from django.contrib.auth import models as auth

from django.db import models

# No related name is needed here, since symmetrical relations are not

# explicitly reversible.

class SelfRefer(models.Model):

    name = models.CharField(max_length=10)

    references = models.ManyToManyField("self")

    related = models.ManyToManyField("self")

    def __str__(self):

        return self.name

class Tag(models.Model):

    name = models.CharField(max_length=10)

    def __str__(self):

        return self.name

# Regression for #11956 -- a many to many to the base class

class TagCollection(Tag):

    tags = models.ManyToManyField(Tag, related_name="tag_collections")

    def __str__(self):

        return self.name

# A related_name is required on one of the ManyToManyField entries here because

# they are both addressable as reverse relations from Tag.

class Entry(models.Model):

    name = models.CharField(max_length=10)

    topics = models.ManyToManyField(Tag)

    related = models.ManyToManyField(Tag, related_name="similar")

    def __str__(self):

        return self.name

# Two models both inheriting from a base model with a self-referential m2m field

class SelfReferChild(SelfRefer):

    pass

class SelfReferChildSibling(SelfRefer):

    pass

# Many-to-Many relation between models, where one of the PK's isn't an Autofield

class Line(models.Model):

    name = models.CharField(max_length=100)

    def __str__(self):

        return self.name

class Worksheet(models.Model):

    id = models.CharField(primary_key=True, max_length=100)

    lines = models.ManyToManyField(Line, blank=True)

# Regression for #11226 -- A model with the same name that another one to

# which it has a m2m relation. This shouldn't cause a name clash between

# the automatically created m2m intermediary table FK field names when

# running migrate

class User(models.Model):

    name = models.CharField(max_length=30)

    friends = models.ManyToManyField(auth.User)

class BadModelWithSplit(models.Model):

    name = models.CharField(max_length=1)

    class Meta:

        abstract = True

    def split(self):

        raise RuntimeError("split should not be called")

class RegressionModelSplit(BadModelWithSplit):

    """

    Model with a split method should not cause an error in add_lazy_relation

    """

    others = models.ManyToManyField("self")

# Regression for #24505 -- Two ManyToManyFields with the same "to" model

# and related_name set to '+'.

class Post(models.Model):

    primary_lines = models.ManyToManyField(Line, related_name="+")

    secondary_lines = models.ManyToManyField(Line, related_name="+")