	precacheStart := time.Now()
+	// Same key as the serving path: square must match what the list surfaces request, or this
+	// warms a key nothing reads.
+	item := &resizedItem{
+		hash:   got.ia.Hash,
+		size:   conf.Server.UICoverArtSize,
+		square: true,
+		ffmpeg: w.ffmpeg,
+		open:   func() (io.ReadCloser, error) { return io.NopCloser(bytes.NewReader(got.data)), nil },
+	}
+	stream, err := w.cache.Get(ctx, item)
+	if err != nil {
+		log.Debug(ctx, "Artwork: Precache failed", "kind", got.ia.ItemKind, "id", got.ia.ItemID, err)
+		return
+	}
+	_, _ = io.Copy(io.Discard, stream)
+	_ = stream.Close()
+	log.Trace(ctx, "Artwork: Precached UI size", "kind", got.ia.ItemKind, "id", got.ia.ItemID,
+		"size", conf.Server.UICoverArtSize, "elapsed", time.Since(precacheStart))
+}
+
+// backoffFor returns min(5s×4^n, giveUpAfter) scaled by (1+jitter), with jitter in [-0.4, 0.4].
+func backoffFor(attempts int, jitter float64) time.Duration {
+	d := min(float64(backoffBase)*math.Pow(4, float64(attempts)), float64(giveUpAfter))
+	return time.Duration(d * (1 + jitter))
+}
+
+func backoff(attempts int) time.Duration {
+	return backoffFor(attempts, rand.Float64()*0.8-0.4) //nolint:gosec // retry jitter, not security-sensitive
+}

core/artwork/worker_soak_test.go

@@ -0,0 +1,146 @@
+package artwork
+
+import (
+	"context"
+	"io"
+	"os"
+	"runtime"
+	"testing"
+	"time"
+
+	"github.com/navidrome/navidrome/conf"
+	"github.com/navidrome/navidrome/conf/configtest"
+	"github.com/navidrome/navidrome/core/agents"
+	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/tests"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+// Deliberately >2000: a leak guard favors a stable signal over speed.
+const soakCycles = 2200
+
+var _ = Describe("Worker soak", func() {
+	It("does not leak goroutines, heap, or fds over many acquisition cycles", func() {
+		if testing.Short() {
+			Skip("skipping soak test in short mode")
+		}
+		DeferCleanup(configtest.SetupConfig())
+
+		repoRoot, err := os.Getwd()
+		Expect(err).ToNot(HaveOccurred())
+
+		libRepo := &tests.MockLibraryRepo{}
+		libRepo.SetData(model.Libraries{{ID: 0, Path: testFileLibPath(repoRoot)}})
+		folderRepo := &fakeFolderRepo{result: []model.Folder{{
+			Path:       "tests/fixtures/artist/an-album",
+			ImageFiles: []string{"cover.jpg"},
+		}}}
+		ffm := tests.NewMockFFmpeg("")
+		ag := agents.GetAgents(&tests.MockDataStore{}, nil)
+		artRepo := tests.CreateMockArtworkRepo()
+		albumRepo := tests.CreateMockAlbumRepo()
+		albumRepo.SetData(model.Albums{
+			{ID: "al-folder", Name: "Folder Album", FolderIDs: []string{"f1"}},
+			{ID: "al-embed", Name: "Embedded Album", EmbedArtPath: "tests/fixtures/artist/an-album/test.mp3", FolderIDs: []string{"f1"}},
+		})
+		ds := &tests.MockDataStore{
+			MockedFolder:  folderRepo,
+			MockedLibrary: libRepo,
+			MockedArtwork: artRepo,
+			MockedAlbum:   albumRepo,
+		}
+		store := NewImageStore(GinkgoT().TempDir())
+		proc := &processor{ds: ds, store: store, resolver: newResolver(ds, ag, ffm, nil)}
+		conf.Server.CoverArtPriority = "cover.jpg, embedded"
+
+		// Dangling refs mirror an entity deleted after being enqueued.
+		items := []model.ArtworkQueueItem{
+			{ItemKind: "al", ItemID: "al-folder"},
+			{ItemKind: "al", ItemID: "al-embed"},
+			{ItemKind: "al", ItemID: "al-does-not-exist"},
+			{ItemKind: "ra", ItemID: "ra-does-not-exist"},
+		}
+
+		fdCount := func() int {
+			if runtime.GOOS != "linux" {
+				return -1
+			}
+			entries, err := os.ReadDir("/proc/self/fd")
+			if err != nil {
+				return -1
+			}
+			return len(entries)
+		}
+
+		settleGoroutines := func() int {
+			// Background goroutines wind down late, so poll for two consecutive equal samples.
+			prev := -1
+			for range 100 {
+				runtime.GC()
+				n := runtime.NumGoroutine()
+				if n == prev {
+					return n
+				}
+				prev = n
+				time.Sleep(10 * time.Millisecond)
+			}
+			return prev
+		}
+
+		baselineGoroutines := settleGoroutines()
+		baselineFDs := fdCount()
+
+		var heapAt10Pct uint64
+		start := time.Now()
+		for i := range soakCycles {
+			it := items[i%len(items)]
+			out, _ := proc.acquire(context.Background(), it)
+
+			// Read-back exercises the surfaces a caller would use after acquisition.
+			if out == outcomeFound {
+				kind, _ := model.ParseKind(it.ItemKind)
+				ia, err := artRepo.GetItemArtwork(kind, it.ItemID, model.ImageTypePrimary)
+				Expect(err).ToNot(HaveOccurred(), "cycle %d: GetItemArtwork", i)
+				art, err := artRepo.GetImage(ia.Hash)
+				Expect(err).ToNot(HaveOccurred(), "cycle %d: GetImage", i)
+				rc, err := store.Open(ia.Hash, art.Mime)
+				switch {
+				case err == nil:
+					_, _ = io.Copy(io.Discard, rc)
+					rc.Close()
+				case os.IsNotExist(err):
+					// Folder-backed art has no store file; that's expected.
+				default:
+					Expect(err).ToNot(HaveOccurred(), "cycle %d: store.Open", i)
+				}
+			}
+
+			if i == soakCycles/10 {
+				runtime.GC()
+				var ms runtime.MemStats
+				runtime.ReadMemStats(&ms)
+				heapAt10Pct = ms.HeapAlloc
+			}
+		}
+		elapsed := time.Since(start)
+
+		finalGoroutines := settleGoroutines()
+		finalFDs := fdCount()
+
+		runtime.GC()
+		var ms runtime.MemStats
+		runtime.ReadMemStats(&ms)
+
+		GinkgoWriter.Printf("soak: cycles=%d elapsed=%s goroutines(baseline=%d final=%d) heap(10%%-mark=%d final=%d) fds(baseline=%d final=%d)\n",
+			soakCycles, elapsed, baselineGoroutines, finalGoroutines, heapAt10Pct, ms.HeapAlloc, baselineFDs, finalFDs)
+
+		Expect(finalGoroutines).To(BeNumerically("<=", baselineGoroutines), "goroutine count grew: baseline=%d final=%d", baselineGoroutines, finalGoroutines)
+		if heapAt10Pct > 0 {
+			Expect(ms.HeapAlloc).To(BeNumerically("<=", 2*heapAt10Pct), "heap did not plateau: 10%%-mark=%d final=%d (final > 2x 10%%-mark)", heapAt10Pct, ms.HeapAlloc)
+		}
+		if runtime.GOOS == "linux" && baselineFDs >= 0 {
+			Expect(finalFDs).To(BeNumerically("<=", baselineFDs), "fd count grew: baseline=%d final=%d", baselineFDs, finalFDs)
+		}
+	})
+})

core/artwork/worker_test.go

@@ -0,0 +1,817 @@
+package artwork
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+	"slices"
+	"sync"
+	"time"
+
+	"github.com/navidrome/navidrome/conf"
+	"github.com/navidrome/navidrome/conf/configtest"
+	"github.com/navidrome/navidrome/core/agents"
+	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/server/events"
+	"github.com/navidrome/navidrome/tests"
+	"github.com/navidrome/navidrome/utils/cache"
+	"github.com/navidrome/navidrome/utils/slice"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+	"go.uber.org/goleak"
+)
+
+type recordingCache struct {
+	cache.FileCache
+	mu       sync.Mutex
+	keys     []string
+	disabled bool
+}
+
+func (c *recordingCache) Disabled(ctx context.Context) bool {
+	return c.disabled || c.FileCache.Disabled(ctx)
+}
+
+func (c *recordingCache) Get(ctx context.Context, arg cache.Item) (*cache.CachedStream, error) {
+	c.mu.Lock()
+	c.keys = append(c.keys, arg.Key())
+	c.mu.Unlock()
+	return c.FileCache.Get(ctx, arg)
+}
+
+func (c *recordingCache) getKeys() []string {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	return slices.Clone(c.keys)
+}
+
+// Simulates a concurrent Enqueue between DequeueBatch and the worker's delete, so
+// DeleteIfUnchanged on the dequeued value no-ops.
+type reenqueueOnDequeue struct {
+	*tests.MockArtworkQueueRepo
+	done bool
+}
+
+func (r *reenqueueOnDequeue) DequeueBatch(n int, kinds ...string) ([]model.ArtworkQueueItem, error) {
+	items, err := r.MockArtworkQueueRepo.DequeueBatch(n, kinds...)
+	if !r.done && len(items) > 0 {
+		r.done = true
+		for k, it := range r.Data {
+			if it.ItemKind == items[0].ItemKind && it.ItemID == items[0].ItemID {
+				it.RetryAt = items[0].RetryAt.Add(time.Minute)
+				r.Data[k] = it
+			}
+		}
+	}
+	return items, err
+}
+
+type fakeEventBroker struct {
+	http.Handler
+	mu     sync.Mutex
+	events []events.Event
+}
+
+func (f *fakeEventBroker) SendMessage(_ context.Context, event events.Event) {
+	f.mu.Lock()
+	defer f.mu.Unlock()
+	f.events = append(f.events, event)
+}
+
+func (f *fakeEventBroker) SendBroadcastMessage(_ context.Context, event events.Event) {
+	f.mu.Lock()
+	defer f.mu.Unlock()
+	f.events = append(f.events, event)
+}
+
+func (f *fakeEventBroker) getEvents() []events.Event {
+	f.mu.Lock()
+	defer f.mu.Unlock()
+	return slices.Clone(f.events)
+}
+
+var _ events.Broker = (*fakeEventBroker)(nil)
+
+func findQueued(q *tests.MockArtworkQueueRepo, kind, id string) *model.ArtworkQueueItem {
+	for _, it := range q.Data {
+		if it.ItemKind == kind && it.ItemID == id {
+			return &it
+		}
+	}
+	return nil
+}
+
+var _ = Describe("Worker", func() {
+	var (
+		ctx        context.Context
+		ds         *tests.MockDataStore
+		folderRepo *fakeFolderRepo
+		libRepo    *tests.MockLibraryRepo
+		ffm        *tests.MockFFmpeg
+		ag         *agents.Agents
+		store      *ImageStore
+		artRepo    *tests.MockArtworkRepo
+		queueRepo  *tests.MockArtworkQueueRepo
+		broker     *fakeEventBroker
+		imgCache   *recordingCache
+		repoRoot   string
+		w          *Worker
+	)
+
+	BeforeEach(func() {
+		DeferCleanup(configtest.SetupConfig())
+		ctx = context.Background()
+		var err error
+		repoRoot, err = os.Getwd()
+		Expect(err).ToNot(HaveOccurred())
+		conf.Server.CacheFolder = conf.NewDir(GinkgoT().TempDir())
+
+		folderRepo = &fakeFolderRepo{}
+		libRepo = &tests.MockLibraryRepo{}
+		libRepo.SetData(model.Libraries{{ID: 0, Path: testFileLibPath(repoRoot)}})
+		ffm = tests.NewMockFFmpeg("")
+		ag = agents.GetAgents(&tests.MockDataStore{}, nil)
+		artRepo = tests.CreateMockArtworkRepo()
+		queueRepo = tests.CreateMockArtworkQueueRepo()
+		ds = &tests.MockDataStore{
+			MockedFolder:       folderRepo,
+			MockedLibrary:      libRepo,
+			MockedArtwork:      artRepo,
+			MockedArtworkQueue: queueRepo,
+		}
+		ds.MockedAlbum = tests.CreateMockAlbumRepo()
+		store = NewImageStore(GinkgoT().TempDir())
+		conf.Server.CoverArtPriority = "cover.jpg, embedded"
+		conf.Server.DevArtworkExternalMaxRPS = 1000 // keep the limiter out of the way of behavior tests
+		broker = &fakeEventBroker{}
+		imgCache = &recordingCache{FileCache: cache.NewFileCache("WorkerTest", "100MB", "images", 0,
+			func(ctx context.Context, arg cache.Item) (io.Reader, error) {
+				return arg.(artworkReader).Reader(ctx)
+			})}
+		// Init walks the cache dir on a goroutine; loaded CI runners can take >1s.
+		Eventually(func() bool { return imgCache.Available(ctx) }, 10*time.Second).Should(BeTrue())
+		w = NewWorker(ds, store, ag, ffm, broker, imgCache)
+	})
+
+	Describe("drain", func() {
+		It("processes a seeded queue item and removes it from the queue", func() {
+			folderRepo.result = []model.Folder{{
+				Path:       "tests/fixtures/artist/an-album",
+				ImageFiles: []string{"cover.jpg"},
+			}}
+			ds.MockedAlbum.(*tests.MockAlbumRepo).SetData(model.Albums{
+				{ID: "al1", Name: "Album", FolderIDs: []string{"f1"}},
+			})
+			Expect(queueRepo.Enqueue(model.ArtworkQueueItem{
+				ItemKind: "al", ItemID: "al1", Priority: model.ArtworkPriorityScan,
+			})).To(Succeed())
+
+			n, err := w.drain(ctx, 2)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(n).To(Equal(1))
+
+			ia, err := artRepo.GetItemArtwork(model.KindAlbumArtwork, "al1", model.ImageTypePrimary)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(ia.Source).To(Equal("folder"))
+
+			count, err := queueRepo.Count()
+			Expect(err).ToNot(HaveOccurred())
+			Expect(count).To(BeZero(), "a found item must be deleted from the queue")
+		})
+
+		It("processes an mf queue item, writing state and storing embedded bytes", func() {
+			conf.Server.EnableMediaFileCoverArt = true
+			ds.MockedMediaFile = tests.CreateMockMediaFileRepo()
+			ds.MockedMediaFile.(*tests.MockMediaFileRepo).SetData(model.MediaFiles{
+				{ID: "mf1", LibraryID: 0, Path: "tests/fixtures/artist/an-album/test.mp3", HasCoverArt: true},
+			})
+			Expect(queueRepo.Enqueue(model.ArtworkQueueItem{
+				ItemKind: "mf", ItemID: "mf1", Priority: model.ArtworkPriorityBump,
+			})).To(Succeed())
+
+			n, err := w.drain(ctx, 2)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(n).To(Equal(1))
+
+			ia, err := artRepo.GetItemArtwork(model.KindMediaFileArtwork, "mf1", model.ImageTypePrimary)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(ia.Source).To(Equal("embedded"))
+			Expect(ia.Hash).ToNot(BeEmpty())
+
+			art, err := artRepo.GetImage(ia.Hash)
+			Expect(err).ToNot(HaveOccurred())
+			r, err := store.Open(ia.Hash, art.Mime)
+			Expect(err).ToNot(HaveOccurred())
+			defer r.Close()
+			data, err := io.ReadAll(r)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(data).ToNot(BeEmpty(), "embedded bytes must be written to the store")
+
+			count, err := queueRepo.Count()
+			Expect(err).ToNot(HaveOccurred())
+			Expect(count).To(BeZero())
+		})
+
+		It("reschedules a failed item via MarkFailed with a backed-off retry_at", func() {
+			conf.Server.CoverArtPriority = "external"
+			ds.MockedAlbum.(*tests.MockAlbumRepo).SetData(model.Albums{{ID: "al4", Name: "Album"}})
+			imageAgents(&fakeImageAgent{name: "failAgent", err: errors.New("agent timed out")})
+			Expect(queueRepo.Enqueue(model.ArtworkQueueItem{ItemKind: "al", ItemID: "al4"})).To(Succeed())
+
+			n, err := w.drain(ctx, 2)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(n).To(Equal(1))
+
+			it := findQueued(queueRepo, "al", "al4")
+			Expect(it).ToNot(BeNil())
+			Expect(it.Attempts).To(Equal(1))
+			Expect(it.RetryAt).To(BeTemporally(">", time.Now()))
+
+			_, err = artRepo.GetItemArtwork(model.KindAlbumArtwork, "al4", model.ImageTypePrimary)
+			Expect(err).To(MatchError(model.ErrNotFound), "a timeout must never settle on absent")
+		})
+
+		It("reschedules a found-stale item via MarkFailed while keeping its served state", func() {
+			conf.Server.CoverArtPriority = "external, cover.jpg"
+			folderRepo.result = []model.Folder{{
+				Path:       "tests/fixtures/artist/an-album",
+				ImageFiles: []string{"cover.jpg"},
+			}}
+			ds.MockedAlbum.(*tests.MockAlbumRepo).SetData(model.Albums{
+				{ID: "alstale", Name: "Album", FolderIDs: []string{"f1"}},
+			})
+			imageAgents(&fakeImageAgent{name: "failAgent", err: errors.New("agent timed out")})
+			Expect(queueRepo.Enqueue(model.ArtworkQueueItem{ItemKind: "al", ItemID: "alstale"})).To(Succeed())
+
+			n, err := w.drain(ctx, 2)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(n).To(Equal(1))
+
+			it := findQueued(queueRepo, "al", "alstale")
+			Expect(it).ToNot(BeNil(), "a found-stale row must survive for a higher-priority retry")
+			Expect(it.Attempts).To(Equal(1))
+			Expect(it.RetryAt).To(BeTemporally(">", time.Now()))
+
+			ia, err := artRepo.GetItemArtwork(model.KindAlbumArtwork, "alstale", model.ImageTypePrimary)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(ia.Source).To(Equal("folder"), "the fallback art is served meanwhile")
+
+			evts := broker.getEvents()
+			Expect(evts).To(HaveLen(1), "the served fallback art must live-refresh the UI")
+			Expect(evts[0].(*events.RefreshResource).Data(evts[0])).To(ContainSubstring("alstale"))
+		})
+
+		It("keeps a row re-enqueued between dequeue and delete", func() {
+			folderRepo.result = []model.Folder{{
+				Path:       "tests/fixtures/artist/an-album",
+				ImageFiles: []string{"cover.jpg"},
+			}}
+			ds.MockedAlbum.(*tests.MockAlbumRepo).SetData(model.Albums{
+				{ID: "al7", Name: "Album", FolderIDs: []string{"f1"}},
+			})
+			racing := &reenqueueOnDequeue{MockArtworkQueueRepo: queueRepo}
+			ds.MockedArtworkQueue = racing
+			w = NewWorker(ds, store, ag, ffm, broker, imgCache)
+			Expect(queueRepo.Enqueue(model.ArtworkQueueItem{
+				ItemKind: "al", ItemID: "al7", Priority: model.ArtworkPriorityScan,
+			})).To(Succeed())
+
+			n, err := w.drain(ctx, 1)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(n).To(Equal(1))
+
+			// The concurrent re-enqueue changed retry_at, so the found-path delete was a no-op.
+			Expect(findQueued(queueRepo, "al", "al7")).ToNot(BeNil())
+			ia, err := artRepo.GetItemArtwork(model.KindAlbumArtwork, "al7", model.ImageTypePrimary)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(ia.Source).To(Equal("folder"))
+		})
+
+		It("keeps a fresh re-enqueue ahead of a stale failure backoff", func() {
+			conf.Server.CoverArtPriority = "external"
+			ds.MockedAlbum.(*tests.MockAlbumRepo).SetData(model.Albums{{ID: "al8", Name: "Album"}})
+			imageAgents(&fakeImageAgent{name: "failAgent", err: errors.New("agent timed out")})
+			racing := &reenqueueOnDequeue{MockArtworkQueueRepo: queueRepo}
+			ds.MockedArtworkQueue = racing
+			w = NewWorker(ds, store, ag, ffm, broker, imgCache)
+			Expect(queueRepo.Enqueue(model.ArtworkQueueItem{ItemKind: "al", ItemID: "al8"})).To(Succeed())
+			dequeued := findQueued(queueRepo, "al", "al8").RetryAt
+
+			n, err := w.drain(ctx, 1)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(n).To(Equal(1))
+
+			// The re-enqueue reset retry_at; the failure path must not stomp it nor bump attempts.
+			it := findQueued(queueRepo, "al", "al8")
+			Expect(it).ToNot(BeNil())
+			Expect(it.Attempts).To(BeZero())
+			Expect(it.RetryAt).To(BeTemporally("==", dequeued.Add(time.Minute)))
+		})
+
+		It("gives up and settles absent once the retry budget is exhausted", func() {
+			conf.Server.CoverArtPriority = "external"
+			ds.MockedAlbum.(*tests.MockAlbumRepo).SetData(model.Albums{{ID: "al9", Name: "Album"}})
+			imageAgents(&fakeImageAgent{name: "failAgent", err: errors.New("agent timed out")})
+			w = NewWorker(ds, store, ag, ffm, broker, imgCache)
+			Expect(queueRepo.Enqueue(model.ArtworkQueueItem{ItemKind: "al", ItemID: "al9"})).To(Succeed())
+			// Age the row past the retry budget.
+			for k, v := range queueRepo.Data {
+				if v.ItemID == "al9" {
+					v.EnqueuedAt = time.Now().Add(-(giveUpAfter + time.Hour))
+					queueRepo.Data[k] = v
+				}
+			}
+
+			n, err := w.drain(ctx, 1)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(n).To(Equal(1))
+
+			Expect(findQueued(queueRepo, "al", "al9")).To(BeNil())
+			ia, err := artRepo.GetItemArtwork(model.KindAlbumArtwork, "al9", model.ImageTypePrimary)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(ia.Hash).To(BeEmpty())
+		})
+
+		It("keeps already-served art when the retry budget is exhausted", func() {
+			conf.Server.CoverArtPriority = "external"
+			ds.MockedAlbum.(*tests.MockAlbumRepo).SetData(model.Albums{{ID: "al10", Name: "Album"}})
+			Expect(artRepo.PutItemArtwork(&model.ItemArtwork{
+				ItemKind: "al", ItemID: "al10", ImageType: model.ImageTypePrimary,
+				Hash: "cafebabe", Source: "external:lastfm",
+			})).To(Succeed())
+			imageAgents(&fakeImageAgent{name: "failAgent", err: errors.New("agent timed out")})
+			w = NewWorker(ds, store, ag, ffm, broker, imgCache)
+			Expect(queueRepo.Enqueue(model.ArtworkQueueItem{ItemKind: "al", ItemID: "al10"})).To(Succeed())
+			for k, v := range queueRepo.Data {
+				if v.ItemID == "al10" {
+					v.EnqueuedAt = time.Now().Add(-(giveUpAfter + time.Hour))
+					queueRepo.Data[k] = v
+				}
+			}
+
+			n, err := w.drain(ctx, 1)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(n).To(Equal(1))
+
+			Expect(findQueued(queueRepo, "al", "al10")).To(BeNil())
+			ia, err := artRepo.GetItemArtwork(model.KindAlbumArtwork, "al10", model.ImageTypePrimary)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(ia.Hash).To(Equal("cafebabe"), "a persistent outage must not discard served art")
+		})
+
+		// Media files are excluded from recheckKinds, so an absent row here would never be
+		// revisited: a transient read error would look permanent.
+		It("does not settle absent on exhaustion for a kind with no recheck path", func() {
+			conf.Server.EnableMediaFileCoverArt = true
+			ds.MockedMediaFile = tests.CreateMockMediaFileRepo()
+			ds.MockedMediaFile.(*tests.MockMediaFileRepo).SetData(model.MediaFiles{
+				{ID: "mfX", LibraryID: 0, Path: "tests/fixtures/artist/an-album/gone.mp3", HasCoverArt: true},
+			})
+			Expect(queueRepo.Enqueue(model.ArtworkQueueItem{ItemKind: "mf", ItemID: "mfX"})).To(Succeed())
+			for k, v := range queueRepo.Data {
+				if v.ItemID == "mfX" {
+					v.EnqueuedAt = time.Now().Add(-(giveUpAfter + time.Hour))
+					queueRepo.Data[k] = v
+				}
+			}
+
+			n, err := w.drain(ctx, 1)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(n).To(Equal(1))
+
+			Expect(findQueued(queueRepo, "mf", "mfX")).To(BeNil(), "the row must stop retrying")
+			_, err = artRepo.GetItemArtwork(model.KindMediaFileArtwork, "mfX", model.ImageTypePrimary)
+			Expect(err).To(MatchError(model.ErrNotFound),
+				"no row leaves the track unresolved, so a later view can still recover it")
+		})
+
+		It("resolves a private playlist under an admin context instead of failing forever", func() {
+			ds.MockedUser = adminUserRepo()
+			vds := &visibilityPlaylistDS{
+				MockDataStore: ds,
+				private:       model.Playlist{ID: "plPriv", OwnerID: "admin"},
+				tracks:        &tests.MockPlaylistTrackRepo{},
+			}
+			w = NewWorker(vds, store, ag, ffm, broker, imgCache)
+			Expect(queueRepo.Enqueue(model.ArtworkQueueItem{ItemKind: "pl", ItemID: "plPriv"})).To(Succeed())
+
+			n, err := w.drain(ctx, 1)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(n).To(Equal(1))
+
+			Expect(findQueued(queueRepo, "pl", "plPriv")).To(BeNil())
+			ia, err := artRepo.GetItemArtwork(model.KindPlaylistArtwork, "plPriv", model.ImageTypePrimary)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(ia.Hash).To(BeEmpty())
+		})
+
+		It("returns zero when the queue is empty", func() {
+			n, err := w.drain(ctx, 2)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(n).To(BeZero())
+		})
+
+		It("broadcasts a single refresh event for the found items in a batch", func() {
+			folderRepo.result = []model.Folder{{
+				Path:       "tests/fixtures/artist/an-album",
+				ImageFiles: []string{"cover.jpg"},
+			}}
+			ds.MockedAlbum.(*tests.MockAlbumRepo).SetData(model.Albums{
+				{ID: "al1", Name: "Album 1", FolderIDs: []string{"f1"}},
+				{ID: "al2", Name: "Album 2", FolderIDs: []string{"f1"}},
+			})
+			Expect(queueRepo.Enqueue(model.ArtworkQueueItem{ItemKind: "al", ItemID: "al1", Priority: model.ArtworkPriorityScan})).To(Succeed())
+			Expect(queueRepo.Enqueue(model.ArtworkQueueItem{ItemKind: "al", ItemID: "al2", Priority: model.ArtworkPriorityScan})).To(Succeed())
+			Expect(queueRepo.Enqueue(model.ArtworkQueueItem{ItemKind: "ar", ItemID: "ar1", Priority: model.ArtworkPriorityScan})).To(Succeed())
+
+			n, err := w.drain(ctx, 3)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(n).To(Equal(3))
+
+			evts := broker.getEvents()
+			Expect(evts).To(HaveLen(1), "exactly one coalesced event per drain batch")
+			rr, ok := evts[0].(*events.RefreshResource)
+			Expect(ok).To(BeTrue())
+			data := rr.Data(rr)
+			Expect(data).To(ContainSubstring(`"album"`))
+			Expect(data).To(ContainSubstring("al1"))
+			Expect(data).To(ContainSubstring("al2"))
+			Expect(data).ToNot(ContainSubstring("artist"), "a failed (unresolved) artist must not be refreshed")
+			Expect(data).ToNot(ContainSubstring("ar1"))
+		})
+
+		DescribeTable("only lists the kinds it actually resolved",
+			func(kinds []string, wantSong bool) {
+				items := slice.Map(kinds, func(k string) model.ArtworkQueueItem {
+					return model.ArtworkQueueItem{ItemKind: k, ItemID: k + "1"}
+				})
+				w.broadcastRefresh(ctx, items)
+
+				evts := broker.getEvents()
+				Expect(evts).To(HaveLen(1))
+				data := evts[0].(*events.RefreshResource).Data(evts[0])
+				if wantSong {
+					Expect(data).To(ContainSubstring(`"song"`))
+				} else {
+					Expect(data).ToNot(ContainSubstring(`"song"`))
+				}
+			},
+			// An album's tracks inherit its art, but the dependent ids are unbounded: the client
+			// fans an album refresh out to the tracks it has loaded.
+			Entry("album alone does not name songs", []string{"al"}, false),
+			Entry("artist alone does not", []string{"ar"}, false),
+			Entry("playlist alone does not", []string{"pl"}, false),
+			Entry("album mixed with others still does not", []string{"ar", "al"}, false),
+			Entry("songs resolving on their own are listed by id", []string{"mf"}, true),
+		)
+
+		It("broadcasts a refresh when an item resolves to absent (removed cover)", func() {
+			conf.Server.CoverArtPriority = "cover.*" // local-only; no folder image → absent
+			ds.MockedAlbum.(*tests.MockAlbumRepo).SetData(model.Albums{{ID: "al3", Name: "Artless"}})
+			folderRepo.result = nil
+			Expect(queueRepo.Enqueue(model.ArtworkQueueItem{ItemKind: "al", ItemID: "al3", Priority: model.ArtworkPriorityScan})).To(Succeed())
+
+			n, err := w.drain(ctx, 2)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(n).To(Equal(1))
+
+			evts := broker.getEvents()
+			Expect(evts).To(HaveLen(1), "a removed cover must live-refresh clients so they drop it")
+			Expect(evts[0].(*events.RefreshResource).Data(evts[0])).To(ContainSubstring("al3"))
+
+			ia, err := artRepo.GetItemArtwork(model.KindAlbumArtwork, "al3", model.ImageTypePrimary)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(ia.Hash).To(BeEmpty(), "the outcome was absent, not found")
+		})
+
+		It("does not broadcast when no item is found", func() {
+			conf.Server.CoverArtPriority = "external"
+			ds.MockedAlbum.(*tests.MockAlbumRepo).SetData(model.Albums{{ID: "alx", Name: "Album"}})
+			imageAgents(&fakeImageAgent{name: "failAgent", err: errors.New("agent timed out")})
+			Expect(queueRepo.Enqueue(model.ArtworkQueueItem{ItemKind: "al", ItemID: "alx"})).To(Succeed())
+
+			n, err := w.drain(ctx, 2)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(n).To(Equal(1))
+
+			Expect(broker.getEvents()).To(BeEmpty(), "a drain with no found items sends no event")
+		})
+	})
+
+	Describe("gate/breaker", func() {
+		It("opens after 5 consecutive external errors and short-circuits the step", func() {
+			var calls int
+			failing := func() (io.ReadCloser, string, error) {
+				calls++
+				return nil, "", errors.New("boom")
+			}
+			for range 5 {
+				_, _, err := w.gate("A", failing)
+				Expect(err).To(HaveOccurred())
+			}
+			Expect(calls).To(Equal(5))
+
+			_, _, err := w.gate("A", failing)
+			Expect(err).To(MatchError(errBreakerOpen))
+			Expect(calls).To(Equal(5), "an open breaker must not call the external step")
+		})
+
+		It("resets the failure count on a successful call", func() {
+			failing := func() (io.ReadCloser, string, error) { return nil, "", errors.New("boom") }
+			ok := func() (io.ReadCloser, string, error) { return io.NopCloser(nil), "p", nil }
+			for range 4 {
+				_, _, _ = w.gate("A", failing)
+			}
+			_, _, err := w.gate("A", ok)
+			Expect(err).ToNot(HaveOccurred())
+
+			var calls int
+			counting := func() (io.ReadCloser, string, error) {
+				calls++
+				return nil, "", errors.New("boom")
+			}
+			for range 5 {
+				_, _, _ = w.gate("A", counting)
+			}
+			Expect(calls).To(Equal(5), "the breaker should have re-closed after the success")
+		})
+
+		It("does not open the breaker on a run of agent not-found misses", func() {
+			// agents.ErrNotFound is a definitive miss, not a fault: artless items must not
+			// trip the breaker, or they would loop in retry instead of settling absent.
+			notFound := func() (io.ReadCloser, string, error) { return nil, "", agents.ErrNotFound }
+			for range breakerThreshold + 3 {
+				_, _, err := w.gate("A", notFound)
+				Expect(err).To(MatchError(agents.ErrNotFound), "a miss passes through, never errBreakerOpen")
+			}
+
+			var calls int
+			counting := func() (io.ReadCloser, string, error) {
+				calls++
+				return nil, "", errors.New("boom")
+			}
+			_, _, _ = w.gate("A", counting)
+			Expect(calls).To(Equal(1), "the breaker stayed closed, so the step still runs")
+		})
+
+		It("isolates each agent's breaker: one open gate does not block another", func() {
+			failing := func() (io.ReadCloser, string, error) { return nil, "", errors.New("boom") }
+			for range breakerThreshold {
+				_, _, _ = w.gate("A", failing)
+			}
+			_, _, err := w.gate("A", failing)
+			Expect(err).To(MatchError(errBreakerOpen), "agent A's breaker is open")
+
+			var bCalls int
+			bStep := func() (io.ReadCloser, string, error) {
+				bCalls++
+				return io.NopCloser(nil), "p", nil
+			}
+			for range breakerThreshold + 2 {
+				_, _, err := w.gate("B", bStep)
+				Expect(err).ToNot(HaveOccurred(), "agent B keeps being called while A is open")
+			}
+			Expect(bCalls).To(Equal(breakerThreshold + 2))
+		})
+	})
+
+	Describe("precache", func() {
+		BeforeEach(func() {
+			folderRepo.result = []model.Folder{{
+				Path:       "tests/fixtures/artist/an-album",
+				ImageFiles: []string{"cover.jpg"},
+			}}
+			ds.MockedAlbum.(*tests.MockAlbumRepo).SetData(model.Albums{
+				{ID: "alpc", Name: "Album", FolderIDs: []string{"f1"}},
+			})
+			conf.Server.UICoverArtSize = 300
+			Expect(queueRepo.Enqueue(model.ArtworkQueueItem{
+				ItemKind: "al", ItemID: "alpc", Priority: model.ArtworkPriorityScan,
+			})).To(Succeed())
+		})
+
+		It("warms the resize cache at the UI cover size after a found acquisition", func() {
+			conf.Server.EnableArtworkPrecache = true
+
+			n, err := w.drain(ctx, 1)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(n).To(Equal(1))
+
+			// The list surfaces request square covers, so warming any other key is wasted work.
+			Expect(imgCache.getKeys()).To(ContainElement(ContainSubstring(".300.true.")))
+		})
+
+		It("skips warming when precache is disabled", func() {
+			conf.Server.EnableArtworkPrecache = false
+
+			n, err := w.drain(ctx, 1)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(n).To(Equal(1))
+
+			Expect(imgCache.getKeys()).To(BeEmpty())
+		})
+
+		// It warms from the bytes acquisition already held, so no state row or store file is needed.
+		It("warms from the acquired bytes without reading them back", func() {
+			conf.Server.EnableArtworkPrecache = true
+			ia := &model.ItemArtwork{
+				ItemKind: "al", ItemID: "unpersisted", ImageType: model.ImageTypePrimary,
+				Hash: "abcdef0123456789", UpdatedAt: time.Now(),
+			}
+
+			data, err := os.ReadFile("tests/fixtures/artist/an-album/cover.jpg")
+			Expect(err).ToNot(HaveOccurred())
+
+			w.precache(ctx, &acquired{ia: ia, mime: "image/jpeg", data: data})
+
+			// Nothing backs that hash on disk, so a hit can only come from the bytes handed in;
+			// the probe refuses to open, proving nothing is re-read.
+			probe := &resizedItem{
+				hash: ia.Hash, size: 300, square: true, ffmpeg: ffm,
+				open: func() (io.ReadCloser, error) { return nil, errors.New("precache must not re-read the source") },
+			}
+			stream, err := imgCache.Get(ctx, probe)
+			Expect(err).ToNot(HaveOccurred())
+			defer stream.Close()
+			Expect(io.ReadAll(stream)).ToNot(BeEmpty())
+		})
+	})
+
+	Describe("drain pools", func() {
+		// A kind in neither pool is never dequeued, with nothing to catch it at compile time.
+		It("covers every kind the worker can process, exactly once", func() {
+			var pooled []string
+			for _, p := range newDrainPools() {
+				pooled = append(pooled, p.kinds...)
+			}
+			for kind := range artworkKindToResource {
+				Expect(pooled).To(ContainElement(kind.Prefix()), "kind %q belongs to no drain pool", kind.Prefix())
+			}
+			Expect(pooled).To(HaveLen(len(artworkKindToResource)), "a kind is claimed by more than one pool")
+		})
+
+		// Artists resolve through a rate-limited agent that holds its slot while waiting, so one
+		// shared pool would park every album behind them.
+		It("resolves albums while artists are stuck on a slow agent", func() {
+			conf.Server.CoverArtPriority = "cover.jpg"
+			conf.Server.ArtistArtPriority = "external"
+			folderRepo.result = []model.Folder{{
+				Path:       "tests/fixtures/artist/an-album",
+				ImageFiles: []string{"cover.jpg"},
+			}}
+			ds.MockedAlbum.(*tests.MockAlbumRepo).SetData(model.Albums{{ID: "alx", Name: "Album", FolderIDs: []string{"f1"}}})
+			ds.MockedArtist = tests.CreateMockArtistRepo()
+
+			// Every artist lookup blocks until released, standing in for the rate limiter.
+			block := make(chan struct{})
+			artists := model.Artists{}
+			for i := range 8 {
+				artists = append(artists, model.Artist{ID: fmt.Sprintf("arx%d", i), Name: "A"})
+			}
+			ds.MockedArtist.(*tests.MockArtistRepo).SetData(artists)
+			imageAgents(&fakeImageAgent{name: "slowAgent", block: block})
+
+			// Artists first, exactly as Backfill orders them.
+			for _, a := range artists {
+				Expect(queueRepo.Enqueue(model.ArtworkQueueItem{
+					ItemKind: "ar", ItemID: a.ID, Priority: model.ArtworkPriorityBackfill,
+				})).To(Succeed())
+			}
+			Expect(queueRepo.Enqueue(model.ArtworkQueueItem{
+				ItemKind: "al", ItemID: "alx", Priority: model.ArtworkPriorityBackfill,
+			})).To(Succeed())
+
+			runCtx, cancel := context.WithCancel(ctx)
+			done := make(chan struct{})
+			go func() { defer close(done); _ = w.Run(runCtx) }()
+			// Join Run: a leaked pool goroutine would race the config snapshot Ginkgo restores.
+			DeferCleanup(func() {
+				cancel()
+				close(block) // unpark the blocked lookups so the pools can unwind
+				<-done
+			})
+
+			Eventually(func() bool {
+				ia, err := artRepo.GetItemArtwork(model.KindAlbumArtwork, "alx", model.ImageTypePrimary)
+				return err == nil && ia.Hash != ""
+			}, 5*time.Second, 50*time.Millisecond).Should(BeTrue(),
+				"a blocked external pool must not hold up local artwork")
+
+			_, err := artRepo.GetItemArtwork(model.KindArtistArtwork, "arx0", model.ImageTypePrimary)
+			Expect(err).To(MatchError(model.ErrNotFound), "artists are still blocked, as intended")
+		})
+	})
+
+	Describe("batching", func() {
+		It("leaves undispatched items queued when cancelled mid-batch", func() {
+			// Every album must resolve, so any dispatched item deletes its row regardless of dequeue order.
+			albums := model.Albums{}
+			for i := range 8 {
+				id := fmt.Sprintf("alc%d", i)
+				albums = append(albums, model.Album{ID: id, Name: "Album"})
+				Expect(queueRepo.Enqueue(model.ArtworkQueueItem{
+					ItemKind: "al", ItemID: id, Priority: model.ArtworkPriorityScan,
+				})).To(Succeed())
+			}
+			ds.MockedAlbum.(*tests.MockAlbumRepo).SetData(albums)
+			cancelledCtx, cancel := context.WithCancel(ctx)
+			cancel()
+
+			_, err := w.drain(cancelledCtx, 1)
+			Expect(err).ToNot(HaveOccurred())
+
+			for i := range 8 {
+				id := fmt.Sprintf("alc%d", i)
+				Expect(findQueued(queueRepo, "al", id)).ToNot(BeNil(), "row "+id+" must survive a cancelled drain")
+			}
+		})
+
+		It("dequeues past the worker pool so one drain covers many items", func() {
+			for i := range 16 {
+				ds.MockedAlbum.(*tests.MockAlbumRepo).SetData(model.Albums{{ID: fmt.Sprintf("alb%d", i), Name: "Album"}})
+				Expect(queueRepo.Enqueue(model.ArtworkQueueItem{
+					ItemKind: "al", ItemID: fmt.Sprintf("alb%d", i), Priority: model.ArtworkPriorityScan,
+				})).To(Succeed())
+			}
+
+			n, err := w.drain(ctx, 2)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(n).To(Equal(16), "a batch sized to the pool would have stopped at 4")
+		})
+	})
+
+	Describe("RunPrune", func() {
+		It("runs a prune under the worker mutex", func() {
+			Expect(w.RunPrune(ctx)).To(Succeed())
+		})
+	})
+
+	Describe("Run", func() {
+		It("exits cleanly when the context is cancelled", func() {
+			runCtx, cancel := context.WithCancel(ctx)
+			done := make(chan error, 1)
+			go func() { done <- w.Run(runCtx) }()
+
+			cancel()
+			Eventually(done, time.Second).Should(Receive(BeNil()))
+		})
+
+		It("does not leak goroutines after Run exits", func() {
+			DeferCleanup(configtest.SetupConfig())
+
+			ignore := goleak.IgnoreCurrent()
+			DeferCleanup(func() { goleak.VerifyNone(GinkgoT(), ignore) })
+
+			localDS := &tests.MockDataStore{MockedArtworkQueue: tests.CreateMockArtworkQueueRepo()}
+			lw := NewWorker(localDS, NewImageStore(GinkgoT().TempDir()), agents.GetAgents(localDS, nil), tests.NewMockFFmpeg(""), &fakeEventBroker{}, imgCache)
+
+			runCtx, cancel := context.WithCancel(ctx)
+			done := make(chan error, 1)
+			go func() { done <- lw.Run(runCtx) }()
+
+			time.Sleep(20 * time.Millisecond) // let the loop settle on the idle select
+			cancel()
+			Eventually(done, 2*time.Second).Should(Receive(BeNil()))
+		})
+	})
+})
+
+var _ = Describe("backoff", func() {
+	It("returns the expected schedule with no jitter", func() {
+		for _, c := range []struct {
+			attempts int
+			want     time.Duration
+		}{
+			{0, 5 * time.Second},
+			{1, 20 * time.Second},
+			{2, 80 * time.Second},
+			{3, 320 * time.Second},
+			{4, 1280 * time.Second},
+			{5, 5120 * time.Second},
+			{6, 20480 * time.Second},
+			{7, 12 * time.Hour},
+			{8, 12 * time.Hour},
+		} {
+			Expect(backoffFor(c.attempts, 0)).To(Equal(c.want), "attempt %d", c.attempts)
+		}
+	})
+
+	It("applies jitter proportionally", func() {
+		base := backoffFor(2, 0)
+		Expect(backoffFor(2, 0.2)).To(Equal(time.Duration(float64(base) * 1.2)))
+		Expect(backoffFor(2, -0.2)).To(Equal(time.Duration(float64(base) * 0.8)))
+	})
+
+	It("keeps random jitter within +/-40%", func() {
+		lo := time.Duration(float64(320*time.Second) * 0.6)
+		hi := time.Duration(float64(320*time.Second) * 1.4)
+		for range 200 {
+			d := backoff(3)
+			Expect(d).To(BeNumerically(">=", lo))
+			Expect(d).To(BeNumerically("<=", hi))
+		}
+	})
+})

core/artwork/worker_timing_test.go

@@ -0,0 +1,76 @@
+package artwork
+
+import (
+	"errors"
+	"io"
+	"testing"
+	"testing/synctest"
+	"time"
+
+	"github.com/navidrome/navidrome/core/agents"
+	"github.com/navidrome/navidrome/tests"
+	. "github.com/onsi/gomega"
+)
+
+// Drives the real breaker state machine with the fake clock. Plain test: testing/synctest
+// needs a *testing.T, which Ginkgo doesn't give.
+func TestArtworkBreakerHalfOpen(t *testing.T) {
+	synctest.Test(t, func(t *testing.T) {
+		g := NewWithT(t)
+		b := newBreaker()
+
+		for range breakerThreshold {
+			b.record("agentA", errors.New("boom"))
+		}
+		g.Expect(b.allow()).To(BeFalse(), "breaker opens after consecutive errors")
+
+		time.Sleep(breakerProbeAfter - time.Nanosecond)
+		g.Expect(b.allow()).To(BeFalse(), "still open before the probe interval")
+
+		time.Sleep(time.Nanosecond)
+		g.Expect(b.allow()).To(BeTrue(), "half-open: one probe is granted")
+		g.Expect(b.allow()).To(BeFalse(), "only a single probe per interval")
+
+		b.record("agentA", errors.New("boom")) // probe fails -> stay open
+		time.Sleep(breakerProbeAfter)
+		g.Expect(b.allow()).To(BeTrue(), "another probe after the next interval")
+
+		b.record("agentA", nil) // probe succeeds -> close
+		g.Expect(b.allow()).To(BeTrue(), "closed breaker admits freely")
+		g.Expect(b.allow()).To(BeTrue())
+	})
+}
+
+func TestArtworkGatePerAgentBreakerIsolation(t *testing.T) {
+	synctest.Test(t, func(t *testing.T) {
+		g := NewWithT(t)
+		w := NewWorker(&tests.MockDataStore{}, NewImageStore(t.TempDir()),
+			agents.GetAgents(&tests.MockDataStore{}, nil), tests.NewMockFFmpeg(""), &fakeEventBroker{}, nil)
+
+		fail := func() (io.ReadCloser, string, error) { return nil, "", errors.New("boom") }
+		for range breakerThreshold {
+			_, _, _ = w.gate("A", fail)
+		}
+		_, _, err := w.gate("A", fail)
+		g.Expect(err).To(MatchError(errBreakerOpen), "A opens after consecutive errors")
+
+		// B has its own breaker, untouched by A being open.
+		var bCalls int
+		bStep := func() (io.ReadCloser, string, error) { bCalls++; return nil, "", errors.New("boom") }
+		for range breakerThreshold - 1 {
+			_, _, err := w.gate("B", bStep)
+			g.Expect(err).To(MatchError("boom"))
+		}
+		g.Expect(bCalls).To(Equal(breakerThreshold-1), "B keeps being called while A is open")
+
+		// After the probe window, A admits exactly one probe again.
+		time.Sleep(breakerProbeAfter)
+		var aCalls int
+		aFail := func() (io.ReadCloser, string, error) { aCalls++; return nil, "", errors.New("boom") }
+		_, _, _ = w.gate("A", aFail)
+		g.Expect(aCalls).To(Equal(1), "A grants a single probe after the interval")
+		_, _, err = w.gate("A", aFail)
+		g.Expect(err).To(MatchError(errBreakerOpen), "the probe failed, so A stays open")
+		g.Expect(aCalls).To(Equal(1))
+	})
+}

core/external/provider.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"errors"
 	"fmt"
-	"net/url"
 	"sort"
 	"strings"
 	"time"
@@ -35,8 +34,6 @@ type Provider interface {
 	UpdateArtistInfo(ctx context.Context, id string, count int, includeNotPresent bool) (*model.Artist, error)
 	SimilarSongs(ctx context.Context, id string, count int) (model.MediaFiles, error)
 	TopSongs(ctx context.Context, artist, artistId string, count int) (model.MediaFiles, error)
-	ArtistImage(ctx context.Context, id string) (*url.URL, error)
-	AlbumImage(ctx context.Context, id string) (*url.URL, error)
 }
 
 type provider struct {
@@ -258,7 +255,7 @@ func (e *provider) populateArtistInfo(ctx context.Context, artist auxArtist) (au
 	// Call all registered agents and collect information
 	g := errgroup.Group{}
 	g.SetLimit(2)
-	g.Go(func() error { e.callGetImage(ctx, e.ag, &artist); return nil })
+	g.Go(func() error { _ = e.callGetImage(ctx, e.ag, &artist); return nil })
 	g.Go(func() error { e.callGetBiography(ctx, e.ag, &artist); return nil })
 	g.Go(func() error { e.callGetURL(ctx, e.ag, &artist); return nil })
 	g.Go(func() error { e.callGetSimilarArtists(ctx, e.ag, &artist, maxSimilarArtists, true); return nil })
@@ -370,76 +367,6 @@ func (e *provider) similarSongsFallback(ctx context.Context, id string, count in
 	return similarSongs, nil
 }
 
-func (e *provider) ArtistImage(ctx context.Context, id string) (*url.URL, error) {
-	artist, err := e.getArtist(ctx, id)
-	if err != nil {
-		return nil, err
-	}
-
-	imageUrl := artist.ArtistImageUrl()
-	if imageUrl == "" {
-		// No cached URL — must fetch from external source synchronously
-		e.callGetImage(ctx, e.ag, &artist)
-		if utils.IsCtxDone(ctx) {
-			log.Warn(ctx, "ArtistImage call canceled", ctx.Err())
-			return nil, ctx.Err()
-		}
-		imageUrl = artist.ArtistImageUrl()
-	} else {
-		// If cached info is expired, enqueue a background refresh so that config changes
-		// (e.g. disabling an agent) take effect without waiting for a full artist info refresh.
-		updatedAt := V(artist.ExternalInfoUpdatedAt)
-		if !updatedAt.IsZero() && time.Since(updatedAt) > conf.Server.DevArtistInfoTimeToLive {
-			log.Debug(ctx, "Artist image info expired, enqueuing background refresh", "artist", artist.Name(), "updatedAt", updatedAt)
-			e.artistQueue.enqueue(&artist)
-		}
-	}
-
-	if imageUrl == "" {
-		return nil, model.ErrNotFound
-	}
-	return url.Parse(imageUrl)
-}
-
-func (e *provider) AlbumImage(ctx context.Context, id string) (*url.URL, error) {
-	album, err := e.getAlbum(ctx, id)
-	if err != nil {
-		return nil, err
-	}
-
-	albumName := album.Name()
-	images, err := e.ag.GetAlbumImages(ctx, albumName, album.AlbumArtist, album.MbzAlbumID)
-	if err != nil {
-		switch {
-		case errors.Is(err, agents.ErrNotFound):
-			log.Trace(ctx, "Album not found in agent", "albumID", id, "name", albumName, "artist", album.AlbumArtist)
-			return nil, model.ErrNotFound
-		case errors.Is(err, context.Canceled):
-			log.Debug(ctx, "GetAlbumImages call canceled", err)
-		default:
-			log.Warn(ctx, "Error getting album images from agent", "albumID", id, "name", albumName, "artist", album.AlbumArtist, err)
-		}
-		return nil, err
-	}
-
-	if len(images) == 0 {
-		log.Warn(ctx, "Agent returned no images without error", "albumID", id, "name", albumName, "artist", album.AlbumArtist)
-		return nil, model.ErrNotFound
-	}
-
-	// Return the biggest image
-	var img agents.ExternalImage
-	for _, i := range images {
-		if img.Size <= i.Size {
-			img = i
-		}
-	}
-	if img.URL == "" {
-		return nil, model.ErrNotFound
-	}
-	return url.Parse(img.URL)
-}
-
 func (e *provider) TopSongs(ctx context.Context, artistName, id string, count int) (model.MediaFiles, error) {
 	artist, err := e.findArtist(ctx, artistName, id)
 	if err != nil {
@@ -524,10 +451,15 @@ func (e *provider) callGetBiography(ctx context.Context, agent agents.ArtistBiog
 	artist.Biography = strings.ReplaceAll(bio, "<a ", "<a target='_blank' ")
 }
 
-func (e *provider) callGetImage(ctx context.Context, agent agents.ArtistImageRetriever, artist *auxArtist) {
+// callGetImage populates artist's image URLs. A transient agent failure is
+// returned as-is; a definitive "no image" is normalized to model.ErrNotFound.
+func (e *provider) callGetImage(ctx context.Context, agent agents.ArtistImageRetriever, artist *auxArtist) error {
 	images, err := agent.GetArtistImages(ctx, artist.ID, artist.Name(), artist.MbzArtistID)
 	if err != nil {
-		return
+		if errors.Is(err, agents.ErrNotFound) {
+			return model.ErrNotFound
+		}
+		return err
 	}
 	sort.Slice(images, func(i, j int) bool { return images[i].Size > images[j].Size })
 
@@ -540,6 +472,7 @@ func (e *provider) callGetImage(ctx context.Context, agent agents.ArtistImageRet
 	if len(images) >= 3 {
 		artist.SmallImageUrl = images[2].URL
 	}
+	return nil
 }
 
 func (e *provider) callGetSimilarArtists(ctx context.Context, agent agents.ArtistSimilarRetriever, artist *auxArtist,

core/external/provider_albumimage_test.go

@@ -1,365 +0,0 @@
-package external_test
-
-import (
-	"context"
-	"errors"
-	"net/url"
-
-	"github.com/navidrome/navidrome/conf"
-	"github.com/navidrome/navidrome/conf/configtest"
-	"github.com/navidrome/navidrome/core/agents"
-	. "github.com/navidrome/navidrome/core/external"
-	"github.com/navidrome/navidrome/core/matcher"
-	"github.com/navidrome/navidrome/model"
-	"github.com/navidrome/navidrome/tests"
-	. "github.com/onsi/ginkgo/v2"
-	. "github.com/onsi/gomega"
-	"github.com/stretchr/testify/mock"
-)
-
-var _ = Describe("Provider - AlbumImage", func() {
-	var ds *tests.MockDataStore
-	var provider Provider
-	var mockArtistRepo *mockArtistRepo
-	var mockAlbumRepo *mockAlbumRepo
-	var mockMediaFileRepo *mockMediaFileRepo
-	var mockAlbumAgent *mockAlbumInfoAgent
-	var ctx context.Context
-
-	BeforeEach(func() {
-		ctx = GinkgoT().Context()
-		DeferCleanup(configtest.SetupConfig())
-		conf.Server.Agents = "mockAlbum" // Configure mock agent
-
-		mockArtistRepo = newMockArtistRepo()
-		mockAlbumRepo = newMockAlbumRepo()
-		mockMediaFileRepo = newMockMediaFileRepo()
-
-		ds = &tests.MockDataStore{
-			MockedArtist:    mockArtistRepo,
-			MockedAlbum:     mockAlbumRepo,
-			MockedMediaFile: mockMediaFileRepo,
-		}
-
-		mockAlbumAgent = newMockAlbumInfoAgent()
-
-		agentsCombined := &mockAgents{albumInfoAgent: mockAlbumAgent}
-		provider = NewProvider(ds, agentsCombined, matcher.New(ds))
-
-		// Default mocks
-		// Mocks for GetEntityByID sequence (initial failed lookups)
-		mockArtistRepo.On("Get", "album-1").Return(nil, model.ErrNotFound).Once()
-		mockArtistRepo.On("Get", "mf-1").Return(nil, model.ErrNotFound).Once()
-		mockAlbumRepo.On("Get", "mf-1").Return(nil, model.ErrNotFound).Once()
-
-		// Default mock for non-existent entities - Use Maybe() for flexibility
-		mockArtistRepo.On("Get", "not-found").Return(nil, model.ErrNotFound).Maybe()
-		mockAlbumRepo.On("Get", "not-found").Return(nil, model.ErrNotFound).Maybe()
-		mockMediaFileRepo.On("Get", "not-found").Return(nil, model.ErrNotFound).Maybe()
-	})
-
-	It("returns the largest image URL when successful", func() {
-		// Arrange
-		mockArtistRepo.On("Get", "album-1").Return(nil, model.ErrNotFound).Once() // Expect GetEntityByID sequence
-		mockAlbumRepo.On("Get", "album-1").Return(&model.Album{ID: "album-1", Name: "Album One", AlbumArtistID: "artist-1"}, nil).Once()
-		// Explicitly mock agent call for this test
-		mockAlbumAgent.On("GetAlbumImages", ctx, "Album One", "", "").
-			Return([]agents.ExternalImage{
-				{URL: "http://example.com/large.jpg", Size: 1000},
-				{URL: "http://example.com/medium.jpg", Size: 500},
-				{URL: "http://example.com/small.jpg", Size: 200},
-			}, nil).Once()
-
-		expectedURL, _ := url.Parse("http://example.com/large.jpg")
-		imgURL, err := provider.AlbumImage(ctx, "album-1")
-
-		Expect(err).ToNot(HaveOccurred())
-		Expect(imgURL).To(Equal(expectedURL))
-		mockArtistRepo.AssertCalled(GinkgoT(), "Get", "album-1") // From GetEntityByID
-		mockAlbumRepo.AssertCalled(GinkgoT(), "Get", "album-1")
-		mockArtistRepo.AssertNotCalled(GinkgoT(), "Get", "artist-1")                       // Artist lookup no longer happens in getAlbum
-		mockAlbumAgent.AssertCalled(GinkgoT(), "GetAlbumImages", ctx, "Album One", "", "") // Expect empty artist name
-	})
-
-	It("returns ErrNotFound if the album is not found in the DB", func() {
-		// Arrange: Explicitly expect the full GetEntityByID sequence for "not-found"
-		mockArtistRepo.On("Get", "not-found").Return(nil, model.ErrNotFound).Once()
-		mockAlbumRepo.On("Get", "not-found").Return(nil, model.ErrNotFound).Once()
-		mockMediaFileRepo.On("Get", "not-found").Return(nil, model.ErrNotFound).Once()
-
-		imgURL, err := provider.AlbumImage(ctx, "not-found")
-
-		Expect(err).To(MatchError("data not found"))
-		Expect(imgURL).To(BeNil())
-		mockArtistRepo.AssertCalled(GinkgoT(), "Get", "not-found")
-		mockAlbumRepo.AssertCalled(GinkgoT(), "Get", "not-found")
-		mockMediaFileRepo.AssertCalled(GinkgoT(), "Get", "not-found")
-		mockAlbumAgent.AssertNotCalled(GinkgoT(), "GetAlbumImages", mock.Anything, mock.Anything, mock.Anything)
-	})
-
-	It("returns the agent error if the agent fails", func() {
-		// Arrange
-		mockArtistRepo.On("Get", "album-1").Return(nil, model.ErrNotFound).Once() // Expect GetEntityByID sequence
-		mockAlbumRepo.On("Get", "album-1").Return(&model.Album{ID: "album-1", Name: "Album One", AlbumArtistID: "artist-1"}, nil).Once()
-
-		agentErr := errors.New("agent failure")
-		// Explicitly mock agent call for this test
-		mockAlbumAgent.On("GetAlbumImages", ctx, "Album One", "", "").Return(nil, agentErr).Once() // Expect empty artist
-
-		imgURL, err := provider.AlbumImage(ctx, "album-1")
-
-		Expect(err).To(MatchError("agent failure"))
-		Expect(imgURL).To(BeNil())
-		mockArtistRepo.AssertCalled(GinkgoT(), "Get", "album-1")
-		mockAlbumRepo.AssertCalled(GinkgoT(), "Get", "album-1")
-		mockArtistRepo.AssertNotCalled(GinkgoT(), "Get", "artist-1")
-		mockAlbumAgent.AssertCalled(GinkgoT(), "GetAlbumImages", ctx, "Album One", "", "") // Expect empty artist
-	})
-
-	It("returns ErrNotFound if the agent returns ErrNotFound", func() {
-		// Arrange
-		mockArtistRepo.On("Get", "album-1").Return(nil, model.ErrNotFound).Once() // Expect GetEntityByID sequence
-		mockAlbumRepo.On("Get", "album-1").Return(&model.Album{ID: "album-1", Name: "Album One", AlbumArtistID: "artist-1"}, nil).Once()
-
-		// Explicitly mock agent call for this test
-		mockAlbumAgent.On("GetAlbumImages", ctx, "Album One", "", "").Return(nil, agents.ErrNotFound).Once() // Expect empty artist
-
-		imgURL, err := provider.AlbumImage(ctx, "album-1")
-
-		Expect(err).To(MatchError("data not found"))
-		Expect(imgURL).To(BeNil())
-		mockArtistRepo.AssertCalled(GinkgoT(), "Get", "album-1")
-		mockAlbumRepo.AssertCalled(GinkgoT(), "Get", "album-1")
-		mockAlbumAgent.AssertCalled(GinkgoT(), "GetAlbumImages", ctx, "Album One", "", "") // Expect empty artist
-	})
-
-	It("returns ErrNotFound if the agent returns no images", func() {
-		// Arrange
-		mockArtistRepo.On("Get", "album-1").Return(nil, model.ErrNotFound).Once() // Expect GetEntityByID sequence
-		mockAlbumRepo.On("Get", "album-1").Return(&model.Album{ID: "album-1", Name: "Album One", AlbumArtistID: "artist-1"}, nil).Once()
-
-		// Explicitly mock agent call for this test
-		mockAlbumAgent.On("GetAlbumImages", ctx, "Album One", "", "").
-			Return([]agents.ExternalImage{}, nil).Once() // Expect empty artist
-
-		imgURL, err := provider.AlbumImage(ctx, "album-1")
-
-		Expect(err).To(MatchError("data not found"))
-		Expect(imgURL).To(BeNil())
-		mockArtistRepo.AssertCalled(GinkgoT(), "Get", "album-1")
-		mockAlbumRepo.AssertCalled(GinkgoT(), "Get", "album-1")
-		mockAlbumAgent.AssertCalled(GinkgoT(), "GetAlbumImages", ctx, "Album One", "", "") // Expect empty artist
-	})
-
-	It("returns context error if context is canceled", func() {
-		// Arrange
-		cctx, cancelCtx := context.WithCancel(ctx)
-		// Mock the necessary DB calls *before* canceling the context
-		mockArtistRepo.On("Get", "album-1").Return(nil, model.ErrNotFound).Once()
-		mockAlbumRepo.On("Get", "album-1").Return(&model.Album{ID: "album-1", Name: "Album One", AlbumArtistID: "artist-1"}, nil).Once()
-		// Expect the agent call even if context is cancelled, returning the context error
-		mockAlbumAgent.On("GetAlbumImages", cctx, "Album One", "", "").Return(nil, context.Canceled).Once()
-		// Cancel the context *before* calling the function under test
-		cancelCtx()
-
-		imgURL, err := provider.AlbumImage(cctx, "album-1")
-
-		Expect(err).To(MatchError("context canceled"))
-		Expect(imgURL).To(BeNil())
-		mockArtistRepo.AssertCalled(GinkgoT(), "Get", "album-1")
-		mockAlbumRepo.AssertCalled(GinkgoT(), "Get", "album-1")
-		// Agent should now be called, verify this expectation
-		mockAlbumAgent.AssertCalled(GinkgoT(), "GetAlbumImages", cctx, "Album One", "", "")
-	})
-
-	It("derives album ID from MediaFile ID", func() {
-		// Arrange: Mock full GetEntityByID for "mf-1" and recursive "album-1"
-		mockArtistRepo.On("Get", "mf-1").Return(nil, model.ErrNotFound).Once()
-		mockAlbumRepo.On("Get", "mf-1").Return(nil, model.ErrNotFound).Once()
-		mockMediaFileRepo.On("Get", "mf-1").Return(&model.MediaFile{ID: "mf-1", Title: "Track One", ArtistID: "artist-1", AlbumID: "album-1"}, nil).Once()
-		mockArtistRepo.On("Get", "album-1").Return(nil, model.ErrNotFound).Once()
-		mockAlbumRepo.On("Get", "album-1").Return(&model.Album{ID: "album-1", Name: "Album One", AlbumArtistID: "artist-1"}, nil).Once()
-
-		// Explicitly mock agent call for this test
-		mockAlbumAgent.On("GetAlbumImages", ctx, "Album One", "", "").
-			Return([]agents.ExternalImage{
-				{URL: "http://example.com/large.jpg", Size: 1000},
-				{URL: "http://example.com/medium.jpg", Size: 500},
-				{URL: "http://example.com/small.jpg", Size: 200},
-			}, nil).Once()
-
-		expectedURL, _ := url.Parse("http://example.com/large.jpg")
-		imgURL, err := provider.AlbumImage(ctx, "mf-1")
-
-		Expect(err).ToNot(HaveOccurred())
-		Expect(imgURL).To(Equal(expectedURL))
-		mockArtistRepo.AssertCalled(GinkgoT(), "Get", "mf-1")
-		mockAlbumRepo.AssertCalled(GinkgoT(), "Get", "mf-1")
-		mockMediaFileRepo.AssertCalled(GinkgoT(), "Get", "mf-1")
-		mockArtistRepo.AssertCalled(GinkgoT(), "Get", "album-1")
-		mockAlbumRepo.AssertCalled(GinkgoT(), "Get", "album-1")
-		mockArtistRepo.AssertNotCalled(GinkgoT(), "Get", "artist-1")
-		mockAlbumAgent.AssertCalled(GinkgoT(), "GetAlbumImages", ctx, "Album One", "", "")
-	})
-
-	It("handles different image orders from agent", func() {
-		// Arrange
-		mockArtistRepo.On("Get", "album-1").Return(nil, model.ErrNotFound).Once() // Expect GetEntityByID sequence
-		mockAlbumRepo.On("Get", "album-1").Return(&model.Album{ID: "album-1", Name: "Album One", AlbumArtistID: "artist-1"}, nil).Once()
-		// Explicitly mock agent call for this test
-		mockAlbumAgent.On("GetAlbumImages", ctx, "Album One", "", "").
-			Return([]agents.ExternalImage{
-				{URL: "http://example.com/small.jpg", Size: 200},
-				{URL: "http://example.com/large.jpg", Size: 1000},
-				{URL: "http://example.com/medium.jpg", Size: 500},
-			}, nil).Once()
-
-		expectedURL, _ := url.Parse("http://example.com/large.jpg")
-		imgURL, err := provider.AlbumImage(ctx, "album-1")
-
-		Expect(err).ToNot(HaveOccurred())
-		Expect(imgURL).To(Equal(expectedURL)) // Should still pick the largest
-		mockAlbumAgent.AssertCalled(GinkgoT(), "GetAlbumImages", ctx, "Album One", "", "")
-	})
-
-	It("handles agent returning only one image", func() {
-		// Arrange
-		mockArtistRepo.On("Get", "album-1").Return(nil, model.ErrNotFound).Once() // Expect GetEntityByID sequence
-		mockAlbumRepo.On("Get", "album-1").Return(&model.Album{ID: "album-1", Name: "Album One", AlbumArtistID: "artist-1"}, nil).Once()
-		// Explicitly mock agent call for this test
-		mockAlbumAgent.On("GetAlbumImages", ctx, "Album One", "", "").
-			Return([]agents.ExternalImage{
-				{URL: "http://example.com/single.jpg", Size: 700},
-			}, nil).Once()
-
-		expectedURL, _ := url.Parse("http://example.com/single.jpg")
-		imgURL, err := provider.AlbumImage(ctx, "album-1")
-
-		Expect(err).ToNot(HaveOccurred())
-		Expect(imgURL).To(Equal(expectedURL))
-		mockAlbumAgent.AssertCalled(GinkgoT(), "GetAlbumImages", ctx, "Album One", "", "")
-	})
-
-	It("returns ErrNotFound if deriving album ID fails", func() {
-		// Arrange: Mock full GetEntityByID for "mf-no-album" and recursive "not-found"
-		mockArtistRepo.On("Get", "mf-no-album").Return(nil, model.ErrNotFound).Once()
-		mockAlbumRepo.On("Get", "mf-no-album").Return(nil, model.ErrNotFound).Once()
-		mockMediaFileRepo.On("Get", "mf-no-album").Return(&model.MediaFile{ID: "mf-no-album", Title: "Track No Album", ArtistID: "artist-1", AlbumID: "not-found"}, nil).Once()
-		mockArtistRepo.On("Get", "not-found").Return(nil, model.ErrNotFound).Once()
-		mockAlbumRepo.On("Get", "not-found").Return(nil, model.ErrNotFound).Once()
-		mockMediaFileRepo.On("Get", "not-found").Return(nil, model.ErrNotFound).Once()
-
-		imgURL, err := provider.AlbumImage(ctx, "mf-no-album")
-
-		Expect(err).To(MatchError("data not found"))
-		Expect(imgURL).To(BeNil())
-		mockArtistRepo.AssertCalled(GinkgoT(), "Get", "mf-no-album")
-		mockAlbumRepo.AssertCalled(GinkgoT(), "Get", "mf-no-album")
-		mockMediaFileRepo.AssertCalled(GinkgoT(), "Get", "mf-no-album")
-		mockArtistRepo.AssertCalled(GinkgoT(), "Get", "not-found")
-		mockAlbumRepo.AssertCalled(GinkgoT(), "Get", "not-found")
-		mockMediaFileRepo.AssertCalled(GinkgoT(), "Get", "not-found")
-		mockAlbumAgent.AssertNotCalled(GinkgoT(), "GetAlbumImages", mock.Anything, mock.Anything, mock.Anything)
-	})
-
-	Context("Unicode handling in album names", func() {
-		var albumWithEnDash *model.Album
-		var expectedURL *url.URL
-
-		const (
-			originalAlbumName   = "Raising Hell–Deluxe" // Album name with en dash
-			normalizedAlbumName = "Raising Hell-Deluxe" // Normalized version with hyphen
-		)
-
-		BeforeEach(func() {
-			// Test with en dash (–) in album name
-			albumWithEnDash = &model.Album{ID: "album-endash", Name: originalAlbumName, AlbumArtistID: "artist-1"}
-			mockArtistRepo.Mock = mock.Mock{} // Reset default expectations
-			mockAlbumRepo.Mock = mock.Mock{}  // Reset default expectations
-			mockArtistRepo.On("Get", "album-endash").Return(nil, model.ErrNotFound).Once()
-			mockAlbumRepo.On("Get", "album-endash").Return(albumWithEnDash, nil).Once()
-
-			expectedURL, _ = url.Parse("http://example.com/album.jpg")
-
-			// Mock the album agent to return an image for the album
-			mockAlbumAgent.On("GetAlbumImages", ctx, mock.AnythingOfType("string"), "", "").
-				Return([]agents.ExternalImage{
-					{URL: "http://example.com/album.jpg", Size: 1000},
-				}, nil).Once()
-		})
-
-		When("DevPreserveUnicodeInExternalCalls is true", func() {
-			BeforeEach(func() {
-				conf.Server.DevPreserveUnicodeInExternalCalls = true
-			})
-
-			It("preserves Unicode characters in album names", func() {
-				// Act
-				imgURL, err := provider.AlbumImage(ctx, "album-endash")
-
-				// Assert
-				Expect(err).ToNot(HaveOccurred())
-				Expect(imgURL).To(Equal(expectedURL))
-				mockAlbumRepo.AssertCalled(GinkgoT(), "Get", "album-endash")
-				// This is the key assertion: ensure the original Unicode name is used
-				mockAlbumAgent.AssertCalled(GinkgoT(), "GetAlbumImages", ctx, originalAlbumName, "", "")
-			})
-		})
-
-		When("DevPreserveUnicodeInExternalCalls is false", func() {
-			BeforeEach(func() {
-				conf.Server.DevPreserveUnicodeInExternalCalls = false
-			})
-
-			It("normalizes Unicode characters", func() {
-				// Act
-				imgURL, err := provider.AlbumImage(ctx, "album-endash")
-
-				// Assert
-				Expect(err).ToNot(HaveOccurred())
-				Expect(imgURL).To(Equal(expectedURL))
-				mockAlbumRepo.AssertCalled(GinkgoT(), "Get", "album-endash")
-				// This assertion ensures the normalized name is used (en dash → hyphen)
-				mockAlbumAgent.AssertCalled(GinkgoT(), "GetAlbumImages", ctx, normalizedAlbumName, "", "")
-			})
-		})
-	})
-})
-
-// mockAlbumInfoAgent implementation
-type mockAlbumInfoAgent struct {
-	mock.Mock
-	agents.AlbumInfoRetriever
-	agents.AlbumImageRetriever
-}
-
-func newMockAlbumInfoAgent() *mockAlbumInfoAgent {
-	m := new(mockAlbumInfoAgent)
-	m.On("AgentName").Return("mockAlbum").Maybe()
-	return m
-}
-
-func (m *mockAlbumInfoAgent) AgentName() string {
-	args := m.Called()
-	return args.String(0)
-}
-
-func (m *mockAlbumInfoAgent) GetAlbumInfo(ctx context.Context, name, artist, mbid string) (*agents.AlbumInfo, error) {
-	args := m.Called(ctx, name, artist, mbid)
-	if args.Get(0) == nil {
-		return nil, args.Error(1)
-	}
-	return args.Get(0).(*agents.AlbumInfo), args.Error(1)
-}
-
-func (m *mockAlbumInfoAgent) GetAlbumImages(ctx context.Context, name, artist, mbid string) ([]agents.ExternalImage, error) {
-	args := m.Called(ctx, name, artist, mbid)
-	if args.Get(0) == nil {
-		return nil, args.Error(1)
-	}
-	return args.Get(0).([]agents.ExternalImage), args.Error(1)
-}
-
-// Ensure mockAgent implements the interfaces
-var _ agents.AlbumInfoRetriever = (*mockAlbumInfoAgent)(nil)
-var _ agents.AlbumImageRetriever = (*mockAlbumInfoAgent)(nil)