import datetime

from django.db import models, DJANGO_VERSION_PICKLE_KEY
from django.utils.translation import ugettext_lazy as _
from django.utils.version import get_major_version


def standalone_number():
    return 1


class Numbers(object):
    @staticmethod
    def get_static_number():
        return 2

    @classmethod
    def get_class_number(cls):
        return 3

    def get_member_number(self):
        return 4

nn = Numbers()


class PreviousDjangoVersionQuerySet(models.QuerySet):
    def __getstate__(self):
        state = super(PreviousDjangoVersionQuerySet, self).__getstate__()
        state[DJANGO_VERSION_PICKLE_KEY] = str(float(get_major_version()) - 0.1)  # previous major version
        return state


class MissingDjangoVersionQuerySet(models.QuerySet):
    def __getstate__(self):
        state = super(MissingDjangoVersionQuerySet, self).__getstate__()
        del state[DJANGO_VERSION_PICKLE_KEY]
        return state


class Group(models.Model):
    name = models.CharField(_('name'), max_length=100)
    objects = models.Manager()
    previous_django_version_objects = PreviousDjangoVersionQuerySet.as_manager()
    missing_django_version_objects = MissingDjangoVersionQuerySet.as_manager()


class Event(models.Model):
    group = models.ForeignKey(Group)


class Happening(models.Model):
    when = models.DateTimeField(blank=True, default=datetime.datetime.now)
    name = models.CharField(blank=True, max_length=100, default=lambda: "test")
    number1 = models.IntegerField(blank=True, default=standalone_number)
    number2 = models.IntegerField(blank=True, default=Numbers.get_static_number)
    number3 = models.IntegerField(blank=True, default=Numbers.get_class_number)
    number4 = models.IntegerField(blank=True, default=nn.get_member_number)


class Container(object):
    # To test pickling we need a class that isn't defined on module, but
    # is still available from app-cache. So, the Container class moves
    # SomeModel outside of module level
    class SomeModel(models.Model):
        somefield = models.IntegerField()


class M2MModel(models.Model):
    groups = models.ManyToManyField(Group)