v2.0.5: Large playlist support + duration verification fix

- Add pagination for playlists (up to 1000 tracks)
- Add duration verification to prevent wrong track downloads
- When Tidal returns wrong version, fallback to Qobuz/Amazon

CHANGELOG.md

@@ -1,5 +1,13 @@
 # Changelog
 
+## [2.0.5] - 2026-01-05
+
+### Added
+- **Large Playlist Support**: Playlists with up to 1000 tracks are now fully fetched (was limited to 100)
+
+### Fixed
+- **Wrong Track Download**: Fixed issue where tracks with same ISRC but different versions (e.g., short/instrumental vs full version) would download the wrong track. Now verifies duration matches before downloading (30 second tolerance).
+
 ## [2.0.4] - 2026-01-04
 
 ### Fixed

go_backend/exports.go

@@ -132,7 +132,8 @@ type DownloadRequest struct {
 	DiscNumber           int    `json:"disc_number"`
 	TotalTracks          int    `json:"total_tracks"`
 	ReleaseDate          string `json:"release_date"`
-	ItemID               string `json:"item_id"` // Unique ID for progress tracking
+	ItemID               string `json:"item_id"`    // Unique ID for progress tracking
+	DurationMS           int    `json:"duration_ms"` // Expected duration in milliseconds (for verification)
 }
 
 // DownloadResponse represents the result of a download

go_backend/qobuz.go

@@ -112,8 +112,96 @@ func (q *QobuzDownloader) SearchTrackByISRC(isrc string) (*QobuzTrack, error) {
 	return nil, fmt.Errorf("no exact ISRC match found for: %s", isrc)
 }
 
+// SearchTrackByISRCWithTitle searches for a track by ISRC with duration verification
+// expectedDurationSec is the expected duration in seconds (0 to skip verification)
+func (q *QobuzDownloader) SearchTrackByISRCWithDuration(isrc string, expectedDurationSec int) (*QobuzTrack, error) {
+	apiBase, _ := base64.StdEncoding.DecodeString("aHR0cHM6Ly93d3cucW9idXouY29tL2FwaS5qc29uLzAuMi90cmFjay9zZWFyY2g/cXVlcnk9")
+	searchURL := fmt.Sprintf("%s%s&limit=50&app_id=%s", string(apiBase), url.QueryEscape(isrc), q.appID)
+
+	req, err := http.NewRequest("GET", searchURL, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	resp, err := DoRequestWithUserAgent(q.client, req)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != 200 {
+		return nil, fmt.Errorf("search failed: HTTP %d", resp.StatusCode)
+	}
+
+	var result struct {
+		Tracks struct {
+			Items []QobuzTrack `json:"items"`
+		} `json:"tracks"`
+	}
+	if err := json.NewDecoder(resp.Body).Decode(&result); err != nil {
+		return nil, err
+	}
+
+	// Find ISRC matches
+	var isrcMatches []*QobuzTrack
+	for i := range result.Tracks.Items {
+		if result.Tracks.Items[i].ISRC == isrc {
+			isrcMatches = append(isrcMatches, &result.Tracks.Items[i])
+		}
+	}
+
+	if len(isrcMatches) > 0 {
+		// Verify duration if provided
+		if expectedDurationSec > 0 {
+			var durationVerifiedMatches []*QobuzTrack
+			for _, track := range isrcMatches {
+				durationDiff := track.Duration - expectedDurationSec
+				if durationDiff < 0 {
+					durationDiff = -durationDiff
+				}
+				// Allow 30 seconds tolerance
+				if durationDiff <= 30 {
+					durationVerifiedMatches = append(durationVerifiedMatches, track)
+				}
+			}
+			
+			if len(durationVerifiedMatches) > 0 {
+				fmt.Printf("[Qobuz] ISRC match with duration verification: '%s' (expected %ds, found %ds)\n", 
+					durationVerifiedMatches[0].Title, expectedDurationSec, durationVerifiedMatches[0].Duration)
+				return durationVerifiedMatches[0], nil
+			}
+			
+			// ISRC matches but duration doesn't
+			fmt.Printf("[Qobuz] WARNING: ISRC %s found but duration mismatch. Expected=%ds, Found=%ds. Rejecting.\n", 
+				isrc, expectedDurationSec, isrcMatches[0].Duration)
+			return nil, fmt.Errorf("ISRC found but duration mismatch: expected %ds, found %ds (likely different version)", 
+				expectedDurationSec, isrcMatches[0].Duration)
+		}
+		
+		// No duration to verify, return first match
+		fmt.Printf("[Qobuz] ISRC match (no duration verification): '%s'\n", isrcMatches[0].Title)
+		return isrcMatches[0], nil
+	}
+
+	if len(result.Tracks.Items) == 0 {
+		return nil, fmt.Errorf("no tracks found for ISRC: %s", isrc)
+	}
+
+	return nil, fmt.Errorf("no exact ISRC match found for: %s", isrc)
+}
+
+// SearchTrackByISRCWithTitle is deprecated, use SearchTrackByISRCWithDuration instead
+func (q *QobuzDownloader) SearchTrackByISRCWithTitle(isrc, expectedTitle string) (*QobuzTrack, error) {
+	return q.SearchTrackByISRCWithDuration(isrc, 0)
+}
+
 // SearchTrackByMetadata searches for a track using artist name and track name
 func (q *QobuzDownloader) SearchTrackByMetadata(trackName, artistName string) (*QobuzTrack, error) {
+	return q.SearchTrackByMetadataWithDuration(trackName, artistName, 0)
+}
+
+// SearchTrackByMetadataWithDuration searches for a track with duration verification
+func (q *QobuzDownloader) SearchTrackByMetadataWithDuration(trackName, artistName string, expectedDurationSec int) (*QobuzTrack, error) {
 	apiBase, _ := base64.StdEncoding.DecodeString("aHR0cHM6Ly93d3cucW9idXouY29tL2FwaS5qc29uLzAuMi90cmFjay9zZWFyY2g/cXVlcnk9")
 
 	// Try multiple search strategies
@@ -129,6 +217,8 @@ func (q *QobuzDownloader) SearchTrackByMetadata(trackName, artistName string) (*
 		queries = append(queries, trackName)
 	}
 
+	var allTracks []QobuzTrack
+
 	for _, query := range queries {
 		searchURL := fmt.Sprintf("%s%s&limit=50&app_id=%s", string(apiBase), url.QueryEscape(query), q.appID)
 
@@ -159,19 +249,50 @@ func (q *QobuzDownloader) SearchTrackByMetadata(trackName, artistName string) (*
 		resp.Body.Close()
 
 		if len(result.Tracks.Items) > 0 {
-			// Return first result with best quality
-			for i := range result.Tracks.Items {
-				track := &result.Tracks.Items[i]
+			allTracks = append(allTracks, result.Tracks.Items...)
+		}
+	}
+
+	if len(allTracks) == 0 {
+		return nil, fmt.Errorf("no tracks found for: %s - %s", artistName, trackName)
+	}
+
+	// If duration verification is requested
+	if expectedDurationSec > 0 {
+		var durationMatches []*QobuzTrack
+		for i := range allTracks {
+			track := &allTracks[i]
+			durationDiff := track.Duration - expectedDurationSec
+			if durationDiff < 0 {
+				durationDiff = -durationDiff
+			}
+			if durationDiff <= 30 {
+				durationMatches = append(durationMatches, track)
+			}
+		}
+
+		if len(durationMatches) > 0 {
+			// Return best quality among duration matches
+			for _, track := range durationMatches {
 				if track.MaximumBitDepth >= 24 {
 					return track, nil
 				}
 			}
-			// Return first result if no hi-res found
-			return &result.Tracks.Items[0], nil
+			return durationMatches[0], nil
 		}
+
+		// No duration match found
+		return nil, fmt.Errorf("no tracks found with matching duration (expected %ds)", expectedDurationSec)
 	}
 
-	return nil, fmt.Errorf("no tracks found for: %s - %s", artistName, trackName)
+	// No duration verification, return best quality
+	for i := range allTracks {
+		track := &allTracks[i]
+		if track.MaximumBitDepth >= 24 {
+			return track, nil
+		}
+	}
+	return &allTracks[0], nil
 }
 
 // getQobuzDownloadURLSequential requests download URL from APIs sequentially
@@ -321,17 +442,20 @@ func downloadFromQobuz(req DownloadRequest) (QobuzDownloadResult, error) {
 		return QobuzDownloadResult{FilePath: "EXISTS:" + existingFile}, nil
 	}
 
+	// Convert expected duration from ms to seconds
+	expectedDurationSec := req.DurationMS / 1000
+
 	var track *QobuzTrack
 	var err error
 
-	// Strategy 1: Search by ISRC
+	// Strategy 1: Search by ISRC with duration verification
 	if req.ISRC != "" {
-		track, err = downloader.SearchTrackByISRC(req.ISRC)
+		track, err = downloader.SearchTrackByISRCWithDuration(req.ISRC, expectedDurationSec)
 	}
 
-	// Strategy 2: Search by metadata
+	// Strategy 2: Search by metadata with duration verification
 	if track == nil {
-		track, err = downloader.SearchTrackByMetadata(req.TrackName, req.ArtistName)
+		track, err = downloader.SearchTrackByMetadataWithDuration(req.TrackName, req.ArtistName, expectedDurationSec)
 	}
 
 	if track == nil {
@@ -342,6 +466,20 @@ func downloadFromQobuz(req DownloadRequest) (QobuzDownloadResult, error) {
 		return QobuzDownloadResult{}, fmt.Errorf("qobuz search failed: %s", errMsg)
 	}
 
+	// Final duration verification
+	if expectedDurationSec > 0 {
+		durationDiff := track.Duration - expectedDurationSec
+		if durationDiff < 0 {
+			durationDiff = -durationDiff
+		}
+		if durationDiff > 30 {
+			return QobuzDownloadResult{}, fmt.Errorf("duration mismatch: expected %ds, found %ds (diff: %ds). Track may be wrong version", 
+				expectedDurationSec, track.Duration, durationDiff)
+		}
+		fmt.Printf("[Qobuz] Duration verified: expected %ds, found %ds (diff: %ds)\n", 
+			expectedDurationSec, track.Duration, durationDiff)
+	}
+
 	// Build filename
 	filename := buildFilenameFromTemplate(req.FilenameFormat, map[string]interface{}{
 		"title":  req.TrackName,

go_backend/spotify.go

@@ -567,6 +567,7 @@ func (c *SpotifyMetadataClient) fetchAlbum(ctx context.Context, albumID, token s
 }
 
 func (c *SpotifyMetadataClient) fetchPlaylist(ctx context.Context, playlistID, token string) (*PlaylistResponsePayload, error) {
+	// First request to get playlist info and first batch of tracks
 	var data struct {
 		Name   string  `json:"name"`
 		Images []image `json:"images"`
@@ -577,7 +578,8 @@ func (c *SpotifyMetadataClient) fetchPlaylist(ctx context.Context, playlistID, t
 			Items []struct {
 				Track *trackFull `json:"track"`
 			} `json:"items"`
-			Total int `json:"total"`
+			Total int    `json:"total"`
+			Next  string `json:"next"`
 		} `json:"tracks"`
 	}
 
@@ -591,7 +593,10 @@ func (c *SpotifyMetadataClient) fetchPlaylist(ctx context.Context, playlistID, t
 	info.Owner.Name = data.Name
 	info.Owner.Images = firstImageURL(data.Images)
 
-	tracks := make([]AlbumTrackMetadata, 0, len(data.Tracks.Items))
+	// Pre-allocate with expected capacity
+	tracks := make([]AlbumTrackMetadata, 0, data.Tracks.Total)
+	
+	// Add first batch of tracks
 	for _, item := range data.Tracks.Items {
 		if item.Track == nil {
 			continue
@@ -615,6 +620,55 @@ func (c *SpotifyMetadataClient) fetchPlaylist(ctx context.Context, playlistID, t
 		})
 	}
 
+	// Fetch remaining tracks using pagination (up to 1000 tracks max)
+	nextURL := data.Tracks.Next
+	maxTracks := 1000
+	
+	for nextURL != "" && len(tracks) < maxTracks {
+		var pageData struct {
+			Items []struct {
+				Track *trackFull `json:"track"`
+			} `json:"items"`
+			Next string `json:"next"`
+		}
+
+		if err := c.getJSON(ctx, nextURL, token, &pageData); err != nil {
+			// Log error but return what we have so far
+			fmt.Printf("[Spotify] Warning: failed to fetch page, returning %d tracks: %v\n", len(tracks), err)
+			break
+		}
+
+		for _, item := range pageData.Items {
+			if item.Track == nil {
+				continue
+			}
+			if len(tracks) >= maxTracks {
+				break
+			}
+			tracks = append(tracks, AlbumTrackMetadata{
+				SpotifyID:   item.Track.ID,
+				Artists:     joinArtists(item.Track.Artists),
+				Name:        item.Track.Name,
+				AlbumName:   item.Track.Album.Name,
+				AlbumArtist: joinArtists(item.Track.Album.Artists),
+				DurationMS:  item.Track.DurationMS,
+				Images:      firstImageURL(item.Track.Album.Images),
+				ReleaseDate: item.Track.Album.ReleaseDate,
+				TrackNumber: item.Track.TrackNumber,
+				TotalTracks: item.Track.Album.TotalTracks,
+				DiscNumber:  item.Track.DiscNumber,
+				ExternalURL: item.Track.ExternalURL.Spotify,
+				ISRC:        item.Track.ExternalID.ISRC,
+				AlbumID:     item.Track.Album.ID,
+				AlbumURL:    item.Track.Album.ExternalURL.Spotify,
+			})
+		}
+
+		nextURL = pageData.Next
+	}
+
+	fmt.Printf("[Spotify] Fetched %d tracks from playlist (total: %d)\n", len(tracks), data.Tracks.Total)
+
 	return &PlaylistResponsePayload{
 		PlaylistInfo: info,
 		TrackList:    tracks,

go_backend/tidal.go

@@ -315,6 +315,28 @@ func (t *TidalDownloader) SearchTrackByISRC(isrc string) (*TidalTrack, error) {
 	return nil, fmt.Errorf("no exact ISRC match found for: %s", isrc)
 }
 
+// normalizeTitle normalizes a track title for comparison (kept for potential future use)
+func normalizeTitle(title string) string {
+	normalized := strings.ToLower(strings.TrimSpace(title))
+	
+	// Remove common suffixes in parentheses or brackets
+	suffixPatterns := []string{
+		" (remaster)", " (remastered)", " (deluxe)", " (deluxe edition)",
+		" (bonus track)", " (single)", " (album version)", " (radio edit)",
+		" [remaster]", " [remastered]", " [deluxe]", " [bonus track]",
+	}
+	for _, suffix := range suffixPatterns {
+		normalized = strings.TrimSuffix(normalized, suffix)
+	}
+	
+	// Remove multiple spaces
+	for strings.Contains(normalized, "  ") {
+		normalized = strings.ReplaceAll(normalized, "  ", " ")
+	}
+	
+	return normalized
+}
+
 // SearchTrackByMetadataWithISRC searches for a track with ISRC matching priority
 func (t *TidalDownloader) SearchTrackByMetadataWithISRC(trackName, artistName, spotifyISRC string, expectedDuration int) (*TidalTrack, error) {
 	token, err := t.GetAccessToken()
@@ -390,14 +412,50 @@ func (t *TidalDownloader) SearchTrackByMetadataWithISRC(trackName, artistName, s
 		return nil, fmt.Errorf("no tracks found for any search query")
 	}
 
-	// Priority 1: Match by ISRC (exact match)
+	// Priority 1: Match by ISRC (exact match) WITH title verification
 	if spotifyISRC != "" {
+		var isrcMatches []*TidalTrack
 		for i := range allTracks {
 			track := &allTracks[i]
 			if track.ISRC == spotifyISRC {
-				return track, nil
+				isrcMatches = append(isrcMatches, track)
 			}
 		}
+		
+		if len(isrcMatches) > 0 {
+			// Verify duration first (most important check)
+			if expectedDuration > 0 {
+				var durationVerifiedMatches []*TidalTrack
+				for _, track := range isrcMatches {
+					durationDiff := track.Duration - expectedDuration
+					if durationDiff < 0 {
+						durationDiff = -durationDiff
+					}
+					// Allow 30 seconds tolerance for duration
+					if durationDiff <= 30 {
+						durationVerifiedMatches = append(durationVerifiedMatches, track)
+					}
+				}
+				
+				if len(durationVerifiedMatches) > 0 {
+					// Return first duration-verified match
+					fmt.Printf("[Tidal] ISRC match with duration verification: '%s' (expected %ds, found %ds)\n", 
+						durationVerifiedMatches[0].Title, expectedDuration, durationVerifiedMatches[0].Duration)
+					return durationVerifiedMatches[0], nil
+				}
+				
+				// ISRC matches but duration doesn't - this is likely wrong version
+				fmt.Printf("[Tidal] WARNING: ISRC %s found but duration mismatch. Expected=%ds, Found=%ds. Rejecting.\n", 
+					spotifyISRC, expectedDuration, isrcMatches[0].Duration)
+				return nil, fmt.Errorf("ISRC found but duration mismatch: expected %ds, found %ds (likely different version/edit)", 
+					expectedDuration, isrcMatches[0].Duration)
+			}
+			
+			// No duration to verify, just return first ISRC match
+			fmt.Printf("[Tidal] ISRC match (no duration verification): '%s'\n", isrcMatches[0].Title)
+			return isrcMatches[0], nil
+		}
+		
 		// If ISRC was provided but no match found, return error
 		return nil, fmt.Errorf("ISRC mismatch: no track found with ISRC %s on Tidal", spotifyISRC)
 	}
@@ -820,6 +878,9 @@ func downloadFromTidal(req DownloadRequest) (TidalDownloadResult, error) {
 		return TidalDownloadResult{FilePath: "EXISTS:" + existingFile}, nil
 	}
 
+	// Convert expected duration from ms to seconds
+	expectedDurationSec := req.DurationMS / 1000
+
 	var track *TidalTrack
 	var err error
 
@@ -831,18 +892,31 @@ func downloadFromTidal(req DownloadRequest) (TidalDownloadResult, error) {
 			trackID, idErr := downloader.GetTrackIDFromURL(tidalURL)
 			if idErr == nil {
 				track, err = downloader.GetTrackInfoByID(trackID)
+				// Verify duration if we have expected duration
+				if track != nil && expectedDurationSec > 0 {
+					durationDiff := track.Duration - expectedDurationSec
+					if durationDiff < 0 {
+						durationDiff = -durationDiff
+					}
+					// Allow 30 seconds tolerance
+					if durationDiff > 30 {
+						fmt.Printf("[Tidal] Duration mismatch from SongLink: expected %ds, got %ds. Rejecting.\n", 
+							expectedDurationSec, track.Duration)
+						track = nil // Reject this match
+					}
+				}
 			}
 		}
 	}
 
-	// Strategy 2: Search by ISRC with multi-strategy fallback
+	// Strategy 2: Search by ISRC with duration verification
 	if track == nil && req.ISRC != "" {
-		track, err = downloader.SearchTrackByMetadataWithISRC(req.TrackName, req.ArtistName, req.ISRC, 0)
+		track, err = downloader.SearchTrackByMetadataWithISRC(req.TrackName, req.ArtistName, req.ISRC, expectedDurationSec)
 	}
 
 	// Strategy 3: Search by metadata only (no ISRC requirement)
 	if track == nil {
-		track, err = downloader.SearchTrackByMetadata(req.TrackName, req.ArtistName)
+		track, err = downloader.SearchTrackByMetadataWithISRC(req.TrackName, req.ArtistName, "", expectedDurationSec)
 	}
 
 	if track == nil {
@@ -853,6 +927,20 @@ func downloadFromTidal(req DownloadRequest) (TidalDownloadResult, error) {
 		return TidalDownloadResult{}, fmt.Errorf("tidal search failed: %s", errMsg)
 	}
 
+	// Final duration verification
+	if expectedDurationSec > 0 {
+		durationDiff := track.Duration - expectedDurationSec
+		if durationDiff < 0 {
+			durationDiff = -durationDiff
+		}
+		if durationDiff > 30 {
+			return TidalDownloadResult{}, fmt.Errorf("duration mismatch: expected %ds, found %ds (diff: %ds). Track may be wrong version", 
+				expectedDurationSec, track.Duration, durationDiff)
+		}
+		fmt.Printf("[Tidal] Duration verified: expected %ds, found %ds (diff: %ds)\n", 
+			expectedDurationSec, track.Duration, durationDiff)
+	}
+
 	// Build filename
 	filename := buildFilenameFromTemplate(req.FilenameFormat, map[string]interface{}{
 		"title":  req.TrackName,

lib/constants/app_info.dart

@@ -1,8 +1,8 @@
 /// App version and info constants
 /// Update version here only - all other files will reference this
 class AppInfo {
-  static const String version = '2.0.4';
-  static const String buildNumber = '34';
+  static const String version = '2.0.5';
+  static const String buildNumber = '35';
   static const String fullVersion = '$version+$buildNumber';
   
   

lib/providers/download_queue_provider.dart

@@ -1007,6 +1007,7 @@ class DownloadQueueNotifier extends Notifier<DownloadQueueState> {
           releaseDate: item.track.releaseDate,
           preferredService: item.service,
           itemId: item.id, // Pass item ID for progress tracking
+          durationMs: item.track.duration, // Duration in ms for verification
         );
       } else {
         result = await PlatformBridge.downloadTrack(
@@ -1025,6 +1026,7 @@ class DownloadQueueNotifier extends Notifier<DownloadQueueState> {
           discNumber: item.track.discNumber ?? 1,
           releaseDate: item.track.releaseDate,
           itemId: item.id, // Pass item ID for progress tracking
+          durationMs: item.track.duration, // Duration in ms for verification
         );
       }
       

lib/services/platform_bridge.dart

@@ -65,6 +65,7 @@ class PlatformBridge {
     int totalTracks = 1,
     String? releaseDate,
     String? itemId,
+    int durationMs = 0,
   }) async {
     final request = jsonEncode({
       'isrc': isrc,
@@ -85,6 +86,7 @@ class PlatformBridge {
       'total_tracks': totalTracks,
       'release_date': releaseDate ?? '',
       'item_id': itemId ?? '',
+      'duration_ms': durationMs,
     });
     
     final result = await _channel.invokeMethod('downloadTrack', request);
@@ -111,6 +113,7 @@ class PlatformBridge {
     String? releaseDate,
     String preferredService = 'tidal',
     String? itemId,
+    int durationMs = 0,
   }) async {
     final request = jsonEncode({
       'isrc': isrc,
@@ -131,6 +134,7 @@ class PlatformBridge {
       'total_tracks': totalTracks,
       'release_date': releaseDate ?? '',
       'item_id': itemId ?? '',
+      'duration_ms': durationMs,
     });
     
     final result = await _channel.invokeMethod('downloadWithFallback', request);

pubspec.yaml

@@ -1,7 +1,7 @@
 name: spotiflac_android
 description: Download Spotify tracks in FLAC from Tidal, Qobuz & Amazon Music
 publish_to: 'none'
-version: 2.0.4+34
+version: 2.0.5+35
 
 environment:
   sdk: ^3.10.0