PROD: расширить контракт новостной ленты

docs/modules/feed-categories.md

@@ -0,0 +1,29 @@
+# Контракт категорий ленты
+
+`GET /feed/?type=project|vacancy|news&limit=6&offset=0` сохраняет стандартную
+пагинацию `count`, `next`, `previous`, `results` и дополнительно возвращает
+`counts` — количество доступных пользователю записей во всей ленте, независимо
+от текущего фильтра и страницы:
+
+```json
+{
+  "counts": {
+    "all": 4,
+    "project": 2,
+    "vacancy": 1,
+    "news": 1,
+    "partnerprogram": 0,
+    "education": 0
+  }
+}
+```
+
+`project` включает новости проектов и записи о новых проектах; `news` — новости
+пользователей. Черновики, закрытые проекты и неактивные вакансии не учитываются,
+как и в самой ленте. Новости программ и образование пока не включены в этот
+endpoint, поэтому их счётчики равны нулю. `all` — сумма доступных категорий.
+
+Каждый элемент `results` теперь содержит `published_at` — дату публикации
+записи ленты. Поле есть и у карточек новостей, и у вакансий, и у новых проектов.
+При одинаковой дате сортировка дополнительно использует первичный ключ (`pk`)
+по убыванию, чтобы последовательность страниц была определённой.

feed/serializers.py

@@ -83,4 +83,5 @@ def to_representation(self, instance):
         return {
             "type_model": type_model,
             "content": content,
+            "published_at": data["datetime_created"],
         }

feed/tests/test_feed_api.py

@@ -1,9 +1,14 @@
+from django.contrib.contenttypes.models import ContentType
 from django.test import TestCase
+from django.utils import timezone
+from django.utils.dateparse import parse_datetime
 from rest_framework.test import APIClient
 
 from core.services import set_like
 from feed.services import create_news_for_model
 from feed.tests.helpers import create_vacancy
+from news.models import News
+from news.services import FEED_RECORD_TEXT
 from news.tests.helpers import (
     create_news_for,
     create_partner_program,
@@ -18,17 +23,26 @@ def setUp(self):
         self.user = create_user(prefix="feed-user")
         self.client.force_authenticate(self.user)
 
+    @staticmethod
+    def get_feed_record(obj):
+        return News.objects.get(
+            content_type=ContentType.objects.get_for_model(obj),
+            object_id=obj.pk,
+            text=FEED_RECORD_TEXT,
+        )
+
     def test_feed_returns_user_news_when_news_filter_requested(self):
         news = create_news_for(self.user, text="User feed news")
 
         response = self.client.get("/feed/?type=news")
 
         self.assertEqual(response.status_code, 200)
         item = response.data["results"][0]
-        self.assertEqual(set(item.keys()), {"type_model", "content"})
+        self.assertEqual(set(item.keys()), {"type_model", "content", "published_at"})
         self.assertEqual(item["type_model"], "news")
         self.assertEqual(item["content"]["id"], news.id)
         self.assertEqual(item["content"]["text"], "User feed news")
+        self.assertEqual(item["published_at"], item["content"]["datetime_created"])
 
     def test_feed_returns_project_news_as_news_content(self):
         project = create_project(name="Feed project")
@@ -38,10 +52,11 @@ def test_feed_returns_project_news_as_news_content(self):
 
         self.assertEqual(response.status_code, 200)
         item = response.data["results"][0]
-        self.assertEqual(set(item.keys()), {"type_model", "content"})
+        self.assertEqual(set(item.keys()), {"type_model", "content", "published_at"})
         self.assertEqual(item["type_model"], "news")
         self.assertEqual(item["content"]["id"], news.id)
         self.assertEqual(item["content"]["text"], "Project feed news")
+        self.assertEqual(parse_datetime(item["published_at"]), news.datetime_created)
 
     def test_feed_ignores_program_news_filter(self):
         program = create_partner_program(name="Feed program")
@@ -61,9 +76,13 @@ def test_feed_returns_project_feed_record_as_project_content(self):
 
         self.assertEqual(response.status_code, 200)
         item = response.data["results"][0]
-        self.assertEqual(set(item.keys()), {"type_model", "content"})
+        self.assertEqual(set(item.keys()), {"type_model", "content", "published_at"})
         self.assertEqual(item["type_model"], "project")
         self.assertEqual(item["content"]["id"], project.id)
+        self.assertEqual(
+            parse_datetime(item["published_at"]),
+            self.get_feed_record(project).datetime_created,
+        )
 
     def test_feed_returns_vacancy_feed_record_as_vacancy_content(self):
         vacancy = create_vacancy(role="Backend developer")
@@ -72,10 +91,100 @@ def test_feed_returns_vacancy_feed_record_as_vacancy_content(self):
 
         self.assertEqual(response.status_code, 200)
         item = response.data["results"][0]
-        self.assertEqual(set(item.keys()), {"type_model", "content"})
+        self.assertEqual(set(item.keys()), {"type_model", "content", "published_at"})
         self.assertEqual(item["type_model"], "vacancy")
         self.assertEqual(item["content"]["id"], vacancy.id)
         self.assertEqual(item["content"]["role"], "Backend developer")
+        self.assertEqual(
+            parse_datetime(item["published_at"]),
+            self.get_feed_record(vacancy).datetime_created,
+        )
+
+    def test_category_counts_are_global_and_respect_visibility(self):
+        project = create_project(name="Visible project")
+        create_news_for(project, text="Visible project news")
+        visible_vacancies = {
+            create_vacancy(project=project, role="First visible vacancy").pk,
+            create_vacancy(project=project, role="Second visible vacancy").pk,
+        }
+        create_news_for(self.user, text="Visible user news")
+        create_news_for(
+            create_project(name="Private project", is_public=False),
+            text="Private project news",
+        )
+        create_news_for(
+            create_project(name="Draft project", draft=True),
+            text="Draft project news",
+        )
+        inactive_vacancy = create_vacancy(
+            project=project,
+            role="Inactive vacancy",
+            is_active=False,
+        )
+        create_news_for_model(inactive_vacancy)
+        create_news_for(create_partner_program(name="Program"), text="Program news")
+
+        first_page = self.client.get("/feed/?type=vacancy&limit=1&offset=0")
+        second_page = self.client.get("/feed/?type=vacancy&limit=1&offset=1")
+
+        expected_counts = {
+            "all": 5,
+            "project": 2,
+            "vacancy": 2,
+            "news": 1,
+            "partnerprogram": 0,
+            "education": 0,
+        }
+        for response in (first_page, second_page):
+            self.assertEqual(response.status_code, 200)
+            self.assertEqual(
+                set(response.data),
+                {"count", "next", "previous", "results", "counts"},
+            )
+            self.assertEqual(response.data["count"], 2)
+            self.assertEqual(len(response.data["results"]), 1)
+            self.assertEqual(response.data["counts"], expected_counts)
+        self.assertEqual(
+            {
+                item["content"]["id"]
+                for response in (first_page, second_page)
+                for item in response.data["results"]
+            },
+            visible_vacancies,
+        )
+
+    def test_feed_uses_pk_as_tie_breaker_across_pages(self):
+        news_items = [
+            create_news_for(self.user, text=f"Same time {index}") for index in range(3)
+        ]
+        News.objects.filter(pk__in=[news.pk for news in news_items]).update(
+            datetime_created=timezone.now()
+        )
+
+        first_page = self.client.get("/feed/?type=news&limit=2&offset=0")
+        second_page = self.client.get("/feed/?type=news&limit=2&offset=2")
+
+        self.assertEqual(first_page.status_code, 200)
+        self.assertEqual(second_page.status_code, 200)
+        self.assertEqual(
+            set(first_page.data),
+            {
+                "count",
+                "next",
+                "previous",
+                "results",
+                "counts",
+            },
+        )
+        ordered_ids = [
+            item["content"]["id"]
+            for response in (first_page, second_page)
+            for item in response.data["results"]
+        ]
+        self.assertEqual(
+            ordered_ids,
+            sorted((news.pk for news in news_items), reverse=True),
+        )
 
     def test_feed_combines_supported_filters_and_ignores_program_news(self):
         project_news = create_news_for(
@@ -91,9 +200,7 @@ def test_feed_combines_supported_filters_and_ignores_program_news(self):
         vacancy = create_vacancy(role="Combined vacancy")
         create_news_for_model(project)
 
-        response = self.client.get(
-            "/feed/?type=project|vacancy|news|partnerprogram"
-        )
+        response = self.client.get("/feed/?type=project|vacancy|news|partnerprogram")
 
         self.assertEqual(response.status_code, 200)
         items_by_text = {

feed/views.py

@@ -1,4 +1,4 @@
-from django.db.models import Q, QuerySet
+from django.db.models import Count, Q, QuerySet
 from rest_framework.views import APIView
 
 from feed.pagination import FeedPagination
@@ -21,20 +21,11 @@ def _get_filter_data(self) -> list[str]:
         news_types: list[str] = filter_queries.split("|")
         if "news" in news_types:
             news_types.append("customuser")
-        return [
-            news_type
-            for news_type in news_types
-            if news_type != "partnerprogram"
-        ]
+        return [news_type for news_type in news_types if news_type != "partnerprogram"]
 
-    def get_queryset(self) -> QuerySet[News]:
-        filters = self._get_filter_data()
-
-        queryset = (
-            News.objects.select_related("content_type")
-            .prefetch_related("content_object", "files")
-            .filter(content_type__model__in=filters)
-            .order_by("-datetime_created")
+    def get_visible_queryset(self) -> QuerySet[News]:
+        queryset = News.objects.select_related("content_type").prefetch_related(
+            "content_object", "files"
         )
 
         existing_object_filters = {
@@ -49,12 +40,32 @@ def get_queryset(self) -> QuerySet[News]:
         }
         for model_name, ids_queryset in existing_object_filters.items():
             queryset = queryset.exclude(
-                Q(content_type__model=model_name)
-                & ~Q(object_id__in=ids_queryset)
+                Q(content_type__model=model_name) & ~Q(object_id__in=ids_queryset)
             )
 
         return queryset
 
+    def get_queryset(self) -> QuerySet[News]:
+        return (
+            self.get_visible_queryset()
+            .filter(content_type__model__in=self._get_filter_data())
+            .order_by("-datetime_created", "-pk")
+        )
+
+    def get_category_counts(self) -> dict[str, int]:
+        # Программы и образование пока не включены в ленту; не считаем скрытый контент.
+        counts = self.get_visible_queryset().aggregate(
+            project=Count("pk", filter=Q(content_type__model="project")),
+            vacancy=Count("pk", filter=Q(content_type__model="vacancy")),
+            news=Count("pk", filter=Q(content_type__model="customuser")),
+        )
+        return {
+            "all": sum(counts.values()),
+            **counts,
+            "partnerprogram": 0,
+            "education": 0,
+        }
+
     def get(self, *args, **kwargs):
         paginator = self.pagination_class()
         paginated_data = paginator.paginate_queryset(self.get_queryset(), self.request)
@@ -66,4 +77,6 @@ def get(self, *args, **kwargs):
             },
             many=True,
         )
-        return paginator.get_paginated_response(serializer.data)
+        response = paginator.get_paginated_response(serializer.data)
+        response.data["counts"] = self.get_category_counts()
+        return response