feat(deezer): add functions to fetch related artists, biographies, and top tracks for an artist

Signed-off-by: Deluan <deluan@navidrome.org>

core/agents/deezer/client.go

@@ -8,8 +8,11 @@ import (
 	"io"
 	"net/http"
 	"net/url"
+	"regexp"
 	"strconv"
+	"strings"
 
+	"github.com/microcosm-cc/bluemonday"
 	"github.com/navidrome/navidrome/log"
 )
 
@@ -81,3 +84,94 @@ func (c *client) parseError(data []byte) error {
 	}
 	return fmt.Errorf("deezer error(%d): %s", deezerError.Error.Code, deezerError.Error.Message)
 }
+
+func (c *client) getRelatedArtists(ctx context.Context, artistID int) ([]Artist, error) {
+	req, err := http.NewRequestWithContext(ctx, "GET", fmt.Sprintf("%s/artist/%d/related", apiBaseURL, artistID), nil)
+	if err != nil {
+		return nil, err
+	}
+
+	var results RelatedArtists
+	err = c.makeRequest(req, &results)
+	if err != nil {
+		return nil, err
+	}
+
+	return results.Data, nil
+}
+
+func (c *client) getTopTracks(ctx context.Context, artistID int, limit int) ([]Track, error) {
+	params := url.Values{}
+	params.Add("limit", strconv.Itoa(limit))
+	req, err := http.NewRequestWithContext(ctx, "GET", fmt.Sprintf("%s/artist/%d/top", apiBaseURL, artistID), nil)
+	if err != nil {
+		return nil, err
+	}
+	req.URL.RawQuery = params.Encode()
+
+	var results TopTracks
+	err = c.makeRequest(req, &results)
+	if err != nil {
+		return nil, err
+	}
+
+	return results.Data, nil
+}
+
+var dzrAppStateRegex = regexp.MustCompile(`window\.__DZR_APP_STATE__\s*=\s*({.+?})\s*</script>`)
+var strictPolicy = bluemonday.StrictPolicy()
+
+func (c *client) getArtistBio(ctx context.Context, artistID int) (string, error) {
+	u := fmt.Sprintf("https://www.deezer.com/en/artist/%d/biography", artistID)
+	req, err := http.NewRequestWithContext(ctx, "GET", u, nil)
+	if err != nil {
+		return "", err
+	}
+
+	log.Trace(ctx, "Fetching Deezer artist biography", "url", u)
+	resp, err := c.httpDoer.Do(req)
+	if err != nil {
+		return "", err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != 200 {
+		return "", fmt.Errorf("deezer: failed to fetch biography: %s", resp.Status)
+	}
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return "", err
+	}
+
+	matches := dzrAppStateRegex.FindSubmatch(body)
+	if len(matches) < 2 {
+		return "", errors.New("deezer: could not find __DZR_APP_STATE__")
+	}
+
+	type appState struct {
+		Bio struct {
+			Bio    string `json:"BIO"`
+			Resume string `json:"RESUME"`
+		} `json:"BIO"`
+	}
+
+	var state appState
+	if err := json.Unmarshal(matches[1], &state); err != nil {
+		return "", fmt.Errorf("deezer: failed to parse __DZR_APP_STATE__: %w", err)
+	}
+
+	var bio string
+	if state.Bio.Bio != "" {
+		bio = state.Bio.Bio
+	} else {
+		bio = state.Bio.Resume
+	}
+
+	return cleanBio(bio), nil
+}
+
+func cleanBio(bio string) string {
+	bio = strings.ReplaceAll(bio, "</p>", "\n")
+	return strictPolicy.Sanitize(bio)
+}

core/agents/deezer/client_test.go

@@ -43,6 +43,20 @@ var _ = Describe("client", func() {
 			Expect(err).To(MatchError(ErrNotFound))
 		})
 	})
+
+	Describe("ArtistBio", func() {
+		It("returns artist bio from a successful request", func() {
+			f, err := os.Open("tests/fixtures/deezer.artist.bio.html")
+			Expect(err).To(BeNil())
+			httpClient.mock("https://www.deezer.com/en/artist/27/biography", http.Response{Body: f, StatusCode: 200})
+
+			bio, err := client.getArtistBio(context.TODO(), 27)
+			Expect(err).To(BeNil())
+			Expect(bio).To(ContainSubstring("Schoolmates Thomas and Guy-Manuel"))
+			Expect(bio).ToNot(ContainSubstring("<p>"))
+			Expect(bio).ToNot(ContainSubstring("</p>"))
+		})
+	})
 })
 
 type fakeHttpClient struct {

core/agents/deezer/deezer.go

@@ -12,6 +12,7 @@ import (
 	"github.com/navidrome/navidrome/log"
 	"github.com/navidrome/navidrome/model"
 	"github.com/navidrome/navidrome/utils/cache"
+	"github.com/navidrome/navidrome/utils/slice"
 )
 
 const deezerAgentName = "deezer"
@@ -88,6 +89,56 @@ func (s *deezerAgent) searchArtist(ctx context.Context, name string) (*Artist, e
 	return &artists[0], err
 }
 
+func (s *deezerAgent) GetSimilarArtists(ctx context.Context, _, name, _ string, limit int) ([]agents.Artist, error) {
+	artist, err := s.searchArtist(ctx, name)
+	if err != nil {
+		return nil, err
+	}
+
+	related, err := s.client.getRelatedArtists(ctx, artist.ID)
+	if err != nil {
+		return nil, err
+	}
+
+	res := slice.Map(related, func(r Artist) agents.Artist {
+		return agents.Artist{
+			Name: r.Name,
+		}
+	})
+	if len(res) > limit {
+		res = res[:limit]
+	}
+	return res, nil
+}
+
+func (s *deezerAgent) GetArtistTopSongs(ctx context.Context, _, artistName, _ string, count int) ([]agents.Song, error) {
+	artist, err := s.searchArtist(ctx, artistName)
+	if err != nil {
+		return nil, err
+	}
+
+	tracks, err := s.client.getTopTracks(ctx, artist.ID, count)
+	if err != nil {
+		return nil, err
+	}
+
+	res := slice.Map(tracks, func(r Track) agents.Song {
+		return agents.Song{
+			Name: r.Title,
+		}
+	})
+	return res, nil
+}
+
+func (s *deezerAgent) GetArtistBiography(ctx context.Context, _, name, _ string) (string, error) {
+	artist, err := s.searchArtist(ctx, name)
+	if err != nil {
+		return "", err
+	}
+
+	return s.client.getArtistBio(ctx, artist.ID)
+}
+
 func init() {
 	conf.AddHook(func() {
 		if conf.Server.Deezer.Enabled {

core/agents/deezer/responses.go

@@ -29,3 +29,38 @@ type Error struct {
 		Code    int    `json:"code"`
 	} `json:"error"`
 }
+
+type RelatedArtists struct {
+	Data  []Artist `json:"data"`
+	Total int      `json:"total"`
+}
+
+type TopTracks struct {
+	Data  []Track `json:"data"`
+	Total int     `json:"total"`
+	Next  string  `json:"next"`
+}
+
+type Track struct {
+	ID           int      `json:"id"`
+	Title        string   `json:"title"`
+	Link         string   `json:"link"`
+	Duration     int      `json:"duration"`
+	Rank         int      `json:"rank"`
+	Preview      string   `json:"preview"`
+	Artist       Artist   `json:"artist"`
+	Album        Album    `json:"album"`
+	Contributors []Artist `json:"contributors"`
+}
+
+type Album struct {
+	ID          int    `json:"id"`
+	Title       string `json:"title"`
+	Cover       string `json:"cover"`
+	CoverSmall  string `json:"cover_small"`
+	CoverMedium string `json:"cover_medium"`
+	CoverBig    string `json:"cover_big"`
+	CoverXl     string `json:"cover_xl"`
+	Tracklist   string `json:"tracklist"`
+	Type        string `json:"type"`
+}

core/agents/deezer/responses_test.go

@@ -35,4 +35,35 @@ var _ = Describe("Responses", func() {
 			Expect(errorResp.Error.Message).To(Equal("Missing parameters: q"))
 		})
 	})
+
+	Describe("Related Artists", func() {
+		It("parses the related artists response correctly", func() {
+			var resp RelatedArtists
+			body, err := os.ReadFile("tests/fixtures/deezer.artist.related.json")
+			Expect(err).To(BeNil())
+			err = json.Unmarshal(body, &resp)
+			Expect(err).To(BeNil())
+
+			Expect(resp.Data).To(HaveLen(20))
+			justice := resp.Data[0]
+			Expect(justice.Name).To(Equal("Justice"))
+			Expect(justice.ID).To(Equal(6404))
+		})
+	})
+
+	Describe("Top Tracks", func() {
+		It("parses the top tracks response correctly", func() {
+			var resp TopTracks
+			body, err := os.ReadFile("tests/fixtures/deezer.artist.top.json")
+			Expect(err).To(BeNil())
+			err = json.Unmarshal(body, &resp)
+			Expect(err).To(BeNil())
+
+			Expect(resp.Data).To(HaveLen(5))
+			track := resp.Data[0]
+			Expect(track.Title).To(Equal("Instant Crush (feat. Julian Casablancas)"))
+			Expect(track.ID).To(Equal(67238732))
+			Expect(track.Album.Title).To(Equal("Random Access Memories"))
+		})
+	})
 })