Update app.py

Fix messages in chat

app.py

@@ -55,17 +55,17 @@ def get_llm_answer(pdf_text, question, history):
     if they have serious concerns whenever appropriate.'''
 
     # Construct the message payload for the API.
-    messages = [{"role": "system", "content": system_prompt}]
-    
-    # Add document context if available.
-    if context:
-        messages.append({"role": "user", "content": f"Use the following document to answer my question:\n\n{context}"})
+    messages = [{"role": "system", "content": system_prompt}, 
+                {"role": "user", "content": f"Use the following document to answer my question:\n\n{context}"}, 
+                {"role":"user", "content": f"Question: {question}"}
+    ]
 
     # Add the conversation history.
     if history:
-        messages.extend(history)
-
-    # Add the latest user question.
+        for msg in history:
+            if msg["role"] in ["user", "assistant"]:
+                messages.append(msg)
+    # Add the new user question
     messages.append({"role": "user", "content": question})
 
     try:
@@ -103,16 +103,22 @@ class PDFChatbot:
         return f"Status: Successfully processed {self.pdf_filename}. You can now ask questions."
 
     def chat(self, user_message, history):
-        if not self.pdf_text:
+        if self.pdf_text is None:
             # Add an instruction to the chatbot window if no PDF is uploaded.
-            history.append([user_message, "Please upload a PDF document first."])
-            return "", history
-
+            #history.append([user_message, "Please upload a PDF document first."])
+            return "Please upload a PDF document first.", history
+        
+        if history is None:
+            history = []
+        context_history = [msg for msg in history if msg["role"] in ["user", "assistant"]]
         # Get the answer from the LLM.
-        answer = get_llm_answer(self.pdf_text, user_message, history)
+        answer = get_llm_answer(self.pdf_text, user_message, context_history)
         
         # Append the user message and the assistant's answer to the history.
-        history.append([user_message, answer])
+        history = history + [
+            {"role": "user", "content": user_message }, 
+            {"role": "assistant", "content": answer }
+        ]
         
         # Return an empty string to clear the input textbox and the updated history.
         return "", history
@@ -131,7 +137,7 @@ with gr.Blocks(theme=gr.themes.Soft()) as demo:
             upload_status = gr.Textbox(label="Status", interactive=False, value="Status: Waiting for PDF...")
         
         with gr.Column(scale=2):
-            chatbot = gr.Chatbot(label="Chat History", bubble_full_width=False, height=500)
+            chatbot = gr.Chatbot(type="messages", label="Chat History", height=500)
             msg_textbox = gr.Textbox(label="Your Question:", interactive=True, placeholder="Type your question here...")
             # Clear button is useful for starting a new conversation.
             clear_btn = gr.ClearButton([msg_textbox, chatbot], value="Clear Chat")