Solution

cinema/models.py

@@ -84,16 +84,22 @@ class Ticket(models.Model):
  row = models.IntegerField()
  seat = models.IntegerField()
 
- def clean(self):
+ @staticmethod
+ def validate_row_and_seat(
+ row: int,
+ seat: int,
+ movie_session: MovieSession,
+ error_to_raise: type[Exception]
+ ) -> None:
  for ticket_attr_value, ticket_attr_name, cinema_hall_attr_name in [
- (self.row, "row", "rows"),
- (self.seat, "seat", "seats_in_row"),
+ (row, "row", "rows"),
+ (seat, "seat", "seats_in_row"),
  ]:
  count_attrs = getattr(
- self.movie_session.cinema_hall, cinema_hall_attr_name
+ movie_session.cinema_hall, cinema_hall_attr_name
  )
  if not (1 <= ticket_attr_value <= count_attrs):
- raise ValidationError(
+ raise error_to_raise(
  {
  ticket_attr_name: f"{ticket_attr_name} "
  f"number must be in available range: "
@@ -102,6 +108,14 @@ def clean(self):
  }
  )
 
+ def clean(self):
+ Ticket.validate_row_and_seat(
+ self.row,
+ self.seat,
+ self.movie_session,
+ ValidationError
+ )
+
  def save(
  self,
  force_insert=False,

cinema/pagination.py

@@ -0,0 +1,7 @@
+from rest_framework.pagination import PageNumberPagination
+
+
+class OrderSetPagination(PageNumberPagination):
+ page_size = 2
+ page_size_query_param = "page_size"
+ max_page_size = 20

cinema/serializers.py

@@ -1,6 +1,16 @@
+from django.db import transaction
 from rest_framework import serializers
+from rest_framework.validators import UniqueTogetherValidator
 
-from cinema.models import Genre, Actor, CinemaHall, Movie, MovieSession
+from cinema.models import (
+ Genre,
+ Actor,
+ CinemaHall,
+ Movie,
+ MovieSession,
+ Order,
+ Ticket
+)
 
 
 class GenreSerializer(serializers.ModelSerializer):
@@ -51,6 +61,22 @@ class Meta:
  fields = ("id", "show_time", "movie", "cinema_hall")
 
 
+class TicketSerializer(serializers.ModelSerializer):
+ class Meta:
+ model = Ticket
+ fields = ("id", "movie_session", "row", "seat")
+
+ def validate(self, attrs):
+ Ticket.validate_row_and_seat(
+ attrs["row"],
+ attrs["seat"],
+ attrs["movie_session"],
+ serializers.ValidationError
+ )
+
+ return attrs
+
+
 class MovieSessionListSerializer(MovieSessionSerializer):
  movie_title = serializers.CharField(source="movie.title", read_only=True)
  cinema_hall_name = serializers.CharField(
@@ -59,6 +85,7 @@ 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 +95,42 @@ class Meta:
  "movie_title",
  "cinema_hall_name",
  "cinema_hall_capacity",
+ "tickets_available",
  )
 
 
 class MovieSessionDetailSerializer(MovieSessionSerializer):
  movie = MovieListSerializer(many=False, read_only=True)
  cinema_hall = CinemaHallSerializer(many=False, read_only=True)
+ taken_places = serializers.SerializerMethodField()
 
  class Meta:
  model = MovieSession
- fields = ("id", "show_time", "movie", "cinema_hall")
+ fields = ("id", "show_time", "movie", "cinema_hall", "taken_places")
+
+ def get_taken_places(self, obj):
+ tickets = Ticket.objects.filter(movie_session=obj)
+ return [{"row": ticket.row, "seat": ticket.seat} for ticket in tickets]
+
+
+class OrderSerializer(serializers.ModelSerializer):
+ tickets = TicketSerializer(many=True, read_only=False, allow_empty=False)
+
+ class Meta:
+ model = Order
+ fields = ("id", "created_at", "tickets")
+
+ def create(self, validated_data):
+ with transaction.atomic():
+ tickets = validated_data.pop("tickets")
+ order = Order.objects.create(**validated_data)
+ for ticket in tickets:
+ Ticket.objects.create(order=order, **ticket)
+
+
+class TicketListSerializer(TicketSerializer):
+ movie_session = MovieSessionListSerializer(read_only=True)
+
+
+class OrderListSerializer(OrderSerializer):
+ tickets = TicketListSerializer(many=True, read_only=True)

cinema/urls.py

@@ -7,6 +7,7 @@
  CinemaHallViewSet,
  MovieViewSet,
  MovieSessionViewSet,
+ OrderViewSet,
 )
 
 router = routers.DefaultRouter()
@@ -15,6 +16,7 @@
 router.register("cinema_halls", CinemaHallViewSet)
 router.register("movies", MovieViewSet)
 router.register("movie_sessions", MovieSessionViewSet)
+router.register("orders", OrderViewSet)
 
 urlpatterns = [path("", include(router.urls))]
 

cinema/views.py

@@ -1,6 +1,17 @@
+from datetime import datetime
+
+from django.db.models import Count, F
 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.serializers import (
  GenreSerializer,
@@ -12,7 +23,11 @@
  MovieDetailSerializer,
  MovieSessionDetailSerializer,
  MovieListSerializer,
+ OrderSerializer,
+ TicketSerializer,
+ OrderListSerializer,
 )
+from cinema.pagination import OrderSetPagination
 
 
 class GenreViewSet(viewsets.ModelViewSet):
@@ -34,6 +49,10 @@ class MovieViewSet(viewsets.ModelViewSet):
  queryset = Movie.objects.all()
  serializer_class = MovieSerializer
 
+ @staticmethod
+ def _params_to_ints_list(query_string):
+ return [int(str_id) for str_id in query_string.split(",")]
+
  def get_serializer_class(self):
  if self.action == "list":
  return MovieListSerializer
@@ -43,11 +62,35 @@ def get_serializer_class(self):
 
  return MovieSerializer
 
+ def get_queryset(self):
+ 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 = self._params_to_ints_list(actors)
+ queryset = queryset.filter(actors__id__in=actors)
+
+ if genres:
+ genres = self._params_to_ints_list(genres)
+ queryset = queryset.filter(genres__id__in=genres)
+
+ if title:
+ queryset = queryset.filter(title__icontains=title)
+
+ return queryset.distinct()
+
 
 class MovieSessionViewSet(viewsets.ModelViewSet):
  queryset = MovieSession.objects.all()
  serializer_class = MovieSessionSerializer
 
+ @staticmethod
+ def _str_to_date(query_string):
+ return datetime.strptime(query_string, "%Y-%m-%d").date()
+
  def get_serializer_class(self):
  if self.action == "list":
  return MovieSessionListSerializer
@@ -56,3 +99,55 @@ def get_serializer_class(self):
  return MovieSessionDetailSerializer
 
  return MovieSessionSerializer
+
+ def get_queryset(self):
+ queryset = self.queryset.select_related("movie")
+
+ if self.action == "list":
+ queryset = queryset.annotate(
+ tickets_available=(
+ F("cinema_hall__rows") * F("cinema_hall__seats_in_row")
+ - Count("tickets")
+ )
+ )
+
+ movie = self.request.query_params.get("movie")
+ date = self.request.query_params.get("date")
+
+ if date:
+ date = self._str_to_date(date)
+ queryset = queryset.filter(show_time__date=date)
+ if movie:
+ queryset = queryset.filter(movie__id=int(movie))
+
+ return queryset.distinct()
+
+
+class TicketViewSet(viewsets.ModelViewSet):
+ queryset = Ticket.objects.all()
+ serializer_class = TicketSerializer
+
+
+class OrderViewSet(viewsets.ModelViewSet):
+ queryset = Order.objects.all()
+ pagination_class = OrderSetPagination
+
+ def get_queryset(self):
+ queryset = self.queryset.filter(user=self.request.user)
+
+ if self.action == "list":
+ queryset = queryset.prefetch_related(
+ "tickets__movie_session__cinema_hall",
+ "tickets__movie_session__movie",
+ )
+
+ return queryset
+
+ def perform_create(self, serializer):
+ serializer.save(user=self.request.user)
+
+ def get_serializer_class(self):
+ if self.action == "list":
+ return OrderListSerializer
+
+ return OrderSerializer

cinema_service/settings.py

@@ -124,7 +124,7 @@
 
 USE_I18N = True
 
-USE_TZ = False
+USE_TZ = True
 
 
 # Static files (CSS, JavaScript, Images)