增加系统提示词，支持dify使用function call

main/xiaozhi-server/core/providers/llm/dify/dify.py

@@ -2,6 +2,7 @@ import json
 from config.logger import setup_logging
 import requests
 from core.providers.llm.base import LLMProviderBase
+from core.providers.llm.system_prompt import get_system_prompt_for_function
 
 TAG = __name__
 logger = setup_logging()
@@ -81,3 +82,23 @@ class LLMProvider(LLMProviderBase):
         except Exception as e:
             logger.bind(tag=TAG).error(f"Error in response generation: {e}")
             yield "【服务响应异常】"
+
+    def response_with_functions(self, session_id, dialogue, functions=None):    
+        if len(dialogue) == 2 and functions is not None and len(functions) > 0:
+            # 第一次调用llm， 取最后一条用户消息，附加tool提示词
+            last_msg = dialogue[-1]["content"]
+            function_str = json.dumps(functions, ensure_ascii=False)
+            modify_msg = get_system_prompt_for_function(function_str) + last_msg
+            dialogue[-1]["content"] = modify_msg 
+
+        # 如果最后一个是 role="tool"，附加到user上
+        if len(dialogue) > 1 and dialogue[-1]["role"] == "tool":
+            assistant_msg = "tool call result: " + dialogue[-1]["content"]
+            while len(dialogue) > 1 :
+                if dialogue[-1]["role"] == "user":
+                    dialogue[-1]["content"] += assistant_msg
+                    break
+                dialogue.pop()
+        
+        for token in self.response(session_id, dialogue):
+            yield token, None