add logs for investigation

sync/signals.py

@@ -96,7 +96,14 @@ def notify_impacted_users(instance):
 def save_model_log_if_possible(instance, signal, created):
 
     users = related_users_registry.get_users(instance.id)
-    # print(f'*** save_model_log >>> users = {users}, instance = {instance}')
+    logger.debug(f'*** save_model_log_if_possible >>> users from registry = {users}, instance = {instance}')
+
+    if not users:
+        logger.warning(f'!!! Registry returned empty users for instance {instance.id} ({instance.__class__.__name__})')
+        # Try to recalculate users as fallback
+        users = related_users(instance)
+        logger.info(f'!!! Recalculated users for fallback: {users}')
+
     if users:
         if signal == post_save or signal == pre_save:
             if created:
@@ -128,8 +135,11 @@ def save_model_log(users, model_operation, model_name, model_id, store_id):
 
     logger.info(f'*** creating ModelLogs for: {model_operation} {model_name} : {users}')
 
+    try:
         with transaction.atomic():
+            created_logs = []
             for user in users:
+                logger.debug(f'Creating ModelLog for user {user.id} ({user.username})')
                 model_log = ModelLog(
                     user=user,
                     operation=model_operation,
@@ -139,6 +149,21 @@ def save_model_log(users, model_operation, model_name, model_id, store_id):
                     device_id=device_id
                 )
                 model_log.save()
+                created_logs.append(model_log.id)
+                logger.debug(f'Successfully created ModelLog {model_log.id}')
+
+            logger.info(f'*** Successfully created {len(created_logs)} ModelLogs: {created_logs}')
+
+            # Verify ModelLogs were actually persisted
+            persisted_count = ModelLog.objects.filter(id__in=created_logs).count()
+            if persisted_count != len(created_logs):
+                logger.error(f'*** PERSISTENCE VERIFICATION FAILED! Created {len(created_logs)} ModelLogs but only {persisted_count} were persisted to database')
+            else:
+                logger.debug(f'*** PERSISTENCE VERIFIED: All {persisted_count} ModelLogs successfully persisted')
+
+    except Exception as e:
+        logger.error(f'*** FAILED to create ModelLogs for: {model_operation} {model_name}, users: {[u.id for u in users]}, error: {e}', exc_info=True)
+        raise
 
     # with transaction.atomic():
     #     for user in users: