from django.contrib.contenttypes.fields import (
    GenericForeignKey, GenericRelation
)
from django.contrib.contenttypes.models import ContentType
from django.db import models
from django.utils.encoding import python_2_unicode_compatible
from django.db.models.deletion import ProtectedError


__all__ = ('Link', 'Place', 'Restaurant', 'Person', 'Address',
           'CharLink', 'TextLink', 'OddRelation1', 'OddRelation2',
           'Contact', 'Organization', 'Note', 'Company')


@python_2_unicode_compatible
class Link(models.Model):
    content_type = models.ForeignKey(ContentType)
    object_id = models.PositiveIntegerField()
    content_object = GenericForeignKey()

    def __str__(self):
        return "Link to %s id=%s" % (self.content_type, self.object_id)


@python_2_unicode_compatible
class Place(models.Model):
    name = models.CharField(max_length=100)
    links = GenericRelation(Link)

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


@python_2_unicode_compatible
class Restaurant(Place):
    def __str__(self):
        return "Restaurant: %s" % self.name


@python_2_unicode_compatible
class Address(models.Model):
    street = models.CharField(max_length=80)
    city = models.CharField(max_length=50)
    state = models.CharField(max_length=2)
    zipcode = models.CharField(max_length=5)
    content_type = models.ForeignKey(ContentType)
    object_id = models.PositiveIntegerField()
    content_object = GenericForeignKey()

    def __str__(self):
        return '%s %s, %s %s' % (self.street, self.city, self.state, self.zipcode)


@python_2_unicode_compatible
class Person(models.Model):
    account = models.IntegerField(primary_key=True)
    name = models.CharField(max_length=128)
    addresses = GenericRelation(Address)

    def __str__(self):
        return self.name


class CharLink(models.Model):
    content_type = models.ForeignKey(ContentType)
    object_id = models.CharField(max_length=100)
    content_object = GenericForeignKey()


class TextLink(models.Model):
    content_type = models.ForeignKey(ContentType)
    object_id = models.TextField()
    content_object = GenericForeignKey()


class OddRelation1(models.Model):
    name = models.CharField(max_length=100)
    clinks = GenericRelation(CharLink)


class OddRelation2(models.Model):
    name = models.CharField(max_length=100)
    tlinks = GenericRelation(TextLink)


# models for test_q_object_or:
class Note(models.Model):
    content_type = models.ForeignKey(ContentType)
    object_id = models.PositiveIntegerField()
    content_object = GenericForeignKey()
    note = models.TextField()


class Contact(models.Model):
    notes = GenericRelation(Note)


class Organization(models.Model):
    name = models.CharField(max_length=255)
    contacts = models.ManyToManyField(Contact, related_name='organizations')


@python_2_unicode_compatible
class Company(models.Model):
    name = models.CharField(max_length=100)
    links = GenericRelation(Link)

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


# For testing #13085 fix, we also use Note model defined above
class Developer(models.Model):
    name = models.CharField(max_length=15)


@python_2_unicode_compatible
class Team(models.Model):
    name = models.CharField(max_length=15)
    members = models.ManyToManyField(Developer)

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

    def __len__(self):
        return self.members.count()


class Guild(models.Model):
    name = models.CharField(max_length=15)
    members = models.ManyToManyField(Developer)

    def __nonzero__(self):

        return self.members.count()


class Tag(models.Model):
    content_type = models.ForeignKey(ContentType, related_name='g_r_r_tags')
    object_id = models.CharField(max_length=15)
    content_object = GenericForeignKey()
    label = models.CharField(max_length=15)


class Board(models.Model):
    name = models.CharField(primary_key=True, max_length=15)


class SpecialGenericRelation(GenericRelation):
    def __init__(self, *args, **kwargs):
        super(SpecialGenericRelation, self).__init__(*args, **kwargs)
        self.editable = True
        self.save_form_data_calls = 0

    def save_form_data(self, *args, **kwargs):
        self.save_form_data_calls += 1


class HasLinks(models.Model):
    links = SpecialGenericRelation(Link)

    class Meta:
        abstract = True


class HasLinkThing(HasLinks):
    pass


class A(models.Model):
    flag = models.NullBooleanField()
    content_type = models.ForeignKey(ContentType)
    object_id = models.PositiveIntegerField()
    content_object = GenericForeignKey('content_type', 'object_id')


class B(models.Model):
    a = GenericRelation(A)

    class Meta:
        ordering = ('id',)


class C(models.Model):
    b = models.ForeignKey(B)

    class Meta:
        ordering = ('id',)


class D(models.Model):
    b = models.ForeignKey(B, null=True)

    class Meta:
        ordering = ('id',)


# Ticket #22998

class Node(models.Model):
    content_type = models.ForeignKey(ContentType)
    object_id = models.PositiveIntegerField()
    content = GenericForeignKey('content_type', 'object_id')


class Content(models.Model):
    nodes = GenericRelation(Node)
    related_obj = models.ForeignKey('Related', on_delete=models.CASCADE)


class Related(models.Model):
    pass


def prevent_deletes(sender, instance, **kwargs):
    raise ProtectedError("Not allowed to delete.", [instance])

models.signals.pre_delete.connect(prevent_deletes, sender=Node)