from django.test import TestCase

from django.core.exceptions import FieldError

from models import Author, Article

def pks(objects):

    """ Return pks to be able to compare lists"""

    return [o.pk for o in objects]

class CustomColumnRegression(TestCase):

    def assertRaisesMessage(self, exc, msg, func, *args, **kwargs):

        try:

            func(*args, **kwargs)

        except Exception, e:

            self.assertEqual(msg, str(e))

            self.assertTrue(isinstance(e, exc), "Expected %s, got %s" % (exc, type(e)))

    def setUp(self):

        self.a1 = Author.objects.create(first_name='John', last_name='Smith')

        self.a2 = Author.objects.create(first_name='Peter', last_name='Jones')

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

    def test_basic_creation(self):

        art = Article(headline='Django lets you build Web apps easily', primary_author=self.a1)

        art.save()

        art.authors = [self.a1, self.a2]

    def test_author_querying(self):

        self.assertQuerysetEqual(

            Author.objects.all().order_by('last_name'),

            ['<Author: Peter Jones>', '<Author: John Smith>']

        )

    def test_author_filtering(self):

        self.assertQuerysetEqual(

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

            ['<Author: John Smith>']

        )

    def test_author_get(self):

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

    def test_filter_on_nonexistant_field(self):

        self.assertRaisesMessage(

            FieldError,

            "Cannot resolve keyword 'firstname' into field. Choices are: Author_ID, article, first_name, last_name, primary_set",

            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)

        self.assertRaisesMessage(

            AttributeError,

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

            getattr,

            a, 'firstname'

        )

        self.assertRaisesMessage(

            AttributeError,

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

            getattr,

            a, 'last'

        )

    def test_m2m_table(self):

        art = Article.objects.create(headline='Django lets you build Web apps easily', primary_author=self.a1)

        art.authors = self.authors

        self.assertQuerysetEqual(

            art.authors.all().order_by('last_name'),

            ['<Author: Peter Jones>', '<Author: John Smith>']

        )

        self.assertQuerysetEqual(

            self.a1.article_set.all(),

            ['<Article: Django lets you build Web apps easily>']

        )

        self.assertQuerysetEqual(

            art.authors.filter(last_name='Jones'),

            ['<Author: Peter Jones>']

        )