Add an API endpoint for the browser mapping (#20800)

docs/topics/api/addons.rst

@@ -974,3 +974,23 @@ Four recommendations are fetched, but only valid, publicly available addons are
     :>json string next: The URL of the next page of results.
     :>json string previous: The URL of the previous page of results.
     :>json array results: An array of :ref:`add-ons <addon-detail-object>`. The following fields are omitted for performance reasons: ``release_notes`` and ``license`` fields on ``current_version`` and ``current_beta_version``, as well as ``picture_url`` from ``authors``.
+
+
+----------------
+Browser Mappings
+----------------
+
+.. _addon-browser-mappings:
+
+This endpoint provides browser mappings of non-Firefox and Firefox extensions.  Added to support the extensions import feature in Firefox.
+
+.. http:get:: /api/v5/addons/browser-mappings/
+
+    .. note::
+        This endpoint uses a larger ``page_size`` than most other API endpoints.
+
+    :query string browser: The browser identifier for this query (required). Must be one of these: ``chrome``.
+    :query int page_size: Maximum number of results to return for the requested page. Defaults to 100.
+    :>json array results: An array containing a mapping of non-Firefox and Firefox extension IDs for a given browser.
+    :>json string results[].extension_id: A non-Firefox extension ID.
+    :>json string results[].addon_guid: The corresponding Firefox add-on ``guid``.

docs/topics/api/overview.rst

@@ -461,6 +461,7 @@ These are `v5` specific changes - `v4` changes apply also.
 * 2023-03-09: added ``host_permissions`` to the response of the version detail endpoint. https://github.com/mozilla/addons-server/issues/20418
 * 2023-04-13: removed signing api from api/v5+ in favor of addon submission api. https://github.com/mozilla/addons-server/issues/20560
 * 2023-06-01: renamed add-ons search endpoint sort by ratings parameter to ``sort=ratings``, ``sort=rating`` is still supported for backwards-compatibility. https://github.com/mozilla/addons-server/issues/20763
+* 2023-06-06: added the /addons/browser-mappings/ endpoint. https://github.com/mozilla/addons-server/issues/20798
 
 .. _`#11380`: https://github.com/mozilla/addons-server/issues/11380/
 .. _`#11379`: https://github.com/mozilla/addons-server/issues/11379/

src/olympia/addons/api_urls.py

@@ -10,6 +10,7 @@ from olympia.tags.views import TagListView
 from .views import (
     AddonAuthorViewSet,
     AddonAutoCompleteSearchView,
+    AddonBrowserMappingView,
     AddonFeaturedView,
     AddonPendingAuthorViewSet,
     AddonPreviewViewSet,
@@ -67,6 +68,11 @@ urls = [
         AddonRecommendationView.as_view(),
         name='addon-recommendations',
     ),
+    re_path(
+        r'^browser-mappings/$',
+        AddonBrowserMappingView.as_view(),
+        name='addon-browser-mappings',
+    ),
 ]
 
 addons_v3 = urls + [

src/olympia/addons/serializers.py

@@ -65,6 +65,7 @@ from .fields import (
 from .models import (
     Addon,
     AddonApprovalsCounter,
+    AddonBrowserMapping,
     AddonUser,
     AddonUserPendingConfirmation,
     DeniedSlug,
@@ -1648,3 +1649,15 @@ class ReplacementAddonSerializer(AMOModelSerializer):
                 coll_match.group('user_id'), coll_match.group('coll_slug')
             )
         return []
+
+
+class AddonBrowserMappingSerializer(AMOModelSerializer):
+    # The source is an annotated field defined in `AddonBrowserMappingView`.
+    addon_guid = serializers.CharField(source='addon__guid')
+
+    class Meta:
+        model = AddonBrowserMapping
+        fields = (
+            'addon_guid',
+            'extension_id',
+        )

src/olympia/addons/tests/test_views.py

@@ -46,6 +46,7 @@ from olympia.amo.tests.test_helpers import get_image_path
 from olympia.amo.urlresolvers import get_outgoing_url
 from olympia.bandwagon.models import CollectionAddon
 from olympia.blocklist.models import Block
+from olympia.constants.browsers import CHROME
 from olympia.constants.categories import CATEGORIES, CATEGORIES_BY_ID
 from olympia.constants.licenses import LICENSE_GPL3
 from olympia.constants.promoted import (
@@ -75,6 +76,7 @@ from olympia.versions.models import (
 from ..models import (
     Addon,
     AddonApprovalsCounter,
+    AddonBrowserMapping,
     AddonCategory,
     AddonRegionalRestrictions,
     AddonReviewerFlags,
@@ -7272,3 +7274,71 @@ class TestAddonPendingAuthorViewSet(TestCase):
         # and not delete either
         response = self.client.delete(self.detail_url)
         assert response.status_code == 403, response.content
+
+
+class TestBrowserMapping(TestCase):
+    def setUp(self):
+        super().setUp()
+
+        self.url = reverse_ns('addon-browser-mappings', api_version='v5')
+
+    def assert_json_results(self, response, expected_results):
+        json = response.json()
+        assert 'results' in json
+        assert 'count' in json
+        assert 'page_size' in json
+        assert json['count'] == expected_results
+        assert json['page_size'] == 100  # We use `LargePageNumberPagination`.
+        return json['results']
+
+    def test_invalid_params(self):
+        for query_string in ['', '?invalid=param', '?browser=not-a-browser']:
+            res = self.client.get(f'{self.url}{query_string}')
+            assert res.status_code == 400
+            assert res['cache-control'] == 's-maxage=0'
+            assert res.json() == {'detail': 'Invalid browser parameter'}
+
+    def test_get(self):
+        addon_1 = addon_factory()
+        extension_id_1 = 'an-extension-id'
+        AddonBrowserMapping.objects.create(
+            addon=addon_1,
+            extension_id=extension_id_1,
+            browser=CHROME,
+        )
+        addon_2 = addon_factory()
+        extension_id_2 = 'another-extension-id'
+        AddonBrowserMapping.objects.create(
+            addon=addon_2,
+            extension_id=extension_id_2,
+            browser=CHROME,
+        )
+        # Shouldn't show up because of the add-on status.
+        AddonBrowserMapping.objects.create(
+            addon=addon_factory(status=amo.STATUS_NOMINATED),
+            extension_id='some-other-extension-id-1',
+            browser=CHROME,
+        )
+        # Shouldn't show up because the browser is unrelated.
+        AddonBrowserMapping.objects.create(
+            addon=addon_1,
+            extension_id='some-other-extension-id-2',
+            browser=0,
+        )
+        # - 1 for counting the number of results
+        # - 1 for fetching the results of the first (and only) page
+        with self.assertNumQueries(2):
+            res = self.client.get(f'{self.url}?browser=chrome')
+
+        assert res.status_code == 200
+        assert res['cache-control'] == 'max-age=86400'
+
+        results = self.assert_json_results(res, 2)
+        assert results[0] == {
+            'extension_id': extension_id_1,
+            'addon_guid': addon_1.guid,
+        }
+        assert results[1] == {
+            'extension_id': extension_id_2,
+            'addon_guid': addon_2.guid,
+        }

src/olympia/addons/views.py

@@ -1,7 +1,7 @@
 from collections import OrderedDict
 
 from django import http
-from django.db.models import Max, Prefetch
+from django.db.models import F, Max, Prefetch
 from django.db.transaction import non_atomic_requests
 from django.shortcuts import redirect
 from django.utils.cache import patch_cache_control
@@ -35,7 +35,7 @@ from olympia.api.authentication import (
     SessionIDAuthentication,
 )
 from olympia.api.exceptions import UnavailableForLegalReasons
-from olympia.api.pagination import ESPageNumberPagination
+from olympia.api.pagination import ESPageNumberPagination, LargePageNumberPagination
 from olympia.api.permissions import (
     AllowAddonAuthor,
     AllowAddonOwner,
@@ -51,6 +51,7 @@ from olympia.api.permissions import (
 )
 from olympia.api.throttling import addon_submission_throttles
 from olympia.api.utils import is_gate_active
+from olympia.constants.browsers import BROWSERS
 from olympia.constants.categories import CATEGORIES_BY_ID
 from olympia.devhub.permissions import IsSubmissionAllowedFor
 from olympia.search.filters import (
@@ -75,9 +76,16 @@ from olympia.versions.models import Version
 
 from .decorators import addon_view_factory
 from .indexers import AddonIndexer
-from .models import Addon, AddonUser, AddonUserPendingConfirmation, ReplacementAddon
+from .models import (
+    Addon,
+    AddonBrowserMapping,
+    AddonUser,
+    AddonUserPendingConfirmation,
+    ReplacementAddon,
+)
 from .serializers import (
     AddonAuthorSerializer,
+    AddonBrowserMappingSerializer,
     AddonEulaPolicySerializer,
     AddonPendingAuthorSerializer,
     AddonSerializer,
@@ -1239,3 +1247,41 @@ class AddonRecommendationView(AddonSearchView):
     def paginate_queryset(self, queryset):
         # We don't need pagination for the fixed number of results.
         return queryset
+
+
+class AddonBrowserMappingView(ListAPIView):
+    authentication_classes = []
+    serializer_class = AddonBrowserMappingSerializer
+    pagination_class = LargePageNumberPagination
+
+    def get(self, request, format=None):
+        browser = self.request.query_params.get('browser', None)
+        if browser not in list(BROWSERS.values()):
+            raise exceptions.ParseError('Invalid browser parameter')
+
+        response = super().get(request, format)
+        # Cache for 24 hours.
+        patch_cache_control(response, max_age=60 * 60 * 24)
+        return response
+
+    def get_queryset(self):
+        browser = next(
+            (
+                key
+                for key in BROWSERS
+                if BROWSERS.get(key) == self.request.query_params.get('browser')
+            ),
+            None,
+        )
+        return AddonBrowserMapping.objects.filter(
+            browser=browser, addon__status__in=amo.APPROVED_STATUSES
+        ).annotate(
+            # This is used in `AddonBrowserMappingSerializer` in order to avoid
+            # unnecessary queries since we only need the add-on GUID.
+            addon__guid=F('addon__guid')
+        )
+
+    @classmethod
+    def as_view(cls, **initkwargs):
+        """The API is read-only so we can turn off atomic requests."""
+        return non_atomic_requests(super().as_view(**initkwargs))

src/olympia/api/pagination.py

@@ -59,3 +59,13 @@ class OneOrZeroPageNumberPagination(CustomPageNumberPagination):
                 ]
             )
         )
+
+
+class LargePageNumberPagination(CustomPageNumberPagination):
+    """
+    A pagination implementation that allows large page sizes. You should
+    probably not use it.
+    """
+
+    max_page_size = 100
+    page_size = 100