import 'dart:async';
import 'dart:convert';
import 'package:flutter/material.dart';
import 'package:get/get.dart';
import 'package:agent_service/agent_service.dart';
import 'package:logger/logger.dart';
import 'package:chat_storage/chat_storage.dart';

class Message {
  final bool isUser;
  final String text;
  final DateTime timestamp;
  final bool isRecognizing; // 是否为语音识别中的临时消息

  Message({
    required this.isUser,
    required this.text,
    DateTime? timestamp,
    this.isRecognizing = false,
  }) : this.timestamp = timestamp ?? DateTime.now();
}

class AgentController extends GetxController {
  static AgentController get to => Get.find();
  
  final logger = Logger();
  
  // 聊天消息列表
  final messages = <Message>[].obs;
  
  // 控制器
  final TextEditingController textController = TextEditingController();
  final ScrollController scrollController = ScrollController();
  
  // 状态标志
  final isInitialized = false.obs;
  final isListening = false.obs;
  final isSpeaking = false.obs;
  final isProcessing = false.obs;
  
  // 输入模式控制
  final isTextInputMode = true.obs;
  
  // 当前输入的文本内容
  final currentText = ''.obs;
  
  // 流事件订阅
  StreamSubscription<AgentServiceEvent>? _eventSubscription;
  
  // 用于跟踪AI回复状态
  bool _isNewAssistantResponse = true;
  String _currentResponseId = '';
  
  // 会话ID
  final String sessionId = 'default_agent';
  
  // 是否已加载聊天记录
  final isHistoryLoaded = false.obs;

  @override
  void onInit() {
    super.onInit();
    _loadChatHistory();
    _subscribeToEvents();
  }

  @override
  void onClose() {
    AgentService.stopConversation();
    AgentService.stopTts();
    textController.dispose();
    scrollController.dispose();
    _eventSubscription?.cancel();
    super.onClose();
  }
  
  // 加载聊天历史记录
  Future<void> _loadChatHistory() async {
    try {
      logger.i('正在加载聊天历史...');
      final result = await ChatStorage.getMessages(
        sessionId: sessionId,
        page: 1,
        pageSize: 20,
      );
      
      if (result.messages.isNotEmpty) {
        // 转换并添加消息到列表
        final historyMessages = result.messages.map((msg) => Message(
          isUser: msg.sender == 'user',
          text: msg.message,
          timestamp: DateTime.parse(msg.timestamp),
        )).toList();
        
        // 消息按时间排序，最新的消息在底部
        historyMessages.sort((a, b) => a.timestamp.compareTo(b.timestamp));
        messages.assignAll(historyMessages);
        
        logger.i('成功加载 ${historyMessages.length} 条聊天记录');
      } else {
        // 没有历史记录时添加欢迎消息
        _addWelcomeMessage();
        logger.i('没有历史记录，添加欢迎消息');
      }
    } catch (e) {
      logger.e('加载聊天历史失败: $e');
      _addWelcomeMessage();
    } finally {
      isHistoryLoaded.value = true;
      
      messages.refresh();
      // 在加载完成后直接定位到底部，无需动画
      WidgetsBinding.instance.addPostFrameCallback((_) {
        scrollController.jumpTo(scrollController.position.maxScrollExtent);
      });
      
    }
  }
  
  // 添加欢迎消息
  void _addWelcomeMessage() {
    messages.add(Message(
      isUser: false,
      text: '你好！我是DeepVoice AI助手，我能帮你:\n\n'
          '• 回答问题和提供信息\n'
          '• 实时语音翻译\n'
          '• 推荐音乐和播客\n'
          '• 语音备忘录和提醒\n'
          '• 控制耳机功能\n\n'
          '有什么我可以帮你的吗？',
    ));
  }

  // 订阅代理服务事件
  void _subscribeToEvents() {
    _eventSubscription = AgentService.events.listen((event) {
      switch (event.type) {
        case AgentServiceEventType.recognitionStarted:
          isListening.value = true;
          isTextInputMode.value = false;
          isTextInputMode.refresh();
          // 只标记识别开始，不添加消息
          break;
        case AgentServiceEventType.recognitionStopped:
          isListening.value = false;
          isTextInputMode.value = true;
          isTextInputMode.refresh();
          break;
          
        case AgentServiceEventType.recognizing:
          final text = event.data['text'] ?? '';
          currentText.value = text; // 保留当前文本，以便其他地方使用
          
          if (text.isNotEmpty) {
            // 查找是否有正在识别中的消息
            final index = messages.lastIndexWhere((msg) => msg.isRecognizing && msg.isUser);
            
            if (index >= 0) {
              // 更新已有的识别中消息
              messages[index] = Message(
                isUser: true,
                text: text,
                isRecognizing: true,
                timestamp: messages[index].timestamp,
              );
            } else {
              // 没有识别中的消息，创建新消息
              messages.add(Message(
                isUser: true,
                text: text,
                isRecognizing: true,
              ));
            }
            messages.refresh();
            _scrollToBottom();
          }
          break;
          
        case AgentServiceEventType.recognitionResult:
          final text = event.data['text'] ?? '';
          
          // 查找是否有正在识别中的消息
          final index = messages.lastIndexWhere((msg) => msg.isRecognizing && msg.isUser);
          
          if (text.isNotEmpty) {
            if (index >= 0) {
              // 将识别中的消息转换为最终消息
              messages[index] = Message(
                isUser: true,
                text: text,
                timestamp: messages[index].timestamp,
              );
              messages.refresh();
            } else {
              // 如果没有找到识别中的消息，添加新消息
              messages.add(Message(isUser: true, text: text));
            }
            
            isProcessing.value = true;
            // 标记为新的AI回复
            _isNewAssistantResponse = true;
            // 滚动到底部
            _scrollToBottom();
          } else if (index >= 0) {
            // 如果识别结果为空，移除临时的识别消息
            messages.removeAt(index);
            messages.refresh();
          }
          break;
          
        case AgentServiceEventType.ttsStarted:
          isSpeaking.value = true;
          break;
          
        case AgentServiceEventType.ttsCompleted:
        case AgentServiceEventType.ttsStopped:
        case AgentServiceEventType.ttsCanceled:
          isSpeaking.value = false;
          break;
          
        case AgentServiceEventType.assistantToken:
          if (!isProcessing.value) isProcessing.value = true;
          
          final token = event.data['token'] ?? '';
          final responseId = event.data['responseId'] ?? '';
          
          if (token.isNotEmpty) {
            // 如果是新的回复或者响应ID改变，创建新消息
            if (_isNewAssistantResponse || (_currentResponseId != responseId && responseId.isNotEmpty)) {
              messages.add(Message(isUser: false, text: token));
              _isNewAssistantResponse = false;
              _currentResponseId = responseId;
            } else {
              // 否则更新最后一条消息
              final lastIndex = messages.length - 1;

              if (lastIndex >= 0 && !messages[lastIndex].isUser) {
                messages[lastIndex] = Message(
                  isUser: false,
                  text: messages[lastIndex].text + token,
                  timestamp: messages[lastIndex].timestamp,
                );
              }
            }
            // 滚动到底部
            _scrollToBottom();
          }
          break;
          
        case AgentServiceEventType.assistantResponse:
          isProcessing.value = false;
          // 标记当前回复完成
          _isNewAssistantResponse = true;
          break;
          
        case AgentServiceEventType.error:
          isListening.value = false;
          isSpeaking.value = false;
          isProcessing.value = false;
          
          // 移除临时的识别消息
          final index = messages.lastIndexWhere((msg) => msg.isRecognizing && msg.isUser);
          if (index >= 0) {
            messages.removeAt(index);
            messages.refresh();
          }
          
          logger.e('代理服务错误: ${event.data['message']}');
          break;
          
        case AgentServiceEventType.autoStop:
          isListening.value = false;
          
          // 移除临时的识别消息
          final index = messages.lastIndexWhere((msg) => msg.isRecognizing && msg.isUser);
          if (index >= 0) {
            // 只有当消息为空或文本太短时才移除
            if (messages[index].text.trim().length < 2) {
              messages.removeAt(index);
              messages.refresh();
            } else {
              // 否则转换为正式消息
              messages[index] = Message(
                isUser: true,
                text: messages[index].text,
                timestamp: messages[index].timestamp,
              );
              messages.refresh();
              
              // 发送此消息到AI处理
              isProcessing.value = true;
              _isNewAssistantResponse = true;
              AgentService.processTextInput(messages[index].text, speakResponse: true);
            }
          }
          break;

        case AgentServiceEventType.functionCall:
          // final functionName = event.data['name'] ?? '';
          // final arguments = event.data['arguments'] ?? '';
          // logger.i('mcp: $functionName, $arguments');
          break;

        case AgentServiceEventType.functionCallResult:
          final result = event.data['result'] ?? '';
          final functionCall = event.data['function_call'] ?? '';
          break;
          
        default:
          break;
      }
    });
  }

  // 滚动到底部
  void _scrollToBottom() {
    WidgetsBinding.instance.addPostFrameCallback((_) {
      if (scrollController.hasClients) {
        try {
          scrollController.animateTo(
            scrollController.position.maxScrollExtent,
            duration: Duration(milliseconds: 300),
            curve: Curves.easeOut,
          );
        } catch (e) {
          logger.e('滚动到底部失败: $e');
        }
      }
    });
  }

  // 发送文本消息
  Future<void> sendTextMessage() async {
    final text = textController.text.trim();
    if (text.isEmpty) return;
    
    final message = Message(isUser: true, text: text);
    messages.add(message);
    textController.clear();
    
    // 滚动到底部
    _scrollToBottom();
    
    try {
      isProcessing.value = true;
      // 标记为新的AI回复
      _isNewAssistantResponse = true;
      await AgentService.processTextInput(text, speakResponse: true);
    } catch (e) {
      logger.e('发送文本消息失败: $e');
      isProcessing.value = false;
    }
  }

  // 开始语音输入
  Future<void> startVoiceInput() async {
    if (isListening.value) return;
    
    try {
      await AgentService.startConversation();
    } catch (e) {
      logger.e('启动语音输入失败: $e');
    }
  }

  // 停止语音输入
  Future<void> stopVoiceInput() async {
    if (!isListening.value) return;
    
    try {
      await AgentService.stopConversation();
    } catch (e) {
      logger.e('停止语音输入失败: $e');
    }
  }

  // 清除聊天历史
  Future<void> clearChat() async {
    try {
      await AgentService.clearChatHistory();
      

      // 清空本地消息列表
      messages.clear();
      
      // 添加欢迎消息
      _addWelcomeMessage();
      
      // 重置回复状态
      _isNewAssistantResponse = true;
    } catch (e) {
      logger.e('清除聊天历史失败: $e');
    }
  }
  
  // 切换输入模式
  void toggleInputMode() {
    isTextInputMode.toggle();
    
    // 切换到语音模式时，直接开始语音输入
    if (!isTextInputMode.value) {
      startVoiceInput();
    }
    // 切换到文本模式时，直接停止语音输入
    else {
      stopVoiceInput();
    }
  }
}