from django.db import models

class Building(models.Model):

    name = models.CharField(max_length=10)

class Device(models.Model):

    building = models.ForeignKey("Building", models.CASCADE)

    name = models.CharField(max_length=10)

class Port(models.Model):

    device = models.ForeignKey("Device", models.CASCADE)

    port_number = models.CharField(max_length=10)

    def __str__(self):

        return "%s/%s" % (self.device.name, self.port_number)

class Connection(models.Model):

    start = models.ForeignKey(

        Port,

        models.CASCADE,

        related_name="connection_start",

        unique=True,

    )

    end = models.ForeignKey(

        Port,

        models.CASCADE,

        related_name="connection_end",

        unique=True,

    )

# Another non-tree hierarchy that exercises code paths similar to the above

# example, but in a slightly different configuration.

class TUser(models.Model):

    name = models.CharField(max_length=200)

class Person(models.Model):

    user = models.ForeignKey(TUser, models.CASCADE, unique=True)

class Organizer(models.Model):

    person = models.ForeignKey(Person, models.CASCADE)

class Student(models.Model):

    person = models.ForeignKey(Person, models.CASCADE)

class Class(models.Model):

    org = models.ForeignKey(Organizer, models.CASCADE)

class Enrollment(models.Model):

    std = models.ForeignKey(Student, models.CASCADE)

    cls = models.ForeignKey(Class, models.CASCADE)

# Models for testing bug #8036.

class Country(models.Model):

    name = models.CharField(max_length=50)

class State(models.Model):

    name = models.CharField(max_length=50)

    country = models.ForeignKey(Country, models.CASCADE)

class ClientStatus(models.Model):

    name = models.CharField(max_length=50)

class Client(models.Model):

    name = models.CharField(max_length=50)

    state = models.ForeignKey(State, models.SET_NULL, null=True)

    status = models.ForeignKey(ClientStatus, models.CASCADE)

class SpecialClient(Client):

    value = models.IntegerField()

# Some model inheritance exercises

class Parent(models.Model):

    name = models.CharField(max_length=10)

class Child(Parent):

    value = models.IntegerField()

class Item(models.Model):

    name = models.CharField(max_length=10)

    child = models.ForeignKey(Child, models.SET_NULL, null=True)

    def __str__(self):

        return self.name

# Models for testing bug #19870.

class Fowl(models.Model):

    name = models.CharField(max_length=10)

class Hen(Fowl):

    pass

class Chick(Fowl):

    mother = models.ForeignKey(Hen, models.CASCADE)

class Base(models.Model):

    name = models.CharField(max_length=10)

    lots_of_text = models.TextField()

    class Meta:

        abstract = True

class A(Base):

    a_field = models.CharField(max_length=10)

class B(Base):

    b_field = models.CharField(max_length=10)

class C(Base):

    c_a = models.ForeignKey(A, models.CASCADE)

    c_b = models.ForeignKey(B, models.CASCADE)

    is_published = models.BooleanField(default=False)