🔧 Fix: Correct chat message format in investigation chatbot

app.py

@@ -839,31 +839,27 @@ with gr.Blocks(
                     )
         
         # =====================================================
-        # Chat Interface Logic
+        # Chat Interface Logic - FIXED MESSAGE FORMAT
         # =====================================================
         
-        # Main investigation button click handler - OPTIMIZED FOR SPEED
         def investigate_fast(message, chat_history, conv_state, inv_results):
-            """Fast response without waiting for analysis"""
+            """Fast response - append to chat immediately"""
             if not message or len(str(message).strip()) < 2:
-                if not chat_history:
-                    chat_history = []
-                return chat_history, conv_state, inv_results
+                # Return current state unchanged
+                return chat_history if chat_history else [], conv_state or [], inv_results or {}
             
-            if not chat_history:
-                chat_history = []
+            # Ensure chat_history is a list
+            history = list(chat_history) if chat_history else []
             
             msg_str = str(message).strip()
             
-            # Quick immediate response
-            response = "🔍 Analyzing... Please wait for insights."
-            updated_history = list(chat_history) if chat_history else []
-            updated_history.append([msg_str, response])
+            # Add user message + loading response as [user, bot] tuple
+            history.append([msg_str, "🔍 Analyzing... Please wait for insights."])
             
-            return updated_history, conv_state + [msg_str], inv_results
+            return history, (conv_state or []) + [msg_str], inv_results or {}
         
         def investigate_complete(message):
-            """Background investigation with full analysis"""
+            """Get investigation results"""
             try:
                 result = ask_investigation_question(message)
                 return result
@@ -872,13 +868,19 @@ with gr.Blocks(
                     "status": "error",
                     "message": f"Error: {str(e)[:80]}",
                     "analysis": {},
-                    "data_preview": []
+                    "data_preview": [],
+                    "total_records": 0
                 }
         
         def update_chat_final(message, chat_history, inv_results):
-            """Update chat with real results"""
-            if not chat_history or not message:
-                return chat_history, inv_results
+            """Update last message with real results"""
+            if not message:
+                return chat_history or [], inv_results or {}
+            
+            # Ensure chat_history is a list
+            history = list(chat_history) if chat_history else []
+            if not history:
+                return history, inv_results or {}
             
             try:
                 # Get investigation result
@@ -890,22 +892,22 @@ with gr.Blocks(
                     ai_response = result.get("answer", "Investigation complete")
                     analysis = result.get("analysis", {})
                     
-                    # Quick summary
+                    # Add quick summary
                     ai_response += f"\n\n**Summary:** {result.get('total_records', 0)} records | {analysis.get('unique_vehicles', 0)} vehicles | {analysis.get('unique_locations', 0)} locations"
                 
-                # Update last message
-                updated = list(chat_history)
-                if updated and updated[-1]:
-                    updated[-1][1] = ai_response
+                # Update last message [user, bot] tuple
+                if history:
+                    history[-1] = [history[-1][0], ai_response]
                 
-                return updated, result
+                return history, result
             except Exception as e:
-                return chat_history, inv_results
+                print(f"Chat update error: {e}")
+                return history, inv_results or {}
         
         def update_detailed_tabs_lightweight(inv_results):
-            """Lightweight tab updates"""
+            """Update detailed analysis tabs"""
             if not inv_results or inv_results.get("status") == "error":
-                return ("No data", "No findings", None, "No metrics")
+                return ("No data available", "No findings yet", None, "No metrics")
             
             try:
                 analysis = inv_results.get("analysis", {})
@@ -914,11 +916,27 @@ with gr.Blocks(
                 # Summary
                 data_info = f"📊 **{total} records** | 🚗 **{analysis.get('unique_vehicles', 0)} vehicles** | 📍 **{analysis.get('unique_locations', 0)} locations**"
                 
-                # Findings (limit to 3)
-                findings = "**Key Findings:**\n" + "\n".join([f"• {f}" for f in analysis.get("key_findings", [])[:3]])
+                # Findings
+                findings_list = analysis.get("key_findings", [])
+                findings = "**Key Findings:**\n" + "\n".join([f"• {f}" for f in findings_list[:3]]) if findings_list else "No key findings"
                 
                 # Data table (limit to 20 rows)
                 df_data = None
+                try:
+                    preview = inv_results.get("data_preview", [])[:20]
+                    if preview:
+                        df_data = pd.DataFrame(preview)
+                except Exception as e:
+                    print(f"DataFrame error: {e}")
+                
+                # Metrics
+                metrics = f"**Confidence:** {analysis.get('confidence_score', 0):.0%}\n**Records:** {total}"
+                
+                return (data_info, findings, df_data, metrics)
+            except Exception as e:
+                print(f"Tab update error: {e}")
+                return ("Error processing data", "Error", None, "Error")
+                df_data = None
                 try:
                     preview = inv_results.get("data_preview", [])[:20]
                     if preview: