from __future__ import absolute_import
import copy

from django.conf import settings
from django.db import models
from django.db.models.loading import cache
from django.test import TestCase
from django.test.utils import override_settings

from .models import (
    Child1,
    Child2,
    Child3,
    Child4,
    Child5,
    Child6,
    Child7,
    AbstractBase1,
    AbstractBase2,
    AbstractBase3,
)


class ManagersRegressionTests(TestCase):
    def test_managers(self):
        Child1.objects.create(name='fred', data='a1')
        Child1.objects.create(name='barney', data='a2')
        Child2.objects.create(name='fred', data='b1', value=1)
        Child2.objects.create(name='barney', data='b2', value=42)
        Child3.objects.create(name='fred', data='c1', comment='yes')
        Child3.objects.create(name='barney', data='c2', comment='no')
        Child4.objects.create(name='fred', data='d1')
        Child4.objects.create(name='barney', data='d2')
        Child5.objects.create(name='fred', comment='yes')
        Child5.objects.create(name='barney', comment='no')
        Child6.objects.create(name='fred', data='f1', value=42)
        Child6.objects.create(name='barney', data='f2', value=42)
        Child7.objects.create(name='fred')
        Child7.objects.create(name='barney')

        self.assertQuerysetEqual(Child1.manager1.all(), ["<Child1: a1>"])
        self.assertQuerysetEqual(Child1.manager2.all(), ["<Child1: a2>"])
        self.assertQuerysetEqual(Child1._default_manager.all(), ["<Child1: a1>"])

        self.assertQuerysetEqual(Child2._default_manager.all(), ["<Child2: b1>"])
        self.assertQuerysetEqual(Child2.restricted.all(), ["<Child2: b2>"])

        self.assertQuerysetEqual(Child3._default_manager.all(), ["<Child3: c1>"])
        self.assertQuerysetEqual(Child3.manager1.all(), ["<Child3: c1>"])
        self.assertQuerysetEqual(Child3.manager2.all(), ["<Child3: c2>"])

        # Since Child6 inherits from Child4, the corresponding rows from f1 and
        # f2 also appear here. This is the expected result.
        self.assertQuerysetEqual(Child4._default_manager.order_by('data'), [
                "<Child4: d1>",
                "<Child4: d2>",
                "<Child4: f1>",
                "<Child4: f2>"
            ]
        )
        self.assertQuerysetEqual(Child4.manager1.all(), [
                "<Child4: d1>",
                "<Child4: f1>"
            ],
            ordered=False
        )
        self.assertQuerysetEqual(Child5._default_manager.all(), ["<Child5: fred>"])
        self.assertQuerysetEqual(Child6._default_manager.all(), ["<Child6: f1>"])
        self.assertQuerysetEqual(Child7._default_manager.order_by('name'), [
                "<Child7: barney>",
                "<Child7: fred>"
            ]
        )

    def test_abstract_manager(self):
        # Accessing the manager on an abstract model should
        # raise an attribute error with an appropriate message.
        try:
            AbstractBase3.objects.all()
            self.fail('Should raise an AttributeError')
        except AttributeError as e:
            # This error message isn't ideal, but if the model is abstract and
            # a lot of the class instantiation logic isn't invoked; if the
            # manager is implied, then we don't get a hook to install the
            # error-raising manager.
            self.assertEqual(str(e), "type object 'AbstractBase3' has no attribute 'objects'")

    def test_custom_abstract_manager(self):
        # Accessing the manager on an abstract model with an custom
        # manager should raise an attribute error with an appropriate
        # message.
        try:
            AbstractBase2.restricted.all()
            self.fail('Should raise an AttributeError')
        except AttributeError as e:
            self.assertEqual(str(e), "Manager isn't available; AbstractBase2 is abstract")

    def test_explicit_abstract_manager(self):
        # Accessing the manager on an abstract model with an explicit
        # manager should raise an attribute error with an appropriate
        # message.
        try:
            AbstractBase1.objects.all()
            self.fail('Should raise an AttributeError')
        except AttributeError as e:
            self.assertEqual(str(e), "Manager isn't available; AbstractBase1 is abstract")

    def test_swappable_manager(self):
        try:
            # This test adds dummy models to the app cache. These
            # need to be removed in order to prevent bad interactions
            # with the flush operation in other tests.
            old_app_models = copy.deepcopy(cache.app_models)
            old_app_store = copy.deepcopy(cache.app_store)

            settings.TEST_SWAPPABLE_MODEL = 'managers_regress.Parent'

            class SwappableModel(models.Model):
                class Meta:
                    swappable = 'TEST_SWAPPABLE_MODEL'

            # Accessing the manager on a swappable model should
            # raise an attribute error with a helpful message
            try:
                SwappableModel.objects.all()
                self.fail('Should raise an AttributeError')
            except AttributeError as e:
                self.assertEqual(str(e), "Manager isn't available; SwappableModel has been swapped for 'managers_regress.Parent'")

        finally:
            del settings.TEST_SWAPPABLE_MODEL
            cache.app_models = old_app_models
            cache.app_store = old_app_store

    def test_custom_swappable_manager(self):
        try:
            # This test adds dummy models to the app cache. These
            # need to be removed in order to prevent bad interactions
            # with the flush operation in other tests.
            old_app_models = copy.deepcopy(cache.app_models)
            old_app_store = copy.deepcopy(cache.app_store)

            settings.TEST_SWAPPABLE_MODEL = 'managers_regress.Parent'

            class SwappableModel(models.Model):

                stuff = models.Manager()

                class Meta:
                    swappable = 'TEST_SWAPPABLE_MODEL'

            # Accessing the manager on a swappable model with an
            # explicit manager should raise an attribute error with a
            # helpful message
            try:
                SwappableModel.stuff.all()
                self.fail('Should raise an AttributeError')
            except AttributeError as e:
                self.assertEqual(str(e), "Manager isn't available; SwappableModel has been swapped for 'managers_regress.Parent'")

        finally:
            del settings.TEST_SWAPPABLE_MODEL
            cache.app_models = old_app_models
            cache.app_store = old_app_store

    def test_explicit_swappable_manager(self):
        try:
            # This test adds dummy models to the app cache. These
            # need to be removed in order to prevent bad interactions
            # with the flush operation in other tests.
            old_app_models = copy.deepcopy(cache.app_models)
            old_app_store = copy.deepcopy(cache.app_store)

            settings.TEST_SWAPPABLE_MODEL = 'managers_regress.Parent'

            class SwappableModel(models.Model):

                objects = models.Manager()

                class Meta:
                    swappable = 'TEST_SWAPPABLE_MODEL'

            # Accessing the manager on a swappable model with an
            # explicit manager should raise an attribute error with a
            # helpful message
            try:
                SwappableModel.objects.all()
                self.fail('Should raise an AttributeError')
            except AttributeError as e:
                self.assertEqual(str(e), "Manager isn't available; SwappableModel has been swapped for 'managers_regress.Parent'")

        finally:
            del settings.TEST_SWAPPABLE_MODEL
            cache.app_models = old_app_models
            cache.app_store = old_app_store