solution

.gitignore

@@ -7,4 +7,5 @@ venv/
 .pytest_cache/
 **__pycache__/
 *.pyc
-app/db.sqlite3
+app/db.sqlite3
+db.sqlite3

cinema/migrations/0001_initial.py

@@ -1,7 +1,7 @@
 # Generated by Django 4.0.4 on 2022-05-09 18:11
 
-from django.db import migrations, models
 import django.db.models.deletion
+from django.db import migrations, models
 
 
 class Migration(migrations.Migration):

cinema/migrations/0002_initial.py

@@ -1,8 +1,8 @@
 # Generated by Django 4.0.4 on 2022-05-09 18:11
 
+import django.db.models.deletion
 from django.conf import settings
 from django.db import migrations, models
-import django.db.models.deletion
 
 
 class Migration(migrations.Migration):
@@ -19,14 +19,16 @@ class Migration(migrations.Migration):
             model_name="order",
             name="user",
             field=models.ForeignKey(
-                on_delete=django.db.models.deletion.CASCADE, to=settings.AUTH_USER_MODEL
+                on_delete=django.db.models.deletion.CASCADE,
+                to=settings.AUTH_USER_MODEL,
             ),
         ),
         migrations.AddField(
             model_name="moviesession",
             name="cinema_hall",
             field=models.ForeignKey(
-                on_delete=django.db.models.deletion.CASCADE, to="cinema.cinemahall"
+                on_delete=django.db.models.deletion.CASCADE,
+                to="cinema.cinemahall",
             ),
         ),
         migrations.AddField(

cinema/migrations/0003_movie_duration.py

@@ -6,13 +6,13 @@
 class Migration(migrations.Migration):
 
     dependencies = [
-        ('cinema', '0002_initial'),
+        ("cinema", "0002_initial"),
     ]
 
     operations = [
         migrations.AddField(
-            model_name='movie',
-            name='duration',
+            model_name="movie",
+            name="duration",
             field=models.IntegerField(default=123),
             preserve_default=False,
         ),

cinema/migrations/0004_alter_genre_name.py

@@ -6,13 +6,13 @@
 class Migration(migrations.Migration):
 
     dependencies = [
-        ('cinema', '0003_movie_duration'),
+        ("cinema", "0003_movie_duration"),
     ]
 
     operations = [
         migrations.AlterField(
-            model_name='genre',
-            name='name',
+            model_name="genre",
+            name="name",
             field=models.CharField(max_length=255, unique=True),
         ),
     ]

cinema/models.py

@@ -1,6 +1,6 @@
+from django.conf import settings
 from django.core.exceptions import ValidationError
 from django.db import models
-from django.conf import settings
 
 
 class CinemaHall(models.Model):
@@ -39,7 +39,7 @@ class Movie(models.Model):
     title = models.CharField(max_length=255)
     description = models.TextField()
     duration = models.IntegerField()
-    genres = models.ManyToManyField(Genre)
+    genres = models.ManyToManyField(Genre, related_name="movies")
     actors = models.ManyToManyField(Actor)
 
     class Meta:
@@ -60,6 +60,10 @@ class Meta:
     def __str__(self):
         return self.movie.title + " " + str(self.show_time)
 
+    @property
+    def available_spots(self) -> int:
+        return self.cinema_hall.capacity - self.tickets.count()
+
 
 class Order(models.Model):
     created_at = models.DateTimeField(auto_now_add=True)

cinema/serializers.py

@@ -1,6 +1,7 @@
 from rest_framework import serializers
 
-from cinema.models import Genre, Actor, CinemaHall, Movie, MovieSession
+from cinema.models import (Actor, CinemaHall, Genre, Movie, MovieSession,
+                           Order, Ticket)
 
 
 class GenreSerializer(serializers.ModelSerializer):
@@ -10,6 +11,8 @@ class Meta:
 
 
 class ActorSerializer(serializers.ModelSerializer):
+    full_name = serializers.CharField(read_only=True)
+
     class Meta:
         model = Actor
         fields = ("id", "first_name", "last_name", "full_name")
@@ -46,9 +49,25 @@ 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 +78,9 @@ class MovieSessionListSerializer(MovieSessionSerializer):
     cinema_hall_capacity = serializers.IntegerField(
         source="cinema_hall.capacity", read_only=True
     )
+    tickets_available = serializers.IntegerField(
+        source="available_spots", read_only=True
+    )
 
     class Meta:
         model = MovieSession
@@ -68,13 +90,43 @@ class Meta:
             "movie_title",
             "cinema_hall_name",
             "cinema_hall_capacity",
+            "tickets_available",
         )
 
 
+class TicketSerializer(serializers.ModelSerializer):
+    movie_session = MovieSessionSerializer(many=False, read_only=True)
+
+    class Meta:
+        model = Ticket
+        fields = ("id", "movie_session", "seat", "row")
+
+
+class TicketListSerializer(serializers.ModelSerializer):
+    class Meta:
+        model = Ticket
+        fields = ("seat", "row")
+
+
 class MovieSessionDetailSerializer(MovieSessionSerializer):
     movie = MovieListSerializer(many=False, read_only=True)
     cinema_hall = CinemaHallSerializer(many=False, read_only=True)
+    taken_places = TicketListSerializer(
+        source="tickets", many=True, read_only=True
+    )
 
     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)
+
+    class Meta:
+        model = Order
+        fields = ("id", "tickets", "created_at")
+
+
+class OrderDetailSerializer(OrderSerializer):
+    tickets = TicketSerializer(many=True, read_only=True)

cinema/urls.py

@@ -1,20 +1,18 @@
-from django.urls import path, include
+from django.urls import include, path
 from rest_framework import routers
 
-from cinema.views import (
-    GenreViewSet,
-    ActorViewSet,
-    CinemaHallViewSet,
-    MovieViewSet,
-    MovieSessionViewSet,
-)
+from cinema.views import (ActorViewSet, CinemaHallViewSet, GenreViewSet,
+                          MovieSessionViewSet, MovieViewSet, OrderViewSet)
 
 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("genres", GenreViewSet, basename="genres")
+router.register("actors", ActorViewSet, basename="actors")
+router.register("cinema_halls", CinemaHallViewSet, basename="cinema_halls")
+router.register("movies", MovieViewSet, basename="movies")
+router.register(
+    "movie_sessions", MovieSessionViewSet, basename="movie_sessions"
+)
+router.register("orders", OrderViewSet, basename="orders")
 
 urlpatterns = [path("", include(router.urls))]
 

cinema/views.py

@@ -1,24 +1,35 @@
 from rest_framework import viewsets
+from rest_framework.pagination import PageNumberPagination
 
-from cinema.models import Genre, Actor, CinemaHall, Movie, MovieSession
-
-from cinema.serializers import (
-    GenreSerializer,
-    ActorSerializer,
-    CinemaHallSerializer,
-    MovieSerializer,
-    MovieSessionSerializer,
-    MovieSessionListSerializer,
-    MovieDetailSerializer,
-    MovieSessionDetailSerializer,
-    MovieListSerializer,
-)
+from cinema.models import Actor, CinemaHall, Genre, Movie, MovieSession, Order
+from cinema.serializers import (ActorSerializer, CinemaHallSerializer,
+                                GenreSerializer, MovieDetailSerializer,
+                                MovieListSerializer, MovieSerializer,
+                                MovieSessionDetailSerializer,
+                                MovieSessionListSerializer,
+                                MovieSessionSerializer, OrderSerializer)
 
 
 class GenreViewSet(viewsets.ModelViewSet):
-    queryset = Genre.objects.all()
+    queryset = Genre.objects.prefetch_related("movies")
     serializer_class = GenreSerializer
 
+    @staticmethod
+    def params_to_ints(qs):
+        return [int(str_id) for str_id in qs.split(",")]
+
+    def get_queryset(self):
+        queryset = self.queryset
+        if genres := self.request.query_params.get("genres"):
+            genre_ids = self.params_to_ints(genres)
+            queryset = queryset.filter(id__in=genre_ids)
+        if actors := self.request.query_params.get("actors"):
+            actor_ids = self.params_to_ints(actors)
+            queryset = queryset.filter(movies__actors__id__in=actor_ids)
+        if title := self.request.query_params.get("title"):
+            queryset = queryset.filter(movies__title__icontains=title)
+        return queryset.distinct()
+
 
 class ActorViewSet(viewsets.ModelViewSet):
     queryset = Actor.objects.all()
@@ -31,28 +42,66 @@ class CinemaHallViewSet(viewsets.ModelViewSet):
 
 
 class MovieViewSet(viewsets.ModelViewSet):
-    queryset = Movie.objects.all()
+    queryset = Movie.objects.select_related().prefetch_related(
+        "genres", "actors"
+    )
     serializer_class = MovieSerializer
 
+    def get_queryset(self):
+        queryset = self.queryset
+        if genres := self.request.query_params.get("genres"):
+            genre_ids = GenreViewSet.params_to_ints(genres)
+            queryset = queryset.filter(genres__id__in=genre_ids)
+        if actors := self.request.query_params.get("actors"):
+            actor_ids = GenreViewSet.params_to_ints(actors)
+            queryset = queryset.filter(actors__id__in=actor_ids)
+        if title := self.request.query_params.get("title"):
+            queryset = queryset.filter(title__icontains=title)
+        return queryset.distinct()
+
     def get_serializer_class(self):
         if self.action == "list":
             return MovieListSerializer
-
         if self.action == "retrieve":
             return MovieDetailSerializer
 
         return MovieSerializer
 
 
 class MovieSessionViewSet(viewsets.ModelViewSet):
-    queryset = MovieSession.objects.all()
+    queryset = MovieSession.objects.select_related(
+        "movie", "cinema_hall"
+    ).prefetch_related("tickets")
     serializer_class = MovieSessionSerializer
 
+    def get_queryset(self):
+        queryset = self.queryset
+        if movie_id := self.request.query_params.get("movie"):
+            queryset = queryset.filter(movie__id=movie_id)
+        if date := self.request.query_params.get("date"):
+            queryset = queryset.filter(show_time__date=date)
+        return queryset.distinct()
+
     def get_serializer_class(self):
         if self.action == "list":
             return MovieSessionListSerializer
-
         if self.action == "retrieve":
             return MovieSessionDetailSerializer
-
         return MovieSessionSerializer
+
+
+class OrderPagination(PageNumberPagination):
+    page_size = 10
+    page_size_query_param = "page_size"
+    max_page_size = 100
+
+
+class OrderViewSet(viewsets.ModelViewSet):
+    serializer_class = OrderSerializer
+    pagination_class = OrderPagination
+
+    def get_queryset(self):
+        return Order.objects.filter(user=self.request.user)
+
+    def perform_create(self, serializer):
+        serializer.save(user=self.request.user)