implement py-tickets-orders

cinema/models.py

@@ -51,8 +51,16 @@ def __str__(self):
 
 class MovieSession(models.Model):
     show_time = models.DateTimeField()
-    movie = models.ForeignKey(Movie, on_delete=models.CASCADE)
-    cinema_hall = models.ForeignKey(CinemaHall, on_delete=models.CASCADE)
+    movie = models.ForeignKey(
+        Movie,
+        on_delete=models.CASCADE,
+        related_name="movie_sessions"
+    )
+    cinema_hall = models.ForeignKey(
+        CinemaHall,
+        on_delete=models.CASCADE,
+        related_name="movie_sessions"
+    )
 
     class Meta:
         ordering = ["-show_time"]
@@ -121,3 +129,20 @@ def __str__(self):
 
     class Meta:
         unique_together = ("movie_session", "row", "seat")
+
+    @staticmethod
+    def validate_seat_and_row(
+            seat: int,
+            num_seats: int,
+            row: int,
+            num_rows: int,
+            error_to_raise
+    ):
+        if not (1 <= seat <= num_seats):
+            raise error_to_raise({
+                "seat": f"seat must be in range [1, {num_seats}], not {seat}"
+            })
+        if not (1 <= row <= num_rows):
+            raise error_to_raise({
+                "seat": f"row must be in range [1, {num_rows}], not {row}"
+            })

cinema/serializers.py

@@ -1,6 +1,17 @@
+from django.db import transaction
 from rest_framework import serializers
+from rest_framework.fields import SerializerMethodField
+from rest_framework.pagination import PageNumberPagination
 
-from cinema.models import Genre, Actor, CinemaHall, Movie, MovieSession
+from cinema.models import (
+    Genre,
+    Actor,
+    CinemaHall,
+    Movie,
+    MovieSession,
+    Order,
+    Ticket
+)
 
 
 class GenreSerializer(serializers.ModelSerializer):
@@ -48,7 +59,7 @@ class Meta:
 class MovieSessionSerializer(serializers.ModelSerializer):
     class Meta:
         model = MovieSession
-        fields = ("id", "show_time", "movie", "cinema_hall")
+        fields = ("id", "show_time", "movie", "cinema_hall", )
 
 
 class MovieSessionListSerializer(MovieSessionSerializer):
@@ -59,6 +70,7 @@ 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 +80,67 @@ class Meta:
             "movie_title",
             "cinema_hall_name",
             "cinema_hall_capacity",
+            "tickets_available"
         )
 
 
+class TicketSerializer(serializers.ModelSerializer):
+    class Meta:
+        model = Ticket
+        fields = ("id", "row", "seat", "movie_session")
+
+    def validate(self, attrs):
+        Ticket.validate_seat_and_row(
+            attrs["seat"],
+            attrs["movie_session"].cinema_hall.seats_in_row,
+            attrs["row"],
+            attrs["movie_session"].cinema_hall.rows,
+            serializers.ValidationError,
+        )
+        return attrs
+
+
 class MovieSessionDetailSerializer(MovieSessionSerializer):
     movie = MovieListSerializer(many=False, read_only=True)
     cinema_hall = CinemaHallSerializer(many=False, read_only=True)
+    taken_places = 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, movie_session):
+        return [
+            {"row": ticket.row, "seat": ticket.seat}
+            for ticket in movie_session.tickets.all()
+        ]
+
+
+class TicketRetrieveSerializer(TicketSerializer):
+    movie_session = MovieSessionListSerializer(many=False, read_only=True)
+
+
+class OrderSetPagination(PageNumberPagination):
+    page_size = 1
+    page_size_query_param = "page_size"
+    max_page_size = 10
+
+
+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 OrderListSerializer(OrderSerializer):
+    tickets = TicketRetrieveSerializer(many=True, read_only=True)

cinema/urls.py

@@ -1,12 +1,14 @@
 from django.urls import path, include
 from rest_framework import routers
 
+from cinema.serializers import OrderSerializer
 from cinema.views import (
     GenreViewSet,
     ActorViewSet,
     CinemaHallViewSet,
     MovieViewSet,
     MovieSessionViewSet,
+    OrdersViewSet
 )
 
 router = routers.DefaultRouter()
@@ -15,6 +17,7 @@
 router.register("cinema_halls", CinemaHallViewSet)
 router.register("movies", MovieViewSet)
 router.register("movie_sessions", MovieSessionViewSet)
+router.register("orders", OrdersViewSet)
 
 urlpatterns = [path("", include(router.urls))]
 

cinema/views.py

@@ -1,6 +1,9 @@
+from django.core.serializers import serialize
 from rest_framework import viewsets
+from rest_framework.pagination import PageNumberPagination
+from django.db.models import Count, F
 
-from cinema.models import Genre, Actor, CinemaHall, Movie, MovieSession
+from cinema.models import Genre, Actor, CinemaHall, Movie, MovieSession, Order
 
 from cinema.serializers import (
     GenreSerializer,
@@ -11,7 +14,9 @@
     MovieSessionListSerializer,
     MovieDetailSerializer,
     MovieSessionDetailSerializer,
-    MovieListSerializer,
+    MovieListSerializer, OrderSerializer,
+    OrderListSerializer,
+    OrderSetPagination
 )
 
 
@@ -34,6 +39,10 @@ class MovieViewSet(viewsets.ModelViewSet):
     queryset = Movie.objects.all()
     serializer_class = MovieSerializer
 
+    @staticmethod
+    def _params_to_ints(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 +52,37 @@ def get_serializer_class(self):
 
         return MovieSerializer
 
+    def get_queryset(self):
+        queryset = self.queryset
+        genres = self.request.query_params.get("genres")
+        actors = self.request.query_params.get("actors")
+        title = self.request.query_params.get("title")
+
+        if genres:
+            genres_ids = self._params_to_ints(genres)
+            queryset = queryset.filter(genres__id__in=genres_ids)
+
+        if actors:
+            actors_ids = self._params_to_ints(actors)
+            queryset = queryset.filter(actors__id__in=actors_ids)
+
+        if title:
+            queryset = queryset.filter(title__contains=title)
+
+        if self.action in ("list", "retrieve"):
+            return queryset.prefetch_related("genres", "actors")
+
+        return queryset.distinct()
+
 
 class MovieSessionViewSet(viewsets.ModelViewSet):
     queryset = MovieSession.objects.all()
     serializer_class = MovieSessionSerializer
 
+    @staticmethod
+    def _params_to_ints(query_string):
+        return [int(str_id) for str_id in query_string.split(",")]
+
     def get_serializer_class(self):
         if self.action == "list":
             return MovieSessionListSerializer
@@ -56,3 +91,51 @@ def get_serializer_class(self):
             return MovieSessionDetailSerializer
 
         return MovieSessionSerializer
+
+    def get_queryset(self):
+        queryset = self.queryset
+        movies = self.request.query_params.get("movies")
+        date = self.request.query_params.get("date")
+        if movies:
+            movies_ids = self._params_to_ints(movies)
+            queryset = queryset.filter(movies__id__in=movies_ids)
+
+        if date:
+            queryset = queryset.filter(show_time__date=date)
+
+        if self.action == "list":
+            queryset = (
+                queryset
+                .select_related("movie", "cinema_hall")
+                .annotate(
+                    tickets_available=(
+                        F("cinema_hall__rows") * F("cinema_hall__seats_in_row")
+                    ) - Count("tickets")
+                )
+            )
+        elif self.action in "retrieve":
+            queryset = queryset.select_related("movie", "cinema_hall")
+
+        return queryset.distinct()
+
+
+class OrdersViewSet(viewsets.ModelViewSet):
+    queryset = Order.objects.all()
+    serializer_class = OrderSerializer
+    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")
+        return queryset
+
+    def perform_create(self, serializer):
+        serializer.save(user=self.request.user)
+
+    def get_serializer_class(self):
+        serializer = self.serializer_class
+        if self.action == "list":
+            serializer = OrderListSerializer
+
+        return serializer

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
+}