refactor: reorganize LLM handler structure and improve tool call parsing

application/llm/handlers/handler_creator.py

@@ -0,0 +1,18 @@
+from application.llm.handlers.base import LLMHandler
+from application.llm.handlers.google import GoogleLLMHandler
+from application.llm.handlers.openai import OpenAILLMHandler
+
+
+class LLMHandlerCreator:
+    handlers = {
+        "openai": OpenAILLMHandler,
+        "google": GoogleLLMHandler,
+        "default": OpenAILLMHandler,
+    }
+
+    @classmethod
+    def create_handler(cls, llm_type: str, *args, **kwargs) -> LLMHandler:
+        handler_class = cls.handlers.get(llm_type.lower())
+        if not handler_class:
+            raise ValueError(f"No LLM handler class found for type {llm_type}")
+        return handler_class(*args, **kwargs)