/**
 * UniApp TTS服务类
 * 封装文字转语音功能，提供简单易用的API
 */

import { API_CONFIG, TTS_CONFIG, UTILS, ERROR_CODES, ERROR_MESSAGES } from './uniapp-tts-config.js';

class TTSService {
  constructor() {
    this.audioContext = null;
    this.isPlaying = false;
    this.isConverting = false;
    this.voiceList = [];
    this.currentAudioUrl = '';
  }

  /**
   * 初始化TTS服务
   * @param {Object} options 配置选项
   */
  async init(options = {}) {
    try {
      // 加载音色列表
      await this.loadVoiceList();
      
      // 初始化音频上下文
      this.initAudioContext();
      
      console.log('TTS服务初始化成功');
      return { success: true };
    } catch (error) {
      console.error('TTS服务初始化失败:', error);
      return { success: false, error: error.message };
    }
  }

  /**
   * 加载音色列表
   */
  async loadVoiceList() {
    try {
      // 先尝试从缓存获取
      const cached = this.getCachedVoiceList();
      if (cached) {
        this.voiceList = cached;
        return cached;
      }

      // 从服务器获取
      const response = await this.request({
        url: API_CONFIG.ENDPOINTS.VOICE_LIST,
        method: 'GET'
      });

      if (response.success && response.result) {
        this.voiceList = response.result;
        this.cacheVoiceList(this.voiceList);
        return this.voiceList;
      } else {
        throw new Error(response.message || '获取音色列表失败');
      }
    } catch (error) {
      console.error('加载音色列表失败:', error);
      throw error;
    }
  }

  /**
   * 文字转语音
   * @param {Object} params 转换参数
   * @param {string} params.text 文本内容
   * @param {number} params.speed 语速
   * @param {number} params.voiceType 音色ID
   * @param {number} params.volume 音量
   * @param {string} params.codec 音频格式
   * @param {string} params.userId 用户ID
   */
  async textToVoice(params) {
    if (this.isConverting) {
      throw new Error('正在转换中，请稍候...');
    }

    // 参数验证
    const validation = this.validateParams(params);
    if (!validation.valid) {
      throw new Error(validation.message);
    }

    this.isConverting = true;
    const startTime = Date.now();

    try {
      // 构建请求参数
      const requestParams = {
        text: params.text,
        speed: params.speed || TTS_CONFIG.SPEED.DEFAULT,
        voiceType: params.voiceType || 0,
        volume: params.volume || TTS_CONFIG.VOLUME.DEFAULT,
        codec: params.codec || TTS_CONFIG.CODEC.DEFAULT,
        userId: params.userId || this.generateUserId()
      };

      // 发起请求
      const audioData = await this.requestBinary({
        url: API_CONFIG.ENDPOINTS.TEXT_TO_VOICE,
        method: 'GET',
        data: requestParams
      });

      if (!audioData || audioData.byteLength === 0) {
        throw new Error('转换失败，未返回音频数据');
      }

      // 创建音频文件
      const audioUrl = await this.createAudioFile(audioData, requestParams.codec);
      
      // 计算转换耗时
      const convertTime = ((Date.now() - startTime) / 1000).toFixed(2);
      
      // 更新当前音频URL
      this.currentAudioUrl = audioUrl;

      return {
        success: true,
        audioUrl: audioUrl,
        audioSize: UTILS.formatFileSize(audioData.byteLength),
        convertTime: convertTime,
        params: requestParams
      };
    } catch (error) {
      console.error('文字转语音失败:', error);
      throw error;
    } finally {
      this.isConverting = false;
    }
  }

  /**
   * 播放音频
   * @param {string} audioUrl 音频文件路径（可选，默认使用最后转换的音频）
   */
  async playAudio(audioUrl) {
    const targetUrl = audioUrl || this.currentAudioUrl;
    
    if (!targetUrl) {
      throw new Error('没有可播放的音频文件');
    }

    if (this.isPlaying) {
      this.stopAudio();
    }

    return new Promise((resolve, reject) => {
      try {
        this.initAudioContext();
        this.audioContext.src = targetUrl;
        this.isPlaying = true;

        this.audioContext.onPlay(() => {
          console.log('音频开始播放');
          resolve({ success: true, action: 'play_started' });
        });

        this.audioContext.onEnded(() => {
          console.log('音频播放结束');
          this.isPlaying = false;
        });

        this.audioContext.onError((error) => {
          console.error('音频播放失败:', error);
          this.isPlaying = false;
          reject(new Error('音频播放失败'));
        });

        this.audioContext.play();
      } catch (error) {
        this.isPlaying = false;
        reject(error);
      }
    });
  }

  /**
   * 停止音频播放
   */
  stopAudio() {
    if (this.audioContext && this.isPlaying) {
      this.audioContext.stop();
      this.isPlaying = false;
      console.log('音频播放已停止');
    }
  }

  /**
   * 暂停音频播放
   */
  pauseAudio() {
    if (this.audioContext && this.isPlaying) {
      this.audioContext.pause();
      console.log('音频播放已暂停');
    }
  }

  /**
   * 获取音色列表
   */
  getVoiceList() {
    return this.voiceList;
  }

  /**
   * 根据ID获取音色信息
   * @param {number} voiceId 音色ID
   */
  getVoiceById(voiceId) {
    return this.voiceList.find(voice => voice.id === voiceId);
  }

  /**
   * 获取当前播放状态
   */
  getPlayStatus() {
    return {
      isPlaying: this.isPlaying,
      isConverting: this.isConverting,
      currentAudioUrl: this.currentAudioUrl
    };
  }

  /**
   * 清理资源
   */
  destroy() {
    if (this.audioContext) {
      this.audioContext.destroy();
      this.audioContext = null;
    }
    this.isPlaying = false;
    this.isConverting = false;
    this.currentAudioUrl = '';
    console.log('TTS服务已销毁');
  }

  // ==================== 私有方法 ====================

  /**
   * 初始化音频上下文
   */
  initAudioContext() {
    if (this.audioContext) {
      this.audioContext.destroy();
    }
    
    // #ifdef MP-WEIXIN
    this.audioContext = wx.createInnerAudioContext();
    // #endif
    
    // #ifdef H5
    this.audioContext = uni.createInnerAudioContext();
    // #endif
  }

  /**
   * 参数验证
   */
  validateParams(params) {
    if (!params || typeof params !== 'object') {
      return { valid: false, message: '参数格式错误' };
    }

    // 验证文本
    const textValidation = UTILS.validateText(params.text);
    if (!textValidation.valid) {
      return textValidation;
    }

    // 验证语速
    if (params.speed !== undefined) {
      const speedValidation = UTILS.validateSpeed(params.speed);
      if (!speedValidation.valid) {
        return speedValidation;
      }
    }

    // 验证音量
    if (params.volume !== undefined) {
      const volumeValidation = UTILS.validateVolume(params.volume);
      if (!volumeValidation.valid) {
        return volumeValidation;
      }
    }

    return { valid: true };
  }

  /**
   * 创建音频文件
   */
  async createAudioFile(arrayBuffer, codec) {
    return new Promise((resolve, reject) => {
      const fileName = `tts_${Date.now()}.${codec}`;
      
      // #ifdef MP-WEIXIN
      const filePath = `${wx.env.USER_DATA_PATH}/${fileName}`;
      wx.getFileSystemManager().writeFile({
        filePath: filePath,
        data: arrayBuffer,
        success: () => resolve(filePath),
        fail: (error) => reject(new Error('创建音频文件失败: ' + error.errMsg))
      });
      // #endif
      
      // #ifdef H5
      // H5环境下创建Blob URL
      const blob = new Blob([arrayBuffer], { type: `audio/${codec}` });
      const url = URL.createObjectURL(blob);
      resolve(url);
      // #endif
    });
  }

  /**
   * 生成用户ID
   */
  generateUserId() {
    // 尝试从存储获取用户ID
    let userId = uni.getStorageSync('tts_user_id');
    if (!userId) {
      userId = 'user_' + Date.now() + '_' + Math.random().toString(36).substr(2, 9);
      uni.setStorageSync('tts_user_id', userId);
    }
    return userId;
  }

  /**
   * 缓存音色列表
   */
  cacheVoiceList(voiceList) {
    const cacheData = {
      data: voiceList,
      timestamp: Date.now()
    };
    uni.setStorageSync('tts_voice_cache', cacheData);
  }

  /**
   * 获取缓存的音色列表
   */
  getCachedVoiceList() {
    try {
      const cached = uni.getStorageSync('tts_voice_cache');
      if (cached && cached.data) {
        // 检查缓存是否过期（24小时）
        const expireTime = 24 * 60 * 60 * 1000;
        if (Date.now() - cached.timestamp < expireTime) {
          return cached.data;
        }
      }
    } catch (error) {
      console.error('获取缓存失败:', error);
    }
    return null;
  }

  /**
   * 通用请求方法
   */
  request(options) {
    return new Promise((resolve, reject) => {
      uni.request({
        url: UTILS.buildApiUrl(options.url),
        method: options.method || 'GET',
        data: options.data || {},
        timeout: API_CONFIG.TIMEOUT,
        header: {
          'Content-Type': 'application/json',
          // 如果需要token认证，在这里添加
          // 'Authorization': 'Bearer ' + uni.getStorageSync('token')
        },
        success: (res) => {
          if (res.statusCode === 200) {
            resolve(res.data);
          } else {
            reject(new Error(`HTTP ${res.statusCode}: ${res.data?.message || '请求失败'}`));
          }
        },
        fail: (error) => {
          reject(new Error(ERROR_MESSAGES[ERROR_CODES.NETWORK_ERROR] || error.errMsg));
        }
      });
    });
  }

  /**
   * 二进制数据请求方法
   */
  requestBinary(options) {
    return new Promise((resolve, reject) => {
      uni.request({
        url: UTILS.buildApiUrl(options.url),
        method: options.method || 'GET',
        data: options.data || {},
        responseType: 'arraybuffer',
        timeout: API_CONFIG.TIMEOUT,
        header: {
          // 如果需要token认证，在这里添加
          // 'Authorization': 'Bearer ' + uni.getStorageSync('token')
        },
        success: (res) => {
          if (res.statusCode === 200) {
            resolve(res.data);
          } else {
            reject(new Error(`HTTP ${res.statusCode}: 请求失败`));
          }
        },
        fail: (error) => {
          reject(new Error(ERROR_MESSAGES[ERROR_CODES.NETWORK_ERROR] || error.errMsg));
        }
      });
    });
  }
}

// 创建单例实例
const ttsService = new TTSService();

// 导出服务实例和类
export { TTSService, ttsService };
export default ttsService;