383 lines
11 KiB
JavaScript
383 lines
11 KiB
JavaScript
const Message = require('../models/Message');
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const ConversationService = require('./ConversationService');
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const LLMApiClient = require('./LLMApiClient');
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const cacheManager = require('../utils/cache');
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class ChatService {
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constructor() {
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this.conversationService = new ConversationService();
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this.llmClient = new LLMApiClient();
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this.cachePrefix = 'chat_service';
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}
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/**
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* 处理用户消息并获取AI回复
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*/
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async processMessage(conversationId, userMessage, options = {}) {
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try {
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// 验证输入
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if (!conversationId || isNaN(conversationId)) {
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throw new Error('无效的对话ID');
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}
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if (!userMessage || userMessage.trim().length === 0) {
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throw new Error('消息内容不能为空');
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}
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const trimmedMessage = userMessage.trim();
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// 确保对话存在
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const conversation = await this.conversationService.getConversationById(conversationId);
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if (!conversation) {
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throw new Error('对话不存在');
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}
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console.log(`处理消息: 对话${conversationId}, 内容: ${trimmedMessage.substring(0, 50)}...`);
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// 1. 保存用户消息
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const userMsg = await Message.create(conversationId, 'user', trimmedMessage);
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// 2. 获取对话历史作为上下文
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const conversationHistory = await this.getConversationContext(conversationId);
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// 3. 检查缓存
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const cacheKey = this.generateCacheKey(conversationHistory);
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let cachedResponse = cacheManager.getCachedApiResponse(conversationHistory);
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let aiResponse;
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if (cachedResponse && !options.skipCache) {
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console.log('使用缓存的AI回复');
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aiResponse = cachedResponse;
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} else {
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// 4. 调用LLM API获取回复
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aiResponse = await this.getLLMResponse(conversationHistory, options);
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// 5. 缓存API响应
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if (aiResponse && !options.skipCache) {
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cacheManager.cacheApiResponse(conversationHistory, aiResponse);
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}
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}
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if (!aiResponse || !aiResponse.content) {
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throw new Error('LLM服务返回无效响应');
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}
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// 6. 保存AI回复
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const aiMsg = await Message.create(conversationId, 'assistant', aiResponse.content);
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// 7. 更新对话活动时间
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await this.conversationService.updateLastActivity(conversationId);
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// 8. 如果是对话的第一条消息，自动生成标题
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if (conversation.title === '新对话') {
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await this.conversationService.generateConversationTitle(conversationId);
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}
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// 9. 更新上下文缓存
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this.updateContextCache(conversationId);
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const result = {
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userMessage: {
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id: userMsg.id,
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content: userMsg.content,
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timestamp: userMsg.timestamp
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},
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aiResponse: {
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id: aiMsg.id,
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content: aiMsg.content,
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timestamp: aiMsg.timestamp
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},
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conversationId: conversationId,
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usage: aiResponse.usage
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};
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console.log(`消息处理完成: 对话${conversationId}`);
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return result;
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} catch (error) {
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console.error('ChatService.processMessage错误:', error);
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throw error;
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}
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}
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/**
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* 处理流式消息响应
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*/
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async processStreamMessage(conversationId, userMessage, options = {}) {
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try {
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// 验证输入
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if (!conversationId || isNaN(conversationId)) {
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throw new Error('无效的对话ID');
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}
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if (!userMessage || userMessage.trim().length === 0) {
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throw new Error('消息内容不能为空');
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}
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const trimmedMessage = userMessage.trim();
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// 确保对话存在
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const conversation = await this.conversationService.getConversationById(conversationId);
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if (!conversation) {
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throw new Error('对话不存在');
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}
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console.log(`处理流式消息: 对话${conversationId}`);
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// 1. 保存用户消息
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const userMsg = await Message.create(conversationId, 'user', trimmedMessage);
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// 2. 获取对话历史
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const conversationHistory = await this.getConversationContext(conversationId);
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// 3. 获取流式响应
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const stream = await this.llmClient.createStreamChatCompletion(conversationHistory, {
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...options,
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stream: true
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});
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// 返回流式响应处理函数
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return {
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userMessage: {
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id: userMsg.id,
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content: userMsg.content,
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timestamp: userMsg.timestamp
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},
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stream: stream,
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conversationId: conversationId
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};
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} catch (error) {
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console.error('ChatService.processStreamMessage错误:', error);
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throw error;
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}
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}
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/**
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* 完成流式消息处理（保存完整的AI回复）
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*/
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async completeStreamMessage(conversationId, aiContent) {
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try {
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if (!aiContent || aiContent.trim().length === 0) {
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throw new Error('AI回复内容为空');
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}
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// 保存AI回复
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const aiMsg = await Message.create(conversationId, 'assistant', aiContent.trim());
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// 更新对话活动时间
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await this.conversationService.updateLastActivity(conversationId);
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// 更新上下文缓存
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this.updateContextCache(conversationId);
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return {
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id: aiMsg.id,
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content: aiMsg.content,
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timestamp: aiMsg.timestamp
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};
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} catch (error) {
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console.error('ChatService.completeStreamMessage错误:', error);
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throw error;
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}
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}
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/**
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* 获取对话上下文
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*/
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async getConversationContext(conversationId, maxTokens = 4000) {
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try {
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// 先尝试从缓存获取
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let context = cacheManager.getConversationContext(conversationId);
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if (context) {
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console.log(`从缓存获取对话上下文: ${conversationId}`);
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return context;
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}
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// 从数据库获取
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context = await Message.getConversationHistory(conversationId, maxTokens);
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// 缓存上下文
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cacheManager.cacheConversationContext(conversationId, context);
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console.log(`获取对话上下文: ${conversationId}, ${context.length}条消息`);
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return context;
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} catch (error) {
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console.error('ChatService.getConversationContext错误:', error);
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throw new Error('获取对话上下文失败');
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}
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}
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/**
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* 调用LLM API获取回复
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*/
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async getLLMResponse(messages, options = {}) {
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try {
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const llmOptions = {
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temperature: options.temperature,
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max_tokens: options.max_tokens,
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top_p: options.top_p,
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frequency_penalty: options.frequency_penalty,
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presence_penalty: options.presence_penalty,
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model: options.model
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};
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// 移除undefined值
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Object.keys(llmOptions).forEach(key => {
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if (llmOptions[key] === undefined) {
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delete llmOptions[key];
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}
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});
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console.log('调用LLM API:', JSON.stringify(llmOptions, null, 2));
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const response = await this.llmClient.createChatCompletion(messages, llmOptions);
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console.log('LLM API响应:', {
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model: response.model,
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usage: response.usage,
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contentLength: response.content?.length || 0
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});
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return response;
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} catch (error) {
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console.error('ChatService.getLLMResponse错误:', error);
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// 根据错误类型返回更友好的错误信息
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if (error.message.includes('API密钥')) {
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throw new Error('AI服务配置错误，请联系管理员');
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} else if (error.message.includes('请求频率')) {
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throw new Error('请求过于频繁，请稍后再试');
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} else if (error.message.includes('网络')) {
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throw new Error('网络连接异常，请检查网络设置');
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} else {
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throw new Error('AI服务暂时不可用，请稍后重试');
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}
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}
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}
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/**
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* 生成缓存键
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*/
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generateCacheKey(messages) {
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const messageString = JSON.stringify(messages);
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return cacheManager.generateKey('chat_completion', messageString);
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}
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/**
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* 更新上下文缓存
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*/
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updateContextCache(conversationId) {
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try {
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// 删除旧的上下文缓存，强制下次重新获取
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cacheManager.deleteConversationContext(conversationId);
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// 清除相关的消息缓存
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this.conversationService.clearConversationCache(conversationId);
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} catch (error) {
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console.error('更新上下文缓存失败:', error);
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}
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}
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/**
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* 重新生成AI回复
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*/
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async regenerateResponse(conversationId, options = {}) {
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try {
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// 获取最后一条用户消息
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const messages = await Message.getRecentMessages(conversationId, 10);
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const lastUserMessage = messages.reverse().find(msg => msg.role === 'user');
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if (!lastUserMessage) {
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throw new Error('没有找到用户消息');
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}
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// 删除最后一条AI回复（如果存在）
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const lastMessage = messages[messages.length - 1];
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if (lastMessage && lastMessage.role === 'assistant') {
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await Message.delete(lastMessage.id);
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console.log('删除上一条AI回复');
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}
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// 获取更新后的对话历史
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const conversationHistory = await this.getConversationContext(conversationId);
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// 强制跳过缓存，重新生成回复
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const aiResponse = await this.getLLMResponse(conversationHistory, {
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...options,
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skipCache: true
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});
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if (!aiResponse || !aiResponse.content) {
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throw new Error('重新生成回复失败');
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}
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// 保存新的AI回复
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const aiMsg = await Message.create(conversationId, 'assistant', aiResponse.content);
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// 更新对话活动时间
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await this.conversationService.updateLastActivity(conversationId);
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// 更新上下文缓存
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this.updateContextCache(conversationId);
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const result = {
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id: aiMsg.id,
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content: aiMsg.content,
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timestamp: aiMsg.timestamp,
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usage: aiResponse.usage
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};
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console.log(`重新生成回复完成: 对话${conversationId}`);
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return result;
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} catch (error) {
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console.error('ChatService.regenerateResponse错误:', error);
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throw error;
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}
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}
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/**
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* 检查LLM服务状态
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*/
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async checkLLMStatus() {
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try {
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const status = await this.llmClient.checkConnection();
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return status;
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} catch (error) {
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console.error('检查LLM状态失败:', error);
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return {
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status: 'error',
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message: '无法连接到LLM服务'
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};
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}
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}
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/**
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* 获取聊天统计信息
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*/
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async getChatStats() {
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try {
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// 这里可以添加更多统计信息
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const cacheStats = cacheManager.getStats();
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return {
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cache: cacheStats,
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llm: {
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connected: (await this.checkLLMStatus()).status === 'connected'
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}
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};
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} catch (error) {
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console.error('获取聊天统计信息失败:', error);
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return {
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error: error.message
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};
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}
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}
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}
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module.exports = ChatService; |