from django.db.models import CharField

from django.db.models.functions import Length

from django.test import TestCase

from django.test.utils import register_lookup

from ..models import Author

class LengthTests(TestCase):

    def test_basic(self):

        Author.objects.create(name="John Smith", alias="smithj")

        Author.objects.create(name="Rhonda")

        authors = Author.objects.annotate(

            name_length=Length("name"),

            alias_length=Length("alias"),

        )

        self.assertQuerysetEqual(

            authors.order_by("name"),

            [(10, 6), (6, None)],

            lambda a: (a.name_length, a.alias_length),

        )

        self.assertEqual(authors.filter(alias_length__lte=Length("name")).count(), 1)

    def test_ordering(self):

        Author.objects.create(name="John Smith", alias="smithj")

        Author.objects.create(name="John Smith", alias="smithj1")

        Author.objects.create(name="Rhonda", alias="ronny")

        authors = Author.objects.order_by(Length("name"), Length("alias"))

        self.assertQuerysetEqual(

            authors,

            [

                ("Rhonda", "ronny"),

                ("John Smith", "smithj"),

                ("John Smith", "smithj1"),

            ],

            lambda a: (a.name, a.alias),

        )

    def test_transform(self):

        with register_lookup(CharField, Length):

            Author.objects.create(name="John Smith", alias="smithj")

            Author.objects.create(name="Rhonda")

            authors = Author.objects.filter(name__length__gt=7)

            self.assertQuerysetEqual(

                authors.order_by("name"), ["John Smith"], lambda a: a.name

            )