import uuid

from datetime import datetime

from time import sleep

from django.contrib.postgres.functions import RandomUUID, TransactionNow

from . import PostgreSQLTestCase

from .models import NowTestModel, UUIDTestModel

class TestTransactionNow(PostgreSQLTestCase):

    def test_transaction_now(self):

        """

        The test case puts everything under a transaction, so two models

        updated with a short gap should have the same time.

        """

        m1 = NowTestModel.objects.create()

        m2 = NowTestModel.objects.create()

        NowTestModel.objects.filter(id=m1.id).update(when=TransactionNow())

        sleep(0.1)

        NowTestModel.objects.filter(id=m2.id).update(when=TransactionNow())

        m1.refresh_from_db()

        m2.refresh_from_db()

        self.assertIsInstance(m1.when, datetime)

        self.assertEqual(m1.when, m2.when)

class TestRandomUUID(PostgreSQLTestCase):

    def test_random_uuid(self):

        m1 = UUIDTestModel.objects.create()

        m2 = UUIDTestModel.objects.create()

        UUIDTestModel.objects.update(uuid=RandomUUID())

        m1.refresh_from_db()

        m2.refresh_from_db()

        self.assertIsInstance(m1.uuid, uuid.UUID)

        self.assertNotEqual(m1.uuid, m2.uuid)