from django.contrib.auth.models import User
from django.test import TestCase

import eav
from eav.managers import EntityManager
from eav.registry import EavConfig
from test_project.models import (
    Doctor,
    Encounter,
    ExampleMetaclassModel,
    ExampleModel,
    Patient,
)


class RegistryTests(TestCase):
    def setUp(self):
        pass

    def tearDown(self):
        pass

    def register_encounter(self):
        class EncounterEav(EavConfig):
            manager_attr = "eav_objects"
            eav_attr = "eav_field"
            generic_relation_attr = "encounter_eav_values"
            generic_relation_related_name = "encounters"

            @classmethod
            def get_attributes(cls):
                return "testing"

        eav.register(Encounter, EncounterEav)

    def test_registering_with_defaults(self):
        eav.register(Patient)
        self.assertTrue(hasattr(Patient, "_eav_config_cls"))
        self.assertEqual(Patient._eav_config_cls.manager_attr, "objects")
        self.assertFalse(Patient._eav_config_cls.manager_only)
        self.assertEqual(Patient._eav_config_cls.eav_attr, "eav")
        self.assertEqual(Patient._eav_config_cls.generic_relation_attr, "eav_values")
        self.assertEqual(Patient._eav_config_cls.generic_relation_related_name, None)
        eav.unregister(Patient)

    def test_registering_overriding_defaults(self):
        eav.register(Patient)
        self.register_encounter()
        self.assertTrue(hasattr(Patient, "_eav_config_cls"))
        self.assertEqual(Patient._eav_config_cls.manager_attr, "objects")
        self.assertEqual(Patient._eav_config_cls.eav_attr, "eav")

        self.assertTrue(hasattr(Encounter, "_eav_config_cls"))
        self.assertEqual(Encounter._eav_config_cls.get_attributes(), "testing")
        self.assertEqual(Encounter._eav_config_cls.manager_attr, "eav_objects")
        self.assertEqual(Encounter._eav_config_cls.eav_attr, "eav_field")
        eav.unregister(Patient)
        eav.unregister(Encounter)

    def test_registering_via_decorator_with_defaults(self):
        self.assertTrue(hasattr(ExampleModel, "_eav_config_cls"))
        self.assertEqual(ExampleModel._eav_config_cls.manager_attr, "objects")
        self.assertEqual(ExampleModel._eav_config_cls.eav_attr, "eav")

    def test_register_via_metaclass_with_defaults(self):
        self.assertTrue(hasattr(ExampleMetaclassModel, "_eav_config_cls"))
        self.assertEqual(ExampleMetaclassModel._eav_config_cls.manager_attr, "objects")
        self.assertEqual(ExampleMetaclassModel._eav_config_cls.eav_attr, "eav")

    def test_unregistering(self):
        old_mgr = Patient.objects
        eav.register(Patient)
        self.assertTrue(Patient.objects.__class__.__name__ == "EntityManager")
        eav.unregister(Patient)
        self.assertFalse(Patient.objects.__class__.__name__ == "EntityManager")
        self.assertEqual(Patient.objects, old_mgr)
        self.assertFalse(hasattr(Patient, "_eav_config_cls"))

    def test_unregistering_via_decorator(self):
        self.assertTrue(ExampleModel.objects.__class__.__name__ == "EntityManager")
        eav.unregister(ExampleModel)
        self.assertFalse(ExampleModel.objects.__class__.__name__ == "EntityManager")

    def test_unregistering_via_metaclass(self):
        self.assertTrue(
            ExampleMetaclassModel.objects.__class__.__name__ == "EntityManager",
        )
        eav.unregister(ExampleMetaclassModel)
        self.assertFalse(
            ExampleMetaclassModel.objects.__class__.__name__ == "EntityManager",
        )

    def test_unregistering_unregistered_model_proceeds_silently(self):
        eav.unregister(Patient)

    def test_double_registering_model_is_harmless(self):
        eav.register(Patient)
        eav.register(Patient)

    def test_doesnt_register_nonmodel(self):
        with self.assertRaises(TypeError):

            @eav.decorators.register_eav()
            class Foo:
                pass

    def test_model_without_local_managers(self):
        """Test when a model doesn't have local_managers."""
        # Check just in case test model changes in the future
        assert bool(User._meta.local_managers) is False
        eav.register(User)
        assert isinstance(User.objects, eav.managers.EntityManager)

        # Reverse check: managers should be empty again
        eav.unregister(User)
        assert bool(User._meta.local_managers) is False


def test_default_manager_stays() -> None:
    """
    Test to ensure default manager remains after registration.

    This test verifies that the default manager of the Doctor model is correctly
    replaced or maintained after registering a new EntityManager. Specifically,
    if the model's Meta default_manager_name isn't set, the test ensures that
    the default manager remains as 'objects' or the first manager declared in
    the class.
    """
    instance_meta = Doctor._meta
    assert instance_meta.default_manager_name is None
    assert isinstance(instance_meta.default_manager, EntityManager)

    # Explicity test this as for our test setup, we want to have a state where
    # the default manager is 'objects'
    assert instance_meta.default_manager.name == "objects"
    assert len(instance_meta.managers) == 2