feat(alert-system): update related montandon event query

Author: sudip-khanal

alert_system/admin.py

@@ -49,11 +49,11 @@ class LoadItemAdmin(admin.ModelAdmin):
 class AlertEmailThreadAdmin(admin.ModelAdmin):
     list_display = (
         "user",
-        "parent_guid",
+        "parent_event_id",
         "root_email_message_id",
     )
     search_fields = (
-        "parent_guid",
+        "parent_event_id",
         "root_email_message_id",
         "user__username",
     )

alert_system/email_processing.py

@@ -66,14 +66,15 @@ def send_alert_email_notification(
         if not is_reply:
             thread = AlertEmailThread.objects.create(
                 user=user,
-                parent_guid=load_item.parent_guid,
+                parent_event_id=load_item.parent_event_id,
                 root_email_message_id=message_id,
                 root_message_sent_at=timezone.now(),
             )
             email_log.thread = thread
             email_log.save(update_fields=["thread"])
             logger.info(
-                f"Alert Email thread created for user [{user.get_full_name()}] " f"with parent_guid [{load_item.parent_guid}]"
+                f"Alert Email thread created for user [{user.get_full_name()}] "
+                f"with parent event [{load_item.parent_event_id}]"
             )
 
         logger.info(f"Alert email sent to [{user.get_full_name()}] for LoadItem ID [{load_item.id}]")
@@ -127,7 +128,7 @@ def process_email_alert(load_item_id: int) -> None:
     existing_threads = {
         thread.user_id: thread
         for thread in AlertEmailThread.objects.filter(
-            parent_guid=load_item.parent_guid,
+            parent_event_id=load_item.parent_event_id,
             user_id__in=user_ids,
         )
     }

alert_system/factories.py

@@ -6,7 +6,9 @@
 
 
 class LoadItemFactory(factory.django.DjangoModelFactory):
-    guid = factory.LazyFunction(lambda: str(uuid4()))
+    parent_event_id = factory.LazyFunction(lambda: str(uuid4()))
+    event_id = factory.LazyFunction(lambda: str(uuid4()))
+    event_url = factory.Sequence(lambda n: f"https://test-events.com/event/{n}")
 
     class Meta:
         model = LoadItem

alert_system/migrations/0002_remove_alertemailthread_unique_user_guid_and_more.py

@@ -0,0 +1,34 @@
+# Generated by Django 4.2.30 on 2026-05-18 08:24
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('alert_system', '0001_initial'),
+    ]
+
+    operations = [
+        migrations.RemoveConstraint(
+            model_name='alertemailthread',
+            name='unique_user_guid',
+        ),
+        migrations.RemoveIndex(
+            model_name='alertemailthread',
+            name='alert_syste_parent__737a31_idx',
+        ),
+        migrations.RenameField(
+            model_name='alertemailthread',
+            old_name='parent_guid',
+            new_name='parent_event_id',
+        ),
+        migrations.AddIndex(
+            model_name='alertemailthread',
+            index=models.Index(fields=['parent_event_id', 'user'], name='alert_syste_parent__7efaa4_idx'),
+        ),
+        migrations.AddConstraint(
+            model_name='alertemailthread',
+            constraint=models.UniqueConstraint(fields=('parent_event_id', 'user'), name='unique_user_parent_event'),
+        ),
+    ]

alert_system/models.py

@@ -280,8 +280,8 @@ class AlertEmailThread(models.Model):
         on_delete=models.CASCADE,
         related_name="alert_email_threads",
     )
-
-    parent_guid = models.CharField(
+    # NOTE: parent_event_id field is same field form the LoadItem model.
+    parent_event_id = models.CharField(
         help_text=_("Identifier linking related LoadItems into the same email thread."),
     )
 
@@ -304,13 +304,13 @@ class Meta:
         verbose_name = _("Email Thread")
         verbose_name_plural = _("Email Threads")
         ordering = ["-id"]
-        constraints = [models.UniqueConstraint(fields=["parent_guid", "user"], name="unique_user_guid")]
+        constraints = [models.UniqueConstraint(fields=["parent_event_id", "user"], name="unique_user_parent_event")]
         indexes = [
-            models.Index(fields=["parent_guid", "user"]),
+            models.Index(fields=["parent_event_id", "user"]),
         ]
 
     def __str__(self):
-        return f"Thread: {self.user.get_full_name()}-{self.parent_guid}"
+        return f"Thread: {self.user.get_full_name()}-{self.parent_event_id}"
 
 
 class AlertEmailLog(models.Model):

alert_system/tests.py

@@ -60,7 +60,7 @@ def setUp(self):
         )
 
         self.eligible_item = LoadItemFactory.create(
-            parent_guid=str(uuid4()),
+            parent_event_id=str(uuid4()),
             connector=self.connector,
             item_eligible=True,
             is_past_event=False,
@@ -107,7 +107,7 @@ def test_sent_email_for_eligible_item(self, mock_send_notification):
         self.assertIsNotNone(log.email_sent_at)
 
         self.assertEqual(thread.user, self.user1)
-        self.assertEqual(thread.parent_guid, self.eligible_item.parent_guid)
+        self.assertEqual(thread.parent_event_id, self.eligible_item.parent_event_id)
         self.assertEqual(thread.root_email_message_id, log.message_id)
         self.assertEqual(log.thread, thread)
 
@@ -121,7 +121,7 @@ def test_sent_email_to_multiple_users(self, mock_send_notification):
         logs = AlertEmailLog.objects.filter(item=self.eligible_item, status=AlertEmailLog.Status.SENT)
         self.assertEqual(logs.count(), 2)
 
-        threads = AlertEmailThread.objects.filter(parent_guid=self.eligible_item.parent_guid)
+        threads = AlertEmailThread.objects.filter(parent_event_id=self.eligible_item.parent_event_id)
         self.assertEqual(threads.count(), 2)
 
         self.assertEqual(mock_send_notification.call_count, 2)
@@ -217,7 +217,7 @@ def test_reply_email_for_existing_thread(self, mock_send_notification):
         )
 
         initial_item = LoadItemFactory.create(
-            parent_guid=str(uuid4()),
+            parent_event_id=str(uuid4()),
             connector=self.connector,
             item_eligible=True,
             is_past_event=False,
@@ -231,7 +231,7 @@ def test_reply_email_for_existing_thread(self, mock_send_notification):
 
         thread = AlertEmailThreadFactory.create(
             user=user,
-            parent_guid=initial_item.parent_guid,
+            parent_event_id=initial_item.parent_event_id,
             root_email_message_id=str(uuid4()),
             root_message_sent_at=timezone.now(),
         )
@@ -247,7 +247,7 @@ def test_reply_email_for_existing_thread(self, mock_send_notification):
         )
 
         update_item = LoadItemFactory.create(
-            parent_guid=initial_item.parent_guid,
+            parent_event_id=initial_item.parent_event_id,
             connector=self.connector,
             item_eligible=True,
             is_past_event=False,
@@ -267,17 +267,17 @@ def test_reply_email_for_existing_thread(self, mock_send_notification):
 
         mock_send_notification.assert_called_once()
 
-        threads = AlertEmailThread.objects.filter(parent_guid=initial_item.parent_guid)
+        threads = AlertEmailThread.objects.filter(parent_event_id=initial_item.parent_event_id)
         self.assertEqual(threads.count(), 1)
 
     @mock.patch("alert_system.email_processing.send_notification")
     def test_reply_email_to_multiple_users(self, mock_send_notification):
 
-        parent_guid = str(uuid4())
+        parent_event_id = str(uuid4())
 
         # Create initial item
         initial_item = LoadItemFactory.create(
-            parent_guid=parent_guid,
+            parent_event_id=parent_event_id,
             connector=self.connector,
             item_eligible=True,
             is_past_event=False,
@@ -292,14 +292,14 @@ def test_reply_email_to_multiple_users(self, mock_send_notification):
         # Create threads for both users
         thread1 = AlertEmailThreadFactory.create(
             user=self.user1,
-            parent_guid=parent_guid,
+            parent_event_id=parent_event_id,
             root_email_message_id="message-id-1",
             root_message_sent_at=timezone.now(),
         )
 
         thread2 = AlertEmailThreadFactory.create(
             user=self.user2,
-            parent_guid=parent_guid,
+            parent_event_id=parent_event_id,
             root_email_message_id="message-id-2",
             root_message_sent_at=timezone.now(),
         )
@@ -325,7 +325,7 @@ def test_reply_email_to_multiple_users(self, mock_send_notification):
         )
 
         related_item = LoadItemFactory.create(
-            parent_guid=parent_guid,
+            parent_event_id=parent_event_id,
             connector=self.connector,
             item_eligible=True,
             is_past_event=False,
@@ -350,7 +350,7 @@ def test_reply_email_to_multiple_users(self, mock_send_notification):
     @mock.patch("alert_system.email_processing.send_notification")
     def test_duplicate_reply(self, mock_send_notification):
 
-        parent_guid = str(uuid4())
+        parent_event_id = str(uuid4())
 
         user = UserFactory.create()
         country = CountryFactory.create(
@@ -366,7 +366,7 @@ def test_duplicate_reply(self, mock_send_notification):
         )
 
         LoadItemFactory.create(
-            parent_guid=parent_guid,
+            parent_event_id=parent_event_id,
             connector=self.connector,
             item_eligible=True,
             is_past_event=False,
@@ -380,13 +380,13 @@ def test_duplicate_reply(self, mock_send_notification):
 
         thread = AlertEmailThreadFactory.create(
             user=user,
-            parent_guid=parent_guid,
+            parent_event_id=parent_event_id,
             root_email_message_id="root-123",
             root_message_sent_at=timezone.now(),
         )
 
         update_item = LoadItemFactory.create(
-            parent_guid=parent_guid,
+            parent_event_id=parent_event_id,
             connector=self.connector,
             item_eligible=True,
             is_past_event=False,

alert_system/utils.py

@@ -11,12 +11,26 @@
 logger = logging.getLogger(__name__)
 
 
+def get_latest_episode_load_item(load_item: LoadItem) -> LoadItem:
+    """
+    Given a load_item, return the sibling LoadItem with the highest
+    episode_number for the same parent_event_id.
+    Falls back to the original load_item if no siblings exist.
+    """
+    latest = LoadItem.objects.filter(parent_event_id=load_item.parent_event_id).order_by("-episode_number").first()
+    return latest or load_item
+
+
 def get_alert_email_context(load_item: LoadItem, user: User):
 
     country_names = []
 
     if load_item.country_codes:
         country_names = list(Country.objects.filter(iso3__in=load_item.country_codes).values_list("name", flat=True))
+
+    # Fetch related_montandon_events from the latest episode
+    latest_episode_item = get_latest_episode_load_item(load_item)
+
     email_context = {
         "user_name": user.get_full_name(),
         "event_title": load_item.event_title,
@@ -26,7 +40,7 @@ def get_alert_email_context(load_item: LoadItem, user: User):
         "total_buildings_exposed": load_item.total_buildings_exposed,
         "hazard_types": load_item.connector.dtype,
         "related_go_events": load_item.related_go_events.all(),
-        "related_montandon_events": load_item.related_montandon_events.filter(item_eligible=True).order_by(
+        "related_montandon_events": latest_episode_item.related_montandon_events.filter(item_eligible=True).order_by(
             "-total_people_exposed"
         ),
         "frontend_url": settings.GO_WEB_URL,