from unittest import mock

from django.apps.registry import Apps, apps
from django.contrib.contenttypes import management as contenttypes_management
from django.contrib.contenttypes.models import ContentType
from django.core.management import call_command
from django.test import TestCase, modify_settings
from django.test.utils import captured_stdout

from .models import ModelWithNullFKToSite, Post


@modify_settings(INSTALLED_APPS={"append": ["empty_models", "no_models"]})
class RemoveStaleContentTypesTests(TestCase):
    # Speed up tests by avoiding retrieving ContentTypes for all test apps.
    available_apps = [
        "contenttypes_tests",
        "empty_models",
        "no_models",
        "django.contrib.contenttypes",
    ]

    @classmethod
    def setUpTestData(cls):
        cls.before_count = ContentType.objects.count()
        cls.content_type = ContentType.objects.create(
            app_label="contenttypes_tests", model="Fake"
        )

    def setUp(self):
        self.app_config = apps.get_app_config("contenttypes_tests")

    def test_interactive_true_with_dependent_objects(self):
        """
        interactive mode (the default) deletes stale content types and warns of
        dependent objects.
        """
        post = Post.objects.create(title="post", content_type=self.content_type)
        # A related object is needed to show that a custom collector with
        # can_fast_delete=False is needed.
        ModelWithNullFKToSite.objects.create(post=post)
        with mock.patch("builtins.input", return_value="yes"):
            with captured_stdout() as stdout:
                call_command("remove_stale_contenttypes", verbosity=2, stdout=stdout)
        self.assertEqual(Post.objects.count(), 0)
        output = stdout.getvalue()
        self.assertIn("- Content type for contenttypes_tests.Fake", output)
        self.assertIn("- 1 contenttypes_tests.Post object(s)", output)
        self.assertIn("- 1 contenttypes_tests.ModelWithNullFKToSite", output)
        self.assertIn("Deleting stale content type", output)
        self.assertEqual(ContentType.objects.count(), self.before_count)

    def test_interactive_true_without_dependent_objects(self):
        """
        interactive mode deletes stale content types even if there aren't any
        dependent objects.
        """
        with mock.patch("builtins.input", return_value="yes"):
            with captured_stdout() as stdout:
                call_command("remove_stale_contenttypes", verbosity=2)
        self.assertIn("Deleting stale content type", stdout.getvalue())
        self.assertEqual(ContentType.objects.count(), self.before_count)

    def test_interactive_false(self):
        """non-interactive mode deletes stale content types."""
        with captured_stdout() as stdout:
            call_command("remove_stale_contenttypes", interactive=False, verbosity=2)
        self.assertIn("Deleting stale content type", stdout.getvalue())
        self.assertEqual(ContentType.objects.count(), self.before_count)

    def test_unavailable_content_type_model(self):
        """A ContentType isn't created if the model isn't available."""
        apps = Apps()
        with self.assertNumQueries(0):
            contenttypes_management.create_contenttypes(
                self.app_config, interactive=False, verbosity=0, apps=apps
            )
        self.assertEqual(ContentType.objects.count(), self.before_count + 1)

    @modify_settings(INSTALLED_APPS={"remove": ["empty_models"]})
    def test_contenttypes_removed_in_installed_apps_without_models(self):
        ContentType.objects.create(app_label="empty_models", model="Fake 1")
        ContentType.objects.create(app_label="no_models", model="Fake 2")
        with mock.patch(
            "builtins.input", return_value="yes"
        ), captured_stdout() as stdout:
            call_command("remove_stale_contenttypes", verbosity=2)
        self.assertNotIn(
            "Deleting stale content type 'empty_models | Fake 1'",
            stdout.getvalue(),
        )
        self.assertIn(
            "Deleting stale content type 'no_models | Fake 2'",
            stdout.getvalue(),
        )
        self.assertEqual(ContentType.objects.count(), self.before_count + 1)

    @modify_settings(INSTALLED_APPS={"remove": ["empty_models"]})
    def test_contenttypes_removed_for_apps_not_in_installed_apps(self):
        ContentType.objects.create(app_label="empty_models", model="Fake 1")
        ContentType.objects.create(app_label="no_models", model="Fake 2")
        with mock.patch(
            "builtins.input", return_value="yes"
        ), captured_stdout() as stdout:
            call_command(
                "remove_stale_contenttypes", include_stale_apps=True, verbosity=2
            )
        self.assertIn(
            "Deleting stale content type 'empty_models | Fake 1'",
            stdout.getvalue(),
        )
        self.assertIn(
            "Deleting stale content type 'no_models | Fake 2'",
            stdout.getvalue(),
        )
        self.assertEqual(ContentType.objects.count(), self.before_count)