v6.4

backend/songlink.go

@@ -22,6 +22,19 @@ type SongLinkURLs struct {
 	AmazonURL string `json:"amazon_url"`
 }
 
+// TrackAvailability represents the availability of a track on different platforms
+type TrackAvailability struct {
+	SpotifyID string `json:"spotify_id"`
+	Tidal     bool   `json:"tidal"`
+	Deezer    bool   `json:"deezer"`
+	Amazon    bool   `json:"amazon"`
+	Qobuz     bool   `json:"qobuz"`
+	TidalURL  string `json:"tidal_url,omitempty"`
+	DeezerURL string `json:"deezer_url,omitempty"`
+	AmazonURL string `json:"amazon_url,omitempty"`
+	QobuzURL  string `json:"qobuz_url,omitempty"`
+}
+
 func NewSongLinkClient() *SongLinkClient {
 	return &SongLinkClient{
 		client: &http.Client{
@@ -148,3 +161,152 @@ func (s *SongLinkClient) GetAllURLsFromSpotify(spotifyTrackID string) (*SongLink
 
 	return urls, nil
 }
+
+// CheckTrackAvailability checks the availability of a track on different platforms
+func (s *SongLinkClient) CheckTrackAvailability(spotifyTrackID string, isrc string) (*TrackAvailability, error) {
+	// Rate limiting: max 10 requests per minute (song.link API limit)
+	now := time.Now()
+	if now.Sub(s.apiCallResetTime) >= time.Minute {
+		s.apiCallCount = 0
+		s.apiCallResetTime = now
+	}
+
+	// If we've hit the limit, wait until the next minute
+	if s.apiCallCount >= 9 {
+		waitTime := time.Minute - now.Sub(s.apiCallResetTime)
+		if waitTime > 0 {
+			fmt.Printf("Rate limit reached, waiting %v...\n", waitTime.Round(time.Second))
+			time.Sleep(waitTime)
+			s.apiCallCount = 0
+			s.apiCallResetTime = time.Now()
+		}
+	}
+
+	// Add delay between requests (7 seconds to be safe)
+	if !s.lastAPICallTime.IsZero() {
+		timeSinceLastCall := now.Sub(s.lastAPICallTime)
+		minDelay := 7 * time.Second
+		if timeSinceLastCall < minDelay {
+			waitTime := minDelay - timeSinceLastCall
+			fmt.Printf("Rate limiting: waiting %v...\n", waitTime.Round(time.Second))
+			time.Sleep(waitTime)
+		}
+	}
+
+	// Decode base64 API URL
+	spotifyBase, _ := base64.StdEncoding.DecodeString("aHR0cHM6Ly9vcGVuLnNwb3RpZnkuY29tL3RyYWNrLw==")
+	spotifyURL := fmt.Sprintf("%s%s", string(spotifyBase), spotifyTrackID)
+
+	apiBase, _ := base64.StdEncoding.DecodeString("aHR0cHM6Ly9hcGkuc29uZy5saW5rL3YxLWFscGhhLjEvbGlua3M/dXJsPQ==")
+	apiURL := fmt.Sprintf("%s%s", string(apiBase), url.QueryEscape(spotifyURL))
+
+	req, err := http.NewRequest("GET", apiURL, nil)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create request: %w", err)
+	}
+
+	fmt.Printf("Checking availability for track: %s\n", spotifyTrackID)
+
+	// Retry logic for rate limit errors
+	maxRetries := 3
+	var resp *http.Response
+	for i := 0; i < maxRetries; i++ {
+		resp, err = s.client.Do(req)
+		if err != nil {
+			return nil, fmt.Errorf("failed to check availability: %w", err)
+		}
+
+		// Update rate limit tracking
+		s.lastAPICallTime = time.Now()
+		s.apiCallCount++
+
+		if resp.StatusCode == 429 {
+			resp.Body.Close()
+			if i < maxRetries-1 {
+				waitTime := 15 * time.Second
+				fmt.Printf("Rate limited by API, waiting %v before retry...\n", waitTime)
+				time.Sleep(waitTime)
+				continue
+			}
+			return nil, fmt.Errorf("API rate limit exceeded after %d retries", maxRetries)
+		}
+
+		if resp.StatusCode != 200 {
+			resp.Body.Close()
+			return nil, fmt.Errorf("API returned status %d", resp.StatusCode)
+		}
+
+		break
+	}
+	defer resp.Body.Close()
+
+	var songLinkResp struct {
+		LinksByPlatform map[string]struct {
+			URL string `json:"url"`
+		} `json:"linksByPlatform"`
+	}
+	if err := json.NewDecoder(resp.Body).Decode(&songLinkResp); err != nil {
+		return nil, fmt.Errorf("failed to decode response: %w", err)
+	}
+
+	availability := &TrackAvailability{
+		SpotifyID: spotifyTrackID,
+	}
+
+	// Check Tidal
+	if tidalLink, ok := songLinkResp.LinksByPlatform["tidal"]; ok && tidalLink.URL != "" {
+		availability.Tidal = true
+		availability.TidalURL = tidalLink.URL
+	}
+
+	// Check Deezer
+	if deezerLink, ok := songLinkResp.LinksByPlatform["deezer"]; ok && deezerLink.URL != "" {
+		availability.Deezer = true
+		availability.DeezerURL = deezerLink.URL
+	}
+
+	// Check Amazon
+	if amazonLink, ok := songLinkResp.LinksByPlatform["amazonMusic"]; ok && amazonLink.URL != "" {
+		availability.Amazon = true
+		availability.AmazonURL = amazonLink.URL
+	}
+
+	// Check Qobuz using ISRC (song.link doesn't support Qobuz)
+	if isrc != "" {
+		qobuzAvailable := checkQobuzAvailability(isrc)
+		availability.Qobuz = qobuzAvailable
+	}
+
+	return availability, nil
+}
+
+// checkQobuzAvailability checks if a track is available on Qobuz using ISRC
+func checkQobuzAvailability(isrc string) bool {
+	client := &http.Client{Timeout: 10 * time.Second}
+	appID := "798273057"
+
+	// Decode base64 API URL
+	apiBase, _ := base64.StdEncoding.DecodeString("aHR0cHM6Ly93d3cucW9idXouY29tL2FwaS5qc29uLzAuMi90cmFjay9zZWFyY2g/cXVlcnk9")
+	searchURL := fmt.Sprintf("%s%s&limit=1&app_id=%s", string(apiBase), isrc, appID)
+
+	resp, err := client.Get(searchURL)
+	if err != nil {
+		return false
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != 200 {
+		return false
+	}
+
+	var searchResp struct {
+		Tracks struct {
+			Total int `json:"total"`
+		} `json:"tracks"`
+	}
+	if err := json.NewDecoder(resp.Body).Decode(&searchResp); err != nil {
+		return false
+	}
+
+	return searchResp.Tracks.Total > 0
+}