import 'dart:async';
import 'package:audio_service/audio_service.dart';
import 'package:get/get.dart';
import 'package:flutter/services.dart';
import 'package:flutter/widgets.dart';
import 'background_agent_service.dart';
import '../../data/providers/agent_provider.dart';
import '../../core/utils/logger.dart';

/// 自定义 AudioHandler，用于捕获媒体按键事件（例如蓝牙耳机按钮）
class MyAudioHandler extends BaseAudioHandler {
  // 定义一个 StreamController 用于向 UI 发送自定义事件
  final StreamController<dynamic> _customEventController =
      StreamController.broadcast();
  bool _isDisposed = false;
  BackgroundAgentService? _backgroundAgent;
  
  // 添加一个标志，表示是否正在处理交互
  bool _isHandlingInteraction = false;
  
  // 添加一个计时器，用于定期更新播放状态
  Timer? _statusUpdateTimer;
  
  // 添加一个变量，记录最后一次媒体按钮事件的时间
  DateTime? _lastMediaButtonEventTime;

  Stream<dynamic> get customEventStream => _customEventController.stream;

  MyAudioHandler() {
    _initializeHandler();
    _initializeBackgroundAgent();
    _startStatusUpdateTimer();
    Logger.info('MyAudioHandler 已创建，准备接收媒体按钮事件');
  }

  void _initializeBackgroundAgent() {
    try {
      if (Get.isRegistered<BackgroundAgentService>()) {
        _backgroundAgent = Get.find<BackgroundAgentService>();
        Logger.info('BackgroundAgent 初始化成功');
      } else {
        _backgroundAgent = Get.put(BackgroundAgentService(), permanent: true);
        Logger.info('BackgroundAgent 已创建并初始化成功');
      }
    } catch (e) {
      Logger.error('初始化 BackgroundAgent 失败', e);
      _backgroundAgent = null;
    }
  }

  void _initializeHandler() {
    try {
      // 设置初始播放状态
      playbackState.add(PlaybackState(
        controls: [
          MediaControl.play,
          MediaControl.pause,
          MediaControl.stop,
          MediaControl.skipToPrevious,
          MediaControl.skipToNext,
        ],
        systemActions: {
          MediaAction.play,
          MediaAction.pause,
          MediaAction.stop,
          MediaAction.skipToPrevious,
          MediaAction.skipToNext,
          MediaAction.seek,
        },
        androidCompactActionIndices: const [0, 1, 2],
        processingState: AudioProcessingState.idle,
        playing: false,
      ));

      // 设置媒体元数据
      final item = MediaItem(
        id: 'deep_voice_audio',
        title: 'Deep Voice Audio',
        album: 'Deep Voice',
        artist: 'Deep Voice',
        genre: 'Speech',
        duration: const Duration(seconds: 1),
        artUri: null, // 移除图片URI
        playable: true,
        displayTitle: 'Deep Voice Audio',
        displaySubtitle: 'Voice Assistant',
        displayDescription: 'TTS Audio',
        extras: const {'source': 'deep_voice'},
      );

      mediaItem.add(item);
      Logger.info('AudioHandler 媒体项已设置');
      
      // 立即更新播放状态，确保通知显示
      _updatePlaybackState(
        playing: true,
        processingState: AudioProcessingState.ready,
      );
    } catch (e) {
      Logger.error('初始化 AudioHandler 失败', e);
    }
  }
  
  // 启动定期更新播放状态的计时器
  void _startStatusUpdateTimer() {
    _statusUpdateTimer?.cancel();
    _statusUpdateTimer = Timer.periodic(Duration(minutes: 5), (timer) {
      try {
        // 定期更新播放状态，确保服务保持活跃
        _updatePlaybackState(
          playing: true,
          processingState: AudioProcessingState.ready,
        );
        Logger.info('定期更新播放状态成功');
      } catch (e) {
        Logger.error('定期更新播放状态失败', e);
      }
    });
  }

  // 更新播放状态
  void _updatePlaybackState({
    required bool playing,
    required AudioProcessingState processingState,
  }) {
    if (_isDisposed) return;

    try {
      playbackState.add(playbackState.value.copyWith(
        playing: playing,
        processingState: processingState,
        updatePosition: Duration.zero,
      ));
      

    } catch (e) {
      Logger.error('更新播放状态失败', e);
    }
  }

  Future<void> _handleInteraction() async {
    // Logger.info('处理媒体按钮交互');
    
    // 防止重复处理
    if (_isHandlingInteraction) {
      Logger.info('已经在处理交互，忽略此次请求');
      return;
    }
    
    _isHandlingInteraction = true;
    
    try {
      // 更新播放状态，确保通知显示
      _updatePlaybackState(
        playing: true,
        processingState: AudioProcessingState.ready,
      );
      
      // 直接获取 personal_assistant agent
      final agent = AgentProvider.getAgentById('personal_assistant');
      if (agent == null) {
        Logger.error('无法获取personal_assistant agent，无法激活语音助手');
        _isHandlingInteraction = false;
        return;
      }

      // 检查app是否在前台
      final isInForeground = Get.context != null &&
          WidgetsBinding.instance.lifecycleState == AppLifecycleState.resumed;
      
      if (isInForeground) {
        // 应用在前台，导航到聊天页面
        Logger.info('应用在前台，导航到聊天页面');
        
        // 如果BackgroundAgent正在运行，先停止它
        if (_backgroundAgent != null && _backgroundAgent!.isProcessing.value) {
          await _backgroundAgent!.stopInteraction();
          Logger.info('已停止后台代理服务，切换到前台模式');
        }
        
        // 导航到聊天页面，并标记需要在进入时播放语音应答
        Get.toNamed('/chat', arguments: {
          'agentId': agent.id,
          'agentName': agent.name,
          'agentVoice': agent.voice,
          'agentAvatar': agent.avatarUrl,
          'agentSubtitle': agent.description,
          'systemPrompt': agent.systemPrompt,
          'welcomeMessage': agent.welcomeMessage,
          'playVoiceOnEnter': true,
        });
      } else {
        // 应用在后台，使用 BackgroundAgent 处理交互
        Logger.info('应用在后台，使用 BackgroundAgent 处理交互');
        if (_backgroundAgent != null) {

          if (_backgroundAgent!.isProcessing.value) {
            // 如果后台服务已在处理，则中断当前响应并回复"我在听"
            Logger.info('检测到媒体按钮再次按下，中断当前AI回复');
            await _backgroundAgent!.respondToNewMediaEvent();
          } else {
            // 首次启动后台服务
            Logger.info('首次启动后台服务');
            await _backgroundAgent!.startAgentInteraction(agent.id);
          }
        } else {
          Logger.error('BackgroundAgent 未初始化，无法处理交互');
          // 尝试重新初始化 BackgroundAgent
          _initializeBackgroundAgent();
        }
      }
    } catch (e) {
      Logger.error('处理媒体按钮交互失败', e);
    } finally {
      _isHandlingInteraction = false;
    }
  }

  @override
  Future<void> play() async {
    Logger.info('收到播放命令');
    try {
      _updatePlaybackState(
        playing: true,
        processingState: AudioProcessingState.ready,
      );
      await _handleInteraction();
    } catch (e) {
      Logger.error('处理播放命令失败', e);
    }
  }

  @override
  Future<void> pause() async {
    Logger.info('收到暂停命令');
    try {
      _updatePlaybackState(
        playing: false,
        processingState: AudioProcessingState.ready,
      );
      await _handleInteraction();
    } catch (e) {
      Logger.error('处理暂停命令失败', e);
    }
  }

  @override
  Future<void> stop() async {
    Logger.info('停止 AudioHandler');
    _isDisposed = true;
    try {
      _statusUpdateTimer?.cancel();
      
      // 如果有正在运行的后台服务，停止它
      if (_backgroundAgent != null && _backgroundAgent!.isProcessing.value) {
        await _backgroundAgent!.stopInteraction();
      }
      
      await super.stop();
      _customEventController.close();
      _updatePlaybackState(
        playing: false,
        processingState: AudioProcessingState.idle,
      );
    } catch (e) {
      Logger.error('停止 AudioHandler 时发生错误', e);
    }
  }

  @override
  Future<void> skipToPrevious() async {
    Logger.info('收到上一曲命令');
    try {
      _updatePlaybackState(
        playing: true,
        processingState: AudioProcessingState.ready,
      );
      await _handleInteraction();
    } catch (e) {
      Logger.error('处理上一曲命令失败', e);
    }
  }

  @override
  Future<void> skipToNext() async {
    Logger.info('收到下一曲命令');
    try {
      _updatePlaybackState(
        playing: true,
        processingState: AudioProcessingState.ready,
      );
      await _handleInteraction();
    } catch (e) {
      Logger.error('处理下一曲命令失败', e);
    }
  }

  @override
  Future<void> seek(Duration position) async {
    Logger.info('收到跳转命令: $position');
  }

  @override
  Future<dynamic> customAction(String name,
      [Map<String, dynamic>? extras]) async {
    Logger.info('收到自定义命令: $name');
    try {
      if (name == 'media_button') {
        Logger.info('收到媒体按钮事件');
        
        // 检查是否是重复触发（防止短时间内多次触发）
        final now = DateTime.now();
        if (_lastMediaButtonEventTime != null) {
          final difference = now.difference(_lastMediaButtonEventTime!);
          if (difference.inMilliseconds < 500) {
            Logger.info('媒体按钮事件触发过于频繁，忽略此次事件');
            return;
          }
        }
        
        // 更新最后一次事件时间
        _lastMediaButtonEventTime = now;
        
        _updatePlaybackState(
          playing: true,
          processingState: AudioProcessingState.ready,
        );
        await _handleInteraction();
      } else if (name == 'ping') {
        // 用于检查服务是否响应的测试命令
        Logger.info('收到 ping 命令，服务正常运行');
        return 'pong';
      }
    } catch (e) {
      Logger.error('处理自定义命令失败', e);
    }
  }

  @override
  Future<void> onTaskRemoved() async {
    Logger.info('服务被系统移除');
    try {
      // 如果有正在运行的后台服务，停止它
      if (_backgroundAgent != null && _backgroundAgent!.isProcessing.value) {
        await _backgroundAgent!.stopInteraction();
      }
      
      await stop();
    } catch (e) {
      Logger.error('处理服务移除失败', e);
    }
  }

  @override
  Future<void> onNotificationDeleted() async {
    Logger.info('通知被用户移除');
    try {
      // 如果有正在运行的后台服务，停止它
      if (_backgroundAgent != null && _backgroundAgent!.isProcessing.value) {
        await _backgroundAgent!.stopInteraction();
      }
      
      await stop();
    } catch (e) {
      Logger.error('处理通知移除失败', e);
    }
  }
}