Add function to convert user input prompt into query

app.py

@@ -77,7 +77,41 @@ def query_or_respond(state: MessagesState):
     llm_with_tools = llm.bind_tools([retrieve])
     response = llm_with_tools.invoke(state["messages"], config={"callbacks": [langfuse_handler]})
     # MessagesState appends messages to state instead of overwriting
-    return {"messages": [response]}
+    return {"messages": [response]} 
+
+def trigger_ai_message_with_tool_call(state: MessagesState) -> AIMessage:
+    """
+    Takes the last user message from the state and returns an AIMessage
+    with example tool_calls populated.
+    
+    Args:
+        state (dict): A dictionary with a 'messages' key containing a list of LangChain messages.
+
+    Returns:
+        AIMessage: An AIMessage with tool_calls based on the last user message.
+    """
+    
+    # Filter for user messages
+    user_messages = [msg for msg in state["messages"] if isinstance(msg, HumanMessage)]
+    
+    if not user_messages:
+        raise ValueError("No user messages found in the previous messages.")
+    
+    last_user_msg = user_messages[-1]
+
+    tool_call = ToolCall(
+        name="retrieve",
+        args={"query": last_user_msg.content},
+        id="tool_call_1"
+    )
+
+    # Construct the AIMessage with tool_calls
+    ai_message = AIMessage(
+        content="Calling the retrieve function...",
+        tool_calls=[tool_call]
+    )
+
+    return {"messages": [ai_message]}
 
 
 graph_builder = StateGraph(MessagesState)