from unittest import mock

from django.conf.global_settings import PASSWORD_HASHERS
from django.contrib.auth import get_user_model
from django.contrib.auth.backends import ModelBackend
from django.contrib.auth.base_user import AbstractBaseUser
from django.contrib.auth.hashers import get_hasher
from django.contrib.auth.models import (
    AnonymousUser, Group, Permission, User, UserManager,
)
from django.contrib.contenttypes.models import ContentType
from django.core import mail
from django.db import connection, migrations
from django.db.migrations.state import ModelState, ProjectState
from django.db.models.signals import post_save
from django.test import (
    SimpleTestCase, TestCase, TransactionTestCase, override_settings,
)

from .models import CustomEmailField, IntegerUsernameUser


class NaturalKeysTestCase(TestCase):

    def test_user_natural_key(self):
        staff_user = User.objects.create_user(username='staff')
        self.assertEqual(User.objects.get_by_natural_key('staff'), staff_user)
        self.assertEqual(staff_user.natural_key(), ('staff',))

    def test_group_natural_key(self):
        users_group = Group.objects.create(name='users')
        self.assertEqual(Group.objects.get_by_natural_key('users'), users_group)


class LoadDataWithoutNaturalKeysTestCase(TestCase):
    fixtures = ['regular.json']

    def test_user_is_created_and_added_to_group(self):
        user = User.objects.get(username='my_username')
        group = Group.objects.get(name='my_group')
        self.assertEqual(group, user.groups.get())


class LoadDataWithNaturalKeysTestCase(TestCase):
    fixtures = ['natural.json']

    def test_user_is_created_and_added_to_group(self):
        user = User.objects.get(username='my_username')
        group = Group.objects.get(name='my_group')
        self.assertEqual(group, user.groups.get())


class LoadDataWithNaturalKeysAndMultipleDatabasesTestCase(TestCase):
    databases = {'default', 'other'}

    def test_load_data_with_user_permissions(self):
        # Create test contenttypes for both databases
        default_objects = [
            ContentType.objects.db_manager('default').create(
                model='examplemodela',
                app_label='app_a',
            ),
            ContentType.objects.db_manager('default').create(
                model='examplemodelb',
                app_label='app_b',
            ),
        ]
        other_objects = [
            ContentType.objects.db_manager('other').create(
                model='examplemodelb',
                app_label='app_b',
            ),
            ContentType.objects.db_manager('other').create(
                model='examplemodela',
                app_label='app_a',
            ),
        ]

        # Now we create the test UserPermission
        Permission.objects.db_manager("default").create(
            name="Can delete example model b",
            codename="delete_examplemodelb",
            content_type=default_objects[1],
        )
        Permission.objects.db_manager("other").create(
            name="Can delete example model b",
            codename="delete_examplemodelb",
            content_type=other_objects[0],
        )

        perm_default = Permission.objects.get_by_natural_key(
            'delete_examplemodelb',
            'app_b',
            'examplemodelb',
        )

        perm_other = Permission.objects.db_manager('other').get_by_natural_key(
            'delete_examplemodelb',
            'app_b',
            'examplemodelb',
        )

        self.assertEqual(perm_default.content_type_id, default_objects[1].id)
        self.assertEqual(perm_other.content_type_id, other_objects[0].id)


class UserManagerTestCase(TransactionTestCase):
    available_apps = [
        'auth_tests',
        'django.contrib.auth',
        'django.contrib.contenttypes',
    ]

    def test_create_user(self):
        email_lowercase = 'normal@normal.com'
        user = User.objects.create_user('user', email_lowercase)
        self.assertEqual(user.email, email_lowercase)
        self.assertEqual(user.username, 'user')
        self.assertFalse(user.has_usable_password())

    def test_create_user_email_domain_normalize_rfc3696(self):
        # According to https://tools.ietf.org/html/rfc3696#section-3
        # the "@" symbol can be part of the local part of an email address
        returned = UserManager.normalize_email(r'Abc\@DEF@EXAMPLE.com')
        self.assertEqual(returned, r'Abc\@DEF@example.com')

    def test_create_user_email_domain_normalize(self):
        returned = UserManager.normalize_email('normal@DOMAIN.COM')
        self.assertEqual(returned, 'normal@domain.com')

    def test_create_user_email_domain_normalize_with_whitespace(self):
        returned = UserManager.normalize_email(r'email\ with_whitespace@D.COM')
        self.assertEqual(returned, r'email\ with_whitespace@d.com')

    def test_empty_username(self):
        with self.assertRaisesMessage(ValueError, 'The given username must be set'):
            User.objects.create_user(username='')

    def test_create_user_is_staff(self):
        email = 'normal@normal.com'
        user = User.objects.create_user('user', email, is_staff=True)
        self.assertEqual(user.email, email)
        self.assertEqual(user.username, 'user')
        self.assertTrue(user.is_staff)

    def test_create_super_user_raises_error_on_false_is_superuser(self):
        with self.assertRaisesMessage(ValueError, 'Superuser must have is_superuser=True.'):
            User.objects.create_superuser(
                username='test', email='test@test.com',
                password='test', is_superuser=False,
            )

    def test_create_superuser_raises_error_on_false_is_staff(self):
        with self.assertRaisesMessage(ValueError, 'Superuser must have is_staff=True.'):
            User.objects.create_superuser(
                username='test', email='test@test.com',
                password='test', is_staff=False,
            )

    def test_make_random_password(self):
        allowed_chars = 'abcdefg'
        password = UserManager().make_random_password(5, allowed_chars)
        self.assertEqual(len(password), 5)
        for char in password:
            self.assertIn(char, allowed_chars)

    def test_runpython_manager_methods(self):
        def forwards(apps, schema_editor):
            UserModel = apps.get_model('auth', 'User')
            user = UserModel.objects.create_user('user1', password='secure')
            self.assertIsInstance(user, UserModel)

        operation = migrations.RunPython(forwards, migrations.RunPython.noop)
        project_state = ProjectState()
        project_state.add_model(ModelState.from_model(User))
        project_state.add_model(ModelState.from_model(Group))
        project_state.add_model(ModelState.from_model(Permission))
        project_state.add_model(ModelState.from_model(ContentType))
        new_state = project_state.clone()
        with connection.schema_editor() as editor:
            operation.state_forwards('test_manager_methods', new_state)
            operation.database_forwards(
                'test_manager_methods',
                editor,
                project_state,
                new_state,
            )
        user = User.objects.get(username='user1')
        self.assertTrue(user.check_password('secure'))


class AbstractBaseUserTests(SimpleTestCase):

    def test_has_usable_password(self):
        """
        Passwords are usable even if they don't correspond to a hasher in
        settings.PASSWORD_HASHERS.
        """
        self.assertIs(User(password='some-gibbberish').has_usable_password(), True)

    def test_normalize_username(self):
        self.assertEqual(IntegerUsernameUser().normalize_username(123), 123)

    def test_clean_normalize_username(self):
        # The normalization happens in AbstractBaseUser.clean()
        ohm_username = 'iamtheΩ'  # U+2126 OHM SIGN
        for model in ('auth.User', 'auth_tests.CustomUser'):
            with self.subTest(model=model), self.settings(AUTH_USER_MODEL=model):
                User = get_user_model()
                user = User(**{User.USERNAME_FIELD: ohm_username, 'password': 'foo'})
                user.clean()
                username = user.get_username()
                self.assertNotEqual(username, ohm_username)
                self.assertEqual(username, 'iamtheΩ')  # U+03A9 GREEK CAPITAL LETTER OMEGA

    def test_default_email(self):
        self.assertEqual(AbstractBaseUser.get_email_field_name(), 'email')

    def test_custom_email(self):
        user = CustomEmailField()
        self.assertEqual(user.get_email_field_name(), 'email_address')


class AbstractUserTestCase(TestCase):
    def test_email_user(self):
        # valid send_mail parameters
        kwargs = {
            "fail_silently": False,
            "auth_user": None,
            "auth_password": None,
            "connection": None,
            "html_message": None,
        }
        user = User(email='foo@bar.com')
        user.email_user(
            subject="Subject here",
            message="This is a message",
            from_email="from@domain.com",
            **kwargs
        )
        self.assertEqual(len(mail.outbox), 1)
        message = mail.outbox[0]
        self.assertEqual(message.subject, "Subject here")
        self.assertEqual(message.body, "This is a message")
        self.assertEqual(message.from_email, "from@domain.com")
        self.assertEqual(message.to, [user.email])

    def test_last_login_default(self):
        user1 = User.objects.create(username='user1')
        self.assertIsNone(user1.last_login)

        user2 = User.objects.create_user(username='user2')
        self.assertIsNone(user2.last_login)

    def test_user_clean_normalize_email(self):
        user = User(username='user', password='foo', email='foo@BAR.com')
        user.clean()
        self.assertEqual(user.email, 'foo@bar.com')

    def test_user_double_save(self):
        """
        Calling user.save() twice should trigger password_changed() once.
        """
        user = User.objects.create_user(username='user', password='foo')
        user.set_password('bar')
        with mock.patch('django.contrib.auth.password_validation.password_changed') as pw_changed:
            user.save()
            self.assertEqual(pw_changed.call_count, 1)
            user.save()
            self.assertEqual(pw_changed.call_count, 1)

    @override_settings(PASSWORD_HASHERS=PASSWORD_HASHERS)
    def test_check_password_upgrade(self):
        """
        password_changed() shouldn't be called if User.check_password()
        triggers a hash iteration upgrade.
        """
        user = User.objects.create_user(username='user', password='foo')
        initial_password = user.password
        self.assertTrue(user.check_password('foo'))
        hasher = get_hasher('default')
        self.assertEqual('pbkdf2_sha256', hasher.algorithm)

        old_iterations = hasher.iterations
        try:
            # Upgrade the password iterations
            hasher.iterations = old_iterations + 1
            with mock.patch('django.contrib.auth.password_validation.password_changed') as pw_changed:
                user.check_password('foo')
                self.assertEqual(pw_changed.call_count, 0)
            self.assertNotEqual(initial_password, user.password)
        finally:
            hasher.iterations = old_iterations


class CustomModelBackend(ModelBackend):
    def with_perm(self, perm, is_active=True, include_superusers=True, backend=None, obj=None):
        if obj is not None and obj.username == 'charliebrown':
            return User.objects.filter(pk=obj.pk)
        return User.objects.filter(username__startswith='charlie')


class UserWithPermTestCase(TestCase):

    @classmethod
    def setUpTestData(cls):
        content_type = ContentType.objects.get_for_model(Group)
        cls.permission = Permission.objects.create(
            name='test', content_type=content_type, codename='test',
        )
        # User with permission.
        cls.user1 = User.objects.create_user('user 1', 'foo@example.com')
        cls.user1.user_permissions.add(cls.permission)
        # User with group permission.
        group1 = Group.objects.create(name='group 1')
        group1.permissions.add(cls.permission)
        group2 = Group.objects.create(name='group 2')
        group2.permissions.add(cls.permission)
        cls.user2 = User.objects.create_user('user 2', 'bar@example.com')
        cls.user2.groups.add(group1, group2)
        # Users without permissions.
        cls.user_charlie = User.objects.create_user('charlie', 'charlie@example.com')
        cls.user_charlie_b = User.objects.create_user('charliebrown', 'charlie@brown.com')
        # Superuser.
        cls.superuser = User.objects.create_superuser(
            'superuser', 'superuser@example.com', 'superpassword',
        )
        # Inactive user with permission.
        cls.inactive_user = User.objects.create_user(
            'inactive_user', 'baz@example.com', is_active=False,
        )
        cls.inactive_user.user_permissions.add(cls.permission)

    def test_invalid_permission_name(self):
        msg = 'Permission name should be in the form app_label.permission_codename.'
        for perm in ('nodots', 'too.many.dots', '...', ''):
            with self.subTest(perm), self.assertRaisesMessage(ValueError, msg):
                User.objects.with_perm(perm)

    def test_invalid_permission_type(self):
        msg = 'The `perm` argument must be a string or a permission instance.'
        for perm in (b'auth.test', object(), None):
            with self.subTest(perm), self.assertRaisesMessage(TypeError, msg):
                User.objects.with_perm(perm)

    def test_invalid_backend_type(self):
        msg = 'backend must be a dotted import path string (got %r).'
        for backend in (b'auth_tests.CustomModelBackend', object()):
            with self.subTest(backend):
                with self.assertRaisesMessage(TypeError, msg % backend):
                    User.objects.with_perm('auth.test', backend=backend)

    def test_basic(self):
        active_users = [self.user1, self.user2]
        tests = [
            ({}, [*active_users, self.superuser]),
            ({'obj': self.user1}, []),
            # Only inactive users.
            ({'is_active': False}, [self.inactive_user]),
            # All users.
            ({'is_active': None}, [*active_users, self.superuser, self.inactive_user]),
            # Exclude superusers.
            ({'include_superusers': False}, active_users),
            (
                {'include_superusers': False, 'is_active': False},
                [self.inactive_user],
            ),
            (
                {'include_superusers': False, 'is_active': None},
                [*active_users, self.inactive_user],
            ),
        ]
        for kwargs, expected_users in tests:
            for perm in ('auth.test', self.permission):
                with self.subTest(perm=perm, **kwargs):
                    self.assertCountEqual(
                        User.objects.with_perm(perm, **kwargs),
                        expected_users,
                    )

    @override_settings(AUTHENTICATION_BACKENDS=['django.contrib.auth.backends.BaseBackend'])
    def test_backend_without_with_perm(self):
        self.assertSequenceEqual(User.objects.with_perm('auth.test'), [])

    def test_nonexistent_permission(self):
        self.assertSequenceEqual(User.objects.with_perm('auth.perm'), [self.superuser])

    def test_nonexistent_backend(self):
        with self.assertRaises(ImportError):
            User.objects.with_perm(
                'auth.test',
                backend='invalid.backend.CustomModelBackend',
            )

    @override_settings(AUTHENTICATION_BACKENDS=['auth_tests.test_models.CustomModelBackend'])
    def test_custom_backend(self):
        for perm in ('auth.test', self.permission):
            with self.subTest(perm):
                self.assertCountEqual(
                    User.objects.with_perm(perm),
                    [self.user_charlie, self.user_charlie_b],
                )

    @override_settings(AUTHENTICATION_BACKENDS=['auth_tests.test_models.CustomModelBackend'])
    def test_custom_backend_pass_obj(self):
        for perm in ('auth.test', self.permission):
            with self.subTest(perm):
                self.assertSequenceEqual(
                    User.objects.with_perm(perm, obj=self.user_charlie_b),
                    [self.user_charlie_b],
                )

    @override_settings(AUTHENTICATION_BACKENDS=[
        'auth_tests.test_models.CustomModelBackend',
        'django.contrib.auth.backends.ModelBackend',
    ])
    def test_multiple_backends(self):
        msg = (
            'You have multiple authentication backends configured and '
            'therefore must provide the `backend` argument.'
        )
        with self.assertRaisesMessage(ValueError, msg):
            User.objects.with_perm('auth.test')

        backend = 'auth_tests.test_models.CustomModelBackend'
        self.assertCountEqual(
            User.objects.with_perm('auth.test', backend=backend),
            [self.user_charlie, self.user_charlie_b],
        )


class IsActiveTestCase(TestCase):
    """
    Tests the behavior of the guaranteed is_active attribute
    """

    def test_builtin_user_isactive(self):
        user = User.objects.create(username='foo', email='foo@bar.com')
        # is_active is true by default
        self.assertIs(user.is_active, True)
        user.is_active = False
        user.save()
        user_fetched = User.objects.get(pk=user.pk)
        # the is_active flag is saved
        self.assertFalse(user_fetched.is_active)

    @override_settings(AUTH_USER_MODEL='auth_tests.IsActiveTestUser1')
    def test_is_active_field_default(self):
        """
        tests that the default value for is_active is provided
        """
        UserModel = get_user_model()
        user = UserModel(username='foo')
        self.assertIs(user.is_active, True)
        # you can set the attribute - but it will not save
        user.is_active = False
        # there should be no problem saving - but the attribute is not saved
        user.save()
        user_fetched = UserModel._default_manager.get(pk=user.pk)
        # the attribute is always true for newly retrieved instance
        self.assertIs(user_fetched.is_active, True)


class TestCreateSuperUserSignals(TestCase):
    """
    Simple test case for ticket #20541
    """
    def post_save_listener(self, *args, **kwargs):
        self.signals_count += 1

    def setUp(self):
        self.signals_count = 0
        post_save.connect(self.post_save_listener, sender=User)

    def tearDown(self):
        post_save.disconnect(self.post_save_listener, sender=User)

    def test_create_user(self):
        User.objects.create_user("JohnDoe")
        self.assertEqual(self.signals_count, 1)

    def test_create_superuser(self):
        User.objects.create_superuser("JohnDoe", "mail@example.com", "1")
        self.assertEqual(self.signals_count, 1)


class AnonymousUserTests(SimpleTestCase):
    no_repr_msg = "Django doesn't provide a DB representation for AnonymousUser."

    def setUp(self):
        self.user = AnonymousUser()

    def test_properties(self):
        self.assertIsNone(self.user.pk)
        self.assertEqual(self.user.username, '')
        self.assertEqual(self.user.get_username(), '')
        self.assertIs(self.user.is_anonymous, True)
        self.assertIs(self.user.is_authenticated, False)
        self.assertIs(self.user.is_staff, False)
        self.assertIs(self.user.is_active, False)
        self.assertIs(self.user.is_superuser, False)
        self.assertEqual(self.user.groups.all().count(), 0)
        self.assertEqual(self.user.user_permissions.all().count(), 0)
        self.assertEqual(self.user.get_user_permissions(), set())
        self.assertEqual(self.user.get_group_permissions(), set())

    def test_str(self):
        self.assertEqual(str(self.user), 'AnonymousUser')

    def test_eq(self):
        self.assertEqual(self.user, AnonymousUser())
        self.assertNotEqual(self.user, User('super', 'super@example.com', 'super'))

    def test_hash(self):
        self.assertEqual(hash(self.user), 1)

    def test_int(self):
        msg = (
            'Cannot cast AnonymousUser to int. Are you trying to use it in '
            'place of User?'
        )
        with self.assertRaisesMessage(TypeError, msg):
            int(self.user)

    def test_delete(self):
        with self.assertRaisesMessage(NotImplementedError, self.no_repr_msg):
            self.user.delete()

    def test_save(self):
        with self.assertRaisesMessage(NotImplementedError, self.no_repr_msg):
            self.user.save()

    def test_set_password(self):
        with self.assertRaisesMessage(NotImplementedError, self.no_repr_msg):
            self.user.set_password('password')

    def test_check_password(self):
        with self.assertRaisesMessage(NotImplementedError, self.no_repr_msg):
            self.user.check_password('password')


class GroupTests(SimpleTestCase):
    def test_str(self):
        g = Group(name='Users')
        self.assertEqual(str(g), 'Users')


class PermissionTests(TestCase):
    def test_str(self):
        p = Permission.objects.get(codename='view_customemailfield')
        self.assertEqual(str(p), 'auth_tests | custom email field | Can view custom email field')
