handle empty tuples

app.py

@@ -26,7 +26,7 @@ def authenticate_and_generate(token, message, history, system_message, max_token
     system_message = str(system_message)
     
     # Construct the prompt with system message, history, and user input
-    history_str = "\n".join([f"User: {str(msg[0])}\nAssistant: {str(msg[1])}" for msg in history if str(msg[0]) and str(msg[1])])
+    history_str = "\n".join([f"User: {str(msg[0])}\nAssistant: {str(msg[1])}" for msg in history if isinstance(msg, (tuple, list)) and len(msg) == 2])
     prompt = system_message + "\n" + history_str
     prompt += f"\nUser: {message}\nAssistant:"