Optimize get_is_unavailable_query

Refactor availability checks to reduce queries:
- Annotate availability in get_custom_package_listing.
- Modify DependencySerializer to use annotations instead of fetching
  the community model.
- Move availability check to PackageListing and update Package's
  is_unavailable.
- Add tests ensuring queries remain under 20 for small datasets;
  larger sets see a drop from 100+ to ~60.

Refs. TS-2276

django/thunderstore/api/cyberstorm/tests/test_package_listing.py

@@ -3,6 +3,8 @@
 from unittest.mock import Mock, PropertyMock, patch
 
 import pytest
+from django.db import connection
+from django.test.utils import CaptureQueriesContext
 from rest_framework.test import APIClient
 
 from thunderstore.api.cyberstorm.views.package_listing import (
@@ -306,9 +308,10 @@ def test_dependency_serializer__reads_is_active_from_correct_field(
     dependency.package.save()
     dependant.dependencies.set([dependency])
 
-    # community_identifier is normally added using annotations, but
-    # it's irrelavant for this test case.
+    # community_identifier and version_is_unavailable is normally added using
+    # annotations, but it's irrelavant for this test case.
     dependency.community_identifier = "greendale"
+    dependency.version_is_unavailable = False
 
     actual = DependencySerializer(dependency).data
 
@@ -317,10 +320,11 @@ def test_dependency_serializer__reads_is_active_from_correct_field(
 
 @pytest.mark.django_db
 def test_dependency_serializer__when_dependency_is_not_active__censors_icon_and_description() -> None:
-    # community_identifier is normally added using annotations, but
-    # it's irrelavant for this test case.
+    # community_identifier and version_is_unavailable is normally added using
+    # annotations, but it's irrelavant for this test case.
     dependency = PackageVersionFactory()
     dependency.community_identifier = "greendale"
+    dependency.version_is_unavailable = False
 
     actual = DependencySerializer(dependency).data
 
@@ -409,3 +413,36 @@ def test_package_listing_is_unavailable(
 
     assert "is_unavailable" in response_dependencies
     assert response_dependencies["is_unavailable"] == return_val
+
+
+@pytest.mark.django_db
+def test_package_listing_query_count(
+    api_client: APIClient, community: Community
+) -> None:
+    package = "Mod"
+    target_ns = NamespaceFactory()
+
+    target_dependencies = [
+        PackageListingFactory(
+            community_=community,
+            package_kwargs={"name": f"{package}_{i}", "namespace": target_ns},
+        )
+        for i in range(10)
+    ]
+
+    target_package = PackageListingFactory(community_=community)
+    target_package.package.latest.dependencies.set(
+        [dep.package.latest.id for dep in target_dependencies],
+    )
+
+    community_id = target_package.community.identifier
+    namespace = target_package.package.namespace.name
+    package_name = target_package.package.name
+
+    url = f"/api/cyberstorm/listing/{community_id}/{namespace}/{package_name}/"
+
+    with CaptureQueriesContext(connection) as ctx:
+        response = api_client.get(url)
+
+    assert response.status_code == 200
+    assert len(ctx.captured_queries) < 20

django/thunderstore/api/cyberstorm/views/package_listing.py

@@ -59,11 +59,9 @@ def get_icon_url(self, obj: PackageVersion) -> Optional[str]:
         return obj.icon.url if obj.is_effectively_active else None
 
     def get_is_unavailable(self, obj: PackageVersion) -> bool:
-        community = Community.objects.filter(
-            identifier=obj.community_identifier
-        ).first()
-
-        return obj.is_unavailable(community)
+        # Annotated result of PackageVersion.is_unavailable
+        # See get_custom_package_listing()
+        return obj.version_is_unavailable
 
 
 class TeamSerializer(serializers.Serializer):
@@ -191,10 +189,14 @@ def get_custom_package_listing(
         package__name__iexact=package_name,
     )
 
+    community = listing.community
+    version_is_unavailable = listing.package.latest.is_unavailable(community)
+
     dependencies = (
         listing.package.latest.dependencies.listed_in(community_id)
         .annotate(
             community_identifier=Value(community_id, CharField()),
+            version_is_unavailable=Value(version_is_unavailable, BooleanField()),
         )
         .select_related("package", "package__namespace")
         .order_by("package__namespace__name", "package__name")

django/thunderstore/community/models/package_listing.py

@@ -320,6 +320,10 @@ def update_categories(self, agent: UserType, categories: List["PackageCategory"]
                 )
         self.categories.set(categories)
 
+    @property
+    def is_unavailable(self):
+        return self.is_rejected or self.is_waiting_for_approval
+
     def can_be_moderated_by_user(self, user: Optional[UserType]) -> bool:
         return self.community.can_user_manage_packages(user)
 

django/thunderstore/community/tests/test_package_listing.py

@@ -1,3 +1,5 @@
+from unittest.mock import PropertyMock, patch
+
 import pytest
 from django.core.exceptions import ValidationError
 from django.db import IntegrityError
@@ -416,3 +418,27 @@ def test_package_listing_filter_with_multiple_community_packages() -> None:
         count = community.package_listings.filter_with_single_community().count()
         assert count == 1
         assert community.aggregated.package_count == count
+
+
+@pytest.mark.django_db
+@pytest.mark.parametrize(
+    ("is_rejected", "is_waiting_for_approval", "expected"),
+    [(True, False, True), (False, True, True), (False, False, False)],
+)
+def test_package_listing_is_unavailable(
+    is_rejected: bool,
+    is_waiting_for_approval: bool,
+    expected: bool,
+) -> None:
+    with patch(
+        "thunderstore.community.models.PackageListing.is_rejected",
+        new_callable=PropertyMock,
+        return_value=is_rejected,
+    ), patch(
+        "thunderstore.community.models.PackageListing.is_waiting_for_approval",
+        new_callable=PropertyMock,
+        return_value=is_waiting_for_approval,
+    ):
+
+        listing = PackageListingFactory()
+        assert listing.is_unavailable == expected

django/thunderstore/repository/models/package.py

@@ -135,23 +135,15 @@ def update_listing(self, has_nsfw_content, categories, community):
             listing.categories.add(*categories)
         listing.save(update_fields=("has_nsfw_content",))
 
-    def listing_is_unavailable(self, listing) -> bool:
-        if listing is None:
-            return True
-
-        return any(
-            [
-                listing.is_rejected,
-                listing.is_waiting_for_approval,
-            ]
-        )
-
     def is_unavailable(self, community) -> bool:
         if self.is_effectively_active is False:
             return True
 
         listing = self.get_package_listing(community)
-        return self.listing_is_unavailable(listing)
+        if listing is None:
+            return True
+
+        return listing.is_unavailable
 
     @cached_property
     def has_wiki(self) -> bool: