Update app.py

app.py

@@ -26,25 +26,29 @@ def respond(user_message, history):
     """
     user_message = user_message.strip().lower()
 
-    # ✅ If user selects a method, ask them to explain their reasoning
-    if user_message in ["bar model", "double number line", "equation"]:
-        response = get_prompt_for_method(user_message)
-        history.append((user_message, response))
-        return "", history
-
-    # ✅ If AI expects an explanation, process the response
-    elif len(history) > 0 and history[-1][1] in [
+    # ✅ Check if the last message in history was a method selection prompt
+    if history and history[-1][1] in [
         get_prompt_for_method("bar model"),
         get_prompt_for_method("double number line"),
         get_prompt_for_method("equation")
     ]:
+        # ✅ Retrieve the last selected method
         last_method = history[-1][1].split("**")[1].split(" ")[0].lower()
         response = get_feedback_for_method(last_method, user_message)
         history.append((user_message, response))
         return "", history
 
-    # ✅ Default response if the message is unclear
-    return "I didn’t understand that. Please select a method first (Bar Model, Double Number Line, or Equation).", history
+    # ✅ If user selects a method, ask them to explain their reasoning
+    if user_message in ["bar model", "double number line", "equation"]:
+        response = get_prompt_for_method(user_message)
+        history.append((user_message, response))
+        return "", history
+
+    # ✅ Default response if input is unclear and no method has been selected
+    if not history or history[-1][0] not in ["bar model", "double number line", "equation"]:
+        return "I didn’t understand that. Please select a method first (Bar Model, Double Number Line, or Equation).", history
+
+    return "", history  # ✅ Keep the conversation flowing without errors
 
 # ✅ Gradio UI Setup
 with gr.Blocks() as demo: