from django.core.exceptions import FieldError

from django.test import TestCase

from .models import Article, Author

class CustomColumnsTests(TestCase):

    @classmethod

    def setUpTestData(cls):

        cls.a1 = Author.objects.create(first_name="John", last_name="Smith")

        cls.a2 = Author.objects.create(first_name="Peter", last_name="Jones")

        cls.authors = [cls.a1, cls.a2]

        cls.article = Article.objects.create(

            headline="Django lets you build web apps easily", primary_author=cls.a1

        )

        cls.article.authors.set(cls.authors)

    def test_query_all_available_authors(self):

        self.assertQuerysetEqual(

            Author.objects.all(),

            [

                "Peter Jones",

                "John Smith",

            ],

            str,

        )

    def test_get_first_name(self):

        self.assertEqual(

            Author.objects.get(first_name__exact="John"),

            self.a1,

        )

    def test_filter_first_name(self):

        self.assertQuerysetEqual(

            Author.objects.filter(first_name__exact="John"),

            [

                "John Smith",

            ],

            str,

        )

    def test_field_error(self):

        msg = (

            "Cannot resolve keyword 'firstname' into field. Choices are: "

            "Author_ID, article, first_name, last_name, primary_set"

        )

        with self.assertRaisesMessage(FieldError, msg):

            Author.objects.filter(firstname__exact="John")

    def test_attribute_error(self):

        with self.assertRaises(AttributeError):

            self.a1.firstname

        with self.assertRaises(AttributeError):

            self.a1.last

    def test_get_all_authors_for_an_article(self):

        self.assertQuerysetEqual(

            self.article.authors.all(),

            [

                "Peter Jones",

                "John Smith",

            ],

            str,

        )

    def test_get_all_articles_for_an_author(self):

        self.assertQuerysetEqual(

            self.a1.article_set.all(),

            [

                "Django lets you build web apps easily",

            ],

            lambda a: a.headline,

        )

    def test_get_author_m2m_relation(self):

        self.assertQuerysetEqual(

            self.article.authors.filter(last_name="Jones"), ["Peter Jones"], str

        )

    def test_author_querying(self):

        self.assertSequenceEqual(

            Author.objects.order_by("last_name"),

            [self.a2, self.a1],

        )

    def test_author_filtering(self):

        self.assertSequenceEqual(

            Author.objects.filter(first_name__exact="John"),

            [self.a1],

        )

    def test_author_get(self):

        self.assertEqual(self.a1, Author.objects.get(first_name__exact="John"))

    def test_filter_on_nonexistent_field(self):

        msg = (

            "Cannot resolve keyword 'firstname' into field. Choices are: "

            "Author_ID, article, first_name, last_name, primary_set"

        )

        with self.assertRaisesMessage(FieldError, msg):

            Author.objects.filter(firstname__exact="John")

    def test_author_get_attributes(self):

        a = Author.objects.get(last_name__exact="Smith")

        self.assertEqual("John", a.first_name)

        self.assertEqual("Smith", a.last_name)

        with self.assertRaisesMessage(

            AttributeError, "'Author' object has no attribute 'firstname'"

        ):

            getattr(a, "firstname")

        with self.assertRaisesMessage(

            AttributeError, "'Author' object has no attribute 'last'"

        ):

            getattr(a, "last")

    def test_m2m_table(self):

        self.assertSequenceEqual(

            self.article.authors.order_by("last_name"),

            [self.a2, self.a1],

        )

        self.assertSequenceEqual(self.a1.article_set.all(), [self.article])

        self.assertSequenceEqual(

            self.article.authors.filter(last_name="Jones"),

            [self.a2],

        )