feat: add caching support with track metadata

lib/extensions/track.dart

@@ -1,4 +1,5 @@
 import 'dart:io';
+import 'dart:typed_data';
 
 import 'package:metadata_god/metadata_god.dart';
 import 'package:path/path.dart';
@@ -37,6 +38,33 @@ extension TrackExtensions on Track {
 
     return this;
   }
+
+  Metadata toMetadata({
+    required int fileLength,
+    Uint8List? imageBytes,
+  }) {
+    return Metadata(
+      title: name,
+      artist: artists?.map((a) => a.name).join(", "),
+      album: album?.name,
+      albumArtist: artists?.map((a) => a.name).join(", "),
+      year: album?.releaseDate != null
+          ? int.tryParse(album!.releaseDate!.split("-").first) ?? 1969
+          : 1969,
+      trackNumber: trackNumber,
+      discNumber: discNumber,
+      durationMs: durationMs?.toDouble() ?? 0.0,
+      fileSize: BigInt.from(fileLength),
+      trackTotal: album?.tracks?.length ?? 0,
+      picture: imageBytes != null
+          ? Picture(
+              data: imageBytes,
+              // Spotify images are always JPEGs
+              mimeType: 'image/jpeg',
+            )
+          : null,
+    );
+  }
 }
 
 extension TrackSimpleExtensions on TrackSimple {

lib/models/parser/range_headers.dart

@@ -0,0 +1,71 @@
+class ContentRangeHeader {
+  final int start;
+  final int end;
+  final int total;
+
+  ContentRangeHeader(this.start, this.end, this.total);
+
+  factory ContentRangeHeader.parse(String value) {
+    if (value.isEmpty) {
+      throw FormatException('Invalid Content-Range header: $value');
+    }
+
+    final parts = value.split(' ');
+    if (parts.length != 2) {
+      throw FormatException('Invalid Content-Range header: $value');
+    }
+
+    final rangeParts = parts[1].split('/');
+    if (rangeParts.length != 2) {
+      throw FormatException('Invalid Content-Range header: $value');
+    }
+
+    final range = rangeParts[0].split('-');
+    if (range.length != 2) {
+      throw FormatException('Invalid Content-Range header: $value');
+    }
+
+    return ContentRangeHeader(
+      int.parse(range[0]),
+      int.parse(range[1]),
+      int.parse(rangeParts[1]),
+    );
+  }
+
+  @override
+  String toString() {
+    return 'bytes $start-$end/$total';
+  }
+}
+
+class RangeHeader {
+  final int start;
+  final int? end;
+
+  RangeHeader(this.start, this.end);
+
+  factory RangeHeader.parse(String value) {
+    if (value.isEmpty) {
+      return RangeHeader(0, null);
+    }
+
+    final parts = value.split('=');
+    if (parts.length != 2) {
+      throw FormatException('Invalid Range header: $value');
+    }
+
+    final ranges = parts[1].split('-');
+
+    return RangeHeader(
+      int.parse(ranges[0]),
+      ranges.elementAtOrNull(1) != null && ranges[1].isNotEmpty
+          ? int.parse(ranges[1])
+          : null,
+    );
+  }
+
+  @override
+  String toString() {
+    return 'bytes=$start-${end ?? ""}';
+  }
+}

lib/provider/download_manager_provider.dart

@@ -1,10 +1,10 @@
 import 'dart:async';
 import 'dart:io';
 
+import 'package:spotube/extensions/track.dart';
 import 'package:spotube/services/logger/logger.dart';
 import 'package:collection/collection.dart';
 import 'package:flutter/foundation.dart';
-import 'package:flutter_cache_manager/flutter_cache_manager.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:metadata_god/metadata_god.dart';
 import 'package:path/path.dart';
@@ -16,6 +16,7 @@ import 'package:spotube/services/download_manager/download_manager.dart';
 import 'package:spotube/services/sourced_track/enums.dart';
 import 'package:spotube/services/sourced_track/sourced_track.dart';
 import 'package:spotube/utils/primitive_utils.dart';
+import 'package:spotube/utils/service_utils.dart';
 
 class DownloadManagerProvider extends ChangeNotifier {
   DownloadManagerProvider({required this.ref})
@@ -53,33 +54,16 @@ class DownloadManagerProvider extends ChangeNotifier {
           await oldFile.delete();
         }
 
-        final imageBytes = await downloadImage(
+        final imageBytes = await ServiceUtils.downloadImage(
           (track.album?.images).asUrlString(
             placeholder: ImagePlaceholder.albumArt,
             index: 1,
           ),
         );
 
-        final metadata = Metadata(
-          title: track.name,
-          artist: track.artists?.map((a) => a.name).join(", "),
-          album: track.album?.name,
-          albumArtist: track.artists?.map((a) => a.name).join(", "),
-          year: track.album?.releaseDate != null
-              ? int.tryParse(track.album!.releaseDate!.split("-").first) ?? 1969
-              : 1969,
-          trackNumber: track.trackNumber,
-          discNumber: track.discNumber,
-          durationMs: track.durationMs?.toDouble() ?? 0.0,
-          fileSize: BigInt.from(await file.length()),
-          trackTotal: track.album?.tracks?.length ?? 0,
-          picture: imageBytes != null
-              ? Picture(
-                  data: imageBytes,
-                  // Spotify images are always JPEGs
-                  mimeType: 'image/jpeg',
-                )
-              : null,
+        final metadata = track.toMetadata(
+          fileLength: await file.length(),
+          imageBytes: imageBytes,
         );
 
         await MetadataGod.writeMetadata(
@@ -116,29 +100,6 @@ class DownloadManagerProvider extends ChangeNotifier {
   final Set<Track> $backHistory;
   final DownloadManager dl;
 
-  /// Spotify Images are always JPEGs
-  Future<Uint8List?> downloadImage(
-    String imageUrl,
-  ) async {
-    try {
-      final fileStream = DefaultCacheManager().getImageFile(imageUrl);
-
-      final bytes = List<int>.empty(growable: true);
-
-      await for (final data in fileStream) {
-        if (data is FileInfo) {
-          bytes.addAll(data.file.readAsBytesSync());
-          break;
-        }
-      }
-
-      return Uint8List.fromList(bytes);
-    } catch (e, stackTrace) {
-      AppLogger.reportError(e, stackTrace);
-      return null;
-    }
-  }
-
   String getTrackFileUrl(Track track) {
     final name =
         "${track.name} - ${track.artists?.asString() ?? ""}.${downloadCodec.name}";

lib/provider/server/routes/playback.dart

@@ -1,14 +1,28 @@
+import 'dart:io';
+
 import 'package:dio/dio.dart' hide Response;
+import 'package:dio/dio.dart' as dio_lib;
 import 'package:flutter/foundation.dart';
 import 'package:hooks_riverpod/hooks_riverpod.dart';
+import 'package:metadata_god/metadata_god.dart';
+import 'package:path/path.dart';
 import 'package:shelf/shelf.dart';
+import 'package:spotube/extensions/artist_simple.dart';
+import 'package:spotube/extensions/image.dart';
+import 'package:spotube/extensions/track.dart';
+import 'package:spotube/models/parser/range_headers.dart';
 import 'package:spotube/provider/audio_player/audio_player.dart';
 import 'package:spotube/provider/audio_player/state.dart';
+
 import 'package:spotube/provider/server/active_sourced_track.dart';
 import 'package:spotube/provider/server/sourced_track.dart';
 import 'package:spotube/provider/user_preferences/user_preferences_provider.dart';
 import 'package:spotube/services/audio_player/audio_player.dart';
 import 'package:spotube/services/logger/logger.dart';
+import 'package:spotube/services/sourced_track/enums.dart';
+import 'package:spotube/services/sourced_track/sourced_track.dart';
+import 'package:path_provider/path_provider.dart' as paths;
+import 'package:spotube/utils/service_utils.dart';
 
 class ServerPlaybackRoutes {
   final Ref ref;
@@ -18,19 +32,140 @@ class ServerPlaybackRoutes {
 
   ServerPlaybackRoutes(this.ref) : dio = Dio();
 
-  /// @get('/stream/<trackId>')
-  Future<Response> getStreamTrackId(Request request, String trackId) async {
-    final options = Options(
+  Future<({dio_lib.Response<Uint8List> response, Uint8List? bytes})>
+      streamTrack(
+    SourcedTrack track,
+    Map<String, dynamic> headers,
+  ) async {
+    final trackCacheFile = File(
+      join(
+        await paths.getApplicationCacheDirectory().then((value) => value.path),
+        'cached_tracks',
+        '${track.name} - ${track.artists?.asString()} (${track.sourceInfo.id}).${track.codec.name}',
+      ),
+    );
+    final trackPartialCacheFile = File("${trackCacheFile.path}.part");
+
+    var options = Options(
       headers: {
-        ...request.headers,
+        ...headers,
         "User-Agent":
             "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/123.0.0.0 Safari/537.36",
         "Cache-Control": "max-age=0",
         "Connection": "keep-alive",
+        "host": Uri.parse(track.url).host,
       },
-      responseType: ResponseType.stream,
+      responseType: ResponseType.bytes,
       validateStatus: (status) => status! < 400,
     );
+
+    final headersRes = await Future<dio_lib.Response?>.value(
+      dio.head(
+        track.url,
+        options: options,
+      ),
+    ).catchError((_) async => null);
+
+    final contentLength = headersRes?.headers.value("content-length");
+
+    if (await trackCacheFile.exists()) {
+      final bytes = await trackCacheFile.readAsBytes();
+      final cachedFileLength = bytes.length;
+
+      return (
+        response: dio_lib.Response<Uint8List>(
+          statusCode: 200,
+          headers: Headers.fromMap({
+            "content-type": ["audio/${track.codec.name}"],
+            "content-length": ["$cachedFileLength"],
+            "accept-ranges": ["bytes"],
+            "content-range": ["bytes 0-$cachedFileLength/$cachedFileLength"],
+          }),
+          requestOptions: RequestOptions(path: track.url),
+        ),
+        bytes: bytes,
+      );
+    }
+
+    /// Forcing partial content range as mpv sometimes greedily wants
+    /// everything at one go. Slows down overall streaming.
+    final range = RangeHeader.parse(headers["range"] ?? "");
+    final contentPartialLength = int.tryParse(contentLength ?? "");
+    if ((range.end == null) &&
+        contentPartialLength != null &&
+        range.start == 0) {
+      options = options.copyWith(
+        headers: {
+          ...?options.headers,
+          "range": "$range${(contentPartialLength * 0.3).ceil()}",
+        },
+      );
+    }
+
+    final res =
+        await dio.get<Uint8List>(track.url, options: options).catchError(
+      (e, stack) async {
+        final sourcedTrack = await ref
+            .read(sourcedTrackProvider(SpotubeMedia(track)).notifier)
+            .switchToAlternativeSources();
+
+        ref.read(activeSourcedTrackProvider.notifier).update(sourcedTrack);
+
+        return await dio.get<Uint8List>(sourcedTrack!.url, options: options);
+      },
+    );
+
+    final bytes = res.data;
+
+    if (bytes == null) {
+      return (response: res, bytes: null);
+    }
+
+    final contentRange =
+        ContentRangeHeader.parse(res.headers.value("content-range") ?? "");
+
+    if (!await trackPartialCacheFile.exists()) {
+      await trackPartialCacheFile.create(recursive: true);
+    }
+
+    // Write the stream to the file based on the range
+    final partialCacheFile =
+        await trackPartialCacheFile.open(mode: FileMode.writeOnlyAppend);
+    int fileLength = 0;
+    try {
+      await partialCacheFile.setPosition(contentRange.start);
+      await partialCacheFile.writeFrom(bytes);
+      fileLength = await partialCacheFile.length();
+    } finally {
+      await partialCacheFile.close();
+    }
+
+    if (fileLength == contentRange.total) {
+      await trackPartialCacheFile.rename(trackCacheFile.path);
+    }
+
+    if (contentRange.total == fileLength && track.codec != SourceCodecs.weba) {
+      final imageBytes = await ServiceUtils.downloadImage(
+        (track.album?.images).asUrlString(
+          placeholder: ImagePlaceholder.albumArt,
+          index: 1,
+        ),
+      );
+
+      await MetadataGod.writeMetadata(
+        file: trackCacheFile.path,
+        metadata: track.toMetadata(
+          fileLength: fileLength,
+          imageBytes: imageBytes,
+        ),
+      );
+    }
+
+    return (bytes: bytes, response: res);
+  }
+
+  /// @get('/stream/<trackId>')
+  Future<Response> getStreamTrackId(Request request, String trackId) async {
     try {
       final track =
           playlist.tracks.firstWhere((element) => element.id == trackId);
@@ -41,48 +176,13 @@ class ServerPlaybackRoutes {
           : await ref.read(sourcedTrackProvider(SpotubeMedia(track)).future);
 
       ref.read(activeSourcedTrackProvider.notifier).update(sourcedTrack);
-      final res = await dio
-          .get(
-        sourcedTrack!.url,
-        options: options.copyWith(
-          headers: {
-            ...options.headers!,
-            "host": Uri.parse(sourcedTrack.url).host,
-          },
-        ),
-      )
-          .catchError((e, stack) async {
-        final sourcedTrack = await ref
-            .read(sourcedTrackProvider(SpotubeMedia(track)).notifier)
-            .switchToAlternativeSources();
 
-        ref.read(activeSourcedTrackProvider.notifier).update(sourcedTrack);
-
-        return await dio.get(
-          sourcedTrack!.url,
-          options: options.copyWith(
-            headers: {
-              ...options.headers!,
-              "host": Uri.parse(sourcedTrack.url).host,
-            },
-          ),
-        );
-      });
-
-      final audioStream =
-          (res.data?.stream as Stream<Uint8List>?)?.asBroadcastStream();
-
-      audioStream!.listen(
-        (event) {},
-        cancelOnError: true,
-      );
+      final (bytes: audioBytes, response: res) =
+          await streamTrack(sourcedTrack!, request.headers);
 
       return Response(
         res.statusCode!,
-        body: audioStream,
-        context: {
-          "shelf.io.buffer_output": false,
-        },
+        body: audioBytes,
         headers: res.headers.map,
       );
     } catch (e, stack) {

lib/utils/service_utils.dart

@@ -1,4 +1,7 @@
+import 'dart:typed_data';
+
 import 'package:dio/dio.dart';
+import 'package:flutter_cache_manager/flutter_cache_manager.dart';
 import 'package:go_router/go_router.dart';
 import 'package:html/dom.dart' hide Text;
 import 'package:spotify/spotify.dart';
@@ -8,6 +11,7 @@ import 'package:spotube/modules/root/update_dialog.dart';
 import 'package:spotube/models/lyrics.dart';
 import 'package:spotube/provider/database/database.dart';
 import 'package:spotube/services/dio/dio.dart';
+import 'package:spotube/services/logger/logger.dart';
 import 'package:spotube/services/sourced_track/sourced_track.dart';
 
 import 'package:spotube/utils/primitive_utils.dart';
@@ -449,4 +453,27 @@ abstract class ServiceUtils {
       );
     }
   }
+
+  /// Spotify Images are always JPEGs
+  static Future<Uint8List?> downloadImage(
+    String imageUrl,
+  ) async {
+    try {
+      final fileStream = DefaultCacheManager().getImageFile(imageUrl);
+
+      final bytes = List<int>.empty(growable: true);
+
+      await for (final data in fileStream) {
+        if (data is FileInfo) {
+          bytes.addAll(data.file.readAsBytesSync());
+          break;
+        }
+      }
+
+      return Uint8List.fromList(bytes);
+    } catch (e, stackTrace) {
+      AppLogger.reportError(e, stackTrace);
+      return null;
+    }
+  }
 }