import json
import uuid

from django.core import exceptions, serializers
from django.db import IntegrityError, connection, models
from django.db.models import CharField, F, Value
from django.db.models.functions import Concat, Repeat
from django.test import (
    SimpleTestCase, TestCase, TransactionTestCase, skipUnlessDBFeature,
)

from .models import (
    NullableUUIDModel, PrimaryKeyUUIDModel, RelatedToUUIDModel, UUIDGrandchild,
    UUIDModel,
)


class TestSaveLoad(TestCase):
    def test_uuid_instance(self):
        instance = UUIDModel.objects.create(field=uuid.uuid4())
        loaded = UUIDModel.objects.get()
        self.assertEqual(loaded.field, instance.field)

    def test_str_instance_no_hyphens(self):
        UUIDModel.objects.create(field='550e8400e29b41d4a716446655440000')
        loaded = UUIDModel.objects.get()
        self.assertEqual(loaded.field, uuid.UUID('550e8400e29b41d4a716446655440000'))

    def test_str_instance_hyphens(self):
        UUIDModel.objects.create(field='550e8400-e29b-41d4-a716-446655440000')
        loaded = UUIDModel.objects.get()
        self.assertEqual(loaded.field, uuid.UUID('550e8400e29b41d4a716446655440000'))

    def test_str_instance_bad_hyphens(self):
        UUIDModel.objects.create(field='550e84-00-e29b-41d4-a716-4-466-55440000')
        loaded = UUIDModel.objects.get()
        self.assertEqual(loaded.field, uuid.UUID('550e8400e29b41d4a716446655440000'))

    def test_null_handling(self):
        NullableUUIDModel.objects.create(field=None)
        loaded = NullableUUIDModel.objects.get()
        self.assertIsNone(loaded.field)

    def test_pk_validated(self):
        with self.assertRaisesMessage(exceptions.ValidationError, 'is not a valid UUID'):
            PrimaryKeyUUIDModel.objects.get(pk={})

        with self.assertRaisesMessage(exceptions.ValidationError, 'is not a valid UUID'):
            PrimaryKeyUUIDModel.objects.get(pk=[])

    def test_wrong_value(self):
        with self.assertRaisesMessage(exceptions.ValidationError, 'is not a valid UUID'):
            UUIDModel.objects.get(field='not-a-uuid')

        with self.assertRaisesMessage(exceptions.ValidationError, 'is not a valid UUID'):
            UUIDModel.objects.create(field='not-a-uuid')


class TestMethods(SimpleTestCase):

    def test_deconstruct(self):
        field = models.UUIDField()
        name, path, args, kwargs = field.deconstruct()
        self.assertEqual(kwargs, {})

    def test_to_python(self):
        self.assertIsNone(models.UUIDField().to_python(None))

    def test_to_python_int_values(self):
        self.assertEqual(
            models.UUIDField().to_python(0),
            uuid.UUID('00000000-0000-0000-0000-000000000000')
        )
        # Works for integers less than 128 bits.
        self.assertEqual(
            models.UUIDField().to_python((2 ** 128) - 1),
            uuid.UUID('ffffffff-ffff-ffff-ffff-ffffffffffff')
        )

    def test_to_python_int_too_large(self):
        # Fails for integers larger than 128 bits.
        with self.assertRaises(exceptions.ValidationError):
            models.UUIDField().to_python(2 ** 128)


class TestQuerying(TestCase):
    @classmethod
    def setUpTestData(cls):
        cls.objs = [
            NullableUUIDModel.objects.create(field=uuid.uuid4()),
            NullableUUIDModel.objects.create(field='550e8400e29b41d4a716446655440000'),
            NullableUUIDModel.objects.create(field=None),
        ]

    def assertSequenceEqualWithoutHyphens(self, qs, result):
        """
        Backends with a native datatype for UUID don't support fragment lookups
        without hyphens because they store values with them.
        """
        self.assertSequenceEqual(
            qs,
            [] if connection.features.has_native_uuid_field else result,
        )

    def test_exact(self):
        self.assertSequenceEqual(
            NullableUUIDModel.objects.filter(field__exact='550e8400e29b41d4a716446655440000'),
            [self.objs[1]]
        )
        self.assertSequenceEqual(
            NullableUUIDModel.objects.filter(
                field__exact='550e8400-e29b-41d4-a716-446655440000'
            ),
            [self.objs[1]],
        )

    def test_iexact(self):
        self.assertSequenceEqualWithoutHyphens(
            NullableUUIDModel.objects.filter(
                field__iexact='550E8400E29B41D4A716446655440000'
            ),
            [self.objs[1]],
        )
        self.assertSequenceEqual(
            NullableUUIDModel.objects.filter(
                field__iexact='550E8400-E29B-41D4-A716-446655440000'
            ),
            [self.objs[1]],
        )

    def test_isnull(self):
        self.assertSequenceEqual(
            NullableUUIDModel.objects.filter(field__isnull=True),
            [self.objs[2]]
        )

    def test_contains(self):
        self.assertSequenceEqualWithoutHyphens(
            NullableUUIDModel.objects.filter(field__contains='8400e29b'),
            [self.objs[1]],
        )
        self.assertSequenceEqual(
            NullableUUIDModel.objects.filter(field__contains='8400-e29b'),
            [self.objs[1]],
        )

    def test_icontains(self):
        self.assertSequenceEqualWithoutHyphens(
            NullableUUIDModel.objects.filter(field__icontains='8400E29B'),
            [self.objs[1]],
        )
        self.assertSequenceEqual(
            NullableUUIDModel.objects.filter(field__icontains='8400-E29B'),
            [self.objs[1]],
        )

    def test_startswith(self):
        self.assertSequenceEqualWithoutHyphens(
            NullableUUIDModel.objects.filter(field__startswith='550e8400e29b4'),
            [self.objs[1]],
        )
        self.assertSequenceEqual(
            NullableUUIDModel.objects.filter(field__startswith='550e8400-e29b-4'),
            [self.objs[1]],
        )

    def test_istartswith(self):
        self.assertSequenceEqualWithoutHyphens(
            NullableUUIDModel.objects.filter(field__istartswith='550E8400E29B4'),
            [self.objs[1]],
        )
        self.assertSequenceEqual(
            NullableUUIDModel.objects.filter(field__istartswith='550E8400-E29B-4'),
            [self.objs[1]],
        )

    def test_endswith(self):
        self.assertSequenceEqualWithoutHyphens(
            NullableUUIDModel.objects.filter(field__endswith='a716446655440000'),
            [self.objs[1]],
        )
        self.assertSequenceEqual(
            NullableUUIDModel.objects.filter(field__endswith='a716-446655440000'),
            [self.objs[1]],
        )

    def test_iendswith(self):
        self.assertSequenceEqualWithoutHyphens(
            NullableUUIDModel.objects.filter(field__iendswith='A716446655440000'),
            [self.objs[1]],
        )
        self.assertSequenceEqual(
            NullableUUIDModel.objects.filter(field__iendswith='A716-446655440000'),
            [self.objs[1]],
        )

    def test_filter_with_expr(self):
        self.assertSequenceEqualWithoutHyphens(
            NullableUUIDModel.objects.annotate(
                value=Concat(Value('8400'), Value('e29b'), output_field=CharField()),
            ).filter(field__contains=F('value')),
            [self.objs[1]],
        )
        self.assertSequenceEqual(
            NullableUUIDModel.objects.annotate(
                value=Concat(Value('8400'), Value('-'), Value('e29b'), output_field=CharField()),
            ).filter(field__contains=F('value')),
            [self.objs[1]],
        )
        self.assertSequenceEqual(
            NullableUUIDModel.objects.annotate(
                value=Repeat(Value('0'), 4, output_field=CharField()),
            ).filter(field__contains=F('value')),
            [self.objs[1]],
        )


class TestSerialization(SimpleTestCase):
    test_data = (
        '[{"fields": {"field": "550e8400-e29b-41d4-a716-446655440000"}, '
        '"model": "model_fields.uuidmodel", "pk": null}]'
    )
    nullable_test_data = (
        '[{"fields": {"field": null}, '
        '"model": "model_fields.nullableuuidmodel", "pk": null}]'
    )

    def test_dumping(self):
        instance = UUIDModel(field=uuid.UUID('550e8400e29b41d4a716446655440000'))
        data = serializers.serialize('json', [instance])
        self.assertEqual(json.loads(data), json.loads(self.test_data))

    def test_loading(self):
        instance = list(serializers.deserialize('json', self.test_data))[0].object
        self.assertEqual(instance.field, uuid.UUID('550e8400-e29b-41d4-a716-446655440000'))

    def test_nullable_loading(self):
        instance = list(serializers.deserialize('json', self.nullable_test_data))[0].object
        self.assertIsNone(instance.field)


class TestValidation(SimpleTestCase):
    def test_invalid_uuid(self):
        field = models.UUIDField()
        with self.assertRaises(exceptions.ValidationError) as cm:
            field.clean('550e8400', None)
        self.assertEqual(cm.exception.code, 'invalid')
        self.assertEqual(cm.exception.message % cm.exception.params, '“550e8400” is not a valid UUID.')

    def test_uuid_instance_ok(self):
        field = models.UUIDField()
        field.clean(uuid.uuid4(), None)  # no error


class TestAsPrimaryKey(TestCase):
    def test_creation(self):
        PrimaryKeyUUIDModel.objects.create()
        loaded = PrimaryKeyUUIDModel.objects.get()
        self.assertIsInstance(loaded.pk, uuid.UUID)

    def test_uuid_pk_on_save(self):
        saved = PrimaryKeyUUIDModel.objects.create(id=None)
        loaded = PrimaryKeyUUIDModel.objects.get()
        self.assertIsNotNone(loaded.id, None)
        self.assertEqual(loaded.id, saved.id)

    def test_uuid_pk_on_bulk_create(self):
        u1 = PrimaryKeyUUIDModel()
        u2 = PrimaryKeyUUIDModel(id=None)
        PrimaryKeyUUIDModel.objects.bulk_create([u1, u2])
        # The two objects were correctly created.
        u1_found = PrimaryKeyUUIDModel.objects.filter(id=u1.id).exists()
        u2_found = PrimaryKeyUUIDModel.objects.exclude(id=u1.id).exists()
        self.assertTrue(u1_found)
        self.assertTrue(u2_found)
        self.assertEqual(PrimaryKeyUUIDModel.objects.count(), 2)

    def test_underlying_field(self):
        pk_model = PrimaryKeyUUIDModel.objects.create()
        RelatedToUUIDModel.objects.create(uuid_fk=pk_model)
        related = RelatedToUUIDModel.objects.get()
        self.assertEqual(related.uuid_fk.pk, related.uuid_fk_id)

    def test_update_with_related_model_instance(self):
        # regression for #24611
        u1 = PrimaryKeyUUIDModel.objects.create()
        u2 = PrimaryKeyUUIDModel.objects.create()
        r = RelatedToUUIDModel.objects.create(uuid_fk=u1)
        RelatedToUUIDModel.objects.update(uuid_fk=u2)
        r.refresh_from_db()
        self.assertEqual(r.uuid_fk, u2)

    def test_update_with_related_model_id(self):
        u1 = PrimaryKeyUUIDModel.objects.create()
        u2 = PrimaryKeyUUIDModel.objects.create()
        r = RelatedToUUIDModel.objects.create(uuid_fk=u1)
        RelatedToUUIDModel.objects.update(uuid_fk=u2.pk)
        r.refresh_from_db()
        self.assertEqual(r.uuid_fk, u2)

    def test_two_level_foreign_keys(self):
        gc = UUIDGrandchild()
        # exercises ForeignKey.get_db_prep_value()
        gc.save()
        self.assertIsInstance(gc.uuidchild_ptr_id, uuid.UUID)
        gc.refresh_from_db()
        self.assertIsInstance(gc.uuidchild_ptr_id, uuid.UUID)


class TestAsPrimaryKeyTransactionTests(TransactionTestCase):
    # Need a TransactionTestCase to avoid deferring FK constraint checking.
    available_apps = ['model_fields']

    @skipUnlessDBFeature('supports_foreign_keys')
    def test_unsaved_fk(self):
        u1 = PrimaryKeyUUIDModel()
        with self.assertRaises(IntegrityError):
            RelatedToUUIDModel.objects.create(uuid_fk=u1)
