part of 'runtime_audio_manager.dart';

extension _RuntimeAudioManagerCache on RuntimeAudioManager {
  void _releaseCachedAudio() {
    _loadLimiter.clearPending();
    for (final path in _audios.keys.toList(growable: false)) {
      _removeAudioRecord(path);
    }

    _channels.clear();
    final players = _players.toList(growable: false);
    _players.clear();
    final pooledPlayers = _sfxPool.toList(growable: false);
    _sfxPool.clear();
    for (final player in [...players, ...pooledPlayers]) {
      player.dispose();
    }
  }

  RuntimeAudioPlayer _takeSfxPlayer() {
    if (_sfxPool.isNotEmpty) {
      return _sfxPool.removeLast();
    }
    return _playerFactory();
  }

  Future<void> _releaseSfxPlayer(RuntimeAudioPlayer player) async {
    if (_disposed || _sfxPool.length >= _maxSfxPoolSize) {
      await player.dispose();
      return;
    }
    _sfxPool.add(player);
  }

  void _touch(_AudioResourceRecord record) {
    record.lastUsed = ++_accessCounter;
  }

  void _enforceAudioBudget() {
    while (_isOverBudget()) {
      final victim = _leastRecentlyUsedAudio();
      if (victim == null || !_removeAudioRecord(victim)) {
        return;
      }
    }
  }

  bool _isOverBudget() {
    final maxBytes = _maxCacheBytes;
    final maxEntries = _maxCacheEntries;
    return (maxBytes != null && _cacheBytes > maxBytes) ||
        (maxEntries != null && _readyAudioCount > maxEntries);
  }

  int get _readyAudioCount => _audios.values
      .where((record) => record.state == GameResourceState.ready)
      .length;

  String? _leastRecentlyUsedAudio() {
    String? victimPath;
    _AudioResourceRecord? victim;
    for (final entry in _audios.entries) {
      final record = entry.value;
      if (record.state != GameResourceState.ready) {
        continue;
      }
      if (victim == null || record.lastUsed < victim.lastUsed) {
        victim = record;
        victimPath = entry.key;
      }
    }
    return victimPath;
  }

  bool _removeAudioRecord(String path) {
    final record = _audios.remove(path);
    if (record == null) {
      return false;
    }
    _cacheBytes -= record.bytes?.length ?? 0;
    if (_cacheBytes < 0) {
      _cacheBytes = 0;
    }
    record
      ..state = GameResourceState.disposed
      ..bytes = null
      ..inflight = null;
    return true;
  }
}