Change final answer extraction

app.py

@@ -22,27 +22,45 @@ class BasicAgent:
         messages = [HumanMessage(content=question)]
         try:
             result = self.graph.invoke({"messages": messages})
+            print("Graph result:", result)
 
-            if not result.get("messages") or len(result["messages"]) == 0:
-                raise ValueError("No messages returned from the graph")
+            if not result or "messages" not in result:
+                print("❌ Graph returned no 'messages' key.")
+                return "I cannot answer that"
+
+            if not result["messages"]:
+                print("❌ Graph returned empty messages list.")
+                return "I cannot answer that"
 
             last_message = result["messages"][-1].content
+            print("🔁 Last message:", repr(last_message))
 
-            final_answer = "I cannot answer that"
+            if not last_message or not last_message.strip():
+                print("❌ Last message is empty or whitespace.")
+                return "I cannot answer that"
 
+            # Try extracting with "FINAL ANSWER:"
             match = re.search(r"(?i)final\s*answer\s*[:\-]?\s*(.+)", last_message, re.DOTALL)
             if match:
-                final_answer = match.group(1).strip()
-            else:
-               # Try to find a name or string answer
-                candidates = [line.strip() for line in last_message.split("\n") if line.strip()]
-                final_answer = next((line for line in reversed(candidates) if len(line.split()) <= 5), last_message.strip())
-
-            return final_answer
-        except Exception as e: 
-            print("Agent processing failed")
-            return
-       
+                final = match.group(1).strip()
+                print("✅ Extracted FINAL ANSWER:", final)
+                return final
+
+            # Fallback: last short non-empty line
+            lines = [line.strip() for line in last_message.split("\n") if line.strip()]
+            for line in reversed(lines):
+                if len(line.split()) <= 5:
+                    print("⚠️ Fallback final answer:", line)
+                    return line
+
+            print("⚠️ No extractable short line; fallback to full last message")
+            return last_message.strip()
+
+        except Exception as e:
+            import traceback
+            traceback.print_exc()
+            print("❌ Exception in agent call:", str(e))
+            return "I cannot answer that"
             
 
 def run_and_submit_all( profile: gr.OAuthProfile | None):