let instance = null;

class AudioManager {
  constructor() {
    if (instance) {
      return instance;
    }
    
    this.audioContext = null;
    this.isPlaying = false;
    this.userDisabled = false;
    this.initialized = false;
    
    try {
      const musicState = uni.getStorageSync('musicState') || {};
      this.userDisabled = musicState.userDisabled === true;
    } catch (e) {
      console.error('读取音乐状态失败:', e);
    }
    
    instance = this;
  }
  
  init() {
    if (this.initialized) return this;
    
    this.audioContext = uni.createInnerAudioContext();
    this.audioContext.src = 'https://des.dayunyuanjian.cn/epicSoul/taozi/bg.m4a';
    this.audioContext.loop = true;
    
    this.audioContext.onPlay(() => {
      this.isPlaying = true;
      this._notifyStateChange();
    });
    
    this.audioContext.onPause(() => {
      this.isPlaying = false;
      this._notifyStateChange();
    });
    
    this.audioContext.onStop(() => {
      this.isPlaying = false;
      this._notifyStateChange();
    });
    
    this.audioContext.onError((res) => {
      this.isPlaying = false;
      this._notifyStateChange();
    });
    
    this.initialized = true;
    return this;
  }
  
  play() {
    if (this.userDisabled) return;
    
    this.init();
    if (!this.isPlaying) {
      this.audioContext.play();
    }
  }
  
  pause() {
    if (!this.initialized || !this.isPlaying) return;

    this.audioContext.pause();
  }
  
  togglePlay() {
    this.init();
    
    if (this.isPlaying) {
      this.pause();
      this.userDisabled = true;
    } else {
      this.userDisabled = false;
      this.play();
    }

    try {
      uni.setStorageSync('musicState', {
        userDisabled: this.userDisabled
      });
    } catch (e) {
      console.error('保存音乐状态失败:', e);
    }
    
    return this.isPlaying;
  }
  
  _notifyStateChange() {
    uni.$emit('audioStateChanged', {
      isPlaying: this.isPlaying,
      userDisabled: this.userDisabled
    });
  }
  
  getPlayingStatus() {
    return this.isPlaying;
  }
  
  getUserDisabled() {
    return this.userDisabled;
  }
}

export default new AudioManager();