# coding: utf-8

"""

Tests for some corner cases with deleting.

"""

from django.db import models

class DefaultRepr(object):

    def __repr__(self):

        return u"<%s: %s>" % (self.__class__.__name__, self.__dict__)

class A(DefaultRepr, models.Model):

    pass

class B(DefaultRepr, models.Model):

    a = models.ForeignKey(A)

class C(DefaultRepr, models.Model):

    b = models.ForeignKey(B)

class D(DefaultRepr, models.Model):

    c = models.ForeignKey(C)

    a = models.ForeignKey(A)

# Simplified, we have:

# A

# B -> A

# C -> B

# D -> C

# D -> A

# So, we must delete Ds first of all, then Cs then Bs then As.

# However, if we start at As, we might find Bs first (in which

# case things will be nice), or find Ds first.

# Some mutually dependent models, but nullable

class E(DefaultRepr, models.Model):

    f = models.ForeignKey('F', null=True, related_name='e_rel')

class F(DefaultRepr, models.Model):

    e = models.ForeignKey(E, related_name='f_rel')