from django.test import TestCase

from .models import SlugPage

class RestrictedConditionsTests(TestCase):

    @classmethod

    def setUpTestData(cls):

        slugs = [

            "a",

            "a/a",

            "a/b",

            "a/b/a",

            "x",

            "x/y/z",

        ]

        SlugPage.objects.bulk_create([SlugPage(slug=slug) for slug in slugs])

    def test_restrictions_with_no_joining_columns(self):

        """

        It's possible to create a working related field that doesn't

        use any joining columns, as long as an extra restriction is supplied.

        """

        a = SlugPage.objects.get(slug="a")

        self.assertEqual(

            [p.slug for p in SlugPage.objects.filter(ascendants=a)],

            ["a", "a/a", "a/b", "a/b/a"],

        )

        self.assertEqual(

            [p.slug for p in a.descendants.all()],

            ["a", "a/a", "a/b", "a/b/a"],

        )

        aba = SlugPage.objects.get(slug="a/b/a")

        self.assertEqual(

            [p.slug for p in SlugPage.objects.filter(descendants__in=[aba])],

            ["a", "a/b", "a/b/a"],

        )

        self.assertEqual(

            [p.slug for p in aba.ascendants.all()],

            ["a", "a/b", "a/b/a"],

        )

    def test_empty_join_conditions(self):

        x = SlugPage.objects.get(slug="x")

        message = "Join generated an empty ON clause."

        with self.assertRaisesMessage(ValueError, message):

            list(SlugPage.objects.filter(containers=x))