feat(deezer): Add artist bio, top tracks, related artists and language support (#4720)

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

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

* feat(deezer): add language support for Deezer API client

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

* fix(deezer): Use GraphQL API for translated biographies

The previous implementation scraped the __DZR_APP_STATE__ from HTML,
which only contained English content. The actual biography displayed
on Deezer's website comes from their GraphQL API at pipe.deezer.com,
which properly respects the Accept-Language header and returns
translated content.

This change:
- Switches from HTML scraping to the GraphQL API
- Uses Accept-Language header instead of URL path for language
- Updates tests to match the new implementation
- Removes unused HTML fixture file

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

* refactor(deezer): move JWT token handling to a separate file for better organization

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

* feat(deezer): enhance JWT token handling with expiration validation

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

* refactor(deezer): change log level for unknown agent warnings from Warn to Debug

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

* fix(deezer): reduce JWT token expiration buffer from 10 minutes to 1 minute

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

---------

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

conf/configuration.go

@@ -176,7 +176,8 @@ type spotifyOptions struct {
 }
 
 type deezerOptions struct {
-	Enabled bool
+	Enabled  bool
+	Language string
 }
 
 type listenBrainzOptions struct {
@@ -566,6 +567,7 @@ func setViperDefaults() {
 	viper.SetDefault("spotify.id", "")
 	viper.SetDefault("spotify.secret", "")
 	viper.SetDefault("deezer.enabled", true)
+	viper.SetDefault("deezer.language", "en")
 	viper.SetDefault("listenbrainz.enabled", true)
 	viper.SetDefault("listenbrainz.baseurl", "https://api.listenbrainz.org/1/")
 	viper.SetDefault("httpsecurityheaders.customframeoptionsvalue", "DENY")

core/agents/agents.go

@@ -87,7 +87,7 @@ func (a *Agents) getEnabledAgentNames() []enabledAgent {
 		} else if isPlugin {
 			validAgents = append(validAgents, enabledAgent{name: name, isPlugin: true})
 		} else {
-			log.Warn("Unknown agent ignored", "name", name)
+			log.Debug("Unknown agent ignored", "name", name)
 		}
 	}
 	return validAgents

core/agents/deezer/client.go

@@ -1,6 +1,7 @@
 package deezer
 
 import (
+	bytes "bytes"
 	"context"
 	"encoding/json"
 	"errors"
@@ -9,11 +10,14 @@ import (
 	"net/http"
 	"net/url"
 	"strconv"
+	"strings"
 
+	"github.com/microcosm-cc/bluemonday"
 	"github.com/navidrome/navidrome/log"
 )
 
 const apiBaseURL = "https://api.deezer.com"
+const authBaseURL = "https://auth.deezer.com"
 
 var (
 	ErrNotFound = errors.New("deezer: not found")
@@ -25,10 +29,15 @@ type httpDoer interface {
 
 type client struct {
 	httpDoer httpDoer
+	language string
+	jwt      jwtToken
 }
 
-func newClient(hc httpDoer) *client {
-	return &client{hc}
+func newClient(hc httpDoer, language string) *client {
+	return &client{
+		httpDoer: hc,
+		language: language,
+	}
 }
 
 func (c *client) searchArtists(ctx context.Context, name string, limit int) ([]Artist, error) {
@@ -53,7 +62,7 @@ func (c *client) searchArtists(ctx context.Context, name string, limit int) ([]A
 	return results.Data, nil
 }
 
-func (c *client) makeRequest(req *http.Request, response interface{}) error {
+func (c *client) makeRequest(req *http.Request, response any) error {
 	log.Trace(req.Context(), fmt.Sprintf("Sending Deezer %s request", req.Method), "url", req.URL)
 	resp, err := c.httpDoer.Do(req)
 	if err != nil {
@@ -81,3 +90,129 @@ 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
+}
+
+const pipeAPIURL = "https://pipe.deezer.com/api"
+
+var strictPolicy = bluemonday.StrictPolicy()
+
+func (c *client) getArtistBio(ctx context.Context, artistID int) (string, error) {
+	jwt, err := c.getJWT(ctx)
+	if err != nil {
+		return "", fmt.Errorf("deezer: failed to get JWT: %w", err)
+	}
+
+	query := map[string]any{
+		"operationName": "ArtistBio",
+		"variables": map[string]any{
+			"artistId": strconv.Itoa(artistID),
+		},
+		"query": `query ArtistBio($artistId: String!) {
+			artist(artistId: $artistId) {
+				bio {
+					full
+				}
+			}
+		}`,
+	}
+
+	body, err := json.Marshal(query)
+	if err != nil {
+		return "", err
+	}
+
+	req, err := http.NewRequestWithContext(ctx, "POST", pipeAPIURL, bytes.NewReader(body))
+	if err != nil {
+		return "", err
+	}
+
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("Accept-Language", c.language)
+	req.Header.Set("Authorization", "Bearer "+jwt)
+
+	log.Trace(ctx, "Fetching Deezer artist biography via GraphQL", "artistId", artistID, "language", c.language)
+	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)
+	}
+
+	data, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return "", err
+	}
+
+	type graphQLResponse struct {
+		Data struct {
+			Artist struct {
+				Bio struct {
+					Full string `json:"full"`
+				} `json:"bio"`
+			} `json:"artist"`
+		} `json:"data"`
+		Errors []struct {
+			Message string `json:"message"`
+		}
+	}
+
+	var result graphQLResponse
+	if err := json.Unmarshal(data, &result); err != nil {
+		return "", fmt.Errorf("deezer: failed to parse GraphQL response: %w", err)
+	}
+
+	if len(result.Errors) > 0 {
+		var errs []error
+		for m := range result.Errors {
+			errs = append(errs, errors.New(result.Errors[m].Message))
+		}
+		err := errors.Join(errs...)
+		return "", fmt.Errorf("deezer: GraphQL error: %w", err)
+	}
+
+	if result.Data.Artist.Bio.Full == "" {
+		return "", errors.New("deezer: biography not found")
+	}
+
+	return cleanBio(result.Data.Artist.Bio.Full), nil
+}
+
+func cleanBio(bio string) string {
+	bio = strings.ReplaceAll(bio, "</p>", "\n")
+	return strictPolicy.Sanitize(bio)
+}

core/agents/deezer/client_auth.go

@@ -0,0 +1,101 @@
+package deezer
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"sync"
+	"time"
+
+	"github.com/lestrrat-go/jwx/v2/jwt"
+	"github.com/navidrome/navidrome/log"
+)
+
+type jwtToken struct {
+	token     string
+	expiresAt time.Time
+	mu        sync.RWMutex
+}
+
+func (j *jwtToken) get() (string, bool) {
+	j.mu.RLock()
+	defer j.mu.RUnlock()
+	if time.Now().Before(j.expiresAt) {
+		return j.token, true
+	}
+	return "", false
+}
+
+func (j *jwtToken) set(token string, expiresIn time.Duration) {
+	j.mu.Lock()
+	defer j.mu.Unlock()
+	j.token = token
+	j.expiresAt = time.Now().Add(expiresIn)
+}
+
+func (c *client) getJWT(ctx context.Context) (string, error) {
+	// Check if we have a valid cached token
+	if token, valid := c.jwt.get(); valid {
+		return token, nil
+	}
+
+	// Fetch a new anonymous token
+	req, err := http.NewRequestWithContext(ctx, "GET", authBaseURL+"/login/anonymous?jo=p&rto=c", nil)
+	if err != nil {
+		return "", err
+	}
+	req.Header.Set("Accept", "application/json")
+
+	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 get JWT token: %s", resp.Status)
+	}
+
+	data, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return "", err
+	}
+
+	type authResponse struct {
+		JWT string `json:"jwt"`
+	}
+
+	var result authResponse
+	if err := json.Unmarshal(data, &result); err != nil {
+		return "", fmt.Errorf("deezer: failed to parse auth response: %w", err)
+	}
+
+	if result.JWT == "" {
+		return "", errors.New("deezer: no JWT token in response")
+	}
+
+	// Parse JWT to get actual expiration time
+	token, err := jwt.ParseString(result.JWT, jwt.WithVerify(false), jwt.WithValidate(false))
+	if err != nil {
+		return "", fmt.Errorf("deezer: failed to parse JWT token: %w", err)
+	}
+
+	// Calculate TTL with a 1-minute buffer for clock skew and network delays
+	expiresAt := token.Expiration()
+	if expiresAt.IsZero() {
+		return "", errors.New("deezer: JWT token has no expiration time")
+	}
+
+	ttl := time.Until(expiresAt) - 1*time.Minute
+	if ttl <= 0 {
+		return "", errors.New("deezer: JWT token already expired or expires too soon")
+	}
+
+	c.jwt.set(result.JWT, ttl)
+	log.Trace(ctx, "Fetched new Deezer JWT token", "expiresAt", expiresAt, "ttl", ttl)
+
+	return result.JWT, nil
+}

core/agents/deezer/client_auth_test.go

@@ -0,0 +1,293 @@
+package deezer
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"io"
+	"net/http"
+	"sync"
+	"time"
+
+	"github.com/lestrrat-go/jwx/v2/jwt"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("JWT Authentication", func() {
+	var httpClient *fakeHttpClient
+	var client *client
+	var ctx context.Context
+
+	BeforeEach(func() {
+		httpClient = &fakeHttpClient{}
+		client = newClient(httpClient, "en")
+		ctx = context.Background()
+	})
+
+	Describe("getJWT", func() {
+		Context("with a valid JWT response", func() {
+			It("successfully fetches and caches a JWT token", func() {
+				testJWT := createTestJWT(5 * time.Minute)
+				httpClient.mock("https://auth.deezer.com/login/anonymous", http.Response{
+					StatusCode: 200,
+					Body:       io.NopCloser(bytes.NewBufferString(fmt.Sprintf(`{"jwt":"%s"}`, testJWT))),
+				})
+
+				token, err := client.getJWT(ctx)
+				Expect(err).To(BeNil())
+				Expect(token).To(Equal(testJWT))
+			})
+
+			It("returns the cached token on subsequent calls", func() {
+				testJWT := createTestJWT(5 * time.Minute)
+				httpClient.mock("https://auth.deezer.com/login/anonymous", http.Response{
+					StatusCode: 200,
+					Body:       io.NopCloser(bytes.NewBufferString(fmt.Sprintf(`{"jwt":"%s"}`, testJWT))),
+				})
+
+				// First call should fetch from API
+				token1, err := client.getJWT(ctx)
+				Expect(err).To(BeNil())
+				Expect(token1).To(Equal(testJWT))
+				Expect(httpClient.lastRequest.URL.Path).To(Equal("/login/anonymous"))
+
+				// Second call should return cached token without hitting API
+				httpClient.lastRequest = nil // Clear last request to verify no new request is made
+				token2, err := client.getJWT(ctx)
+				Expect(err).To(BeNil())
+				Expect(token2).To(Equal(testJWT))
+				Expect(httpClient.lastRequest).To(BeNil()) // No new request made
+			})
+
+			It("parses the JWT expiration time correctly", func() {
+				expectedExpiration := time.Now().Add(5 * time.Minute)
+				testToken, err := jwt.NewBuilder().
+					Expiration(expectedExpiration).
+					Build()
+				Expect(err).To(BeNil())
+				testJWT, err := jwt.Sign(testToken, jwt.WithInsecureNoSignature())
+				Expect(err).To(BeNil())
+
+				httpClient.mock("https://auth.deezer.com/login/anonymous", http.Response{
+					StatusCode: 200,
+					Body:       io.NopCloser(bytes.NewBufferString(fmt.Sprintf(`{"jwt":"%s"}`, string(testJWT)))),
+				})
+
+				token, err := client.getJWT(ctx)
+				Expect(err).To(BeNil())
+				Expect(token).ToNot(BeEmpty())
+
+				// Verify the token is cached until close to expiration
+				// The cache should expire 1 minute before the JWT expires
+				expectedCacheExpiry := expectedExpiration.Add(-1 * time.Minute)
+				Expect(client.jwt.expiresAt).To(BeTemporally("~", expectedCacheExpiry, 2*time.Second))
+			})
+		})
+
+		Context("with JWT tokens that expire soon", func() {
+			It("rejects tokens that expire in less than 1 minute", func() {
+				// Create a token that expires in 30 seconds (less than 1-minute buffer)
+				testJWT := createTestJWT(30 * time.Second)
+				httpClient.mock("https://auth.deezer.com/login/anonymous", http.Response{
+					StatusCode: 200,
+					Body:       io.NopCloser(bytes.NewBufferString(fmt.Sprintf(`{"jwt":"%s"}`, testJWT))),
+				})
+
+				_, err := client.getJWT(ctx)
+				Expect(err).To(HaveOccurred())
+				Expect(err.Error()).To(ContainSubstring("JWT token already expired or expires too soon"))
+			})
+
+			It("rejects already expired tokens", func() {
+				// Create a token that expired 1 minute ago
+				testJWT := createTestJWT(-1 * time.Minute)
+				httpClient.mock("https://auth.deezer.com/login/anonymous", http.Response{
+					StatusCode: 200,
+					Body:       io.NopCloser(bytes.NewBufferString(fmt.Sprintf(`{"jwt":"%s"}`, testJWT))),
+				})
+
+				_, err := client.getJWT(ctx)
+				Expect(err).To(HaveOccurred())
+				Expect(err.Error()).To(ContainSubstring("JWT token already expired or expires too soon"))
+			})
+
+			It("accepts tokens that expire in more than 1 minute", func() {
+				// Create a token that expires in 2 minutes (just over the 1-minute buffer)
+				testJWT := createTestJWT(2 * time.Minute)
+				httpClient.mock("https://auth.deezer.com/login/anonymous", http.Response{
+					StatusCode: 200,
+					Body:       io.NopCloser(bytes.NewBufferString(fmt.Sprintf(`{"jwt":"%s"}`, testJWT))),
+				})
+
+				token, err := client.getJWT(ctx)
+				Expect(err).To(BeNil())
+				Expect(token).ToNot(BeEmpty())
+			})
+		})
+
+		Context("with invalid responses", func() {
+			It("handles HTTP error responses", func() {
+				httpClient.mock("https://auth.deezer.com/login/anonymous", http.Response{
+					StatusCode: 500,
+					Body:       io.NopCloser(bytes.NewBufferString(`{"error":"Internal server error"}`)),
+				})
+
+				_, err := client.getJWT(ctx)
+				Expect(err).To(HaveOccurred())
+				Expect(err.Error()).To(ContainSubstring("failed to get JWT token"))
+			})
+
+			It("handles malformed JSON responses", func() {
+				httpClient.mock("https://auth.deezer.com/login/anonymous", http.Response{
+					StatusCode: 200,
+					Body:       io.NopCloser(bytes.NewBufferString(`{invalid json}`)),
+				})
+
+				_, err := client.getJWT(ctx)
+				Expect(err).To(HaveOccurred())
+				Expect(err.Error()).To(ContainSubstring("failed to parse auth response"))
+			})
+
+			It("handles responses with empty JWT field", func() {
+				httpClient.mock("https://auth.deezer.com/login/anonymous", http.Response{
+					StatusCode: 200,
+					Body:       io.NopCloser(bytes.NewBufferString(`{"jwt":""}`)),
+				})
+
+				_, err := client.getJWT(ctx)
+				Expect(err).To(HaveOccurred())
+				Expect(err.Error()).To(Equal("deezer: no JWT token in response"))
+			})
+
+			It("handles invalid JWT tokens", func() {
+				httpClient.mock("https://auth.deezer.com/login/anonymous", http.Response{
+					StatusCode: 200,
+					Body:       io.NopCloser(bytes.NewBufferString(`{"jwt":"not-a-valid-jwt"}`)),
+				})
+
+				_, err := client.getJWT(ctx)
+				Expect(err).To(HaveOccurred())
+				Expect(err.Error()).To(ContainSubstring("failed to parse JWT token"))
+			})
+
+			It("rejects JWT tokens without expiration", func() {
+				// Create a JWT without expiration claim
+				testToken, err := jwt.NewBuilder().
+					Claim("custom", "value").
+					Build()
+				Expect(err).To(BeNil())
+
+				// Verify token has no expiration
+				Expect(testToken.Expiration().IsZero()).To(BeTrue())
+
+				testJWT, err := jwt.Sign(testToken, jwt.WithInsecureNoSignature())
+				Expect(err).To(BeNil())
+
+				httpClient.mock("https://auth.deezer.com/login/anonymous", http.Response{
+					StatusCode: 200,
+					Body:       io.NopCloser(bytes.NewBufferString(fmt.Sprintf(`{"jwt":"%s"}`, string(testJWT)))),
+				})
+
+				_, err = client.getJWT(ctx)
+				Expect(err).To(HaveOccurred())
+				Expect(err.Error()).To(Equal("deezer: JWT token has no expiration time"))
+			})
+		})
+
+		Context("token caching behavior", func() {
+			It("fetches a new token when the cached token expires", func() {
+				// First token expires in 5 minutes
+				firstJWT := createTestJWT(5 * time.Minute)
+				httpClient.mock("https://auth.deezer.com/login/anonymous", http.Response{
+					StatusCode: 200,
+					Body:       io.NopCloser(bytes.NewBufferString(fmt.Sprintf(`{"jwt":"%s"}`, firstJWT))),
+				})
+
+				token1, err := client.getJWT(ctx)
+				Expect(err).To(BeNil())
+				Expect(token1).To(Equal(firstJWT))
+
+				// Manually expire the cached token
+				client.jwt.expiresAt = time.Now().Add(-1 * time.Second)
+
+				// Second token with different expiration (10 minutes)
+				secondJWT := createTestJWT(10 * time.Minute)
+				httpClient.mock("https://auth.deezer.com/login/anonymous", http.Response{
+					StatusCode: 200,
+					Body:       io.NopCloser(bytes.NewBufferString(fmt.Sprintf(`{"jwt":"%s"}`, secondJWT))),
+				})
+
+				token2, err := client.getJWT(ctx)
+				Expect(err).To(BeNil())
+				Expect(token2).To(Equal(secondJWT))
+				Expect(token2).ToNot(Equal(token1))
+			})
+		})
+	})
+
+	Describe("jwtToken cache", func() {
+		var cache *jwtToken
+
+		BeforeEach(func() {
+			cache = &jwtToken{}
+		})
+
+		It("returns false for expired tokens", func() {
+			cache.set("test-token", -1*time.Second) // Already expired
+			token, valid := cache.get()
+			Expect(valid).To(BeFalse())
+			Expect(token).To(BeEmpty())
+		})
+
+		It("returns true for valid tokens", func() {
+			cache.set("test-token", 4*time.Minute)
+			token, valid := cache.get()
+			Expect(valid).To(BeTrue())
+			Expect(token).To(Equal("test-token"))
+		})
+
+		It("is thread-safe for concurrent access", func() {
+			wg := sync.WaitGroup{}
+
+			// Writer goroutine
+			wg.Go(func() {
+				for i := 0; i < 100; i++ {
+					cache.set(fmt.Sprintf("token-%d", i), 1*time.Hour)
+					time.Sleep(1 * time.Millisecond)
+				}
+			})
+
+			// Reader goroutine
+			wg.Go(func() {
+				for i := 0; i < 100; i++ {
+					cache.get()
+					time.Sleep(1 * time.Millisecond)
+				}
+			})
+
+			// Wait for both goroutines to complete
+			wg.Wait()
+
+			// Verify final state is valid
+			token, valid := cache.get()
+			Expect(valid).To(BeTrue())
+			Expect(token).To(HavePrefix("token-"))
+		})
+	})
+})
+
+// createTestJWT creates a valid JWT token for testing purposes
+func createTestJWT(expiresIn time.Duration) string {
+	token, err := jwt.NewBuilder().
+		Expiration(time.Now().Add(expiresIn)).
+		Build()
+	if err != nil {
+		panic(fmt.Sprintf("failed to create test JWT: %v", err))
+	}
+	signed, err := jwt.Sign(token, jwt.WithInsecureNoSignature())
+	if err != nil {
+		panic(fmt.Sprintf("failed to sign test JWT: %v", err))
+	}
+	return string(signed)
+}

core/agents/deezer/client_test.go

@@ -2,10 +2,11 @@ package deezer
 
 import (
 	"bytes"
-	"context"
+	"fmt"
 	"io"
 	"net/http"
 	"os"
+	"time"
 
 	. "github.com/onsi/ginkgo/v2"
 	. "github.com/onsi/gomega"
@@ -17,7 +18,7 @@ var _ = Describe("client", func() {
 
 	BeforeEach(func() {
 		httpClient = &fakeHttpClient{}
-		client = newClient(httpClient)
+		client = newClient(httpClient, "en")
 	})
 
 	Describe("ArtistImages", func() {
@@ -26,7 +27,7 @@ var _ = Describe("client", func() {
 			Expect(err).To(BeNil())
 			httpClient.mock("https://api.deezer.com/search/artist", http.Response{Body: f, StatusCode: 200})
 
-			artists, err := client.searchArtists(context.TODO(), "Michael Jackson", 20)
+			artists, err := client.searchArtists(GinkgoT().Context(), "Michael Jackson", 20)
 			Expect(err).To(BeNil())
 			Expect(artists).To(HaveLen(17))
 			Expect(artists[0].Name).To(Equal("Michael Jackson"))
@@ -39,10 +40,136 @@ var _ = Describe("client", func() {
 				Body:       io.NopCloser(bytes.NewBufferString(`{"data":[],"total":0}`)),
 			})
 
-			_, err := client.searchArtists(context.TODO(), "Michael Jackson", 20)
+			_, err := client.searchArtists(GinkgoT().Context(), "Michael Jackson", 20)
 			Expect(err).To(MatchError(ErrNotFound))
 		})
 	})
+
+	Describe("ArtistBio", func() {
+		BeforeEach(func() {
+			// Mock the JWT token endpoint with a valid JWT that expires in 5 minutes
+			testJWT := createTestJWT(5 * time.Minute)
+			httpClient.mock("https://auth.deezer.com/login/anonymous", http.Response{
+				StatusCode: 200,
+				Body:       io.NopCloser(bytes.NewBufferString(fmt.Sprintf(`{"jwt":"%s","refresh_token":""}`, testJWT))),
+			})
+		})
+
+		It("returns artist bio from a successful request", func() {
+			f, err := os.Open("tests/fixtures/deezer.artist.bio.json")
+			Expect(err).To(BeNil())
+			httpClient.mock("https://pipe.deezer.com/api", http.Response{Body: f, StatusCode: 200})
+
+			bio, err := client.getArtistBio(GinkgoT().Context(), 27)
+			Expect(err).To(BeNil())
+			Expect(bio).To(ContainSubstring("Schoolmates Thomas and Guy-Manuel"))
+			Expect(bio).ToNot(ContainSubstring("<p>"))
+			Expect(bio).ToNot(ContainSubstring("</p>"))
+		})
+
+		It("uses the configured language", func() {
+			client = newClient(httpClient, "fr")
+			// Mock JWT token for the new client instance with a valid JWT
+			testJWT := createTestJWT(5 * time.Minute)
+			httpClient.mock("https://auth.deezer.com/login/anonymous", http.Response{
+				StatusCode: 200,
+				Body:       io.NopCloser(bytes.NewBufferString(fmt.Sprintf(`{"jwt":"%s","refresh_token":""}`, testJWT))),
+			})
+			f, err := os.Open("tests/fixtures/deezer.artist.bio.json")
+			Expect(err).To(BeNil())
+			httpClient.mock("https://pipe.deezer.com/api", http.Response{Body: f, StatusCode: 200})
+
+			_, err = client.getArtistBio(GinkgoT().Context(), 27)
+			Expect(err).To(BeNil())
+			Expect(httpClient.lastRequest.Header.Get("Accept-Language")).To(Equal("fr"))
+		})
+
+		It("includes the JWT token in the request", func() {
+			f, err := os.Open("tests/fixtures/deezer.artist.bio.json")
+			Expect(err).To(BeNil())
+			httpClient.mock("https://pipe.deezer.com/api", http.Response{Body: f, StatusCode: 200})
+
+			_, err = client.getArtistBio(GinkgoT().Context(), 27)
+			Expect(err).To(BeNil())
+			// Verify that the Authorization header has the Bearer token format
+			authHeader := httpClient.lastRequest.Header.Get("Authorization")
+			Expect(authHeader).To(HavePrefix("Bearer "))
+			Expect(len(authHeader)).To(BeNumerically(">", 20)) // JWT tokens are longer than 20 chars
+		})
+
+		It("handles GraphQL errors", func() {
+			errorResponse := `{
+				"data": {
+					"artist": {
+						"bio": {
+							"full": ""
+						}
+					}
+				},
+				"errors": [
+					{
+						"message": "Artist not found"
+					},
+					{
+						"message": "Invalid artist ID"
+					}
+				]
+			}`
+			httpClient.mock("https://pipe.deezer.com/api", http.Response{
+				StatusCode: 200,
+				Body:       io.NopCloser(bytes.NewBufferString(errorResponse)),
+			})
+
+			_, err := client.getArtistBio(GinkgoT().Context(), 999)
+			Expect(err).To(HaveOccurred())
+			Expect(err.Error()).To(ContainSubstring("GraphQL error"))
+			Expect(err.Error()).To(ContainSubstring("Artist not found"))
+			Expect(err.Error()).To(ContainSubstring("Invalid artist ID"))
+		})
+
+		It("handles empty biography", func() {
+			emptyBioResponse := `{
+				"data": {
+					"artist": {
+						"bio": {
+							"full": ""
+						}
+					}
+				}
+			}`
+			httpClient.mock("https://pipe.deezer.com/api", http.Response{
+				StatusCode: 200,
+				Body:       io.NopCloser(bytes.NewBufferString(emptyBioResponse)),
+			})
+
+			_, err := client.getArtistBio(GinkgoT().Context(), 27)
+			Expect(err).To(MatchError("deezer: biography not found"))
+		})
+
+		It("handles JWT token fetch failure", func() {
+			httpClient.mock("https://auth.deezer.com/login/anonymous", http.Response{
+				StatusCode: 500,
+				Body:       io.NopCloser(bytes.NewBufferString(`{"error":"Internal server error"}`)),
+			})
+
+			_, err := client.getArtistBio(GinkgoT().Context(), 27)
+			Expect(err).To(HaveOccurred())
+			Expect(err.Error()).To(ContainSubstring("failed to get JWT"))
+		})
+
+		It("handles JWT token that expires too soon", func() {
+			// Create a JWT that expires in 30 seconds (less than the 1-minute buffer)
+			expiredJWT := createTestJWT(30 * time.Second)
+			httpClient.mock("https://auth.deezer.com/login/anonymous", http.Response{
+				StatusCode: 200,
+				Body:       io.NopCloser(bytes.NewBufferString(fmt.Sprintf(`{"jwt":"%s","refresh_token":""}`, expiredJWT))),
+			})
+
+			_, err := client.getArtistBio(GinkgoT().Context(), 27)
+			Expect(err).To(HaveOccurred())
+			Expect(err.Error()).To(ContainSubstring("JWT token already expired or expires too soon"))
+		})
+	})
 })
 
 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"
@@ -32,7 +33,7 @@ func deezerConstructor(dataStore model.DataStore) agents.Interface {
 		Timeout: consts.DefaultHttpClientTimeOut,
 	}
 	cachedHttpClient := cache.NewHTTPClient(httpClient, consts.DefaultHttpClientTimeOut)
-	agent.client = newClient(cachedHttpClient)
+	agent.client = newClient(cachedHttpClient, conf.Server.Deezer.Language)
 	return agent
 }
 
@@ -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"))
+		})
+	})
 })

tests/fixtures/deezer.artist.bio.json

@@ -0,0 +1,9 @@
+{
+  "data": {
+    "artist": {
+      "bio": {
+        "full": "<p>Schoolmates Thomas and Guy-Manuel began their career in 1992 with the indie rock trio Darlin' (named after The Beach Boys song) but were scathingly dismissed by Melody Maker magazine as \"daft punk.\" Turning to house-inspired electronica, they used the put down as a name for their DJ-ing partnership and became a hugely successful and influential dance act.</p>"
+      }
+    }
+  }
+}