fixbug：OpenAI

api/services/ai.service.ts

@@ -14,14 +14,27 @@ import axios from 'axios';
 
 dotenv.config();
 
-const openai = new OpenAI({
-  apiKey: process.env.OPENAI_API_KEY,
-  baseURL: process.env.OPENAI_API_BASE_URL || 'https://api.siliconflow.cn/v1',
-});
-
 const MODEL = process.env.MODEL_NAME || 'Qwen/Qwen2.5-7B-Instruct';
 
 export class AIService {
+  private static _openai: OpenAI | null = null;
+
+  static get openai() {
+    if (!this._openai) {
+      const apiKey = process.env.OPENAI_API_KEY || 'sk-no-key-provided';
+      
+      if (!process.env.OPENAI_API_KEY) {
+        console.warn('[AIService] 未检测到 OPENAI_API_KEY，AI 功能将不可用。请在环境变量中设置。');
+      }
+
+      this._openai = new OpenAI({
+        apiKey: apiKey,
+        baseURL: process.env.OPENAI_API_BASE_URL || 'https://api.siliconflow.cn/v1',
+      });
+    }
+    return this._openai;
+  }
+
   /**
    * 增强型 RAG 检索对话 (Enterprise Grade: Hybrid Search + Rerank + Agentic Flow)
    */
@@ -110,7 +123,7 @@ export class AIService {
     // ... (保持不变)
     
     // 5. 流式生成响应
-    const stream = await openai.chat.completions.create({
+    const stream = await AIService.openai.chat.completions.create({
       model: model || MODEL,
       messages: [
         { 
@@ -158,7 +171,7 @@ ${context || '无本地知识库匹配。'}
 
   static async generateTitle(query: string, response: string): Promise<string> {
     try {
-      const completion = await openai.chat.completions.create({
+      const completion = await AIService.openai.chat.completions.create({
         model: MODEL,
         messages: [
           { 
@@ -319,7 +332,7 @@ ${context || '无本地知识库匹配。'}
   }
 
   static async getEmbedding(text: string): Promise<number[]> {
-    const response = await openai.embeddings.create({
+    const response = await AIService.openai.embeddings.create({
       model: 'BAAI/bge-m3',
       input: text.replace(/\n/g, ' ').slice(0, 8192),
     });

api/services/workflow.service.ts

@@ -63,10 +63,7 @@ export class WorkflowService {
     try {
       // 构造类似 Chat 的请求，直接利用 AIService 调用 OpenAI
       // 由于 AIService.chatWithKnowledge 是为 RAG 设计的，我们这里手动调用 openai 以获得更好的控制
-      const completion = await new OpenAI({
-        apiKey: process.env.OPENAI_API_KEY,
-        baseURL: process.env.OPENAI_API_BASE_URL || 'https://api.siliconflow.cn/v1',
-      }).chat.completions.create({
+      const completion = await AIService.openai.chat.completions.create({
         model: 'Qwen/Qwen2.5-7B-Instruct',
         messages: [
           { role: 'system', content: systemPrompt },