完成RAG测试

backend/services/llm_service.py

@@ -93,5 +93,28 @@ class LLMService:
             logger.error(f"Rerank Exception: {e}")
             # 降级策略
             return documents[:top_n]
+    def chat(self, prompt: str, system_prompt: str = None, model: str = "qwen-turbo") -> str:
+        """
+        [新增] 通用对话生成接口，用于RAG的最终回答或作为测试裁判(Judge)
+        """
+        messages = []
+        if system_prompt:
+            messages.append({'role': 'system', 'content': system_prompt})
+        messages.append({'role': 'user', 'content': prompt})
 
+        try:
+            resp = dashscope.Generation.call(
+                model=model,
+                messages=messages,
+                result_format='message'
+            )
+            if resp.status_code == HTTPStatus.OK:
+                return resp.output.choices[0].message.content
+            else:
+                logger.error(f"Chat API Error: {resp}")
+                return "Error generating response."
+        except Exception as e:
+            logger.error(f"Chat Exception: {e}")
+            return "Error generating response."
+        
 llm_service = LLMService()