Refactor app.py for lazy loading to fix Space timeout

app.py

@@ -24,22 +24,32 @@ app_state = {
     'demo_data': None,
     'demo_labels': None,
     'composition_active': False,
-    'auto_mode': False
+    'auto_mode': False,
+    'ch_names': None
 }
 
-sound_manager = SoundManager()
-data_processor = EEGDataProcessor()
-classifier = MotorImageryClassifier()
+sound_manager = None
+data_processor = None
+classifier = None
 
-# Load demo data
-existing_files = [f for f in DEMO_DATA_PATHS if os.path.exists(f)]
-if existing_files:
-    app_state['demo_data'], app_state['demo_labels'], app_state['ch_names'] = data_processor.process_files(existing_files)
-else:
-    app_state['demo_data'], app_state['demo_labels'], app_state['ch_names'] = None, None, None
-
-if app_state['demo_data'] is not None:
-    classifier.load_model(n_chans=app_state['demo_data'].shape[1], n_times=app_state['demo_data'].shape[2])
+def lazy_init():
+    global sound_manager, data_processor, classifier
+    if sound_manager is None:
+        sound_manager = SoundManager()
+    if data_processor is None:
+        data_processor = EEGDataProcessor()
+    if classifier is None:
+        classifier = MotorImageryClassifier()
+    # Load demo data and model if not already loaded
+    if app_state['demo_data'] is None or app_state['demo_labels'] is None or app_state['ch_names'] is None:
+        existing_files = [f for f in DEMO_DATA_PATHS if os.path.exists(f)]
+        if existing_files:
+            app_state['demo_data'], app_state['demo_labels'], app_state['ch_names'] = data_processor.process_files(existing_files)
+        else:
+            app_state['demo_data'], app_state['demo_labels'], app_state['ch_names'] = None, None, None
+    if app_state['demo_data'] is not None and classifier is not None and not hasattr(classifier, '_model_loaded'):
+        classifier.load_model(n_chans=app_state['demo_data'].shape[1], n_times=app_state['demo_data'].shape[2])
+        classifier._model_loaded = True
 
 # --- Helper Functions ---
 def get_movement_sounds() -> Dict[str, str]:
@@ -153,6 +163,7 @@ def start_composition():
     Start the composition process.
     '''
     global app_state
+    lazy_init()
     if not app_state['composition_active']:
         app_state['composition_active'] = True
         sound_manager.start_new_cycle()
@@ -182,17 +193,14 @@ def start_composition():
     else:
         result = {'sound_added': False}
     fig = create_eeg_plot(epoch_data, true_label_name, predicted_name, confidence, result['sound_added'], app_state.get('ch_names'))
-    
     # Only play completed movement sounds (layered)
     sounds = get_movement_sounds()
     completed_movements = sound_manager.movements_completed
-
     # Assign audio paths only for completed movements
     left_hand_audio = sounds.get('left_hand') if 'left_hand' in completed_movements else None
     right_hand_audio = sounds.get('right_hand') if 'right_hand' in completed_movements else None
     left_leg_audio = sounds.get('left_leg') if 'left_leg' in completed_movements else None
     right_leg_audio = sounds.get('right_leg') if 'right_leg' in completed_movements else None
-
     # 2. Movement Commands: show mapping for all movements
     movement_emojis = {
         "left_hand": "🫲",
@@ -200,7 +208,6 @@ def start_composition():
         "left_leg": "🦵",
         "right_leg": "🦵",
     }
-
     movement_command_lines = []
     # Show 'Now Playing' for all completed movements (layers that are currently playing)
     completed_movements = sound_manager.movements_completed
@@ -224,10 +231,8 @@ def start_composition():
         else:
             movement_command_lines.append(f"{emoji} {pretty_movement}: {pretty_instrument}")
     movement_command_text = "🎼 Composition Mode - Movement to Stems Mapping\n" + "\n".join(movement_command_lines)
-
     # 3. Next Trial: always prompt user
     next_trial_text = "Imagine next movement"
-
     composition_info = sound_manager.get_composition_info()
     status_text = format_composition_summary(composition_info)
     return (
@@ -578,4 +583,4 @@ if __name__ == "__main__":
     demo = create_interface()
     demo.launch(server_name="0.0.0.0", server_port=7867)
 
-    
+