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';

/// 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;
  String _systemPrompt = '';
  
  // 添加一个标志，表示是否正在处理交互
  bool _isHandlingInteraction = false;

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

  MyAudioHandler() {
    _initializeHandler();
    _initializeBackgroundAgent();
    _initializeSystemPrompt();
    print('MyAudioHandler 已创建，准备接收媒体按钮事件');
  }

  void _initializeSystemPrompt() {
    try {
      final agent = AgentProvider.getAgentById('personal_assistant');
      _systemPrompt = agent?.systemPrompt ?? '';
    } catch (e) {
      print('初始化 SystemPrompt 失败: $e');
      _systemPrompt = '';
    }
  }

  void _initializeBackgroundAgent() {
    try {
      if (Get.isRegistered<BackgroundAgentService>()) {
        _backgroundAgent = Get.find<BackgroundAgentService>();
      } else {
        _backgroundAgent = Get.put(BackgroundAgentService(), permanent: true);
      }
      print('BackgroundAgent 初始化成功');
    } catch (e) {
      print('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);
      print('AudioHandler 媒体项已设置');
    } catch (e) {
      print('初始化 AudioHandler 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) {
      print('更新播放状态失败: $e');
    }
  }

  Future<void> _handleInteraction() async {
    print('处理媒体按钮交互');
    
    // 防止重复处理
    if (_isHandlingInteraction) {
      print('已经在处理交互，忽略此次请求');
      return;
    }
    
    _isHandlingInteraction = true;
    
    try {
      if (_systemPrompt.isEmpty) {
        print('系统提示为空，无法激活语音助手');
        return;
      }

      if (Get.context != null &&
          WidgetsBinding.instance.lifecycleState == AppLifecycleState.resumed) {
        // 应用在前台，导航到聊天页面
        print('应用在前台，导航到聊天页面');
        final agent = AgentProvider.getAgentById('personal_assistant');
        if (agent != null) {
          // 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,
            '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
        print('应用在后台，使用 BackgroundAgent 处理交互');
        if (_backgroundAgent != null) {
          // 调用 BackgroundAgent 的语音识别和 AI 交互功能
          await _backgroundAgent!.handleAgentInteraction(_systemPrompt);
        } else {
          print('BackgroundAgent 未初始化，无法处理交互');
        }
      }
    } catch (e) {
      print('处理媒体按钮交互失败: $e');
    } finally {
      _isHandlingInteraction = false;
    }
  }

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

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

  @override
  Future<void> stop() async {
    print('停止 AudioHandler');
    _isDisposed = true;
    try {
      await super.stop();
      _customEventController.close();
      _updatePlaybackState(
        playing: false,
        processingState: AudioProcessingState.idle,
      );
    } catch (e) {
      print('停止 AudioHandler 时发生错误: $e');
    }
  }

  @override
  Future<void> skipToPrevious() async {
    print('收到上一曲命令');
    try {
      await _handleInteraction();
    } catch (e) {
      print('处理上一曲命令失败: $e');
    }
  }

  @override
  Future<void> skipToNext() async {
    print('收到下一曲命令');
    try {
      await _handleInteraction();
    } catch (e) {
      print('处理下一曲命令失败: $e');
    }
  }

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

  @override
  Future<dynamic> customAction(String name,
      [Map<String, dynamic>? extras]) async {
    print('收到自定义命令: $name');
    try {
      if (name == 'media_button') {
        print('收到媒体按钮事件');
        await _handleInteraction();
      }
    } catch (e) {
      print('处理自定义命令失败: $e');
    }
    return null;
  }

  @override
  Future<void> onTaskRemoved() async {
    print('服务被系统移除');
    try {
      await stop();
    } catch (e) {
      print('处理服务移除失败: $e');
    }
  }

  @override
  Future<void> onNotificationDeleted() async {
    print('通知被用户移除');
    try {
      await stop();
    } catch (e) {
      print('处理通知移除失败: $e');
    }
  }
}