users/management/commands/send_notifications.py

@@ -1,5 +1,4 @@
 """Send user notifications as emails, at most once delivery."""
-from collections import defaultdict
 import logging
 
 from django.conf import settings
@@ -15,37 +14,33 @@ logger.setLevel(logging.INFO)
 
 class Command(BaseCommand):
     def handle(self, *args, **options):  # noqa: D102
-        logger.info('start, checking for outstanding notifications')
-        notifications = Notification.objects.filter(processed_by_mailer_at=None)
-        batched_by_recipient = defaultdict(list)
-        for n in notifications:
-            batched_by_recipient[n.recipient].append(n)
-
-        for recipient, batch in batched_by_recipient.items():
-            to_send = []
-            for n in batch:
+        unprocessed_notifications = Notification.objects.filter(processed_by_mailer_at=None)
+        for n in unprocessed_notifications:
+            logger.info(f'processing Notification pk={n.pk}')
             n.processed_by_mailer_at = timezone.now()
+            recipient = n.recipient
             if not recipient.is_subscribed_to_notification_emails:
+                logger.info(f'{recipient} is not subscribed, skipping')
+                n.save()
                 continue
             # check that email is confirmed to avoid spamming unsuspecting email owners
             if recipient.confirmed_email_at is None:
+                logger.info(f'{recipient} has unconfirmed email, skipping')
+                n.save()
                 continue
             n.sent = True
-                to_send.append(n)
             # first mark as processed, then send: avoid spamming in case of a crash-loop
-            Notification.objects.bulk_update(batch, ['processed_by_mailer_at', 'sent'])
-            if len(to_send) > 0:
-                logger.info(f'sending an email to {recipient} about {len(to_send)} notifications')
-                send_batch_notification_email(recipient, to_send)
-        logger.info('finish')
+            n.save()
+            logger.info(f'sending an email to {recipient}: {n.action}')
+            send_notification_email(n)
 
 
-def send_batch_notification_email(recipient, notifications):
+def send_notification_email(notification):
     subject = 'New activity'
-    message = '\n\n'.join([n.format_email_txt() for n in notifications])
+    message = notification.format_email_txt()
     send_mail(
         subject,
         message,
         settings.DEFAULT_FROM_EMAIL,
-        [recipient.email],
+        [notification.recipient.email],
     )