from django.contrib.contenttypes.fields import GenericForeignKey, GenericRelation

from django.contrib.contenttypes.models import ContentType

from django.db import models

class Author(models.Model):

    name = models.CharField(max_length=100)

    age = models.IntegerField()

    friends = models.ManyToManyField("self", blank=True)

class Publisher(models.Model):

    name = models.CharField(max_length=255)

    num_awards = models.IntegerField()

class ItemTag(models.Model):

    tag = models.CharField(max_length=100)

    content_type = models.ForeignKey(ContentType, models.CASCADE)

    object_id = models.PositiveIntegerField()

    content_object = GenericForeignKey("content_type", "object_id")

class Book(models.Model):

    isbn = models.CharField(max_length=9)

    name = models.CharField(max_length=255)

    pages = models.IntegerField()

    rating = models.FloatField()

    price = models.DecimalField(decimal_places=2, max_digits=6)

    authors = models.ManyToManyField(Author)

    contact = models.ForeignKey(Author, models.CASCADE, related_name="book_contact_set")

    publisher = models.ForeignKey(Publisher, models.CASCADE)

    pubdate = models.DateField()

    tags = GenericRelation(ItemTag)

    class Meta:

        ordering = ("name",)

class Store(models.Model):

    name = models.CharField(max_length=255)

    books = models.ManyToManyField(Book)

    original_opening = models.DateTimeField()

    friday_night_closing = models.TimeField()

class Entries(models.Model):

    EntryID = models.AutoField(primary_key=True, db_column="Entry ID")

    Entry = models.CharField(unique=True, max_length=50)

    Exclude = models.BooleanField(default=False)

class Clues(models.Model):

    ID = models.AutoField(primary_key=True)

    EntryID = models.ForeignKey(

        Entries, models.CASCADE, verbose_name="Entry", db_column="Entry ID"

    )

    Clue = models.CharField(max_length=150)

class WithManualPK(models.Model):

    # The generic relations regression test needs two different model

    # classes with the same PK value, and there are some (external)

    # DB backends that don't work nicely when assigning integer to AutoField

    # column (MSSQL at least).

    id = models.IntegerField(primary_key=True)

class HardbackBook(Book):

    weight = models.FloatField()

# Models for ticket #21150

class Alfa(models.Model):

    name = models.CharField(max_length=10, null=True)

class Bravo(models.Model):

    pass

class Charlie(models.Model):

    alfa = models.ForeignKey(Alfa, models.SET_NULL, null=True)

    bravo = models.ForeignKey(Bravo, models.SET_NULL, null=True)

class SelfRefFK(models.Model):

    name = models.CharField(max_length=50)

    parent = models.ForeignKey(

        "self", models.SET_NULL, null=True, blank=True, related_name="children"

    )