Fix: Use proper Gradio Chatbot format with role/content dictionaries

app.py

@@ -647,52 +647,82 @@ with gr.Blocks(
         def chat_investigate(message, chat_history, conv_state, inv_results):
             """Process investigation with chat-like conversational flow"""
             
-            if not message or len(message.strip()) < 2:
+            # Validate input
+            if not message or len(str(message).strip()) < 2:
                 if not chat_history:
                     chat_history = []
                 return chat_history, conv_state, inv_results
             
-            # Ensure chat_history is a list
-            if chat_history is None:
+            # Initialize empty history if needed
+            if not chat_history:
                 chat_history = []
             
-            # Run investigation
-            result = ask_investigation_question(message)
-            
-            # Format response for chat
-            if result.get("status") == "error":
-                error_msg = result.get("message", "Investigation failed")
-                ai_response = f"Error: {error_msg}"
-            else:
-                # Build comprehensive response for chat
-                answer = result.get("answer", "")
-                analysis = result.get("analysis", {})
-                
-                ai_response = f"""Investigation Results
-
-Summary: {result.get('total_records', 0)} records retrieved | {analysis.get('unique_vehicles', 0)} vehicles | {analysis.get('unique_locations', 0)} locations
-
-Analysis: {answer}
-"""
+            try:
+                # Run investigation
+                result = ask_investigation_question(message)
                 
-                # Add key findings
-                if analysis.get("key_findings"):
-                    ai_response += "\nKey Findings:\n"
-                    for finding in analysis.get("key_findings", [])[:3]:
-                        ai_response += f"- {finding}\n"
+                # Format response for chat
+                if result.get("status") == "error":
+                    error_msg = result.get("message", "Investigation failed")
+                    ai_response = f"Error: {error_msg}"
+                else:
+                    # Build comprehensive response for chat
+                    answer = result.get("answer", "")
+                    analysis = result.get("analysis", {})
+                    
+                    ai_response = f"""Investigation Results
+
+Summary: {result.get('total_records', 0)} records | {analysis.get('unique_vehicles', 0)} vehicles | {analysis.get('unique_locations', 0)} locations
+
+{answer}"""
+                    
+                    # Add key findings
+                    findings = analysis.get("key_findings", [])
+                    if findings:
+                        ai_response += "\n\nKey Findings:"
+                        for finding in findings[:3]:
+                            ai_response += f"\n- {finding}"
+                    
+                    # Store full results for detailed tabs
+                    inv_results = result
                 
-                # Store full results for detailed tabs
-                inv_results = result
-            
-            # Add complete [user, assistant] pair to chat history
-            try:
+                # Create proper Gradio format with role/content
                 msg_str = str(message).strip()
                 resp_str = str(ai_response).strip()
-                chat_history = list(chat_history) + [[msg_str, resp_str]]
+                
+                new_msg = {
+                    "role": "user",
+                    "content": msg_str
+                }
+                new_response = {
+                    "role": "assistant", 
+                    "content": resp_str
+                }
+                
+                # Add to chat history
+                updated_history = list(chat_history) if chat_history else []
+                updated_history.append(new_msg)
+                updated_history.append(new_response)
+                
+                return updated_history, conv_state + [msg_str], inv_results
+                
             except Exception as e:
-                print(f"Chat formatting error: {e}")
-            
-            return chat_history, conv_state + [message], inv_results
+                # Error handling
+                error_str = f"Error: {str(e)[:100]}"
+                msg_dict = {
+                    "role": "user",
+                    "content": str(message).strip()
+                }
+                error_dict = {
+                    "role": "assistant",
+                    "content": error_str
+                }
+                
+                updated_history = list(chat_history) if chat_history else []
+                updated_history.append(msg_dict)
+                updated_history.append(error_dict)
+                
+                return updated_history, conv_state, inv_results
         
         def update_detailed_tabs(inv_results):
             """Update detailed tabs based on investigation results"""