from django.db.models import Q, Sum
from django.db.models.deletion import ProtectedError
from django.db.utils import IntegrityError
from django.forms.models import modelform_factory
from django.test import TestCase, skipIfDBFeature

from .models import (
    A, Address, B, Board, C, Cafe, CharLink, Company, Contact, Content, D,
    Developer, Guild, HasLinkThing, Link, Node, Note, OddRelation1,
    OddRelation2, Organization, Person, Place, Related, Restaurant, Tag, Team,
    TextLink,
)


class GenericRelationTests(TestCase):

    def test_inherited_models_content_type(self):
        """
        GenericRelations on inherited classes use the correct content type.
        """
        p = Place.objects.create(name="South Park")
        r = Restaurant.objects.create(name="Chubby's")
        l1 = Link.objects.create(content_object=p)
        l2 = Link.objects.create(content_object=r)
        self.assertEqual(list(p.links.all()), [l1])
        self.assertEqual(list(r.links.all()), [l2])

    def test_reverse_relation_pk(self):
        """
        The correct column name is used for the primary key on the
        originating model of a query.  See #12664.
        """
        p = Person.objects.create(account=23, name='Chef')
        Address.objects.create(street='123 Anywhere Place',
                               city='Conifer', state='CO',
                               zipcode='80433', content_object=p)

        qs = Person.objects.filter(addresses__zipcode='80433')
        self.assertEqual(1, qs.count())
        self.assertEqual('Chef', qs[0].name)

    def test_charlink_delete(self):
        oddrel = OddRelation1.objects.create(name='clink')
        CharLink.objects.create(content_object=oddrel)
        oddrel.delete()

    def test_textlink_delete(self):
        oddrel = OddRelation2.objects.create(name='tlink')
        TextLink.objects.create(content_object=oddrel)
        oddrel.delete()

    def test_coerce_object_id_remote_field_cache_persistence(self):
        restaurant = Restaurant.objects.create()
        CharLink.objects.create(content_object=restaurant)
        charlink = CharLink.objects.latest('pk')
        self.assertIs(charlink.content_object, charlink.content_object)
        # If the model (Cafe) uses more than one level of multi-table inheritance.
        cafe = Cafe.objects.create()
        CharLink.objects.create(content_object=cafe)
        charlink = CharLink.objects.latest('pk')
        self.assertIs(charlink.content_object, charlink.content_object)

    def test_q_object_or(self):
        """
        SQL query parameters for generic relations are properly
        grouped when OR is used (#11535).

        In this bug the first query (below) works while the second, with the
        query parameters the same but in reverse order, does not.

        The issue is that the generic relation conditions do not get properly
        grouped in parentheses.
        """
        note_contact = Contact.objects.create()
        org_contact = Contact.objects.create()
        Note.objects.create(note='note', content_object=note_contact)
        org = Organization.objects.create(name='org name')
        org.contacts.add(org_contact)
        # search with a non-matching note and a matching org name
        qs = Contact.objects.filter(Q(notes__note__icontains=r'other note') |
                                    Q(organizations__name__icontains=r'org name'))
        self.assertIn(org_contact, qs)
        # search again, with the same query parameters, in reverse order
        qs = Contact.objects.filter(
            Q(organizations__name__icontains=r'org name') |
            Q(notes__note__icontains=r'other note'))
        self.assertIn(org_contact, qs)

    def test_join_reuse(self):
        qs = Person.objects.filter(
            addresses__street='foo'
        ).filter(
            addresses__street='bar'
        )
        self.assertEqual(str(qs.query).count('JOIN'), 2)

    def test_generic_relation_ordering(self):
        """
        Ordering over a generic relation does not include extraneous
        duplicate results, nor excludes rows not participating in the relation.
        """
        p1 = Place.objects.create(name="South Park")
        p2 = Place.objects.create(name="The City")
        c = Company.objects.create(name="Chubby's Intl.")
        Link.objects.create(content_object=p1)
        Link.objects.create(content_object=c)

        places = list(Place.objects.order_by('links__id'))

        def count_places(place):
            return len([p for p in places if p.id == place.id])

        self.assertEqual(len(places), 2)
        self.assertEqual(count_places(p1), 1)
        self.assertEqual(count_places(p2), 1)

    def test_target_model_is_unsaved(self):
        """Test related to #13085"""
        # Fails with another, ORM-level error
        dev1 = Developer(name='Joe')
        note = Note(note='Deserves promotion', content_object=dev1)
        with self.assertRaises(IntegrityError):
            note.save()

    def test_target_model_len_zero(self):
        """
        Saving a model with a GenericForeignKey to a model instance whose
        __len__ method returns 0 (Team.__len__() here) shouldn't fail (#13085).
        """
        team1 = Team.objects.create(name='Backend devs')
        note = Note(note='Deserve a bonus', content_object=team1)
        note.save()

    def test_target_model_bool_false(self):
        """
        Saving a model with a GenericForeignKey to a model instance whose
        __bool__ method returns False (Guild.__bool__() here) shouldn't fail
        (#13085).
        """
        g1 = Guild.objects.create(name='First guild')
        note = Note(note='Note for guild', content_object=g1)
        note.save()

    @skipIfDBFeature('interprets_empty_strings_as_nulls')
    def test_gfk_to_model_with_empty_pk(self):
        """Test related to #13085"""
        # Saving model with GenericForeignKey to model instance with an
        # empty CharField PK
        b1 = Board.objects.create(name='')
        tag = Tag(label='VP', content_object=b1)
        tag.save()

    def test_ticket_20378(self):
        # Create a couple of extra HasLinkThing so that the autopk value
        # isn't the same for Link and HasLinkThing.
        hs1 = HasLinkThing.objects.create()
        hs2 = HasLinkThing.objects.create()
        hs3 = HasLinkThing.objects.create()
        hs4 = HasLinkThing.objects.create()
        l1 = Link.objects.create(content_object=hs3)
        l2 = Link.objects.create(content_object=hs4)
        self.assertSequenceEqual(HasLinkThing.objects.filter(links=l1), [hs3])
        self.assertSequenceEqual(HasLinkThing.objects.filter(links=l2), [hs4])
        self.assertSequenceEqual(HasLinkThing.objects.exclude(links=l2), [hs1, hs2, hs3])
        self.assertSequenceEqual(HasLinkThing.objects.exclude(links=l1), [hs1, hs2, hs4])

    def test_ticket_20564(self):
        b1 = B.objects.create()
        b2 = B.objects.create()
        b3 = B.objects.create()
        c1 = C.objects.create(b=b1)
        c2 = C.objects.create(b=b2)
        c3 = C.objects.create(b=b3)
        A.objects.create(flag=None, content_object=b1)
        A.objects.create(flag=True, content_object=b2)
        self.assertSequenceEqual(C.objects.filter(b__a__flag=None), [c1, c3])
        self.assertSequenceEqual(C.objects.exclude(b__a__flag=None), [c2])

    def test_ticket_20564_nullable_fk(self):
        b1 = B.objects.create()
        b2 = B.objects.create()
        b3 = B.objects.create()
        d1 = D.objects.create(b=b1)
        d2 = D.objects.create(b=b2)
        d3 = D.objects.create(b=b3)
        d4 = D.objects.create()
        A.objects.create(flag=None, content_object=b1)
        A.objects.create(flag=True, content_object=b1)
        A.objects.create(flag=True, content_object=b2)
        self.assertSequenceEqual(D.objects.exclude(b__a__flag=None), [d2])
        self.assertSequenceEqual(D.objects.filter(b__a__flag=None), [d1, d3, d4])
        self.assertSequenceEqual(B.objects.filter(a__flag=None), [b1, b3])
        self.assertSequenceEqual(B.objects.exclude(a__flag=None), [b2])

    def test_extra_join_condition(self):
        # A crude check that content_type_id is taken in account in the
        # join/subquery condition.
        self.assertIn("content_type_id", str(B.objects.exclude(a__flag=None).query).lower())
        # No need for any joins - the join from inner query can be trimmed in
        # this case (but not in the above case as no a objects at all for given
        # B would then fail).
        self.assertNotIn(" join ", str(B.objects.exclude(a__flag=True).query).lower())
        self.assertIn("content_type_id", str(B.objects.exclude(a__flag=True).query).lower())

    def test_annotate(self):
        hs1 = HasLinkThing.objects.create()
        hs2 = HasLinkThing.objects.create()
        HasLinkThing.objects.create()
        b = Board.objects.create(name=str(hs1.pk))
        Link.objects.create(content_object=hs2)
        link = Link.objects.create(content_object=hs1)
        Link.objects.create(content_object=b)
        qs = HasLinkThing.objects.annotate(Sum('links')).filter(pk=hs1.pk)
        # If content_type restriction isn't in the query's join condition,
        # then wrong results are produced here as the link to b will also match
        # (b and hs1 have equal pks).
        self.assertEqual(qs.count(), 1)
        self.assertEqual(qs[0].links__sum, link.id)
        link.delete()
        # Now if we don't have proper left join, we will not produce any
        # results at all here.
        # clear cached results
        qs = qs.all()
        self.assertEqual(qs.count(), 1)
        # Note - 0 here would be a nicer result...
        self.assertIs(qs[0].links__sum, None)
        # Finally test that filtering works.
        self.assertEqual(qs.filter(links__sum__isnull=True).count(), 1)
        self.assertEqual(qs.filter(links__sum__isnull=False).count(), 0)

    def test_filter_targets_related_pk(self):
        HasLinkThing.objects.create()
        hs2 = HasLinkThing.objects.create()
        link = Link.objects.create(content_object=hs2)
        self.assertNotEqual(link.object_id, link.pk)
        self.assertSequenceEqual(HasLinkThing.objects.filter(links=link.pk), [hs2])

    def test_editable_generic_rel(self):
        GenericRelationForm = modelform_factory(HasLinkThing, fields='__all__')
        form = GenericRelationForm()
        self.assertIn('links', form.fields)
        form = GenericRelationForm({'links': None})
        self.assertTrue(form.is_valid())
        form.save()
        links = HasLinkThing._meta.get_field('links')
        self.assertEqual(links.save_form_data_calls, 1)

    def test_ticket_22998(self):
        related = Related.objects.create()
        content = Content.objects.create(related_obj=related)
        Node.objects.create(content=content)

        # deleting the Related cascades to the Content cascades to the Node,
        # where the pre_delete signal should fire and prevent deletion.
        with self.assertRaises(ProtectedError):
            related.delete()

    def test_ticket_22982(self):
        place = Place.objects.create(name='My Place')
        self.assertIn('GenericRelatedObjectManager', str(place.links))

    def test_filter_on_related_proxy_model(self):
        place = Place.objects.create()
        Link.objects.create(content_object=place)
        self.assertEqual(Place.objects.get(link_proxy__object_id=place.id), place)

    def test_generic_reverse_relation_with_mti(self):
        """
        Filtering with a reverse generic relation, where the GenericRelation
        comes from multi-table inheritance.
        """
        place = Place.objects.create(name='Test Place')
        link = Link.objects.create(content_object=place)
        result = Link.objects.filter(places=place)
        self.assertCountEqual(result, [link])

    def test_generic_reverse_relation_with_abc(self):
        """
        The reverse generic relation accessor (targets) is created if the
        GenericRelation comes from an abstract base model (HasLinks).
        """
        thing = HasLinkThing.objects.create()
        link = Link.objects.create(content_object=thing)
        self.assertCountEqual(link.targets.all(), [thing])
