Update app.py

app.py

@@ -1,7 +1,7 @@
 import gradio as gr
 from pdf_bot import create_qa_chain_from_pdf
 
-qa_chain = None
+qa_chain = None  # Global chain reference
 
 css = """
 #chatbot { 
@@ -27,25 +27,22 @@ def upload_pdf(pdf_file_path):
         qa_chain = create_qa_chain_from_pdf(pdf_file_path)
         return gr.update(visible=True), f"✅ PDF `{pdf_file_path.split('/')[-1]}` loaded successfully!"
     except Exception as e:
-        qa_chain = None
         return gr.update(visible=False), f"❌ Error: {e}"
 
 def respond(message, chat_history):
     global qa_chain
     if qa_chain is None:
-        chat_history.append(("User", message))
-        chat_history.append(("Bot", "⚠️ Please upload a PDF first."))
-        return "", chat_history
-
+        return message, chat_history + [{"role": "assistant", "content": "⚠️ Please upload a PDF first."}]
+    
     try:
         result = qa_chain({"query": message})
         answer = result["result"]
-        chat_history.append(("User", message))
-        chat_history.append(("Bot", answer))
+        chat_history.append({"role": "user", "content": message})
+        chat_history.append({"role": "assistant", "content": answer})
         return "", chat_history
     except Exception as e:
-        chat_history.append(("User", message))
-        chat_history.append(("Bot", f"❌ Error: {e}"))
+        chat_history.append({"role": "user", "content": message})
+        chat_history.append({"role": "assistant", "content": f"❌ Error: {e}"})
         return "", chat_history
 
 def create_interface():
@@ -57,7 +54,8 @@ def create_interface():
 
         pdf_input = gr.File(label="Upload PDF", type="filepath", file_types=[".pdf"])
         status = gr.Markdown()
-        chatbot = gr.Chatbot(elem_id="chatbot", visible=False)
+
+        chatbot = gr.Chatbot(elem_id="chatbot", visible=False, type="messages")  # ✅ fixed type here
 
         examples = [
             "What are the admission requirements?",
@@ -87,4 +85,4 @@ def create_interface():
 
 if __name__ == "__main__":
     demo = create_interface()
-    demo.launch()
+    demo.launch()