from __future__ import absolute_import

from datetime import date
import traceback

from django.db import IntegrityError
from django.test import TestCase, TransactionTestCase

from .models import Person, ManualPrimaryKeyTest, Profile, Tag, Thing


class GetOrCreateTests(TestCase):
    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")

        # get_or_create should raise IntegrityErrors with the full traceback.
        # This is tested by checking that a known method call is in the traceback.
        # We cannot use assertRaises/assertRaises here because we need to inspect
        # the actual traceback. Refs #16340.
        try:
            ManualPrimaryKeyTest.objects.get_or_create(id=1, data="Different")
        except IntegrityError as e:
            formatted_traceback = traceback.format_exc()
            self.assertIn('obj.save', formatted_traceback)


class GetOrCreateTransactionTests(TransactionTestCase):

    def test_get_or_create_integrityerror(self):
        # Regression test for #15117. Requires a TransactionTestCase on
        # databases that delay integrity checks until the end of transactions,
        # otherwise the exception is never raised.
        try:
            Profile.objects.get_or_create(person=Person(id=1))
        except IntegrityError:
            pass
        else:
            self.skipTest("This backend does not support integrity checks.")


class GetOrCreateThroughManyToMany(TestCase):

    def test_get_get_or_create(self):
        tag = Tag.objects.create(text='foo')
        a_thing = Thing.objects.create(name='a')
        a_thing.tags.add(tag)
        obj, created = a_thing.tags.get_or_create(text='foo')

        self.assertFalse(created)
        self.assertEqual(obj.pk, tag.pk)

    def test_create_get_or_create(self):
        a_thing = Thing.objects.create(name='a')
        obj, created = a_thing.tags.get_or_create(text='foo')

        self.assertTrue(created)
        self.assertEqual(obj.text, 'foo')
        self.assertIn(obj, a_thing.tags.all())

    def test_something(self):
        Tag.objects.create(text='foo')
        a_thing = Thing.objects.create(name='a')
        self.assertRaises(IntegrityError, a_thing.tags.get_or_create, text='foo')