from datetime import date

from django.db import IntegrityError

from django.test import TransactionTestCase

from models import Person, ManualPrimaryKeyTest

class GetOrCreateTests(TransactionTestCase):

    def test_get_or_create(self):

        p = Person.objects.create(

            first_name='John', last_name='Lennon', birthday=date(1940, 10, 9)

        )

        p, created = Person.objects.get_or_create(

            first_name="John", last_name="Lennon", defaults={

                "birthday": date(1940, 10, 9)

            }

        )

        self.assertFalse(created)

        self.assertEqual(Person.objects.count(), 1)

        p, created = Person.objects.get_or_create(

            first_name='George', last_name='Harrison', defaults={

                'birthday': date(1943, 2, 25)

            }

        )

        self.assertTrue(created)

        self.assertEqual(Person.objects.count(), 2)

        # If we execute the exact same statement, it won't create a Person.

        p, created = Person.objects.get_or_create(

            first_name='George', last_name='Harrison', defaults={

                'birthday': date(1943, 2, 25)

            }

        )

        self.assertFalse(created)

        self.assertEqual(Person.objects.count(), 2)

        # If you don't specify a value or default value for all required

        # fields, you will get an error.

        self.assertRaises(IntegrityError,

            Person.objects.get_or_create, first_name="Tom", last_name="Smith"

        )

        # If you specify an existing primary key, but different other fields,

        # then you will get an error and data will not be updated.

        m = ManualPrimaryKeyTest.objects.create(id=1, data="Original")

        self.assertRaises(IntegrityError,

            ManualPrimaryKeyTest.objects.get_or_create, id=1, data="Different"

        )

        self.assertEqual(ManualPrimaryKeyTest.objects.get(id=1).data, "Original")