refactoring LLM adapters and service layer

src/text_generation/services/language_models/language_model_response_service.py

@@ -1,10 +1,14 @@
-import abc
+from src.text_generation.services.language_models.abstract_language_model_response_service import AbstractLanguageModelResponseService
+from src.text_generation.adapters.llm.language_model import LanguageModel
 
-class AbstractLanguageModelResponseService(abc.ABC):
-    @abc.abstractmethod
-    def invoke(self, user_input: str) -> str:
-        raise NotImplementedError
 
-class LanguageModelResponseService(AbstractLanguageModelResponseService):
-    def __call__(self, *args, **kwds):
-        pass
+class TextGenerationResponseService(AbstractLanguageModelResponseService):
+    
+    def invoke(self, user_prompt: str) -> str:
+
+        if not user_prompt:
+            raise ValueError(f"Parameter 'user_prompt' cannot be empty or None")
+        
+        llm = LanguageModel()
+        response = llm.invoke(user_prompt=user_prompt)
+        return response