import 'dart:async';
import 'dart:io';
import 'package:flutter/services.dart';
import 'package:get/get.dart';
import '../../core/utils/logger.dart';
import 'package:flutter_dotenv/flutter_dotenv.dart';
import 'package:path_provider/path_provider.dart';

/// 语音合成事件类型
enum SynthesisEventType {
  /// 合成开始
  synthesisStarted,
  
  /// 合成进度更新
  synthesisProgress,
  
  /// 合成完成
  synthesisCompleted,
  
  /// 合成取消
  synthesisCanceled,
  
  /// 合成错误
  error,
}

/// 语音合成事件
class SynthesisEvent {
  /// 事件类型
  final SynthesisEventType type;
  
  /// 音频文件路径（仅在 synthesisCompleted 类型中有效）
  final String? audioFilePath;
  
  /// 进度百分比（仅在 synthesisProgress 类型中有效）
  final int? progressPercent;
  
  /// 错误信息（仅在 error 和 synthesisCanceled 类型中有效）
  final String? error;
  
  /// 取消原因（仅在 synthesisCanceled 类型中有效）
  final String? reason;
  
  /// 错误详情（仅在 synthesisCanceled 类型中有效）
  final String? errorDetails;
  
  SynthesisEvent({
    required this.type,
    this.audioFilePath,
    this.progressPercent,
    this.error,
    this.reason,
    this.errorDetails,
  });
  
  /// 从原生事件映射创建合成事件
  factory SynthesisEvent.fromMap(Map<dynamic, dynamic> map) {
    final eventType = map['eventType'] as String;
    
    SynthesisEventType type;
    switch (eventType) {
      case 'synthesisStarted':
        type = SynthesisEventType.synthesisStarted;
        break;
      case 'synthesisProgress':
        type = SynthesisEventType.synthesisProgress;
        break;
      case 'synthesisCompleted':
        type = SynthesisEventType.synthesisCompleted;
        break;
      case 'synthesisCanceled':
        type = SynthesisEventType.synthesisCanceled;
        break;
      case 'error':
        type = SynthesisEventType.error;
        break;
      default:
        throw ArgumentError('未知事件类型: $eventType');
    }
    
    return SynthesisEvent(
      type: type,
      audioFilePath: map['audioFilePath'] as String?,
      progressPercent: map['progressPercent'] as int?,
      error: map['error'] as String?,
      reason: map['reason'] as String?,
      errorDetails: map['errorDetails'] as String?,
    );
  }
  
  @override
  String toString() {
    return 'SynthesisEvent{type: $type, audioFilePath: $audioFilePath, progressPercent: $progressPercent, error: $error, reason: $reason, errorDetails: $errorDetails}';
  }
}

/// TTS 状态
enum TtsState {
  /// 空闲
  idle,
  
  /// 合成中
  synthesizing,
  
  /// 播放中
  playing,
  
  /// 已停止
  stopped,
}

/// Azure 文本转语音服务
class AzureTtsService extends GetxService {
  static AzureTtsService get to => Get.find();
  
  // 方法通道
  static const MethodChannel _methodChannel = MethodChannel('com.example.deep_voice/azure_tts');
  
  // 事件通道
  static const EventChannel _eventChannel = EventChannel('com.example.deep_voice/azure_tts_events');
  
  // 是否已初始化
  bool _isInitialized = false;
  bool get isInitialized => _isInitialized;
  
  // 当前TTS状态
  final Rx<TtsState> _ttsState = TtsState.idle.obs;
  TtsState get ttsState => _ttsState.value;
  
  // 合成相关
  StreamController<SynthesisEvent>? _eventStreamController;
  StreamSubscription? _eventSubscription;
  
  // 公开的事件流
  Stream<SynthesisEvent>? _synthesisStream;
  Stream<SynthesisEvent>? get synthesisStream => _synthesisStream;
  
  // 当前语音名称
  String _currentVoice = 'zh-CN-XiaoxiaoNeural';
  String get currentVoice => _currentVoice;
  set currentVoice(String voice) {
    _currentVoice = voice;
    _setVoice(voice);
  }
  
  // 语速 (-100 to 100)
  int _rate = 0;
  int get rate => _rate;
  set rate(int value) {
    if (value < -100 || value > 100) {
      throw ArgumentError('语速必须在 -100 到 100 之间');
    }
    _rate = value;
    _setSpeechRate(value);
  }
  
  // 音调 (-100 to 100)
  int _pitch = 0;
  int get pitch => _pitch;
  set pitch(int value) {
    if (value < -100 || value > 100) {
      throw ArgumentError('音调必须在 -100 到 100 之间');
    }
    _pitch = value;
    _setPitch(value);
  }
  
  // 音量 (0 to 100)
  int _volume = 100;
  int get volume => _volume;
  set volume(int value) {
    if (value < 0 || value > 100) {
      throw ArgumentError('音量必须在 0 到 100 之间');
    }
    _volume = value;
    _setVolume(value);
  }
  
  // 可用的语音列表
  final RxList<Map<String, String>> _voices = <Map<String, String>>[].obs;
  List<Map<String, String>> get voices => _voices;
  
  /// 初始化 Azure 文本转语音服务
  /// 
  /// [subscriptionKey] Azure 语音服务的订阅密钥
  /// [serviceRegion] Azure 语音服务的区域
  /// [defaultVoice] 默认语音名称，默认为中文女声
  Future<bool> initialize({
    String? subscriptionKey,
    String? serviceRegion,
    String? defaultVoice,
  }) async {
    if (_isInitialized) return true;
    
    try {
      // 从环境变量中读取配置，如果没有传入参数
      final key = subscriptionKey ?? dotenv.env['AZURE_TTS_SUBSCRIPTION_KEY'] ?? '';
      final region = serviceRegion ?? dotenv.env['AZURE_TTS_SERVICE_REGION'] ?? 'eastasia';
      final voice = defaultVoice ?? dotenv.env['AZURE_TTS_DEFAULT_VOICE'] ?? 'zh-CN-XiaoxiaoNeural';
      
      // 检查配置是否完整
      if (key.isEmpty) {
        Logger.warning('Azure 文本转语音服务的订阅密钥未设置，请检查 .env 文件');
        return false;
      }
      
      // 设置事件监听
      _setupEventChannel();
      
      final result = await _methodChannel.invokeMethod<bool>(
        'initialize',
        {
          'subscriptionKey': key,
          'serviceRegion': region,
          'defaultVoice': voice,
        },
      );
      
      _isInitialized = result ?? false;
      
      if (_isInitialized) {
        Logger.info('Azure 文本转语音服务初始化成功');
        _currentVoice = voice;
        
        // 获取可用语音列表
        await getAvailableVoices();
      } else {
        Logger.error('Azure 文本转语音服务初始化失败');
      }
      
      return _isInitialized;
    } catch (e) {
      Logger.error('初始化 Azure 文本转语音服务失败', e);
      _isInitialized = false;
      return false;
    }
  }
  
  /// 设置事件通道监听
  void _setupEventChannel() {
    // 创建事件流控制器
    _eventStreamController = StreamController<SynthesisEvent>.broadcast();
    
    // 设置事件监听
    _eventSubscription = _eventChannel
        .receiveBroadcastStream()
        .map<SynthesisEvent>((dynamic event) => SynthesisEvent.fromMap(event))
        .listen(
          (event) {
            _handleSynthesisEvent(event);
            _eventStreamController?.add(event);
          },
          onError: (error) {
            Logger.error('Azure 文本转语音事件流错误', error);
            _eventStreamController?.addError(error);
          },
        );
    
    // 设置公开的流
    _synthesisStream = _eventStreamController?.stream;
  }
  
  /// 处理合成事件
  void _handleSynthesisEvent(SynthesisEvent event) {
    switch (event.type) {
      case SynthesisEventType.synthesisStarted:
        _ttsState.value = TtsState.synthesizing;
        break;
      case SynthesisEventType.synthesisCompleted:
        _ttsState.value = TtsState.idle;
        break;
      case SynthesisEventType.synthesisCanceled:
      case SynthesisEventType.error:
        _ttsState.value = TtsState.idle;
        break;
      default:
        // 其他事件类型不需要特殊处理
        break;
    }
  }
  
  /// 获取可用的语音列表
  Future<List<Map<String, String>>> getAvailableVoices() async {
    _checkInitialized();
    
    try {
      final result = await _methodChannel.invokeMethod<List<dynamic>>('getAvailableVoices');
      
      if (result != null) {
        final voicesList = result.map((item) {
          final map = Map<String, dynamic>.from(item as Map);
          return {
            'name': map['name'] as String,
            'locale': map['locale'] as String,
            'gender': map['gender'] as String,
            'displayName': map['displayName'] as String,
          };
        }).toList();
        
        _voices.value = List<Map<String, String>>.from(voicesList);
        return _voices;
      }
      
      return [];
    } catch (e) {
      Logger.error('获取可用语音列表失败', e);
      return [];
    }
  }
  
  /// 设置语音
  Future<bool> _setVoice(String voiceName) async {
    _checkInitialized();
    
    try {
      final result = await _methodChannel.invokeMethod<bool>(
        'setVoice',
        {'voiceName': voiceName},
      );
      return result ?? false;
    } catch (e) {
      Logger.error('设置语音失败', e);
      return false;
    }
  }
  
  /// 设置语速
  Future<bool> _setSpeechRate(int rate) async {
    _checkInitialized();
    
    try {
      final result = await _methodChannel.invokeMethod<bool>(
        'setSpeechRate',
        {'rate': rate},
      );
      return result ?? false;
    } catch (e) {
      Logger.error('设置语速失败', e);
      return false;
    }
  }
  
  /// 设置音调
  Future<bool> _setPitch(int pitch) async {
    _checkInitialized();
    
    try {
      final result = await _methodChannel.invokeMethod<bool>(
        'setPitch',
        {'pitch': pitch},
      );
      return result ?? false;
    } catch (e) {
      Logger.error('设置音调失败', e);
      return false;
    }
  }
  
  /// 设置音量
  Future<bool> _setVolume(int volume) async {
    _checkInitialized();
    
    try {
      final result = await _methodChannel.invokeMethod<bool>(
        'setVolume',
        {'volume': volume},
      );
      return result ?? false;
    } catch (e) {
      Logger.error('设置音量失败', e);
      return false;
    }
  }
  
  /// 合成文本为语音并保存到文件
  /// 
  /// [text] 要合成的文本
  /// [fileName] 保存的文件名（不包含路径和扩展名）
  /// 
  /// 返回保存的音频文件路径，如果失败则返回 null
  Future<String?> synthesizeToFile(String text, String fileName) async {
    _checkInitialized();
    
    if (text.isEmpty) {
      Logger.warning('合成文本为空');
      return null;
    }
    
    try {
      // 获取临时目录
      final tempDir = await getTemporaryDirectory();
      final filePath = '${tempDir.path}/$fileName.wav';
      
      // 设置状态
      _ttsState.value = TtsState.synthesizing;
      
      final result = await _methodChannel.invokeMethod<String>(
        'synthesizeToFile',
        {
          'text': text,
          'filePath': filePath,
        },
      );
      
      // 合成完成后设置状态
      _ttsState.value = TtsState.idle;
      
      return result;
    } catch (e) {
      Logger.error('合成文本到文件失败', e);
      
      // 发生错误时设置状态
      _ttsState.value = TtsState.idle;
      
      return null;
    }
  }
  
  /// 合成文本并直接播放
  /// 
  /// [text] 要合成并播放的文本
  /// 
  /// 返回是否成功开始播放
  Future<bool> speak(String text) async {
    _checkInitialized();
    
    if (text.isEmpty) {
      Logger.warning('播放文本为空');
      return false;
    }
    
    try {
      // 设置状态
      _ttsState.value = TtsState.synthesizing;
      
      final result = await _methodChannel.invokeMethod<bool>(
        'speak',
        {'text': text},
      );
      
      if (result == true) {
        _ttsState.value = TtsState.playing;
      } else {
        _ttsState.value = TtsState.idle;
      }
      
      return result ?? false;
    } catch (e) {
      Logger.error('合成并播放文本失败', e);
      
      // 发生错误时设置状态
      _ttsState.value = TtsState.idle;
      
      return false;
    }
  }
  
  /// 停止播放
  Future<bool> stop() async {
    _checkInitialized();
    
    try {
      final result = await _methodChannel.invokeMethod<bool>('stop');
      
      if (result == true) {
        _ttsState.value = TtsState.stopped;
      }
      
      return result ?? false;
    } catch (e) {
      Logger.error('停止播放失败', e);
      return false;
    }
  }
  
  /// 暂停播放
  Future<bool> pause() async {
    _checkInitialized();
    
    try {
      final result = await _methodChannel.invokeMethod<bool>('pause');
      return result ?? false;
    } catch (e) {
      Logger.error('暂停播放失败', e);
      return false;
    }
  }
  
  /// 恢复播放
  Future<bool> resume() async {
    _checkInitialized();
    
    try {
      final result = await _methodChannel.invokeMethod<bool>('resume');
      return result ?? false;
    } catch (e) {
      Logger.error('恢复播放失败', e);
      return false;
    }
  }
  
  /// 检查是否已初始化
  void _checkInitialized() {
    if (!_isInitialized) {
      throw StateError('Azure 文本转语音服务未初始化');
    }
  }
  
  /// 释放资源
  Future<void> dispose() async {
    try {
      await _eventSubscription?.cancel();
      _eventSubscription = null;
      
      // 只有在控制器存在且未关闭时才关闭
      if (_eventStreamController != null && !_eventStreamController!.isClosed) {
        await _eventStreamController?.close();
      }
      _eventStreamController = null;
      
      _synthesisStream = null;
      
      if (_isInitialized) {
        await _methodChannel.invokeMethod<bool>('dispose');
      }
      
      _isInitialized = false;
      Logger.info('Azure 文本转语音服务资源已释放');
    } catch (e) {
      Logger.error('释放 Azure 文本转语音服务资源失败', e);
    }
  }
  
  @override
  void onClose() {
    dispose();
    super.onClose();
  }
}