CurrentPlaylist cache & load from cache support

lib/components/Playlist/PlaylistView.dart

@@ -23,7 +23,7 @@ class PlaylistView extends HookConsumerWidget {
   playPlaylist(Playback playback, List<Track> tracks,
       {Track? currentTrack}) async {
     currentTrack ??= tracks.first;
-    var isPlaylistPlaying = playback.currentPlaylist?.id != null &&
+    final isPlaylistPlaying = playback.currentPlaylist?.id != null &&
         playback.currentPlaylist?.id == playlist.id;
     if (!isPlaylistPlaying) {
       playback.setCurrentPlaylist = CurrentPlaylist(

lib/models/CurrentPlaylist.dart

@@ -1,5 +1,60 @@
 import 'package:spotify/spotify.dart';
 
+extension AlbumJson on AlbumSimple {
+  Map<String, dynamic> toJson() {
+    return {
+      "albumType": albumType,
+      "id": id,
+      "name": name,
+      "images": images
+          ?.map((image) => {
+                "height": image.height,
+                "url": image.url,
+                "width": image.width,
+              })
+          .toList(),
+    };
+  }
+}
+
+extension ArtistJson on ArtistSimple {
+  Map<String, dynamic> toJson() {
+    return {
+      "href": href,
+      "id": id,
+      "name": name,
+      "type": type,
+      "uri": uri,
+    };
+  }
+}
+
+extension TrackJson on Track {
+  Map<String, dynamic> toJson() {
+    return {
+      "album": album?.toJson(),
+      "artists": artists?.map((artist) => artist.toJson()).toList(),
+      "availableMarkets": availableMarkets,
+      "discNumber": discNumber,
+      "duration": duration.toString(),
+      "durationMs": durationMs,
+      "explicit": explicit,
+      // "externalIds": externalIds,
+      // "externalUrls": externalUrls,
+      "href": href,
+      "id": id,
+      "isPlayable": isPlayable,
+      // "linkedFrom": linkedFrom,
+      "name": name,
+      "popularity": popularity,
+      "previewUrl": previewUrl,
+      "trackNumber": trackNumber,
+      "type": type,
+      "uri": uri,
+    };
+  }
+}
+
 class CurrentPlaylist {
   List<Track>? _tempTrack;
   List<Track> tracks;
@@ -14,6 +69,16 @@ class CurrentPlaylist {
     required this.thumbnail,
   });
 
+  static CurrentPlaylist fromJson(Map<String, dynamic> map) {
+    return CurrentPlaylist(
+      id: map["id"],
+      tracks: List.castFrom<dynamic, Track>(
+          map["tracks"].map((track) => Track.fromJson(track)).toList()),
+      name: map["name"],
+      thumbnail: map["thumbnail"],
+    );
+  }
+
   List<String> get trackIds => tracks.map((e) => e.id!).toList();
 
   bool shuffle() {
@@ -35,4 +100,13 @@ class CurrentPlaylist {
     }
     return false;
   }
+
+  Map<String, dynamic> toJson() {
+    return {
+      "id": id,
+      "name": name,
+      "tracks": tracks.map((track) => track.toJson()).toList(),
+      "thumbnail": thumbnail,
+    };
+  }
 }

lib/provider/Playback.dart

@@ -1,9 +1,10 @@
 import 'dart:async';
+import 'dart:convert';
 
 import 'package:audio_service/audio_service.dart';
-import 'package:flutter/cupertino.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:just_audio/just_audio.dart';
+import 'package:shared_preferences/shared_preferences.dart';
 import 'package:spotify/spotify.dart';
 import 'package:spotube/helpers/artist-to-string.dart';
 import 'package:spotube/helpers/image-to-url-string.dart';
@@ -13,9 +14,10 @@ import 'package:spotube/models/Logger.dart';
 import 'package:spotube/provider/UserPreferences.dart';
 import 'package:spotube/provider/YouTube.dart';
 import 'package:spotube/utils/AudioPlayerHandler.dart';
+import 'package:spotube/utils/PersistedChangeNotifier.dart';
 import 'package:youtube_explode_dart/youtube_explode_dart.dart';
 
-class Playback extends ChangeNotifier {
+class Playback extends PersistedChangeNotifier {
   AudioSource? _currentAudioSource;
   final _logger = getLogger(Playback);
   CurrentPlaylist? _currentPlaylist;
@@ -38,13 +40,15 @@ class Playback extends ChangeNotifier {
     CurrentPlaylist? currentPlaylist,
     Track? currentTrack,
   })  : _currentPlaylist = currentPlaylist,
-        _currentTrack = currentTrack {
+        _currentTrack = currentTrack,
+        super() {
     player.onNextRequest = () {
       movePlaylistPositionBy(1);
     };
     player.onPreviousRequest = () {
       movePlaylistPositionBy(-1);
     };
+
     _init();
   }
 
@@ -52,7 +56,7 @@ class Playback extends ChangeNotifier {
   StreamSubscription<Duration>? _positionStream;
   StreamSubscription<bool>? _playingStream;
 
-  void _init() {
+  void _init() async {
     _playingStream = player.core.playingStream.listen(
       (playing) {
         _isPlaying = playing;
@@ -119,12 +123,14 @@ class Playback extends ChangeNotifier {
     _logger.v("[Setting Current Track] ${track.name} - ${track.id}");
     _currentTrack = track;
     notifyListeners();
+    updatePersistence();
   }
 
   set setCurrentPlaylist(CurrentPlaylist playlist) {
     _logger.v("[Current Playlist Changed] ${playlist.name} - ${playlist.id}");
     _currentPlaylist = playlist;
     notifyListeners();
+    updatePersistence();
   }
 
   void reset() {
@@ -135,6 +141,7 @@ class Playback extends ChangeNotifier {
     _currentPlaylist = null;
     _currentTrack = null;
     notifyListeners();
+    updatePersistence(clearNullEntries: true);
   }
 
   /// sets the provided id matched track's uri\
@@ -147,6 +154,7 @@ class Playback extends ChangeNotifier {
           _currentPlaylist!.tracks.indexWhere((element) => element.id == id);
       if (index == -1) return false;
       _currentPlaylist!.tracks[index].uri = uri;
+      updatePersistence();
       return _currentPlaylist!.tracks[index].uri == uri;
     } catch (e) {
       return false;
@@ -170,6 +178,7 @@ class Playback extends ChangeNotifier {
         duration = null;
         _currentTrack = track;
         notifyListeners();
+        updatePersistence();
         // starts to play the newly entered next/prev track
         startPlaying();
       }
@@ -202,6 +211,7 @@ class Playback extends ChangeNotifier {
               .then((value) async {
             _currentTrack = track;
             notifyListeners();
+            updatePersistence();
           });
           // await player.play();
           return;
@@ -215,6 +225,7 @@ class Playback extends ChangeNotifier {
           audioQuality: preferences.audioQuality,
         );
         if (setTrackUriById(track.id!, spotubeTrack.ytUri)) {
+          logger.v("[Track Direct Source] - ${spotubeTrack.ytUri}");
           _currentAudioSource = AudioSource.uri(Uri.parse(spotubeTrack.ytUri));
           await player.core
               .setAudioSource(
@@ -224,6 +235,7 @@ class Playback extends ChangeNotifier {
               .then((value) {
             _currentTrack = spotubeTrack;
             notifyListeners();
+            updatePersistence();
           });
           // await player.play();
         }
@@ -246,6 +258,36 @@ class Playback extends ChangeNotifier {
       notifyListeners();
     }
   }
+
+  @override
+  FutureOr<void> loadFromLocal(Map<String, dynamic> map) {
+    if (map["currentPlaylist"] != null) {
+      _currentPlaylist =
+          CurrentPlaylist.fromJson(jsonDecode(map["currentPlaylist"]));
+    }
+    if (map["currentTrack"] != null) {
+      _currentTrack = Track.fromJson(jsonDecode(map["currentTrack"]));
+      startPlaying().then((_) {
+        Timer.periodic(const Duration(milliseconds: 100), (timer) {
+          if (player.core.playing) {
+            player.pause();
+            timer.cancel();
+          }
+        });
+      });
+    }
+  }
+
+  @override
+  FutureOr<Map<String, dynamic>> toMap() {
+    return {
+      "currentPlaylist": currentPlaylist != null
+          ? jsonEncode(currentPlaylist?.toJson())
+          : null,
+      "currentTrack":
+          currentTrack != null ? jsonEncode(currentTrack?.toJson()) : null,
+    };
+  }
 }
 
 final playbackProvider = ChangeNotifierProvider<Playback>((ref) {

lib/utils/PersistedChangeNotifier.dart

@@ -37,7 +37,7 @@ abstract class PersistedChangeNotifier extends ChangeNotifier {
 
   FutureOr<Map<String, dynamic>> toMap();
 
-  Future<void> updatePersistence() async {
+  Future<void> updatePersistence({bool clearNullEntries = false}) async {
     for (final entry in (await toMap()).entries) {
       if (entry.value is bool) {
         await _localStorage.setBool(entry.key, entry.value);
@@ -47,6 +47,8 @@ abstract class PersistedChangeNotifier extends ChangeNotifier {
         await _localStorage.setDouble(entry.key, entry.value);
       } else if (entry.value is String) {
         await _localStorage.setString(entry.key, entry.value);
+      } else if (entry.value == null && clearNullEntries) {
+        _localStorage.remove(entry.key);
       }
     }
   }