feat: persist and expose plugin playlist ValidUntil in Subsonic API

Add a ValidUntil field to the Playlist model and persist it from the
plugin's GetPlaylistResponse during sync. This allows clients to know
when a plugin playlist's data will be refreshed. The value is exposed
in the OpenSubsonic playlist response alongside the existing
smart playlist ValidUntil calculation. The migration is consolidated
into a single multi-statement ExecContext call.

db/migrations/20260305051806_add_plugin_playlist_fields.go

@@ -12,27 +12,21 @@ func init() {
 }
 
 func upAddPluginPlaylistFields(ctx context.Context, tx *sql.Tx) error {
-	_, err := tx.ExecContext(ctx, `ALTER TABLE playlist ADD COLUMN plugin_id VARCHAR(255) NOT NULL DEFAULT '';`)
+	_, err := tx.ExecContext(ctx, `
-	if err != nil {
+ALTER TABLE playlist ADD COLUMN plugin_id VARCHAR(255) NOT NULL DEFAULT '';
-		return err
+ALTER TABLE playlist ADD COLUMN plugin_playlist_id VARCHAR(255) NOT NULL DEFAULT '';
-	}
+ALTER TABLE playlist ADD COLUMN valid_until DATETIME DEFAULT NULL;
-	_, err = tx.ExecContext(ctx, `ALTER TABLE playlist ADD COLUMN plugin_playlist_id VARCHAR(255) NOT NULL DEFAULT '';`)
+CREATE UNIQUE INDEX IF NOT EXISTS idx_playlist_plugin ON playlist(plugin_id, plugin_playlist_id, owner_id) WHERE plugin_id != '';
-	if err != nil {
+`)
-		return err
-	}
-	_, err = tx.ExecContext(ctx, `CREATE UNIQUE INDEX IF NOT EXISTS idx_playlist_plugin ON playlist(plugin_id, plugin_playlist_id, owner_id) WHERE plugin_id != '';`)
 	return err
 }
 
 func downAddPluginPlaylistFields(ctx context.Context, tx *sql.Tx) error {
-	_, err := tx.ExecContext(ctx, `DROP INDEX IF EXISTS idx_playlist_plugin;`)
+	_, err := tx.ExecContext(ctx, `
-	if err != nil {
+DROP INDEX IF EXISTS idx_playlist_plugin;
-		return err
+ALTER TABLE playlist DROP COLUMN valid_until;
-	}
+ALTER TABLE playlist DROP COLUMN plugin_playlist_id;
-	_, err = tx.ExecContext(ctx, `ALTER TABLE playlist DROP COLUMN plugin_playlist_id;`)
+ALTER TABLE playlist DROP COLUMN plugin_id;
-	if err != nil {
+`)
-		return err
-	}
-	_, err = tx.ExecContext(ctx, `ALTER TABLE playlist DROP COLUMN plugin_id;`)
 	return err
 }

model/playlist.go

@@ -32,8 +32,9 @@ type Playlist struct {
 	EvaluatedAt *time.Time         `structs:"evaluated_at" json:"evaluatedAt"`
 
 	// Plugin playlist attributes
-	PluginID         string `structs:"plugin_id" json:"pluginId,omitempty"`
+	PluginID         string     `structs:"plugin_id" json:"pluginId,omitempty"`
-	PluginPlaylistID string `structs:"plugin_playlist_id" json:"pluginPlaylistId,omitempty"`
+	PluginPlaylistID string     `structs:"plugin_playlist_id" json:"pluginPlaylistId,omitempty"`
+	ValidUntil       *time.Time `structs:"valid_until" json:"validUntil,omitempty"`
 }
 
 func (pls Playlist) IsReadOnly() bool {

plugins/playlist_provider.go

@@ -200,6 +200,10 @@ func (p *playlistSyncer) syncPlaylist(info capabilities.PlaylistInfo, dbID strin
 		PluginID:         p.pluginName,
 		PluginPlaylistID: info.ID,
 	}
+	if resp.ValidUntil > 0 {
+		t := time.Unix(resp.ValidUntil, 0)
+		pls.ValidUntil = &t
+	}
 
 	// Set tracks from matched media files
 	pls.AddMediaFiles(matched)

plugins/playlist_provider_test.go

@@ -75,6 +75,7 @@ var _ = Describe("PlaylistProvider", Ordered, func() {
 			Expect(dailyMix1.PluginID).To(Equal("test-playlist-provider"))
 			Expect(dailyMix1.PluginPlaylistID).To(Equal("daily-mix-1"))
 			Expect(dailyMix1.Public).To(BeFalse())
+			Expect(dailyMix1.ValidUntil).To(BeNil())
 		})
 
 		It("generates deterministic playlist IDs", func() {

server/subsonic/playlists.go

@@ -168,9 +168,10 @@ func buildOSPlaylist(ctx context.Context, p model.Playlist) *responses.OpenSubso
 	if p.IsReadOnly() {
 		pls.Readonly = true
 
-		// ValidUntil only applies to smart playlists
 		if p.IsSmartPlaylist() && p.EvaluatedAt != nil {
 			pls.ValidUntil = P(p.EvaluatedAt.Add(conf.Server.SmartPlaylistRefreshDelay))
+		} else if p.IsPluginPlaylist() && p.ValidUntil != nil {
+			pls.ValidUntil = p.ValidUntil
 		}
 	} else {
 		user, ok := request.UserFrom(ctx)

server/subsonic/playlists_test.go

@@ -177,13 +177,23 @@ var _ = Describe("buildPlaylist", func() {
 			}
 		})
 
-		It("marks plugin playlist as readonly", func() {
+		It("marks plugin playlist as readonly with no ValidUntil when not set", func() {
 			ctx = request.WithUser(ctx, model.User{ID: "1234", UserName: "admin"})
 			result := router.buildPlaylist(ctx, playlist)
 			Expect(result.Readonly).To(BeTrue())
 			Expect(result.ValidUntil).To(BeNil())
 		})
 
+		It("exposes ValidUntil when set on the model", func() {
+			validUntil := time.Date(2023, 3, 1, 12, 0, 0, 0, time.UTC)
+			playlist.ValidUntil = &validUntil
+
+			ctx = request.WithUser(ctx, model.User{ID: "1234", UserName: "admin"})
+			result := router.buildPlaylist(ctx, playlist)
+			Expect(result.Readonly).To(BeTrue())
+			Expect(result.ValidUntil).To(Equal(&validUntil))
+		})
+
 		It("marks plugin playlist as readonly even for non-owner", func() {
 			ctx = request.WithUser(ctx, model.User{ID: "other-user", UserName: "other"})
 			result := router.buildPlaylist(ctx, playlist)