import 'dart:async';
import 'package:flutter_dotenv/flutter_dotenv.dart';
import 'package:open_ai_service/open_ai_service.dart';
import 'package:get/get.dart';
import 'ai_service.dart';

/// OpenAI服务适配器 - 连接AiService接口与OpenAIService插件
class OpenAIServiceAdapter implements AiService {
  final OpenAIService _openAIService = OpenAIService();
  StreamSubscription<OpenAIEvent>? _eventSubscription;
  final StreamController<String> _tokenStreamController = StreamController<String>.broadcast();
  bool _isProcessingStream = false;
  
  /// 构造函数
  OpenAIServiceAdapter() {
    printInfo(info: '创建OpenAIServiceAdapter实例');
    _setupEventListener();
  }
  
  /// 设置事件监听器
  void _setupEventListener() {
    try {
      // 首先确保访问eventStream以初始化底层事件通道
      _openAIService.eventStream;
      
      // 设置事件处理
      _eventSubscription = _openAIService.eventStream.listen(
        (event) {
          if (!_isProcessingStream) return;
          
          try {
            switch (event.type) {
              case OpenAIEventType.token:
                if (event.content is String) {
                  _tokenStreamController.add(event.content as String);
                } else {
                  printInfo(info: '收到非字符串类型的token: ${event.content}');
                }
                break;
              case OpenAIEventType.complete:
                _isProcessingStream = false;
                break;
              case OpenAIEventType.error:
                if (event.content is String) {
                  _tokenStreamController.addError(event.content as String);
                } else {
                  _tokenStreamController.addError('未知错误: ${event.content}');
                }
                _isProcessingStream = false;
                break;
              case OpenAIEventType.functionCall:
                try {
                  if (event.content is Map) {
                    _tokenStreamController.addError('收到函数调用，该流仅支持文本响应');
                  } else {
                    _tokenStreamController.addError('收到未知格式的函数调用');
                    printError(info: '函数调用格式错误: ${event.content}');
                  }
                } catch (e) {
                  printError(info: '处理函数调用事件出错: $e');
                  _tokenStreamController.addError('处理函数调用失败: $e');
                }
                _isProcessingStream = false;
                break;
            }
          } catch (e) {
            printError(info: '处理事件出错: $e');
            _tokenStreamController.addError('处理事件失败: $e');
            _isProcessingStream = false;
          }
        },
        onError: (error) {
          printError(info: '事件流错误: $error');
          _tokenStreamController.addError('事件流错误: $error');
          _isProcessingStream = false;
        },
        onDone: () {
          printInfo(info: '事件流已关闭');
          _isProcessingStream = false;
        },
      );
    } catch (e) {
      printError(info: '设置事件监听器失败: $e');
    }
  }
  
  /// 初始化OpenAI服务
  Future<bool> initialize() async {
    try {
      // 从.env文件中读取配置
      final apiKey = dotenv.env['OPENAI_API_KEY'] ?? '';
      final baseUrl = dotenv.env['OPENAI_BASE_URL'] ?? '';
      final model = dotenv.env['OPENAI_MODEL'] ?? '';
      
      printInfo(info: '从.env读取OpenAI配置');
      printInfo(info: '基础URL: $baseUrl');
      printInfo(info: '模型名称: $model');
      
      if (apiKey.isEmpty) {
        printError(info: '错误: OpenAI API密钥未配置，请在.env文件中设置OPENAI_API_KEY');
        return false;
      }
      
      // 初始化OpenAI服务
      final result = await _openAIService.initialize(
        apiKey: apiKey,
        baseUrl: baseUrl,
        model: model,
      );
      
      if (result) {
        printInfo(info: 'OpenAI服务初始化成功');
      } else {
        printError(info: 'OpenAI服务初始化失败');
      }
      
      return result;
    } catch (e) {
      printError(info: 'OpenAI服务初始化异常: $e');
      return false;
    }
  }
  
  /// 发送消息并获取回复
  @override
  Future<String> sendMessage({
    required List<Map<String, String>> messages,
    required String systemPrompt,
  }) async {
    try {
      // 在方法内直接转换
      final convertedMessages = messages.map((m) => 
          Map<String, dynamic>.from(m)).toList();
      
      // 发送消息并获取回复
      final response = await _openAIService.sendMessage(
        messages: convertedMessages,
      );
      
      return response;
    } catch (e) {
      printError(info: 'OpenAI发送消息失败: $e');
      throw '发送消息失败: $e';
    }
  }
  
  /// 发送消息并获取流式回复
  @override
  Stream<String> sendMessageStream({
    required List<Map<String, String>> messages,
    required String systemPrompt,
  }) async* {
    try {
      // 在方法内直接转换
      final convertedMessages = messages.map((m) => 
          Map<String, dynamic>.from(m)).toList();
      
      // 创建用于接收token的控制器
      final localController = StreamController<String>();
      
      // 标记开始处理流
      _isProcessingStream = true;
      
      // 添加从广播流到本地流的订阅
      final subscription = _tokenStreamController.stream.listen(
        (token) => localController.add(token),
        onError: (error) {
          printError(info: '令牌流错误: $error');
          localController.addError(error);
          localController.close();
        },
        onDone: () {
          printInfo(info: '令牌流已完成');
          localController.close();
        }
      );
      
      // 当本地控制器关闭时，取消订阅
      localController.onCancel = () {
        subscription.cancel();
      };
      
      // 启动流式消息请求
      bool started = false;
      try {
        started = await _openAIService.sendMessageStream(
          messages: convertedMessages,
        );
      } catch (e) {
        printError(info: '启动消息流失败: $e');
        localController.addError('启动消息流失败: $e');
        localController.close();
        _isProcessingStream = false;
        throw '启动消息流失败: $e';
      }
      
      if (!started) {
        printError(info: '无法启动消息流');
        localController.addError('无法启动消息流');
        localController.close();
        _isProcessingStream = false;
        throw '无法启动消息流';
      }
      
      // 通过yield*将controller的流转发
      yield* localController.stream;
    } catch (e) {
      printError(info: 'OpenAI流式消息处理失败: $e');
      throw '流式消息处理失败: $e';
    }
  }
  
  /// 注册函数
  Future<bool> registerFunction(String name, String description, Map<String, dynamic> parameters) async {
    try {
      final result = await _openAIService.registerFunction(
        name: name,
        description: description,
        parameters: parameters,
      );
      
      if (result) {
        printInfo(info: '函数 "$name" 注册成功');
      } else {
        printError(info: '函数 "$name" 注册失败');
      }
      
      return result;
    } catch (e) {
      printError(info: '注册函数失败: $e');
      return false;
    }
  }
  
  /// 释放资源
  void dispose() {
    try {
      _isProcessingStream = false;
      _eventSubscription?.cancel();
      _tokenStreamController.close();
      printInfo(info: 'OpenAIServiceAdapter资源已释放');
    } catch (e) {
      printError(info: '释放资源时出错: $e');
    }
  }

}