deepvoice_client/lib/modules/chat/controllers/chat_controller.dart

import 'package:get/get.dart';
import 'package:flutter/material.dart';
import 'package:get_storage/get_storage.dart';
import 'dart:convert';
import 'package:flutter/rendering.dart';
import '../../../data/services/volcano_ai_service.dart';
import '../../../data/services/volcano_tts_api_service.dart';
import '../models/message_model.dart';
import '../controllers/voice_input_controller.dart';
import 'dart:async';

class ChatController extends GetxController {
  String agentId = '';
  String agentName = '';
  String agentAvatar = '';
  String? agentSubtitle;
  String systemPrompt = '';
  String welcomeMessage = '';
  bool playVoiceOnEnter = false;

  final VolcanoAIService _aiService = VolcanoAIService();
  late final VolcanoTtsApiService _ttsService;
  static const String _storagePrefix = 'chat_history_';

  final messages = <Message>[].obs;
  final isLoading = false.obs;
  late final TextEditingController messageController;
  late final ScrollController scrollController;
  final _storage = GetStorage();
  
  // TTS启用状态
  final isTtsEnabled = true.obs;
  
  // 用于存储当前正在流式生成的消息
  final RxString currentStreamMessage = ''.obs;
  Message? _currentAssistantMessage;
  bool _isDisposed = false;
  
  // TTS事件订阅
  StreamSubscription? _ttsEventSubscription;
  bool _isTtsSpeaking = false;
  
  // 语音输入相关状态
  final isRecording = false.obs;
  final recordingText = ''.obs;
  final isVoiceInputVisible = false.obs;
  final isVoiceConnecting = true.obs;
  final isVoiceMuted = false.obs;
  Message? _currentVoiceMessage;
  
  // 添加一个标志，表示当前是否有正在进行的语音识别
  final isRecognizing = false.obs;
  
  // 输入框状态
  final isInputCollapsed = false.obs;
  final isVoiceMode = true.obs;  // 默认为语音模式
  final isRecordingVoice = false.obs; // 是否正在录音（按住说话状态）
  
  // 添加是否在底部的状态变量
  final RxBool isAtBottom = true.obs;
  
  // 切换输入框折叠状态
  void toggleInputCollapsed() {
    isInputCollapsed.value = !isInputCollapsed.value;
  }
  
  // 切换语音/文本输入模式
  void toggleInputMode() {
    isVoiceMode.value = !isVoiceMode.value;
  }

  // 开始语音输入
  void startVoiceInput() {
    // 确保先停止任何可能正在进行的语音识别会话
    if (Get.isRegistered<VoiceInputController>()) {
      final voiceController = Get.find<VoiceInputController>();
      voiceController.stopRecording();
      Get.delete<VoiceInputController>();
    }
    
    // 如果TTS正在播放，先停止它
    if (_isTtsSpeaking) {
      try {
        // 立即停止当前声音播放
        _ttsService.stop();
        // 结束当前TTS会话
        _ttsService.endSession();
        _isTtsSpeaking = false;
      } catch (e) {
        debugPrint('停止TTS播放失败: $e');
      }
    }
    
    // 如果正在处理AI响应，中断处理
    if (isLoading.value) {
      isLoading.value = false;
      // 清除当前正在生成的消息
      if (_currentAssistantMessage != null) {
        // 如果消息内容为空，则移除该消息
        if (_currentAssistantMessage!.content.isEmpty) {
          messages.remove(_currentAssistantMessage);
        }
        _currentAssistantMessage = null;
      }
      currentStreamMessage.value = '';
    }
    
    isVoiceInputVisible.value = true;
    isVoiceConnecting.value = true;
    isRecording.value = false;
    recordingText.value = '';
    isRecognizing.value = false;
    
    // 当语音面板打开时，确保ListView滚动到适当位置，防止最后的消息被遮挡
    WidgetsBinding.instance.addPostFrameCallback((_) {
      if (!_isDisposed && scrollController.hasClients && messages.isNotEmpty) {
        // 计算需要额外滚动的距离（语音面板高度）
        final extraScrollDistance = 120.0;
        
        // 获取当前滚动位置
        final currentPosition = scrollController.position.pixels;
        final maxScrollExtent = scrollController.position.maxScrollExtent;
        
        // 如果已经接近底部，则向上滚动一定距离，确保最后的消息可见
        if (maxScrollExtent - currentPosition < extraScrollDistance) {
          scrollController.animateTo(
            currentPosition + extraScrollDistance,
            duration: const Duration(milliseconds: 300),
            curve: Curves.easeOut,
          );
        }
      }
    });
    
    // 创建语音输入控制器
    Get.put(VoiceInputController(
      onRecordingResult: handleVoiceResult,
      onClosePanel: stopVoiceInput,
      onRecognizing: handleRecognizing,
    ));
    
      // 滚动到底部
      _scrollToBottom(animate: true);
  }

  void startRecording() {
    if (!isVoiceConnecting.value && isVoiceInputVisible.value) {
      // 不再需要禁用TTS，因为已启用回声消除
      
      // 当用户开始说话时，停止当前TTS播放
      if (_isTtsSpeaking) {
        try {
          // 立即停止当前声音播放
          _ttsService.stop();
          // 结束当前TTS会话
          _ttsService.endSession();
          _isTtsSpeaking = false;
        } catch (e) {
          debugPrint('停止TTS播放失败: $e');
        }
      }
      
      // 如果正在处理AI响应，中断处理
      if (isLoading.value) {
        isLoading.value = false;
        // 清除当前正在生成的消息
        if (_currentAssistantMessage != null) {
          // 如果消息内容为空，则移除该消息
          if (_currentAssistantMessage!.content.isEmpty) {
            messages.remove(_currentAssistantMessage);
          }
          _currentAssistantMessage = null;
        }
        currentStreamMessage.value = '';
      }
      
      isRecording.value = true;
    }
  }

  void stopRecording() {
    if (isRecording.value) {
      isRecording.value = false;
    }
  }

  void toggleMute() {
    isVoiceMuted.value = !isVoiceMuted.value;
  }

  void stopVoiceInput() {
    // 停止语音识别
    if (Get.isRegistered<VoiceInputController>()) {
      try {
        Get.find<VoiceInputController>().stopRecording();
        Get.delete<VoiceInputController>();
      } catch (e) {
        debugPrint('停止语音输入失败: $e');
      }
    }
    
    // 重置状态
    isVoiceInputVisible.value = false;
    isVoiceConnecting.value = true;
    isRecording.value = false;
    recordingText.value = '';
    isRecognizing.value = false;
    
    // 清理临时语音消息
    if (_currentVoiceMessage != null && (_currentVoiceMessage!.content == '🎤 ...' || _currentVoiceMessage!.content.startsWith('🎤 '))) {
      messages.remove(_currentVoiceMessage);
    }
    _currentVoiceMessage = null;
    
    // 滚动到底部
    WidgetsBinding.instance.addPostFrameCallback((_) {
      if (!_isDisposed && messages.isNotEmpty) {
        _scrollToBottom(animate: true);
      }
    });
    
    // 重置按住说话状态

    // 删除语音输入控制器
    try {
      if (Get.isRegistered<VoiceInputController>()) {
        Get.delete<VoiceInputController>();
      }
    } catch (e) {
      debugPrint('Error deleting VoiceInputController: $e');
    }
    
    // 确保按住说话状态被重置
    isRecordingVoice.value = false;
  }

  void handleRecognizing(String text) {
    if (text.isEmpty) return;
    
    // 如果TTS正在播放，确保停止它
    if (_isTtsSpeaking) {
      try {
        // 立即停止当前声音播放
        _ttsService.stop();
        // 不需要每次都结束会话，只需要停止当前播放
        _isTtsSpeaking = false;
      } catch (e) {
        debugPrint('停止TTS播放失败: $e');
      }
    }
    
    // 更新识别中的文本
    recordingText.value = text;
    
    // 如果还没有创建临时语音消息，则创建一个
    if (_currentVoiceMessage == null) {
      _currentVoiceMessage = Message(
        role: 'user',
        content: '🎤 $text',
        timestamp: DateTime.now(),
      );
      messages.add(_currentVoiceMessage!);
      isRecognizing.value = true;
      
      // 滚动到底部
      _scrollToBottom(animate: true);
    } else {
      // 更新现有的临时语音消息
      final index = messages.indexWhere((msg) => 
        msg.timestamp == _currentVoiceMessage!.timestamp && 
        msg.role == _currentVoiceMessage!.role);
      
      if (index != -1) {
        messages[index] = Message(
          role: 'user',
          content: '🎤 $text',
          timestamp: _currentVoiceMessage!.timestamp,
        );
        
        // 滚动到底部
        _scrollToBottom(animate: false);
      }
    }
  }

  void handleVoiceResult(String text) {
    if (text.isEmpty) return;
    
    Message userMessage;
    
    // 处理现有的临时语音消息
    if (_currentVoiceMessage != null) {
      final index = messages.indexWhere((msg) => 
        msg.timestamp == _currentVoiceMessage!.timestamp && 
        msg.role == _currentVoiceMessage!.role);
      
      if (index != -1) {
        // 更新消息，移除麦克风图标
        userMessage = Message(
          role: 'user',
          content: text,
          timestamp: _currentVoiceMessage!.timestamp,
        );
        messages[index] = userMessage;
      } else {
        // 创建新消息
        userMessage = Message(
          role: 'user',
          content: text,
          timestamp: DateTime.now(),
        );
        messages.add(userMessage);
      }
    } else {
      // 创建新消息
      userMessage = Message(
        role: 'user',
        content: text,
        timestamp: DateTime.now(),
      );
      messages.add(userMessage);
    }
    
    // 保存聊天历史
    _saveChatHistory();
    
    // 滚动到底部
    _scrollToBottom(animate: true);
    
    // 重置状态
    _currentVoiceMessage = null;
    isRecognizing.value = false;
    
    // 处理AI响应
    _processAIResponse(userMessage);
  }
  
  // 处理AI响应
  Future<void> _processAIResponse(Message userMessage) async {
    if (_isDisposed) return;
    
    // TTS会话状态
    bool ttsSessionStarted = false;
    const speaker = 'zh_female_shuangkuaisisi_moon_bigtts';
    
    // 创建一个标志，用于跟踪流是否应该继续处理
    bool shouldContinueProcessing = true;
    
    // 创建监听器，用于检测用户交互
    StreamSubscription? voiceInputSubscription;
    StreamSubscription? voicePanelSubscription;
    
    try {
      isLoading.value = true;
      
      // 创建助手消息
      currentStreamMessage.value = '';
      _currentAssistantMessage = Message(
        role: 'assistant',
        content: '',
        timestamp: DateTime.now(),
      );
      messages.add(_currentAssistantMessage!);
      
      // 准备TTS会话
      if (isTtsEnabled.value) {
        await _ttsService.endSession();
        
        if (!_ttsService.isConnected.value) {
          await _ttsService.connect();
        }
        
        ttsSessionStarted = await _ttsService.startSession(speaker);
      }

      // 设置监听器，检测用户是否开始说话
      voiceInputSubscription = isRecording.listen((isRecordingNow) {
        if (isRecordingNow) {
          // 用户开始说话，设置标志为false
          shouldContinueProcessing = false;
          
          // 如果TTS正在播放，立即停止
          if (_isTtsSpeaking) {
            try {
              _ttsService.stop();
              _isTtsSpeaking = false;
            } catch (e) {
              debugPrint('停止TTS播放失败: $e');
            }
          }
        }
      });
      
      // 设置监听器，检测用户是否打开语音输入面板
      voicePanelSubscription = isVoiceInputVisible.listen((isVisible) {
        if (isVisible) {
          // 用户打开语音输入面板，设置标志为false
          shouldContinueProcessing = false;
          
          // 如果TTS正在播放，立即停止
          if (_isTtsSpeaking) {
            try {
              _ttsService.stop();
              _isTtsSpeaking = false;
            } catch (e) {
              debugPrint('停止TTS播放失败: $e');
            }
          }
        }
      });

      // 处理AI流式响应
      await for (final chunk in _aiService.sendMessageStream(
        messages: messages.map((m) => {'role': m.role, 'content': m.content}).toList(),
        systemPrompt: systemPrompt,
      )) {
        // 检查是否应该继续处理
        if (_isDisposed || !shouldContinueProcessing) {
          // 用户开始说话或控制器已销毁，中止流处理
          break;
        }

        // 更新UI
        currentStreamMessage.value += chunk;
        _updateAssistantMessage(currentStreamMessage.value);

        // 直接将文本片段发送到TTS接口
        if (isTtsEnabled.value && ttsSessionStarted && chunk.isNotEmpty) {
          await _ttsService.speak(chunk, speaker: speaker);
        }
      }
      
      // 结束TTS会话
      if (isTtsEnabled.value && ttsSessionStarted) {
        await _ttsService.endSession();
      }

      // 保存聊天历史
      if (!_isDisposed) {
        await _saveChatHistory();
      }
    } catch (e) {
      // 错误处理
      if (!_isDisposed) {
        if (_currentAssistantMessage != null) {
          messages.remove(_currentAssistantMessage);
        }
        
        Get.snackbar('Error', 'Failed to get response from AI', snackPosition: SnackPosition.BOTTOM);
        
        // 结束TTS会话
        if (isTtsEnabled.value && ttsSessionStarted) {
          await _ttsService.endSession();
        }
      }
    } finally {
      // 取消监听器
      voiceInputSubscription?.cancel();
      voicePanelSubscription?.cancel();
      
      // 重置状态
      if (!_isDisposed) {
        _currentAssistantMessage = null;
        currentStreamMessage.value = '';
        isLoading.value = false;
      }
    }
  }

  // 播放文本（用于独立播放场景）
  Future<void> _speakText(String text) async {
    if (text.isEmpty || !isTtsEnabled.value) return;
    
    try {
      if (!_ttsService.isConnected.value) {
        await _ttsService.connect();
      }
      
      const speaker = 'zh_female_shuangkuaisisi_moon_bigtts';
      
      await _ttsService.startSession(speaker);
      await _ttsService.speak(text, speaker: speaker);
      await _ttsService.endSession();
    } catch (e) {
      debugPrint('TTS播放出错: $e');
      await _ttsService.endSession();
    }
  }

  // 确保滚动到底部
  void _ensureScrollToBottom() {
    _scrollToBottom();
    
    // 延迟滚动以确保视图已构建
    Future.delayed(const Duration(milliseconds: 100), () {
      if (!_isDisposed) _scrollToBottom(animate: true);
    });
    
    // 帧回调确保在渲染后滚动
    WidgetsBinding.instance.addPostFrameCallback((_) {
      if (!_isDisposed) _scrollToBottom(animate: true);
    });
  }

  // 滚动监听器
  void _scrollListener() {
    if (_isDisposed) return;
    
    // 检测是否接近底部
    if (scrollController.hasClients) {
      final maxScroll = scrollController.position.maxScrollExtent;
      final currentScroll = scrollController.offset;
      isAtBottom.value = (maxScroll - currentScroll) < 50;
    }
  }

  @override
  void onInit() {
    super.onInit();
    messageController = TextEditingController();
    scrollController = ScrollController();
    
    // 清理可能存在的语音输入控制器
    if (Get.isRegistered<VoiceInputController>()) {
      try {
        Get.find<VoiceInputController>().stopRecording();
        Get.delete<VoiceInputController>();
      } catch (e) {
        debugPrint('清理语音控制器失败: $e');
      }
    }
    
    // 初始化服务和数据
    _initTtsService();
    _initFromArguments();
    _initializeController();
    
    // 添加滚动监听器
    scrollController.addListener(_scrollListener);
    
    // 确保滚动到底部
    _ensureScrollToBottom();
  }

  void _initFromArguments() {
    try {
      final arguments = Get.arguments;
      if (arguments == null) {
        throw Exception('No arguments provided to ChatController');
      }

      final args = arguments as Map<String, dynamic>;
      agentId = args['agentId'] as String? ?? '';
      agentName = args['agentName'] as String? ?? 'Assistant';
      agentAvatar = args['agentAvatar'] as String? ?? 'assets/images/default_avatar.png';
      agentSubtitle = args['agentSubtitle'] as String?;
      systemPrompt = args['systemPrompt'] as String? ?? '';
      welcomeMessage = args['welcomeMessage'] as String? ?? 'Hello! How can I help you today?';
      playVoiceOnEnter = args['playVoiceOnEnter'] as bool? ?? false;

      if (agentId.isEmpty) {
        throw Exception('Invalid agent ID');
      }
    } catch (e) {
      debugPrint('🔴 Error initializing ChatController: $e');
      Get.back();  // 返回上一页
      Get.snackbar(
        'Error',
        'Failed to initialize chat: Invalid parameters',
        snackPosition: SnackPosition.BOTTOM,
      );
    }
  }

  void _initTtsService() {
    _ttsService = Get.find<VolcanoTtsApiService>();
    isTtsEnabled.value = true;
    
    // 设置TTS事件监听
    _setupTtsEventListener();
  }
  
  void _setupTtsEventListener() {
    _ttsEventSubscription = _ttsService.eventStream.listen(_handleTtsEvent);
  }
  
  void _handleTtsEvent(Map<String, dynamic> event) {
    if (_isDisposed) return;
    
    final String eventType = event['eventType'] as String? ?? 'unknown';
    
    // 根据事件类型更新TTS状态
    switch (eventType) {
      case 'ttsSentenceStart':
      case 'playbackStarted':
      case 'synthesisBegin':
        _isTtsSpeaking = true;
        break;
      case 'ttsSentenceEnd':
      case 'playbackCompleted':
      case 'synthesisEnd':
      case 'sessionFinished':
      case 'connectionFinished':
      case 'connectionFailed':
      case 'sessionFailed':
      case 'playbackError':
        _isTtsSpeaking = false;
        break;
    }
  }

  Future<void> _initializeController() async {
    try {
      await _loadChatHistory();

      await _showWelcomeMessages();
    } catch (e) {
      Get.snackbar(
        'Error',
        'Failed to initialize chat: $e',
        snackPosition: SnackPosition.BOTTOM,
      );
    }
  }

  Future<void> _showWelcomeMessages() async {
    if (!agentName.isNotEmpty || !playVoiceOnEnter) return;
    
    try {
      // 生成动态问候语
      await _generatePersonalizedGreeting();
      await _saveChatHistory();
      _scrollToBottom(animate: true);
      
      // 添加系统消息
      messages.add(Message(
        role: 'system',
        content: '已为您自动启用连续语音对话模式，您可以直接开始说话',
        timestamp: DateTime.now(),
      ));
      await _saveChatHistory();
      
      // 启动语音输入
      Future.delayed(const Duration(milliseconds: 300), () {
        if (!_isDisposed) {
          startVoiceInput();
        }
      });
    } catch (e) {
      debugPrint('显示欢迎消息失败: $e');
      
      // 播放静态欢迎消息
      if (isTtsEnabled.value) {
        _speakText(welcomeMessage);
      }
      
      // 仍然启动语音输入
      if (!_isDisposed) {
        Future.delayed(const Duration(milliseconds: 300), () {
          startVoiceInput();
        });
      }
    }
  }

  Future<void> _generatePersonalizedGreeting() async {
    if (_isDisposed) return;

    try {
      // 创建助手消息
      currentStreamMessage.value = '';
      _currentAssistantMessage = Message(
        role: 'assistant',
        content: '',
        timestamp: DateTime.now(),
      );
      messages.add(_currentAssistantMessage!);

      // 构建问候语请求
      final greetingMessages = [
        {'role': 'system', 'content': systemPrompt},
        {'role': 'user', 'content': '请用一句简短的话向我打个招呼，要体现你的特点，不要超过18个字。'},
      ];

      // 生成问候语
      String fullGreeting = '';
      await for (final chunk in _aiService.sendMessageStream(
        messages: greetingMessages,
        systemPrompt: systemPrompt,
      )) {
        if (_isDisposed) break;

        // 更新消息内容
        currentStreamMessage.value += chunk;
        _updateAssistantMessage(currentStreamMessage.value);
        fullGreeting += chunk;
      }

      // 播放问候语
      if (isTtsEnabled.value && fullGreeting.isNotEmpty) {
        await _speakText(fullGreeting);
      }
    } catch (e) {
      debugPrint('生成问候语失败: $e');
      if (_currentAssistantMessage != null) {
        messages.remove(_currentAssistantMessage);
      }
    } finally {
      if (!_isDisposed) {
        _currentAssistantMessage = null;
        currentStreamMessage.value = '';
      }
    }
  }

  @override
  void onClose() {
    _isDisposed = true;
    
    // 停止语音输入和TTS
    stopVoiceInput();
    
    // 确保TTS完全停止并清理资源
    if (isTtsEnabled.value) {
      try {

        _ttsService.stop();
        // 停止当前TTS播放并清除未播放的数据
        _ttsService.endSession();
        
        // 确保断开TTS连接，释放所有资源
        _ttsService.disconnect();
      } catch (e) {
        debugPrint('关闭TTS服务时出错: $e');
      }
    }
    
    // 取消TTS事件订阅
    if (_ttsEventSubscription != null) {
      _ttsEventSubscription!.cancel();
      _ttsEventSubscription = null;
    }
    
    // 重置状态
    currentStreamMessage.value = '';
    _currentAssistantMessage = null;
    _isTtsSpeaking = false;

    // 释放控制器
    messageController.dispose();
    scrollController.dispose();
    
    super.onClose();
  }

  Future<void> _loadChatHistory() async {
    try {
      final historyJson = _storage.read('${_storagePrefix}$agentId');
      if (historyJson != null) {
        final List<dynamic> historyList = json.decode(historyJson);
        messages.value = historyList.map((item) => Message.fromJson(item)).toList();
        
        // 如果有历史消息，等待下一帧再滚动到底部
        if (messages.isNotEmpty) {
          WidgetsBinding.instance.addPostFrameCallback((_) {
            _scrollToBottom(animate: true);
          });
        }
      }
    } catch (e) {
      Get.snackbar(
        'Error',
        'Failed to load chat history: $e',
        snackPosition: SnackPosition.BOTTOM,
      );
    }
  }

  Future<void> _saveChatHistory() async {
    try {
      final historyJson =
          json.encode(messages.map((msg) => msg.toJson()).toList());
      await _storage.write('${_storagePrefix}$agentId', historyJson);
    } catch (e) {
      Get.snackbar(
        'Error',
        'Failed to save chat history: $e',
        snackPosition: SnackPosition.BOTTOM,
      );
    }
  }

  void _scrollToBottom({bool animate = false}) {
    if (!scrollController.hasClients) return;
    
    final position = scrollController.position.maxScrollExtent;
    if (animate) {
      scrollController.animateTo(
        position,
        duration: const Duration(milliseconds: 300),
        curve: Curves.easeOut,
      );
    } else {
      scrollController.jumpTo(position);
    }
  }

  void _updateAssistantMessage(String content) {
    if (_currentAssistantMessage == null) return;
    
    final index = messages.indexWhere((msg) =>
        msg.timestamp == _currentAssistantMessage?.timestamp &&
        msg.role == _currentAssistantMessage?.role);

    if (index != -1) {
      // 使用非空断言，因为我们已经在方法开始时检查了非空
      final timestamp = _currentAssistantMessage!.timestamp;
      messages[index] = Message(
        role: 'assistant',
        content: content,
        timestamp: timestamp,
      );
      // 只在非初始化阶段滚动
      if (!playVoiceOnEnter || content.isNotEmpty) {
        _scrollToBottom(animate: false);
      }
    }
  }

  void clearMessage() {
    if (!_isDisposed && messageController.text.isNotEmpty) {
      messageController.clear();
    }
  }

  Future<void> sendMessage() async {
    if (_isDisposed) return;
    
    final text = messageController.text.trim();
    if (text.isEmpty) return;

    // 创建用户消息
    final userMessage = Message(
      role: 'user',
      content: text,
      timestamp: DateTime.now(),
    );
    messages.add(userMessage);
    clearMessage();
    await _saveChatHistory();
    _scrollToBottom(animate: true);

    // 处理AI响应
    await _processAIResponse(userMessage);
  }

  Future<void> clearChat() async {
    try {
      messages.clear();
      await _storage.remove('${_storagePrefix}$agentId');
      await _showWelcomeMessages();
    } catch (e) {
      Get.snackbar(
        'Error',
        'Failed to clear chat: $e',
        snackPosition: SnackPosition.BOTTOM,
      );
    }
  }

  void toggleTTS() {
    // 切换TTS启用状态
    isTtsEnabled.toggle();
    if (!isTtsEnabled.value) {
      _ttsService.endSession();
    }
  }

  /// 生成简单的问候语
  Future<void> generateSimpleGreeting() async {
    if (_isDisposed) return;

    try {
      // 创建助手消息
      currentStreamMessage.value = '';
      _currentAssistantMessage = Message(
        role: 'assistant',
        content: '',
        timestamp: DateTime.now(),
      );
      messages.add(_currentAssistantMessage!);

      // 构建用于生成问候语的消息列表
      final greetingMessages = [
        {'role': 'system', 'content': systemPrompt},
        {'role': 'user', 'content': '请用一句简短的话向我打个招呼，要体现你的特点，不要超过12个字。'},
      ];

      // 生成问候语
      String fullGreeting = '';
      await for (final chunk in _aiService.sendMessageStream(
        messages: greetingMessages,
        systemPrompt: systemPrompt,
      )) {
        if (_isDisposed) break;

        // 更新消息内容
        currentStreamMessage.value += chunk;
        _updateAssistantMessage(currentStreamMessage.value);
        fullGreeting += chunk;
      }

      // 播放问候语
      if (isTtsEnabled.value && fullGreeting.isNotEmpty) {
        await _speakText(fullGreeting);
      }
    } catch (e) {
      debugPrint('生成问候语失败: $e');
      // 移除未完成的消息
      if (_currentAssistantMessage != null) {
        messages.remove(_currentAssistantMessage);
      }
    } finally {
      if (!_isDisposed) {
        _currentAssistantMessage = null;
        currentStreamMessage.value = '';
      }
    }
  }

  // 开始按住说话
  void startPressToTalk() {
    isRecordingVoice.value = true;
    
    startVoiceInput();
  }
  
  // 结束按住说话
  void endPressToTalk() {
    isRecordingVoice.value = false;
    
    stopVoiceInput();
  }
}