import 'dart:async';
import 'dart:convert';
import 'package:flutter/services.dart';
import 'package:get/get.dart';
import 'package:flutter/foundation.dart';
import 'package:flutter_dotenv/flutter_dotenv.dart';
import 'dart:developer' as developer;

/// 火山语音识别服务
/// 负责与原生层的火山语音识别引擎交互
class VoiceRecognitionService extends GetxService {
  // 方法通道，用于调用原生方法
  static const MethodChannel _methodChannel =
      MethodChannel('com.example.deep_voice/speech_recognition');
  
  // 事件通道，用于接收原生层的事件
  static const EventChannel _eventChannel =
      EventChannel('com.example.deep_voice/speech_recognition_events');

  // 状态变量
  final isInitialized = false.obs;
  final isListening = false.obs;
  final isConnecting = true.obs;
  
  // 识别结果
  final recognizedText = ''.obs;
  
  // 回调函数
  Function(String)? onRecognitionResult;
  Function(String)? onError;
  Function()? onRecognitionComplete;
  Function(String)? onConnectionStatusChanged;
  Function(String)? onSentenceComplete;
  
  // 事件流订阅
  StreamSubscription? _eventSubscription;
  
  // 火山语音识别的 AppKey 和 AccessKey
  late final String _appKey;
  late final String _accessKey;
  late final String _cluster;

  @override
  void onInit() {
    developer.log('VoiceRecognitionService: 初始化服务', name: 'VoiceRecognition');
    super.onInit();
    _loadCredentials();
    _setupEventListener();
  }

  /// 加载火山语音识别的凭证
  void _loadCredentials() {
    try {
      _appKey = dotenv.env['VOLC_SPEECH_APP_KEY'] ?? '';
      _accessKey = dotenv.env['VOLC_SPEECH_ACCESS_KEY'] ?? '';
      _cluster = dotenv.env['VOLC_SPEECH_CLUSTER'] ?? 'volcano_asr';
      
      developer.log('VoiceRecognitionService: 加载凭证 - AppKey: ${_appKey.isNotEmpty ? '已设置' : '未设置'}, AccessKey: ${_accessKey.isNotEmpty ? '已设置' : '未设置'}, Cluster: $_cluster', name: 'VoiceRecognition');
      
      if (_appKey.isEmpty || _accessKey.isEmpty) {
        developer.log('VoiceRecognitionService: 警告 - 火山语音识别凭证未设置，请在 .env 文件中设置 VOLC_SPEECH_APP_KEY 和 VOLC_SPEECH_ACCESS_KEY', name: 'VoiceRecognition');
      }
    } catch (e, stack) {
      developer.log('VoiceRecognitionService: 加载火山语音识别凭证失败: $e', name: 'VoiceRecognition');
      developer.log('VoiceRecognitionService: 错误堆栈: $stack', name: 'VoiceRecognition');
    }
  }

  /// 设置事件监听器
  void _setupEventListener() {
    try {
      developer.log('VoiceRecognitionService: 设置事件监听器', name: 'VoiceRecognition');
      _eventSubscription = _eventChannel.receiveBroadcastStream().listen(
        (dynamic event) {
          _handleEvent(event.toString());
        },
        onError: (dynamic error) {
          developer.log('VoiceRecognitionService: 事件通道错误: $error', name: 'VoiceRecognition');
          if (onError != null) {
            onError!('事件通道错误: $error');
          }
        },
      );
    } catch (e, stack) {
      developer.log('VoiceRecognitionService: 设置事件监听器失败: $e', name: 'VoiceRecognition');
      developer.log('VoiceRecognitionService: 错误堆栈: $stack', name: 'VoiceRecognition');
    }
  }

  /// 处理来自原生层的事件
  void _handleEvent(String eventJson) {
    try {
      developer.log('VoiceRecognitionService: 收到原始事件数据: $eventJson', name: 'VoiceRecognition');
      
      final eventData = jsonDecode(eventJson);
      final eventName = eventData['event'];
      final data = eventData['data'];
      
      developer.log('VoiceRecognitionService: 收到事件: $eventName, 数据: $data', name: 'VoiceRecognition');
      
      switch (eventName) {
        case 'status':
          _handleStatusEvent(data.toString());
          break;
        case 'result':
          _handleResultEvent(data.toString());
          break;
        case 'error':
          _handleErrorEvent(data.toString());
          break;
        case 'vad':
          _handleVadEvent(data.toString());
          break;
        default:
          developer.log('VoiceRecognitionService: 未知事件类型: $eventName', name: 'VoiceRecognition');
          break;
      }
    } catch (e, stack) {
      developer.log('VoiceRecognitionService: 处理事件失败: $e', name: 'VoiceRecognition');
      developer.log('VoiceRecognitionService: 错误堆栈: $stack', name: 'VoiceRecognition');
    }
  }

  /// 处理状态事件
  void _handleStatusEvent(String status) {
    developer.log('VoiceRecognitionService: 状态变更: $status', name: 'VoiceRecognition');
    
    switch (status) {
      case 'initialized':
        isInitialized.value = true;
        isConnecting.value = false;
        developer.log('VoiceRecognitionService: 引擎初始化完成', name: 'VoiceRecognition');
        break;
      case 'listening':
        isListening.value = true;
        developer.log('VoiceRecognitionService: 开始监听', name: 'VoiceRecognition');
        break;
      case 'idle':
        isListening.value = false;
        developer.log('VoiceRecognitionService: 停止监听', name: 'VoiceRecognition');
        break;
    }
    
    if (onConnectionStatusChanged != null) {
      onConnectionStatusChanged!(status);
    }
  }

  /// 处理识别结果事件
  void _handleResultEvent(String resultJson) {
    try {
      final resultData = jsonDecode(resultJson);
      final text = resultData['text'];
      final isFinal = resultData['isFinal'];
      
      developer.log('VoiceRecognitionService: 识别结果: $text, 是否最终结果: $isFinal', name: 'VoiceRecognition');
      
      // 更新识别文本
      recognizedText.value = text;
      
      // 调用回调函数
      if (onRecognitionResult != null) {
        onRecognitionResult!(text);
      }
      
      // 如果是最终结果，调用完成回调
      if (isFinal && text.isNotEmpty) {
        developer.log('VoiceRecognitionService: 句子识别完成: $text', name: 'VoiceRecognition');
        
        if (onSentenceComplete != null) {
          onSentenceComplete!(text);
        }
        
        if (onRecognitionComplete != null) {
          onRecognitionComplete!();
        }
      }
    } catch (e, stack) {
      developer.log('VoiceRecognitionService: 处理识别结果失败: $e', name: 'VoiceRecognition');
      developer.log('VoiceRecognitionService: 错误堆栈: $stack', name: 'VoiceRecognition');
    }
  }

  /// 处理错误事件
  void _handleErrorEvent(String errorJson) {
    try {
      final errorData = jsonDecode(errorJson);
      final errorMessage = errorData['message'];
      final errorCode = errorData['code'] ?? 'unknown';
      
      developer.log('VoiceRecognitionService: 语音识别错误: 代码=$errorCode, 消息=$errorMessage', name: 'VoiceRecognition', error: errorMessage);
      
      if (onError != null) {
        onError!(errorMessage);
      }
    } catch (e, stack) {
      developer.log('VoiceRecognitionService: 处理错误事件失败: $e', name: 'VoiceRecognition');
      developer.log('VoiceRecognitionService: 错误堆栈: $stack', name: 'VoiceRecognition');
    }
  }

  /// 处理 VAD 事件
  void _handleVadEvent(String vadState) {
    // 可以根据需要处理 VAD 状态变化
    developer.log('VoiceRecognitionService: VAD 状态: $vadState', name: 'VoiceRecognition');
  }

  /// 检查引擎能力和支持的指令
  Future<void> checkEngineCapabilities() async {
    try {
      developer.log('VoiceRecognitionService: 检查引擎能力', name: 'VoiceRecognition');
      
      // 检查是否已初始化
      if (!isInitialized.value) {
        developer.log('VoiceRecognitionService: 引擎未初始化，尝试初始化', name: 'VoiceRecognition');
        await initialize();
      }
      
      // 调用原生方法检查引擎能力
      final result = await _methodChannel.invokeMethod<String>('checkEngineCapabilities');
      developer.log('VoiceRecognitionService: 引擎能力检查结果: $result', name: 'VoiceRecognition');
      
      if (result != null) {
        try {
          final capabilities = jsonDecode(result);
          developer.log('VoiceRecognitionService: 引擎版本: ${capabilities['version']}', name: 'VoiceRecognition');
          
          if (capabilities['supported_params'] != null) {
            developer.log('VoiceRecognitionService: 支持的参数: ${capabilities['supported_params']}', name: 'VoiceRecognition');
          }
          
          if (capabilities['supported_directives'] != null) {
            developer.log('VoiceRecognitionService: 支持的指令: ${capabilities['supported_directives']}', name: 'VoiceRecognition');
          }
        } catch (e) {
          developer.log('VoiceRecognitionService: 解析能力结果失败: $e', name: 'VoiceRecognition');
        }
      }
    } catch (e, stack) {
      developer.log('VoiceRecognitionService: 检查引擎能力失败: $e', name: 'VoiceRecognition', error: e);
      developer.log('VoiceRecognitionService: 错误堆栈: $stack', name: 'VoiceRecognition');
    }
  }

  /// 初始化语音识别引擎
  Future<void> initialize() async {
    try {
      developer.log('VoiceRecognitionService: 开始初始化语音引擎', name: 'VoiceRecognition');
      isConnecting.value = true;
      
      // 检查凭证
      if (_appKey.isEmpty || _accessKey.isEmpty) {
        developer.log('VoiceRecognitionService: 凭证未设置，无法初始化', name: 'VoiceRecognition', error: '火山语音识别凭证未设置');
        throw '火山语音识别凭证未设置';
      }
      
      // 添加详细日志
      developer.log('VoiceRecognitionService: 使用凭证 AppKey: $_appKey, AccessKey: ${_accessKey.substring(0, 4)}***, Cluster: $_cluster', name: 'VoiceRecognition');
      
      // 调用原生方法初始化引擎
      try {
        final result = await _methodChannel.invokeMethod<String>(
          'initialize',
          {
            'appKey': _appKey,
            'accessKey': _accessKey,
            'cluster': _cluster,
          },
        );
        
        developer.log('VoiceRecognitionService: 初始化结果: $result', name: 'VoiceRecognition');
        
        // 初始化成功后，检查引擎能力
        await checkEngineCapabilities();
      } catch (e) {
        developer.log('VoiceRecognitionService: 初始化方法调用失败: $e', name: 'VoiceRecognition', error: e);
        
        // 尝试检查引擎是否已初始化
        try {
          final isEngineInitialized = await _methodChannel.invokeMethod<bool>('isInitialized') ?? false;
          if (isEngineInitialized) {
            developer.log('VoiceRecognitionService: 引擎已经初始化，忽略错误', name: 'VoiceRecognition');
            isInitialized.value = true;
            isConnecting.value = false;
            
            // 引擎已初始化，检查引擎能力
            await checkEngineCapabilities();
            return;
          }
        } catch (checkError) {
          developer.log('VoiceRecognitionService: 检查引擎初始化状态失败: $checkError', name: 'VoiceRecognition');
        }
        
        // 如果检查失败或引擎未初始化，则重新抛出异常
        rethrow;
      }
      
      // 初始化成功后，状态会通过事件通道更新
    } catch (e, stack) {
      isConnecting.value = false;
      developer.log('VoiceRecognitionService: 初始化语音识别引擎失败: $e', name: 'VoiceRecognition', error: e);
      developer.log('VoiceRecognitionService: 错误堆栈: $stack', name: 'VoiceRecognition');
      
      String errorMessage = '初始化失败: $e';
      
      // 提供更具体的错误信息
      if (e.toString().contains('error code: -7')) {
        errorMessage = '初始化失败: 无法创建日志目录，请检查应用权限';
        developer.log('VoiceRecognitionService: 错误代码 -7: 无法创建日志目录', name: 'VoiceRecognition');
      } else if (e.toString().contains('INIT_ERROR')) {
        errorMessage = '初始化失败: 引擎初始化错误，请检查网络连接和凭证';
        developer.log('VoiceRecognitionService: INIT_ERROR: 引擎初始化错误', name: 'VoiceRecognition');
      }
      
      if (onError != null) {
        onError!(errorMessage);
      }
      rethrow;
    }
  }

  /// 开始语音识别
  Future<void> startRecognition() async {
    try {
      developer.log('VoiceRecognitionService: 开始语音识别', name: 'VoiceRecognition');
      
      // 检查是否已初始化
      if (!isInitialized.value) {
        developer.log('VoiceRecognitionService: 引擎未初始化，尝试初始化', name: 'VoiceRecognition');
        await initialize();
      }
      
      developer.log('VoiceRecognitionService: 调用原生方法 startRecognition', name: 'VoiceRecognition');
      
      // 调用原生方法开始识别
      final result = await _methodChannel.invokeMethod<String>('startRecognition');
      developer.log('VoiceRecognitionService: 开始识别结果: $result', name: 'VoiceRecognition');
      
      // 状态会通过事件通道更新
    } catch (e, stack) {
      developer.log('VoiceRecognitionService: 开始语音识别失败: $e', name: 'VoiceRecognition', error: e);
      developer.log('VoiceRecognitionService: 错误堆栈: $stack', name: 'VoiceRecognition');
      
      if (onError != null) {
        onError!('开始识别失败: $e');
      }
      rethrow;
    }
  }

  /// 停止语音识别
  Future<void> stopRecognition() async {
    try {
      developer.log('VoiceRecognitionService: 停止语音识别', name: 'VoiceRecognition');
      
      // 检查是否已初始化
      if (!isInitialized.value) {
        developer.log('VoiceRecognitionService: 引擎未初始化，无法停止识别', name: 'VoiceRecognition');
        return;
      }
      
      developer.log('VoiceRecognitionService: 调用原生方法 stopRecognition', name: 'VoiceRecognition');
      
      // 调用原生方法停止识别
      final result = await _methodChannel.invokeMethod<String>('stopRecognition');
      developer.log('VoiceRecognitionService: 停止识别结果: $result', name: 'VoiceRecognition');
      
      // 状态会通过事件通道更新
    } catch (e, stack) {
      developer.log('VoiceRecognitionService: 停止语音识别失败: $e', name: 'VoiceRecognition', error: e);
      developer.log('VoiceRecognitionService: 错误堆栈: $stack', name: 'VoiceRecognition');
      
      if (onError != null) {
        onError!('停止识别失败: $e');
      }
    }
  }

  @override
  void onClose() {
    developer.log('VoiceRecognitionService: 关闭服务', name: 'VoiceRecognition');
    
    // 取消事件订阅
    _eventSubscription?.cancel();
    
    // 停止识别
    stopRecognition();
    
    super.onClose();
  }
}