from __future__ import unicode_literals

from django.db import models
from django.utils.encoding import python_2_unicode_compatible


@python_2_unicode_compatible
class Building(models.Model):
    name = models.CharField(max_length=10)

    def __str__(self):
        return "Building: %s" % self.name


@python_2_unicode_compatible
class Device(models.Model):
    building = models.ForeignKey('Building')
    name = models.CharField(max_length=10)

    def __str__(self):
        return "device '%s' in building %s" % (self.name, self.building)


@python_2_unicode_compatible
class Port(models.Model):
    device = models.ForeignKey('Device')
    port_number = models.CharField(max_length=10)

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


@python_2_unicode_compatible
class Connection(models.Model):
    start = models.ForeignKey(Port, related_name='connection_start',
            unique=True)
    end = models.ForeignKey(Port, related_name='connection_end', unique=True)

    def __str__(self):
        return "%s to %s" % (self.start, self.end)

# 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, unique=True)


class Organizer(models.Model):
    person = models.ForeignKey(Person)


class Student(models.Model):
    person = models.ForeignKey(Person)


class Class(models.Model):
    org = models.ForeignKey(Organizer)


class Enrollment(models.Model):
    std = models.ForeignKey(Student)
    cls = models.ForeignKey(Class)

# 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)


class ClientStatus(models.Model):
    name = models.CharField(max_length=50)


class Client(models.Model):
    name = models.CharField(max_length=50)
    state = models.ForeignKey(State, null=True)
    status = models.ForeignKey(ClientStatus)


class SpecialClient(Client):
    value = models.IntegerField()

# Some model inheritance exercises


@python_2_unicode_compatible
class Parent(models.Model):
    name = models.CharField(max_length=10)

    def __str__(self):
        return self.name


class Child(Parent):
    value = models.IntegerField()


@python_2_unicode_compatible
class Item(models.Model):
    name = models.CharField(max_length=10)
    child = models.ForeignKey(Child, null=True)

    def __str__(self):
        return self.name

# Models for testing bug #19870.


@python_2_unicode_compatible
class Fowl(models.Model):
    name = models.CharField(max_length=10)

    def __str__(self):
        return self.name


class Hen(Fowl):
    pass


class Chick(Fowl):
    mother = models.ForeignKey(Hen)


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)
    c_b = models.ForeignKey(B)
    is_published = models.BooleanField(default=False)
