import datetime
from copy import deepcopy

from django.core.exceptions import FieldError, MultipleObjectsReturned
from django.db import models, transaction
from django.db.utils import IntegrityError
from django.test import TestCase, ignore_warnings
from django.utils import six
from django.utils.deprecation import RemovedInDjango20Warning
from django.utils.translation import ugettext_lazy

from .models import (
    Article, Category, Child, City, District, First, Parent, Record, Relation,
    Reporter, School, Student, Third, ToFieldChild,
)


class ManyToOneTests(TestCase):
    def setUp(self):
        # Create a few Reporters.
        self.r = Reporter(first_name='John', last_name='Smith', email='john@example.com')
        self.r.save()
        self.r2 = Reporter(first_name='Paul', last_name='Jones', email='paul@example.com')
        self.r2.save()
        # Create an Article.
        self.a = Article(headline="This is a test", pub_date=datetime.date(2005, 7, 27), reporter=self.r)
        self.a.save()

    def test_get(self):
        # Article objects have access to their related Reporter objects.
        r = self.a.reporter
        self.assertEqual(r.id, self.r.id)
        # These are strings instead of unicode strings because that's what was used in
        # the creation of this reporter (and we haven't refreshed the data from the
        # database, which always returns unicode strings).
        self.assertEqual((r.first_name, self.r.last_name), ('John', 'Smith'))

    def test_create(self):
        # You can also instantiate an Article by passing the Reporter's ID
        # instead of a Reporter object.
        a3 = Article(headline="Third article", pub_date=datetime.date(2005, 7, 27), reporter_id=self.r.id)
        a3.save()
        self.assertEqual(a3.reporter.id, self.r.id)

        # Similarly, the reporter ID can be a string.
        a4 = Article(headline="Fourth article", pub_date=datetime.date(2005, 7, 27), reporter_id=str(self.r.id))
        a4.save()
        self.assertEqual(repr(a4.reporter), "<Reporter: John Smith>")

    def test_add(self):
        # Create an Article via the Reporter object.
        new_article = self.r.article_set.create(headline="John's second story", pub_date=datetime.date(2005, 7, 29))
        self.assertEqual(repr(new_article), "<Article: John's second story>")
        self.assertEqual(new_article.reporter.id, self.r.id)

        # Create a new article, and add it to the article set.
        new_article2 = Article(headline="Paul's story", pub_date=datetime.date(2006, 1, 17))
        msg = "<Article: Paul's story> instance isn't saved. Use bulk=False or save the object first."
        with self.assertRaisesMessage(ValueError, msg):
            self.r.article_set.add(new_article2)

        self.r.article_set.add(new_article2, bulk=False)
        self.assertEqual(new_article2.reporter.id, self.r.id)
        self.assertQuerysetEqual(
            self.r.article_set.all(),
            ["<Article: John's second story>", "<Article: Paul's story>", "<Article: This is a test>"]
        )

        # Add the same article to a different article set - check that it moves.
        self.r2.article_set.add(new_article2)
        self.assertEqual(new_article2.reporter.id, self.r2.id)
        self.assertQuerysetEqual(self.r2.article_set.all(), ["<Article: Paul's story>"])

        # Adding an object of the wrong type raises TypeError.
        with transaction.atomic():
            with six.assertRaisesRegex(self, TypeError,
                                       "'Article' instance expected, got <Reporter.*"):
                self.r.article_set.add(self.r2)
        self.assertQuerysetEqual(
            self.r.article_set.all(),
            ["<Article: John's second story>", "<Article: This is a test>"]
        )

    def test_set(self):
        new_article = self.r.article_set.create(headline="John's second story", pub_date=datetime.date(2005, 7, 29))
        new_article2 = self.r2.article_set.create(headline="Paul's story", pub_date=datetime.date(2006, 1, 17))

        # Assign the article to the reporter.
        new_article2.reporter = self.r
        new_article2.save()
        self.assertEqual(repr(new_article2.reporter), "<Reporter: John Smith>")
        self.assertEqual(new_article2.reporter.id, self.r.id)
        self.assertQuerysetEqual(self.r.article_set.all(), [
            "<Article: John's second story>",
            "<Article: Paul's story>",
            "<Article: This is a test>",
        ])
        self.assertQuerysetEqual(self.r2.article_set.all(), [])

        # Set the article back again.
        self.r2.article_set.set([new_article, new_article2])
        self.assertQuerysetEqual(self.r.article_set.all(), ["<Article: This is a test>"])
        self.assertQuerysetEqual(
            self.r2.article_set.all(),
            ["<Article: John's second story>", "<Article: Paul's story>"]
        )

        # Funny case - because the ForeignKey cannot be null,
        # existing members of the set must remain.
        self.r.article_set.set([new_article])
        self.assertQuerysetEqual(
            self.r.article_set.all(),
            ["<Article: John's second story>", "<Article: This is a test>"]
        )
        self.assertQuerysetEqual(self.r2.article_set.all(), ["<Article: Paul's story>"])

    def test_reverse_assignment_deprecation(self):
        msg = (
            "Direct assignment to the reverse side of a related set is "
            "deprecated due to the implicit save() that happens. Use "
            "article_set.set() instead."
        )
        with self.assertRaisesMessage(RemovedInDjango20Warning, msg):
            self.r2.article_set = []

    def test_assign(self):
        new_article = self.r.article_set.create(headline="John's second story", pub_date=datetime.date(2005, 7, 29))
        new_article2 = self.r2.article_set.create(headline="Paul's story", pub_date=datetime.date(2006, 1, 17))

        # Assign the article to the reporter directly using the descriptor.
        new_article2.reporter = self.r
        new_article2.save()
        self.assertEqual(repr(new_article2.reporter), "<Reporter: John Smith>")
        self.assertEqual(new_article2.reporter.id, self.r.id)
        self.assertQuerysetEqual(self.r.article_set.all(), [
            "<Article: John's second story>",
            "<Article: Paul's story>",
            "<Article: This is a test>",
        ])
        self.assertQuerysetEqual(self.r2.article_set.all(), [])

        # Set the article back again using set() method.
        self.r2.article_set.set([new_article, new_article2])
        self.assertQuerysetEqual(self.r.article_set.all(), ["<Article: This is a test>"])
        self.assertQuerysetEqual(
            self.r2.article_set.all(),
            ["<Article: John's second story>", "<Article: Paul's story>"]
        )

        # Because the ForeignKey cannot be null, existing members of the set
        # must remain.
        self.r.article_set.set([new_article])
        self.assertQuerysetEqual(
            self.r.article_set.all(),
            ["<Article: John's second story>", "<Article: This is a test>"]
        )
        self.assertQuerysetEqual(self.r2.article_set.all(), ["<Article: Paul's story>"])
        # Reporter cannot be null - there should not be a clear or remove method
        self.assertFalse(hasattr(self.r2.article_set, 'remove'))
        self.assertFalse(hasattr(self.r2.article_set, 'clear'))

    def test_selects(self):
        self.r.article_set.create(headline="John's second story", pub_date=datetime.date(2005, 7, 29))
        self.r2.article_set.create(headline="Paul's story", pub_date=datetime.date(2006, 1, 17))
        # Reporter objects have access to their related Article objects.
        self.assertQuerysetEqual(self.r.article_set.all(), [
            "<Article: John's second story>",
            "<Article: This is a test>",
        ])
        self.assertQuerysetEqual(self.r.article_set.filter(headline__startswith='This'), ["<Article: This is a test>"])
        self.assertEqual(self.r.article_set.count(), 2)
        self.assertEqual(self.r2.article_set.count(), 1)
        # Get articles by id
        self.assertQuerysetEqual(Article.objects.filter(id__exact=self.a.id), ["<Article: This is a test>"])
        self.assertQuerysetEqual(Article.objects.filter(pk=self.a.id), ["<Article: This is a test>"])
        # Query on an article property
        self.assertQuerysetEqual(Article.objects.filter(headline__startswith='This'), ["<Article: This is a test>"])
        # The API automatically follows relationships as far as you need.
        # Use double underscores to separate relationships.
        # This works as many levels deep as you want. There's no limit.
        # Find all Articles for any Reporter whose first name is "John".
        self.assertQuerysetEqual(
            Article.objects.filter(reporter__first_name__exact='John'),
            ["<Article: John's second story>", "<Article: This is a test>"]
        )
        # Check that implied __exact also works
        self.assertQuerysetEqual(
            Article.objects.filter(reporter__first_name='John'),
            ["<Article: John's second story>", "<Article: This is a test>"]
        )
        # Query twice over the related field.
        self.assertQuerysetEqual(
            Article.objects.filter(reporter__first_name__exact='John', reporter__last_name__exact='Smith'),
            ["<Article: John's second story>", "<Article: This is a test>"]
        )
        # The underlying query only makes one join when a related table is referenced twice.
        queryset = Article.objects.filter(reporter__first_name__exact='John', reporter__last_name__exact='Smith')
        self.assertNumQueries(1, list, queryset)
        self.assertEqual(queryset.query.get_compiler(queryset.db).as_sql()[0].count('INNER JOIN'), 1)

        # The automatically joined table has a predictable name.
        self.assertQuerysetEqual(
            Article.objects.filter(reporter__first_name__exact='John').extra(
                where=["many_to_one_reporter.last_name='Smith'"]),
            ["<Article: John's second story>", "<Article: This is a test>"]
        )
        # ... and should work fine with the unicode that comes out of forms.Form.cleaned_data
        self.assertQuerysetEqual(
            (Article.objects
                .filter(reporter__first_name__exact='John')
                .extra(where=["many_to_one_reporter.last_name='%s'" % 'Smith'])),
            ["<Article: John's second story>", "<Article: This is a test>"]
        )
        # Find all Articles for a Reporter.
        # Use direct ID check, pk check, and object comparison
        self.assertQuerysetEqual(
            Article.objects.filter(reporter__id__exact=self.r.id),
            [
                "<Article: John's second story>",
                "<Article: This is a test>",
            ])
        self.assertQuerysetEqual(
            Article.objects.filter(reporter__pk=self.r.id),
            [
                "<Article: John's second story>",
                "<Article: This is a test>",
            ])
        self.assertQuerysetEqual(
            Article.objects.filter(reporter=self.r.id),
            [
                "<Article: John's second story>",
                "<Article: This is a test>",
            ])
        self.assertQuerysetEqual(
            Article.objects.filter(reporter=self.r),
            [
                "<Article: John's second story>",
                "<Article: This is a test>",
            ])
        self.assertQuerysetEqual(
            Article.objects.filter(reporter__in=[self.r.id, self.r2.id]).distinct(),
            [
                "<Article: John's second story>",
                "<Article: Paul's story>",
                "<Article: This is a test>",
            ])
        self.assertQuerysetEqual(
            Article.objects.filter(reporter__in=[self.r, self.r2]).distinct(),
            [
                "<Article: John's second story>",
                "<Article: Paul's story>",
                "<Article: This is a test>",
            ])
        # You can also use a queryset instead of a literal list of instances.
        # The queryset must be reduced to a list of values using values(),
        # then converted into a query
        self.assertQuerysetEqual(
            Article.objects.filter(
                reporter__in=Reporter.objects.filter(first_name='John').values('pk').query
            ).distinct(),
            [
                "<Article: John's second story>",
                "<Article: This is a test>",
            ])

    def test_reverse_selects(self):
        a3 = Article.objects.create(
            headline="Third article",
            pub_date=datetime.date(2005, 7, 27),
            reporter_id=self.r.id,
        )
        Article.objects.create(
            headline="Fourth article",
            pub_date=datetime.date(2005, 7, 27),
            reporter_id=self.r.id,
        )
        john_smith = ["<Reporter: John Smith>"]
        # Reporters can be queried
        self.assertQuerysetEqual(Reporter.objects.filter(id__exact=self.r.id), john_smith)
        self.assertQuerysetEqual(Reporter.objects.filter(pk=self.r.id), john_smith)
        self.assertQuerysetEqual(Reporter.objects.filter(first_name__startswith='John'), john_smith)
        # Reporters can query in opposite direction of ForeignKey definition
        self.assertQuerysetEqual(Reporter.objects.filter(article__id__exact=self.a.id), john_smith)
        self.assertQuerysetEqual(Reporter.objects.filter(article__pk=self.a.id), john_smith)
        self.assertQuerysetEqual(Reporter.objects.filter(article=self.a.id), john_smith)
        self.assertQuerysetEqual(Reporter.objects.filter(article=self.a), john_smith)
        self.assertQuerysetEqual(Reporter.objects.filter(article__in=[self.a.id, a3.id]).distinct(), john_smith)
        self.assertQuerysetEqual(Reporter.objects.filter(article__in=[self.a.id, a3]).distinct(), john_smith)
        self.assertQuerysetEqual(Reporter.objects.filter(article__in=[self.a, a3]).distinct(), john_smith)
        self.assertQuerysetEqual(
            Reporter.objects.filter(article__headline__startswith='T'),
            ["<Reporter: John Smith>", "<Reporter: John Smith>"],
            ordered=False
        )
        self.assertQuerysetEqual(Reporter.objects.filter(article__headline__startswith='T').distinct(), john_smith)

        # Counting in the opposite direction works in conjunction with distinct()
        self.assertEqual(Reporter.objects.filter(article__headline__startswith='T').count(), 2)
        self.assertEqual(Reporter.objects.filter(article__headline__startswith='T').distinct().count(), 1)

        # Queries can go round in circles.
        self.assertQuerysetEqual(
            Reporter.objects.filter(article__reporter__first_name__startswith='John'),
            [
                "<Reporter: John Smith>",
                "<Reporter: John Smith>",
                "<Reporter: John Smith>",
            ],
            ordered=False
        )
        self.assertQuerysetEqual(
            Reporter.objects.filter(article__reporter__first_name__startswith='John').distinct(),
            john_smith
        )
        self.assertQuerysetEqual(Reporter.objects.filter(article__reporter__exact=self.r).distinct(), john_smith)

        # Check that implied __exact also works.
        self.assertQuerysetEqual(Reporter.objects.filter(article__reporter=self.r).distinct(), john_smith)

        # It's possible to use values() calls across many-to-one relations.
        # (Note, too, that we clear the ordering here so as not to drag the
        # 'headline' field into the columns being used to determine uniqueness)
        d = {'reporter__first_name': 'John', 'reporter__last_name': 'Smith'}
        qs = Article.objects.filter(
            reporter=self.r,
        ).distinct().order_by().values('reporter__first_name', 'reporter__last_name')
        self.assertEqual([d], list(qs))

    def test_select_related(self):
        # Check that Article.objects.select_related().dates() works properly when
        # there are multiple Articles with the same date but different foreign-key
        # objects (Reporters).
        r1 = Reporter.objects.create(first_name='Mike', last_name='Royko', email='royko@suntimes.com')
        r2 = Reporter.objects.create(first_name='John', last_name='Kass', email='jkass@tribune.com')
        Article.objects.create(headline='First', pub_date=datetime.date(1980, 4, 23), reporter=r1)
        Article.objects.create(headline='Second', pub_date=datetime.date(1980, 4, 23), reporter=r2)
        self.assertEqual(
            list(Article.objects.select_related().dates('pub_date', 'day')),
            [datetime.date(1980, 4, 23), datetime.date(2005, 7, 27)]
        )
        self.assertEqual(
            list(Article.objects.select_related().dates('pub_date', 'month')),
            [datetime.date(1980, 4, 1), datetime.date(2005, 7, 1)]
        )
        self.assertEqual(
            list(Article.objects.select_related().dates('pub_date', 'year')),
            [datetime.date(1980, 1, 1), datetime.date(2005, 1, 1)]
        )

    def test_delete(self):
        self.r.article_set.create(headline="John's second story", pub_date=datetime.date(2005, 7, 29))
        self.r2.article_set.create(headline="Paul's story", pub_date=datetime.date(2006, 1, 17))
        Article.objects.create(headline="Third article", pub_date=datetime.date(2005, 7, 27), reporter_id=self.r.id)
        Article.objects.create(
            headline="Fourth article",
            pub_date=datetime.date(2005, 7, 27),
            reporter_id=str(self.r.id),
        )
        # If you delete a reporter, his articles will be deleted.
        self.assertQuerysetEqual(
            Article.objects.all(),
            [
                "<Article: Fourth article>",
                "<Article: John's second story>",
                "<Article: Paul's story>",
                "<Article: Third article>",
                "<Article: This is a test>",
            ]
        )
        self.assertQuerysetEqual(
            Reporter.objects.order_by('first_name'),
            ["<Reporter: John Smith>", "<Reporter: Paul Jones>"]
        )
        self.r2.delete()
        self.assertQuerysetEqual(
            Article.objects.all(),
            [
                "<Article: Fourth article>",
                "<Article: John's second story>",
                "<Article: Third article>",
                "<Article: This is a test>",
            ]
        )
        self.assertQuerysetEqual(Reporter.objects.order_by('first_name'), ["<Reporter: John Smith>"])
        # You can delete using a JOIN in the query.
        Reporter.objects.filter(article__headline__startswith='This').delete()
        self.assertQuerysetEqual(Reporter.objects.all(), [])
        self.assertQuerysetEqual(Article.objects.all(), [])

    def test_explicit_fk(self):
        # Create a new Article with get_or_create using an explicit value
        # for a ForeignKey.
        a2, created = Article.objects.get_or_create(
            headline="John's second test",
            pub_date=datetime.date(2011, 5, 7),
            reporter_id=self.r.id,
        )
        self.assertTrue(created)
        self.assertEqual(a2.reporter.id, self.r.id)

        # You can specify filters containing the explicit FK value.
        self.assertQuerysetEqual(
            Article.objects.filter(reporter_id__exact=self.r.id),
            ["<Article: John's second test>", "<Article: This is a test>"]
        )

        # Create an Article by Paul for the same date.
        a3 = Article.objects.create(
            headline="Paul's commentary",
            pub_date=datetime.date(2011, 5, 7),
            reporter_id=self.r2.id,
        )
        self.assertEqual(a3.reporter.id, self.r2.id)

        # Get should respect explicit foreign keys as well.
        with self.assertRaises(MultipleObjectsReturned):
            Article.objects.get(reporter_id=self.r.id)
        self.assertEqual(
            repr(a3),
            repr(Article.objects.get(reporter_id=self.r2.id, pub_date=datetime.date(2011, 5, 7)))
        )

    def test_deepcopy_and_circular_references(self):
        # Regression for #12876 -- Model methods that include queries that
        # recursive don't cause recursion depth problems under deepcopy.
        self.r.cached_query = Article.objects.filter(reporter=self.r)
        self.assertEqual(repr(deepcopy(self.r)), "<Reporter: John Smith>")

    def test_manager_class_caching(self):
        r1 = Reporter.objects.create(first_name='Mike')
        r2 = Reporter.objects.create(first_name='John')

        # Same twice
        self.assertIs(r1.article_set.__class__, r1.article_set.__class__)

        # Same as each other
        self.assertIs(r1.article_set.__class__, r2.article_set.__class__)

    def test_create_relation_with_ugettext_lazy(self):
        reporter = Reporter.objects.create(first_name='John', last_name='Smith', email='john.smith@example.com')
        lazy = ugettext_lazy('test')
        reporter.article_set.create(headline=lazy, pub_date=datetime.date(2011, 6, 10))
        notlazy = six.text_type(lazy)
        article = reporter.article_set.get()
        self.assertEqual(article.headline, notlazy)

    def test_values_list_exception(self):