Solution

cinema/pagination.py

@@ -0,0 +1,7 @@
+from rest_framework.pagination import PageNumberPagination
+
+
+class OrdersPagination(PageNumberPagination):
+    page_size = 10
+    page_size_query_param = "page_size"
+    max_page_size = 100

cinema/serializers.py

@@ -1,6 +1,16 @@
+from django.db import transaction
 from rest_framework import serializers
+from rest_framework.relations import PrimaryKeyRelatedField
 
-from cinema.models import Genre, Actor, CinemaHall, Movie, MovieSession
+from cinema.models import (
+    Genre,
+    Actor,
+    CinemaHall,
+    Movie,
+    MovieSession,
+    Order,
+    Ticket,
+)
 
 
 class GenreSerializer(serializers.ModelSerializer):
@@ -78,3 +88,47 @@ class MovieSessionDetailSerializer(MovieSessionSerializer):
     class Meta:
         model = MovieSession
         fields = ("id", "show_time", "movie", "cinema_hall")
+
+
+class TicketSerializer(serializers.ModelSerializer):
+    movie_session = PrimaryKeyRelatedField(
+        queryset=MovieSession.objects.all()
+    )
+
+    class Meta:
+        model = Ticket
+        fields = ("id", "row", "seat", "movie_session")
+
+
+class TicketDetailSerializer(TicketSerializer):
+    movie_session = MovieSessionListSerializer(many=False, read_only=True)
+
+    def validate(self, data):
+        data = super(TicketSerializer, self).validate(data)
+        ticket = Ticket(
+            movie_session=data.get("movie_session"),
+            row=data.get("row"),
+            seat=data.get("seat"),
+        )
+        ticket.full_clean()
+        return data
+
+
+class OrderSerializer(serializers.ModelSerializer):
+    tickets = TicketSerializer(many=True, read_only=False, allow_empty=False)
+
+    class Meta:
+        model = Order
+        fields = ["id", "tickets", "created_at"]
+
+    def create(self, validated_data):
+        with transaction.atomic():
+            tickets_data = validated_data.pop("tickets")
+            order = Order.objects.create(**validated_data)
+            for ticket_data in tickets_data:
+                Ticket.objects.create(order=order, **ticket_data)
+            return order
+
+
+class OrderDetailSerializer(OrderSerializer):
+    tickets = TicketDetailSerializer(many=True, read_only=True)

cinema/urls.py

@@ -7,15 +7,19 @@
     CinemaHallViewSet,
     MovieViewSet,
     MovieSessionViewSet,
+    OrderViewSet,
+    TicketViewSet,
 )
 
+app_name = "cinema"
+
 router = routers.DefaultRouter()
 router.register("genres", GenreViewSet)
 router.register("actors", ActorViewSet)
 router.register("cinema_halls", CinemaHallViewSet)
 router.register("movies", MovieViewSet)
 router.register("movie_sessions", MovieSessionViewSet)
+router.register("orders", OrderViewSet, basename="orders")
+router.register("tickets", TicketViewSet)
 
 urlpatterns = [path("", include(router.urls))]
-
-app_name = "cinema"

cinema/views.py

@@ -1,6 +1,16 @@
+from django.db.models import F, Count
 from rest_framework import viewsets
 
-from cinema.models import Genre, Actor, CinemaHall, Movie, MovieSession
+from cinema.models import (
+    Genre,
+    Actor,
+    CinemaHall,
+    Movie,
+    MovieSession,
+    Order,
+    Ticket,
+)
+from cinema.pagination import OrdersPagination
 
 from cinema.serializers import (
     GenreSerializer,
@@ -12,6 +22,9 @@
     MovieDetailSerializer,
     MovieSessionDetailSerializer,
     MovieListSerializer,
+    OrderSerializer,
+    TicketSerializer,
+    OrderDetailSerializer,
 )
 
 
@@ -43,6 +56,28 @@ def get_serializer_class(self):
 
         return MovieSerializer
 
+    def get_queryset(self):
+        queryset = super().get_queryset()
+        if self.action in ["list", "retrieve"]:
+            queryset = self.queryset.prefetch_related("actors", "genres")
+
+        actors = self.request.query_params.get("actors")
+        genres = self.request.query_params.get("genres")
+        title = self.request.query_params.get("title")
+
+        if actors:
+            actors_ids = [int(str_id) for str_id in actors.split(",")]
+            queryset = queryset.filter(actors__id__in=actors_ids)
+
+        if genres:
+            genres_ids = [int(str_id) for str_id in genres.split(",")]
+            queryset = queryset.filter(genres__id__in=genres_ids)
+
+        if title:
+            queryset = queryset.filter(title__icontains=title)
+
+        return queryset.distinct()
+
 
 class MovieSessionViewSet(viewsets.ModelViewSet):
     queryset = MovieSession.objects.all()
@@ -56,3 +91,54 @@ def get_serializer_class(self):
             return MovieSessionDetailSerializer
 
         return MovieSessionSerializer
+
+    def get_queryset(self):
+        queryset = super().get_queryset()
+
+        if self.action == "retrieve":
+            queryset = queryset.select_related("movie")
+
+        elif self.action == "list":
+            queryset = (
+                queryset
+                .select_related("cinema_hall")
+                .annotate(
+                    tickets_available=(
+                        F("cinema_hall__rows")
+                        * F("cinema_hall__seats_in_row")
+                        - Count("tickets")
+                    )
+                )
+            ).order_by("id")
+
+        movie = self.request.query_params.get("movie")
+        date = self.request.query_params.get("date")
+
+        if movie:
+            queryset = queryset.filter(movie__id=movie)
+
+        if date:
+            queryset = queryset.filter(show_time__date=date)
+
+        return queryset.distinct()
+
+
+class OrderViewSet(viewsets.ModelViewSet):
+    queryset = Order.objects.all()
+    pagination_class = OrdersPagination
+
+    def get_serializer_class(self):
+        if self.action in ["create", "update", "partial_update"]:
+            return OrderSerializer
+        return OrderDetailSerializer
+
+    def get_queryset(self):
+        return Order.objects.filter(user=self.request.user)
+
+    def perform_create(self, serializer):
+        serializer.save(user=self.request.user)
+
+
+class TicketViewSet(viewsets.ModelViewSet):
+    queryset = Ticket.objects.all()
+    serializer_class = TicketSerializer

cinema_service/settings.py

@@ -124,7 +124,7 @@
 
 USE_I18N = True
 
-USE_TZ = False
+USE_TZ = True
 
 
 # Static files (CSS, JavaScript, Images)
@@ -136,3 +136,9 @@
 # https://docs.djangoproject.com/en/4.0/ref/settings/#default-auto-field
 
 DEFAULT_AUTO_FIELD = "django.db.models.BigAutoField"
+
+REST_FRAMEWORK = {
+    "DEFAULT_PAGINATION_CLASS":
+        "rest_framework.pagination.LimitOffsetPagination",
+    "PAGE_SIZE": 10,
+}