add message send tasks and respect dynamic send setting

shiftregister/app/migrations/0002_message_sent_at.py

@@ -0,0 +1,18 @@
+# Generated by Django 4.0.4 on 2022-04-27 16:47
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("app", "0001_initial"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="message",
+            name="sent_at",
+            field=models.DateTimeField(null=True),
+        ),
+    ]

shiftregister/app/models.py

@@ -103,6 +103,7 @@ class Message(models.Model):
     text = models.CharField(max_length=160)
     to = models.ForeignKey(Helper, on_delete=models.CASCADE)
     created_at = models.DateTimeField(auto_now_add=True)
+    sent_at = models.DateTimeField(null=True)
 
     def __str__(self):
         return f"{self.to.name}({self.created_at}): {self.text}"
@@ -127,6 +128,10 @@ class LoginToken(models.Model):
         msg.save()
         self.sent_at = timezone.now()
         self.save()
+        # import here to break import cycle
+        from .tasks import send_message
+
+        send_message.apply_async((msg.pk,))
 
     def get_absolute_url(self):
         return reverse("token_login", kwargs={"token": self.id})

shiftregister/app/tasks.py

@@ -1,6 +1,38 @@
 from celery import shared_task
+from .models import Message
+from django.db import transaction
+from django.utils import timezone
+from dynamic_preferences.registries import global_preferences_registry
 
+global_preferences = global_preferences_registry.manager()
 
+# cron task to send normal messages(reminders,changes) in batches
 @shared_task
-def test():
-    return "Hello, Celery!"
+def send_messages():
+    if not global_preferences["helper__send_sms"]:
+        print("sms disabled, not sending")
+        return
+    with transaction.atomic():
+        for msg in Message.objects.select_for_update().filter(sent_at__isnull=True):
+            if msg.sent_at:
+                continue
+            print(f"TODO: send message @{msg.to.phone} {msg.text}")
+            msg.sent_at = timezone.now()
+            msg.save()
+
+
+# singlemessage so registration links arrive faster.
+# will silently fail when messages are disabled.
+# those messages will be picked up by the cron send later
+# once we have decided to continue sending messages
+@shared_task
+def send_message(msgid):
+    if not global_preferences["helper__send_sms"]:
+        return
+    with transaction.atomic():
+        msg = Message.objects.select_for_update().get(pk=msgid)
+        if msg.sent_at:
+            return
+        print(f"TODO: send message @{msg.to.phone} {msg.text}")
+        msg.sent_at = timezone.now()
+        msg.save()