Solution

cinema/serializers.py

@@ -1,6 +1,14 @@
 from rest_framework import serializers
 
-from cinema.models import Genre, Actor, CinemaHall, Movie, MovieSession
+from cinema.models import (
+    Genre,
+    Actor,
+    CinemaHall,
+    Movie,
+    MovieSession,
+    Ticket,
+    Order
+)
 
 
 class GenreSerializer(serializers.ModelSerializer):
@@ -46,9 +54,25 @@ class Meta:
 
 
 class MovieSessionSerializer(serializers.ModelSerializer):
+    movie_title = serializers.CharField(source="movie.title", read_only=True)
+    cinema_hall_name = serializers.CharField(
+        source="cinema_hall.name", read_only=True
+    )
+    cinema_hall_capacity = serializers.IntegerField(
+        source="cinema_hall.capacity", read_only=True
+    )
+
     class Meta:
         model = MovieSession
-        fields = ("id", "show_time", "movie", "cinema_hall")
+        fields = (
+            "id",
+            "show_time",
+            "movie",
+            "cinema_hall",
+            "movie_title",
+            "cinema_hall_name",
+            "cinema_hall_capacity"
+        )
 
 
 class MovieSessionListSerializer(MovieSessionSerializer):
@@ -59,6 +83,7 @@ class MovieSessionListSerializer(MovieSessionSerializer):
     cinema_hall_capacity = serializers.IntegerField(
         source="cinema_hall.capacity", read_only=True
     )
+    tickets_available = serializers.IntegerField(read_only=True)
 
     class Meta:
         model = MovieSession
@@ -68,13 +93,58 @@ class Meta:
             "movie_title",
             "cinema_hall_name",
             "cinema_hall_capacity",
+            "tickets_available",
         )
 
 
+class TicketSerializer(serializers.ModelSerializer):
+    movie_session = MovieSessionSerializer(read_only=True)
+
+    class Meta:
+        model = Ticket
+        fields = ("id", "row", "seat", "movie_session")
+
+    def validate(self, data):
+        data = super().validate(data)
+        ticket = Ticket(
+            movie_session=data.get("movie_session"),
+            row=data.get("row"),
+            seat=data.get("seat"),
+        )
+        ticket.full_clean()
+        return data
+
+
+class TicketRowSeatSerializer(serializers.ModelSerializer):
+    class Meta:
+        model = Ticket
+        fields = ("row", "seat")
+
+
 class MovieSessionDetailSerializer(MovieSessionSerializer):
     movie = MovieListSerializer(many=False, read_only=True)
     cinema_hall = CinemaHallSerializer(many=False, read_only=True)
+    taken_places = TicketRowSeatSerializer(
+        many=True,
+        read_only=True,
+        source="tickets"
+    )
 
     class Meta:
         model = MovieSession
-        fields = ("id", "show_time", "movie", "cinema_hall")
+        fields = ("id", "show_time", "movie", "cinema_hall", "taken_places")
+
+
+class OrderSerializer(serializers.ModelSerializer):
+    tickets = TicketSerializer(many=True, read_only=True, allow_null=False)
+
+    class Meta:
+        model = Order
+        fields = ("id", "created_at", "tickets")
+
+    def create(self, validated_data):
+        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

cinema/urls.py

@@ -7,6 +7,8 @@
     CinemaHallViewSet,
     MovieViewSet,
     MovieSessionViewSet,
+    OrderViewSet,
+    TicketViewSet
 )
 
 router = routers.DefaultRouter()
@@ -15,6 +17,8 @@
 router.register("cinema_halls", CinemaHallViewSet)
 router.register("movies", MovieViewSet)
 router.register("movie_sessions", MovieSessionViewSet)
+router.register("orders", OrderViewSet)
+router.register("tickets", TicketViewSet)
 
 urlpatterns = [path("", include(router.urls))]
 

cinema/views.py

@@ -1,6 +1,19 @@
-from rest_framework import viewsets
+import re
+from rest_framework.response import Response
 
-from cinema.models import Genre, Actor, CinemaHall, Movie, MovieSession
+from django.db.models import Count, F
+from rest_framework import viewsets
+from rest_framework.pagination import PageNumberPagination
+from datetime import datetime
+from cinema.models import (
+    Genre,
+    Actor,
+    CinemaHall,
+    Movie,
+    MovieSession,
+    Order,
+    Ticket
+)
 
 from cinema.serializers import (
     GenreSerializer,
@@ -12,26 +25,40 @@
     MovieDetailSerializer,
     MovieSessionDetailSerializer,
     MovieListSerializer,
+    OrderSerializer,
+    TicketSerializer
 )
 
 
 class GenreViewSet(viewsets.ModelViewSet):
     queryset = Genre.objects.all()
     serializer_class = GenreSerializer
 
+    def list(self, request, *args, **kwargs):
+        queryset = self.get_queryset()
+        serializer = self.get_serializer(queryset, many=True)
+        return Response(serializer.data)
+
 
 class ActorViewSet(viewsets.ModelViewSet):
     queryset = Actor.objects.all()
     serializer_class = ActorSerializer
 
+    def list(self, request, *args, **kwargs):
+        queryset = self.get_queryset()
+        serializer = self.get_serializer(queryset, many=True)
+        return Response(serializer.data)
+
 
 class CinemaHallViewSet(viewsets.ModelViewSet):
     queryset = CinemaHall.objects.all()
     serializer_class = CinemaHallSerializer
 
+    pagination_class = None
+
 
 class MovieViewSet(viewsets.ModelViewSet):
-    queryset = Movie.objects.all()
+    queryset = Movie.objects.prefetch_related("genres", "actors")
     serializer_class = MovieSerializer
 
     def get_serializer_class(self):
@@ -43,16 +70,82 @@ def get_serializer_class(self):
 
         return MovieSerializer
 
+    def get_queryset(self):
+        queryset = super().get_queryset()
+
+        title = self.request.query_params.get("title", None)
+        actors = self.request.query_params.get("actors", None)
+        genres = self.request.query_params.get("genres", None)
+
+        if title:
+            queryset = queryset.filter(title__icontains=title)
+
+        if genres:
+            genres_ids = [int(str_id) for str_id in genres.split(",")]
+            queryset = queryset.filter(genres__in=genres_ids)
+
+        if actors:
+            actors_ids = [int(str_id) for str_id in actors.split(",")]
+            queryset = queryset.filter(actors__in=actors_ids)
+
+        return queryset.distinct()
+
+    def paginate_queryset(self, queryset):
+        return None
+
 
 class MovieSessionViewSet(viewsets.ModelViewSet):
-    queryset = MovieSession.objects.all()
+    queryset = MovieSession.objects.select_related("movie", "cinema_hall")
     serializer_class = MovieSessionSerializer
 
+    pagination_class = None
+
     def get_serializer_class(self):
         if self.action == "list":
             return MovieSessionListSerializer
-
-        if self.action == "retrieve":
+        elif self.action == "retrieve":
             return MovieSessionDetailSerializer
-
         return MovieSessionSerializer
+
+    def get_queryset(self):
+        queryset = super().get_queryset()
+
+        movie = self.request.query_params.get("movie")
+        if movie:
+            queryset = queryset.filter(movie__id=movie)
+
+        date = self.request.query_params.get("date")
+        if date:
+            try:
+                date_obj = datetime.strptime(date, "%Y-%m-%d").date()
+                queryset = queryset.filter(show_time__date=date_obj)
+            except ValueError:
+                return queryset.none()
+
+        queryset = queryset.annotate(
+            tickets_available=(
+                F("cinema_hall__rows") * F("cinema_hall__seats_in_row")
+                - Count("tickets")
+            )
+        ).order_by("id")
+
+        return queryset.distinct()
+
+
+class OrderPagination(PageNumberPagination):
+    page_size = 5
+
+
+class OrderListCreateView(viewsets.ModelViewSet):
+    pagination_class = OrderPagination
+
+
+class OrderViewSet(viewsets.ModelViewSet):
+    queryset = Order.objects.all()
+    serializer_class = OrderSerializer
+    pagination_class = OrderPagination
+
+
+class TicketViewSet(viewsets.ModelViewSet):
+    queryset = Ticket.objects.all()
+    serializer_class = TicketSerializer

cinema_service/settings.py

@@ -136,3 +136,10 @@
 # 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.PageNumberPagination"
+    ),
+    "PAGE_SIZE": 5,
+}