1
// fields
2
int _onlineSwitchToken = 0;
3
int? _pendingOnlineSwitchIndex;
4
int? _queuedOnlineSwitchIndex;
5

6
Future<void> playAtIndex(int index) async {
7
  if (_isOnlinePlaylist && _onlineSongList != null && _urlResolver != null) {
8
    if (_isSwitchingOnlineTrack) {
9
      _queuedOnlineSwitchIndex = index;
10
      debugPrint(
11
        '[AudioManager][SWITCH] switching in progress, queue target index=$index',
12
      );
13
      return;
14
    }
15

16
    _isSwitchingOnlineTrack = true;
17
    _pendingOnlineSwitchIndex = index;
18
    final switchToken = ++_onlineSwitchToken;
19

20
    try {
21
      // ... resolve / set source / play
22

23
      if (switchToken != _onlineSwitchToken) {
24
        debugPrint('[AudioManager][SWITCH] stale switch ignored token=$switchToken');
25
        return;
26
      }
27

28
      _currentIndex = index;
29
      mediaItem.add(queue.value[index]);
30
      _updatePlaybackState();
31
    } finally {
32
      if (switchToken == _onlineSwitchToken) {
33
        _isSwitchingOnlineTrack = false;
34
        _pendingOnlineSwitchIndex = null;
35

36
        final queued = _queuedOnlineSwitchIndex;
37
        if (queued != null && queued != _currentIndex) {
38
          _queuedOnlineSwitchIndex = null;
39
          unawaited(playAtIndex(queued));
40
        } else {
41
          _queuedOnlineSwitchIndex = null;
42
        }
43
      }
44
    }
45
  }
46
}

1
@override
2
Future<void> skipToNext() async {
3
  final baseIndex = (_isOnlinePlaylist && _isSwitchingOnlineTrack)
4
      ? (_pendingOnlineSwitchIndex ?? _currentIndex)
5
      : _currentIndex;
6

7
  final nextIndex = baseIndex < _playlist.length - 1 ? baseIndex + 1 : 0;
8

9
  if (_isOnlinePlaylist && _isSwitchingOnlineTrack) {
10
    _queuedOnlineSwitchIndex = nextIndex;
11
    debugPrint('[AudioManager][CMD] skipToNext queued targetIndex=$nextIndex');
12
    return;
13
  }
14

15
  await playAtIndex(nextIndex);
16
}

1
int _onlinePlaylistSessionToken = 0;
2
bool _isSettingOnlinePlaylist = false;
3

4
Future<void> setOnlinePlaylist(...) async {
5
  final sessionToken = ++_onlinePlaylistSessionToken;
6
  _isSettingOnlinePlaylist = true;
7

8
  try {
9
    await _player.setAudioSource(_onlineConcatenatingSource!, initialIndex: 0);
10
    if (sessionToken != _onlinePlaylistSessionToken) return;
11

12
    mediaItem.add(mediaItems[_currentIndex]);
13
    _updatePlaybackState();
14
    await play();
15
    if (sessionToken != _onlinePlaylistSessionToken) return;
16
  } finally {
17
    if (sessionToken == _onlinePlaylistSessionToken) {
18
      _isSettingOnlinePlaylist = false;
19
    }
20
  }
21
}
22

23
// 手动切歌时，取消旧启动会话
24
if (_isSettingOnlinePlaylist) {
25
  _onlinePlaylistSessionToken++;
26
  _isSettingOnlinePlaylist = false;
27
}

1
await _setOnlineSingleSource(audioSource, playlistIndex: index);
2
debugPrint('[AudioManager][SWITCH] iOS cached source set ok index=$index');
3

4
// 不 await，避免 iOS 后台场景 play() 返回很慢导致 UI 卡旧状态
5
final playFuture = _player.play();
6
unawaited(playFuture.then((_) {
7
  debugPrint('[AudioManager][SWITCH] iOS cached play completed index=$index');
8
}));
9

10
debugPrint('[AudioManager][SWITCH] iOS cached play requested index=$index');
11

12
// 继续提交 currentIndex / mediaItem / playbackState
13
_currentIndex = index;
14
mediaItem.add(queue.value[index]);
15
_updatePlaybackState();

1
Widget _buildAdditionalControls(
2
  BuildContext context,
3
  AudioPlaybackState state,
4
) {
5
  final currentSong = state.currentSong; // 不再读 audioManager.currentSong
6
  // ...
7
}
8

9
Widget _buildLyricsSection(BuildContext context, AudioPlaybackState state) {
10
  final currentSongId = state.currentSong?.id;
11
  // ...
12
}
13

14
void _showPlayQueueSheet(BuildContext context, AudioPlaybackState state) {
15
  int currentIndex = state.currentIndex ?? -1;
16
  // fallback 再按 state.currentSong 匹配
17
}