feat(transit): serve platform=all ads to specific platforms + admin bulk retag

src/transit/admin.py

@@ -99,3 +99,12 @@ class AdAdmin(IslandScopedAdmin):
     list_filter = ('island', 'platform', 'status')
     search_fields = ('entity', 'description')
     date_hierarchy = 'start'
+    actions = ('set_platform_to_all',)
+
+    @admin.action(description='Set platform to all (selected)')
+    def set_platform_to_all(self, request, queryset):
+        updated = queryset.update(platform='all')
+        self.message_user(
+            request,
+            f'{updated} ad{"s" if updated != 1 else ""} set to platform=all.',
+        )

src/transit/services/ads.py

@@ -5,6 +5,7 @@
 from datetime import datetime
 from difflib import SequenceMatcher
 
+from django.db.models import Q
 from django.utils import timezone
 
 from transit.models import Ad, Stop, StopGroup
@@ -62,7 +63,9 @@ def select_ad(*, advertise_on: str, platform: str, now_ts: float | None = None)
 
     ads = Ad.objects.filter(status='active', start__lte=ad_dt, end__gte=ad_dt)
     if platform != 'all':
-        ads = ads.filter(platform=platform)
+        # A specific client platform (e.g. ios/android) is eligible for both its
+        # own targeted campaigns and any cross-platform `platform='all'` campaign.
+        ads = ads.filter(Q(platform=platform) | Q(platform='all'))
 
     if advertise_on in ('home', 'all'):
         if advertise_on != 'all':
@@ -77,11 +80,10 @@ def select_ad(*, advertise_on: str, platform: str, now_ts: float | None = None)
 
     ad = ads.order_by('?').first()
     if ad is None:
-        ad = (
-            Ad.objects.filter(platform=platform, status='default')
-            .order_by('?')
-            .first()
-        )
+        default_qs = Ad.objects.filter(status='default')
+        if platform != 'all':
+            default_qs = default_qs.filter(Q(platform=platform) | Q(platform='all'))
+        ad = default_qs.order_by('?').first()
     if ad is None and platform not in ('all', ''):
         # Dev sqlite often has android-only defaults; serve any default rather than 404
         ad = Ad.objects.filter(status='default').order_by('?').first()

src/transit/tests/test_ads.py

@@ -0,0 +1,101 @@
+"""Tests for ad selection platform filtering and the admin bulk retag action."""
+
+from __future__ import annotations
+
+from datetime import timedelta
+
+from django.contrib.admin.sites import AdminSite
+from django.test import RequestFactory, TestCase
+from django.utils import timezone
+
+from tenancy.services import for_island
+from transit.admin import AdAdmin
+from transit.models import Ad
+from transit.services.ads import select_ad
+from transit.tests.fixtures import ensure_transit_fixtures
+
+
+class _DummyMessages:
+    def __init__(self):
+        self.messages = []
+
+    def add(self, level, message, extra_tags=''):
+        self.messages.append(message)
+
+
+class SelectAdPlatformTests(TestCase):
+    def setUp(self):
+        self.island, _, _ = ensure_transit_fixtures()
+        self.now = timezone.now()
+
+    def _make_ad(self, *, platform: str, status: str = 'active', advertise_on: str = 'home') -> Ad:
+        return Ad.objects.create(
+            island=self.island,
+            entity=f'{platform}-{status}',
+            media='https://example.com/banner.png',
+            start=self.now - timedelta(days=1),
+            end=self.now + timedelta(days=1),
+            advertise_on=advertise_on,
+            platform=platform,
+            status=status,
+        )
+
+    def test_platform_all_active_returned_for_ios(self):
+        ad = self._make_ad(platform='all')
+        with for_island(self.island):
+            selected = select_ad(advertise_on='home', platform='ios')
+        self.assertEqual(selected, ad)
+
+    def test_platform_web_not_returned_for_ios(self):
+        self._make_ad(platform='web')
+        with for_island(self.island):
+            selected = select_ad(advertise_on='home', platform='ios')
+        self.assertIsNone(selected)
+
+    def test_platform_web_default_fallback_for_ios(self):
+        default = self._make_ad(platform='all', status='default')
+        self._make_ad(platform='web')
+        with for_island(self.island):
+            selected = select_ad(advertise_on='home', platform='ios')
+        self.assertEqual(selected, default)
+
+    def test_ios_targeted_ad_returned_for_ios(self):
+        ad = self._make_ad(platform='ios')
+        with for_island(self.island):
+            selected = select_ad(advertise_on='home', platform='ios')
+        self.assertEqual(selected, ad)
+
+
+class AdAdminBulkActionTests(TestCase):
+    def setUp(self):
+        self.island, _, _ = ensure_transit_fixtures()
+        self.now = timezone.now()
+        self.admin = AdAdmin(Ad, AdminSite())
+        self.factory = RequestFactory()
+
+    def _make_ad(self, platform: str) -> Ad:
+        return Ad.objects.create(
+            island=self.island,
+            entity=f'ad-{platform}',
+            media='https://example.com/banner.png',
+            start=self.now - timedelta(days=1),
+            end=self.now + timedelta(days=1),
+            advertise_on='home',
+            platform=platform,
+            status='active',
+        )
+
+    def test_set_platform_to_all_updates_selected(self):
+        a = self._make_ad('web')
+        b = self._make_ad('android')
+        request = self.factory.post('/admin/')
+        request._messages = _DummyMessages()
+
+        queryset = Ad.objects.filter(id__in=[a.id, b.id])
+        self.admin.set_platform_to_all(request, queryset)
+
+        a.refresh_from_db()
+        b.refresh_from_db()
+        self.assertEqual(a.platform, 'all')
+        self.assertEqual(b.platform, 'all')
+        self.assertEqual(request._messages.messages, ['2 ads set to platform=all.'])