fix(player): volume slider, prefetching of media_kit and stuttering on sponsorblock skip

lib/provider/proxy_playlist/proxy_playlist_provider.dart

@@ -20,6 +20,9 @@ import 'package:youtube_explode_dart/youtube_explode_dart.dart';
 /// * [x] Prefetch next track as [SpotubeTrack] on 80% of current track
 /// * [ ] Mixed Queue containing both [SpotubeTrack] and [LocalTrack]
 /// * [ ] Caching and loading of cache of tracks
+/// * [ ] Shuffling and loop => playlist, track, none
+/// * [ ] Alternative Track Source
+/// * [x] Blacklisting of tracks and artist
 ///
 /// Don'ts:
 /// * It'll not have any proxy method for [SpotubeAudioPlayer]
@@ -48,7 +51,8 @@ class ProxyPlaylistNotifier extends StateNotifier<ProxyPlaylist>
       notificationService = await AudioServices.create(ref, this);
 
       audioPlayer.currentIndexChangedStream.listen((index) async {
-        if (index == -1) return;
+        if (index == -1 || index == state.active) return;
+
         final track = state.tracks.elementAtOrNull(index);
         if (track == null) return;
         notificationService.addTrack(track);
@@ -60,14 +64,26 @@ class ProxyPlaylistNotifier extends StateNotifier<ProxyPlaylist>
       });
 
       bool isPreSearching = false;
-      audioPlayer.percentCompletedStream(80).listen((_) async {
+      audioPlayer.percentCompletedStream(60).listen((percent) async {
         if (isPreSearching) return;
         try {
           isPreSearching = true;
 
+          final softReplace =
+              SpotubeAudioPlayer.mkSupportedPlatform && percent <= 98;
+
           // TODO: Make repeat mode sensitive changes later
-          final track =
-              await ensureNthSourcePlayable(audioPlayer.currentIndex + 1);
+          final track = await ensureNthSourcePlayable(
+            audioPlayer.currentIndex + 1,
+
+            /// [MediaKit] doesn't fully support replacing source, so we need
+            /// to check if the platform is supported or not and replace the
+            /// actual playlist with a playlist that contains the next track
+            /// at 98% >= progress
+            softReplace: softReplace,
+            exclusive: SpotubeAudioPlayer.mkSupportedPlatform,
+          );
+
           if (track != null) {
             state = state.copyWith(tracks: mergeTracks([track], state.tracks));
           }
@@ -109,8 +125,7 @@ class ProxyPlaylistNotifier extends StateNotifier<ProxyPlaylist>
             preferences.skipSponsorSegments) {
           for (final segment in activeTrack.skipSegments) {
             if (pos.inSeconds < segment["start"]! ||
-                pos.inSeconds > segment["end"]!) continue;
-            await audioPlayer.pause();
+                pos.inSeconds >= segment["end"]!) continue;
             await audioPlayer.seek(Duration(seconds: segment["end"]!));
           }
         }
@@ -118,7 +133,11 @@ class ProxyPlaylistNotifier extends StateNotifier<ProxyPlaylist>
     }();
   }
 
-  Future<SpotubeTrack?> ensureNthSourcePlayable(int n) async {
+  Future<SpotubeTrack?> ensureNthSourcePlayable(
+    int n, {
+    bool softReplace = false,
+    bool exclusive = false,
+  }) async {
     final sources = audioPlayer.sources;
     if (n < 0 || n > sources.length - 1) return null;
     final nthSource = sources.elementAtOrNull(n);
@@ -127,19 +146,23 @@ class ProxyPlaylistNotifier extends StateNotifier<ProxyPlaylist>
     final nthTrack = state.tracks.firstWhereOrNull(
       (element) => element.id == getIdFromUnPlayable(nthSource),
     );
-    if (nthTrack == null ||
-        nthTrack is SpotubeTrack ||
-        nthTrack is LocalTrack) {
+    if (nthTrack == null || nthTrack is LocalTrack) {
       return null;
     }
 
-    final nthFetchedTrack =
-        await SpotubeTrack.fetchFromTrack(nthTrack, preferences);
+    final nthFetchedTrack = nthTrack is SpotubeTrack
+        ? nthTrack
+        : await SpotubeTrack.fetchFromTrack(nthTrack, preferences);
 
+    if (nthSource == nthFetchedTrack.ytUri) return null;
+
+    if (!softReplace) {
       await audioPlayer.replaceSource(
         nthSource,
         nthFetchedTrack.ytUri,
+        exclusive: exclusive,
       );
+    }
 
     return nthFetchedTrack;
   }

lib/services/audio_player/audio_player.dart

@@ -64,15 +64,16 @@ class SpotubeAudioPlayer {
   }
 
   /// Stream that emits when the player is almost (%) complete
-  Stream<void> percentCompletedStream(double percent) {
+  Stream<int> percentCompletedStream(double percent) {
     return positionStream
-        .asyncMap((event) async => [event, await duration])
-        .where((event) {
-      final position = event[0] as Duration;
-      final duration = event[1] as Duration;
-
-      return position.inSeconds > duration.inSeconds * percent / 100;
-    }).asBroadcastStream();
+        .asyncMap(
+          (position) async => (await duration)?.inSeconds == 0
+              ? 0
+              : (position.inSeconds / (await duration)!.inSeconds * 100)
+                  .toInt(),
+        )
+        .where((event) => event >= percent)
+        .asBroadcastStream();
   }
 
   Stream<bool> get playingStream {
@@ -143,12 +144,8 @@ class SpotubeAudioPlayer {
           .map((event) => event.index)
           .asBroadcastStream();
     } else {
-      return _justAudio!.positionDiscontinuityStream
-          .where(
-            (event) =>
-                event.reason == ja.PositionDiscontinuityReason.autoAdvance,
-          )
-          .map((event) => currentIndex)
+      return _justAudio!.sequenceStateStream
+          .map((event) => event?.currentIndex ?? -1)
           .asBroadcastStream();
     }
   }
@@ -237,6 +234,7 @@ class SpotubeAudioPlayer {
     }
   }
 
+  /// Returns the current volume of the player, between 0 and 1
   double get volume {
     if (mkSupportedPlatform) {
       return _mkPlayer!.state.volume / 100;
@@ -320,8 +318,10 @@ class SpotubeAudioPlayer {
     await _justAudio?.seek(position);
   }
 
+  /// Volume is between 0 and 1
   Future<void> setVolume(double volume) async {
-    await _mkPlayer?.setVolume(volume);
+    assert(volume >= 0 && volume <= 1);
+    await _mkPlayer?.setVolume(volume * 100);
     await _justAudio?.setVolume(volume);
   }
 
@@ -391,7 +391,7 @@ class SpotubeAudioPlayer {
     if (mkSupportedPlatform) {
       return _mkPlayer!.state.playlist.index;
     } else {
-      return _justAudio!.sequenceState!.currentIndex;
+      return _justAudio!.sequenceState?.currentIndex ?? -1;
     }
   }
 
@@ -447,13 +447,18 @@ class SpotubeAudioPlayer {
     }
   }
 
-  Future<void> replaceSource(String oldSource, String newSource) async {
-    final willBeReplacedIndex = sources.indexOf(oldSource);
-    if (willBeReplacedIndex == -1) return;
+  Future<void> replaceSource(
+    String oldSource,
+    String newSource, {
+    bool exclusive = false,
+  }) async {
+    final oldSourceIndex = sources.indexOf(oldSource);
+    if (oldSourceIndex == -1) return;
 
     if (mkSupportedPlatform) {
       final sourcesCp = sources.toList();
-      sourcesCp[willBeReplacedIndex] = newSource;
+      sourcesCp[oldSourceIndex] = newSource;
+
       await _mkPlayer!.open(
         mk.Playlist(
           sourcesCp.map(mk.Media.new).toList(),
@@ -461,20 +466,21 @@ class SpotubeAudioPlayer {
         ),
         play: false,
       );
+      if (exclusive) await jumpTo(oldSourceIndex);
     } else {
       await addTrack(newSource);
-      await removeTrack(willBeReplacedIndex);
+      await removeTrack(oldSourceIndex);
 
       int newSourceIndex = sources.indexOf(newSource);
       while (newSourceIndex == -1) {
         await Future.delayed(const Duration(milliseconds: 100));
         newSourceIndex = sources.indexOf(newSource);
       }
-      await moveTrack(newSourceIndex, willBeReplacedIndex);
+      await moveTrack(newSourceIndex, oldSourceIndex);
       newSourceIndex = sources.indexOf(newSource);
-      while (newSourceIndex != willBeReplacedIndex) {
+      while (newSourceIndex != oldSourceIndex) {
         await Future.delayed(const Duration(milliseconds: 100));
-        await moveTrack(newSourceIndex, willBeReplacedIndex);
+        await moveTrack(newSourceIndex, oldSourceIndex);
         newSourceIndex = sources.indexOf(newSource);
       }
     }