Solution

.gitignore

@@ -7,4 +7,6 @@ venv/
 .pytest_cache/
 **__pycache__/
 *.pyc
-app/db.sqlite3
+app/db.sqlite3
+.sqlite
+.db3

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

@@ -1,19 +1,6 @@
-from django.core.exceptions import ValidationError
 from django.db import models
 from django.conf import settings
-
-
-class CinemaHall(models.Model):
-    name = models.CharField(max_length=255)
-    rows = models.IntegerField()
-    seats_in_row = models.IntegerField()
-
-    @property
-    def capacity(self) -> int:
-        return self.rows * self.seats_in_row
-
-    def __str__(self):
-        return self.name
+from django.core.exceptions import ValidationError
 
 
 class Genre(models.Model):
@@ -27,13 +14,26 @@ class Actor(models.Model):
     first_name = models.CharField(max_length=255)
     last_name = models.CharField(max_length=255)
 
-    def __str__(self):
-        return self.first_name + " " + self.last_name
-
     @property
     def full_name(self):
         return f"{self.first_name} {self.last_name}"
 
+    def __str__(self):
+        return self.full_name
+
+
+class CinemaHall(models.Model):
+    name = models.CharField(max_length=255)
+    rows = models.IntegerField()
+    seats_in_row = models.IntegerField()
+
+    @property
+    def capacity(self):
+        return self.rows * self.seats_in_row
+
+    def __str__(self):
+        return self.name
+
 
 class Movie(models.Model):
     title = models.CharField(max_length=255)
@@ -42,9 +42,6 @@ class Movie(models.Model):
     genres = models.ManyToManyField(Genre)
     actors = models.ManyToManyField(Actor)
 
-    class Meta:
-        ordering = ["title"]
-
     def __str__(self):
         return self.title
 
@@ -54,70 +51,47 @@ class MovieSession(models.Model):
     movie = models.ForeignKey(Movie, on_delete=models.CASCADE)
     cinema_hall = models.ForeignKey(CinemaHall, on_delete=models.CASCADE)
 
-    class Meta:
-        ordering = ["-show_time"]
-
     def __str__(self):
-        return self.movie.title + " " + str(self.show_time)
+        return f"{self.movie.title} - {self.show_time}"
 
 
 class Order(models.Model):
     created_at = models.DateTimeField(auto_now_add=True)
-    user = models.ForeignKey(
-        settings.AUTH_USER_MODEL, on_delete=models.CASCADE
-    )
+    user = models.ForeignKey(settings.AUTH_USER_MODEL,
+                             on_delete=models.CASCADE)
 
     def __str__(self):
-        return str(self.created_at)
-
-    class Meta:
-        ordering = ["-created_at"]
+        return f"Order {self.id} - {self.created_at}"
 
 
 class Ticket(models.Model):
     movie_session = models.ForeignKey(
         MovieSession, on_delete=models.CASCADE, related_name="tickets"
     )
-    order = models.ForeignKey(
-        Order, on_delete=models.CASCADE, related_name="tickets"
-    )
+    order = models.ForeignKey(Order, on_delete=models.CASCADE,
+                              related_name="tickets")
     row = models.IntegerField()
     seat = models.IntegerField()
 
+    class Meta:
+        unique_together = ("movie_session", "row", "seat")
+
     def clean(self):
-        for ticket_attr_value, ticket_attr_name, cinema_hall_attr_name in [
-            (self.row, "row", "rows"),
-            (self.seat, "seat", "seats_in_row"),
-        ]:
-            count_attrs = getattr(
-                self.movie_session.cinema_hall, cinema_hall_attr_name
+        if not (1 <= self.row <= self.movie_session.cinema_hall.rows):
+            raise ValidationError(
+                f"Row number must be between 1 and "
+                f"{self.movie_session.cinema_hall.rows}"
             )
-            if not (1 <= ticket_attr_value <= count_attrs):
-                raise ValidationError(
-                    {
-                        ticket_attr_name: f"{ticket_attr_name} "
-                        f"number must be in available range: "
-                        f"(1, {cinema_hall_attr_name}): "
-                        f"(1, {count_attrs})"
-                    }
-                )
-
-    def save(
-        self,
-        force_insert=False,
-        force_update=False,
-        using=None,
-        update_fields=None,
-    ):
+        if not (1 <= self.seat <= self.movie_session.cinema_hall.seats_in_row):
+            raise ValidationError(
+                f"Seat number must be between 1 and "
+                f"{self.movie_session.cinema_hall.seats_in_row}"
+            )
+
+    def save(self, *args, **kwargs):
         self.full_clean()
-        super(Ticket, self).save(
-            force_insert, force_update, using, update_fields
-        )
+        super().save(*args, **kwargs)
 
     def __str__(self):
-        return (
-            f"{str(self.movie_session)} (row: {self.row}, seat: {self.seat})"
-        )
-
-    class Meta:
-        unique_together = ("movie_session", "row", "seat")
+        return (f"Ticket for {self.movie_session} - "
+                f"Row {self.row}, Seat {self.seat}")

cinema/serializers.py

@@ -1,6 +1,12 @@
 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):
@@ -10,6 +16,8 @@ class Meta:
 
 
 class ActorSerializer(serializers.ModelSerializer):
+    full_name = serializers.CharField(source="full_name", read_only=True)
+
     class Meta:
         model = Actor
         fields = ("id", "first_name", "last_name", "full_name")
@@ -27,38 +35,26 @@ class Meta:
         fields = ("id", "title", "description", "duration", "genres", "actors")
 
 
-class MovieListSerializer(MovieSerializer):
-    genres = serializers.SlugRelatedField(
-        many=True, read_only=True, slug_field="name"
-    )
+class MovieListSerializer(serializers.ModelSerializer):
+    genres = serializers.SlugRelatedField(many=True, read_only=True,
+                                          slug_field="name")
     actors = serializers.SlugRelatedField(
         many=True, read_only=True, slug_field="full_name"
     )
 
-
-class MovieDetailSerializer(MovieSerializer):
-    genres = GenreSerializer(many=True, read_only=True)
-    actors = ActorSerializer(many=True, read_only=True)
-
     class Meta:
         model = Movie
         fields = ("id", "title", "description", "duration", "genres", "actors")
 
 
-class MovieSessionSerializer(serializers.ModelSerializer):
-    class Meta:
-        model = MovieSession
-        fields = ("id", "show_time", "movie", "cinema_hall")
-
-
-class MovieSessionListSerializer(MovieSessionSerializer):
+class MovieSessionListSerializer(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_name = serializers.CharField(source="cinema_hall.name",
+                                             read_only=True)
     cinema_hall_capacity = serializers.IntegerField(
         source="cinema_hall.capacity", read_only=True
     )
+    tickets_available = serializers.SerializerMethodField()
 
     class Meta:
         model = MovieSession
@@ -68,13 +64,30 @@ class Meta:
             "movie_title",
             "cinema_hall_name",
             "cinema_hall_capacity",
+            "tickets_available",
         )
 
+    def get_tickets_available(self, obj):
+        return obj.cinema_hall.capacity - obj.tickets.count()
 
-class MovieSessionDetailSerializer(MovieSessionSerializer):
-    movie = MovieListSerializer(many=False, read_only=True)
-    cinema_hall = CinemaHallSerializer(many=False, read_only=True)
 
+class TicketSerializer(serializers.ModelSerializer):
     class Meta:
-        model = MovieSession
-        fields = ("id", "show_time", "movie", "cinema_hall")
+        model = Ticket
+        fields = ("id", "row", "seat", "movie_session")
+
+
+class OrderSerializer(serializers.ModelSerializer):
+    tickets = TicketSerializer(many=True)
+
+    class Meta:
+        model = Order
+        fields = ("id", "tickets", "created_at")
+
+    def create(self, validated_data):
+        tickets_data = validated_data.pop("tickets")
+        user = self.context["request"].user
+        order = Order.objects.create(user=user)
+        for ticket_data in tickets_data:
+            Ticket.objects.create(order=order, **ticket_data)
+        return order

cinema/tests/test_actor_api.py

@@ -16,9 +16,7 @@ def test_get_actors(self):
         response = self.client.get("/api/cinema/actors/")
         self.assertEqual(response.status_code, status.HTTP_200_OK)
         actors_full_names = [actor["full_name"] for actor in response.data]
-        self.assertEqual(
-            sorted(actors_full_names), ["George Clooney", "Keanu Reeves"]
-        )
+        self.assertEqual(sorted(actors_full_names), ["George Clooney", "Keanu Reeves"])
 
     def test_post_actors(self):
         response = self.client.post(

cinema/tests/test_cinema_hall_api.py

@@ -31,9 +31,7 @@ def test_get_cinema_halls(self):
         self.assertEqual(response.status_code, status.HTTP_200_OK)
         self.assertEqual(response.data[0]["name"], blue_hall["name"])
         self.assertEqual(response.data[0]["rows"], blue_hall["rows"])
-        self.assertEqual(
-            response.data[0]["seats_in_row"], blue_hall["seats_in_row"]
-        )
+        self.assertEqual(response.data[0]["seats_in_row"], blue_hall["seats_in_row"])
         vip_hall = {
             "name": "VIP",
             "rows": 6,
@@ -43,9 +41,7 @@ def test_get_cinema_halls(self):
         self.assertEqual(response.status_code, status.HTTP_200_OK)
         self.assertEqual(response.data[1]["name"], vip_hall["name"])
         self.assertEqual(response.data[1]["rows"], vip_hall["rows"])
-        self.assertEqual(
-            response.data[1]["seats_in_row"], vip_hall["seats_in_row"]
-        )
+        self.assertEqual(response.data[1]["seats_in_row"], vip_hall["seats_in_row"])
 
     def test_post_cinema_halls(self):
         response = self.client.post(
@@ -72,9 +68,7 @@ def test_get_cinema_hall(self):
         self.assertEqual(response.status_code, status.HTTP_200_OK)
         self.assertEqual(response.data["name"], vip_hall["name"])
         self.assertEqual(response.data["rows"], vip_hall["rows"])
-        self.assertEqual(
-            response.data["seats_in_row"], vip_hall["seats_in_row"]
-        )
+        self.assertEqual(response.data["seats_in_row"], vip_hall["seats_in_row"])
         self.assertEqual(response.data["capacity"], vip_hall["capacity"])
 
     def test_get_invalid_cinema_hall(self):

cinema/tests/test_movie_api.py

@@ -15,9 +15,7 @@ def setUp(self):
         self.comedy = Genre.objects.create(
             name="Comedy",
         )
-        self.actress = Actor.objects.create(
-            first_name="Kate", last_name="Winslet"
-        )
+        self.actress = Actor.objects.create(first_name="Kate", last_name="Winslet")
         self.movie = Movie.objects.create(
             title="Titanic",
             description="Titanic description",
@@ -42,21 +40,15 @@ def test_get_movies(self):
             self.assertEqual(movies.data[0][field], titanic[field])
 
     def test_get_movies_with_genres_filtering(self):
-        movies = self.client.get(
-            f"/api/cinema/movies/?genres={self.comedy.id}"
-        )
+        movies = self.client.get(f"/api/cinema/movies/?genres={self.comedy.id}")
         self.assertEqual(len(movies.data), 1)
-        movies = self.client.get(
-            f"/api/cinema/movies/?genres={self.comedy.id},2,3"
-        )
+        movies = self.client.get(f"/api/cinema/movies/?genres={self.comedy.id},2,3")
         self.assertEqual(len(movies.data), 1)
         movies = self.client.get("/api/cinema/movies/?genres=123213")
         self.assertEqual(len(movies.data), 0)
 
     def test_get_movies_with_actors_filtering(self):
-        movies = self.client.get(
-            f"/api/cinema/movies/?actors={self.actress.id}"
-        )
+        movies = self.client.get(f"/api/cinema/movies/?actors={self.actress.id}")
         self.assertEqual(len(movies.data), 1)
         movies = self.client.get(f"/api/cinema/movies/?actors={123}")
         self.assertEqual(len(movies.data), 0)
@@ -111,9 +103,7 @@ def test_get_movie(self):
         self.assertEqual(response.data["genres"][1]["name"], "Comedy")
         self.assertEqual(response.data["actors"][0]["first_name"], "Kate")
         self.assertEqual(response.data["actors"][0]["last_name"], "Winslet")
-        self.assertEqual(
-            response.data["actors"][0]["full_name"], "Kate Winslet"
-        )
+        self.assertEqual(response.data["actors"][0]["full_name"], "Kate Winslet")
 
     def test_get_invalid_movie(self):
         response = self.client.get("/api/cinema/movies/100/")