from django.conf import settings
from django.contrib.auth.models import Permission
from django.core.files import File
from django.db.models.query import QuerySet
from django.test import TestCase

import factory
from taggit.models import Tag

from ..models import Image, Pin
from ...users.models import User


TEST_IMAGE_PATH = settings.SITE_ROOT + 'screenshot.png'


class UserFactory(factory.Factory):
    FACTORY_FOR = User

    username = factory.Sequence(lambda n: 'user_{}'.format(n))
    email = factory.Sequence(lambda n: 'user_{}@example.com'.format(n))

    @factory.post_generation(extract_prefix='password')
    def set_password(self, create, extracted, **kwargs):
        self.set_password(extracted)
        self.save()

    @factory.post_generation(extract_prefix='user_permissions')
    def set_user_permissions(self, create, extracted, **kwargs):
        self.user_permissions = Permission.objects.filter(codename__in=['add_pin', 'add_image'])

class TagFactory(factory.Factory):
    FACTORY_FOR = Tag

    name = factory.Sequence(lambda n: 'tag_{}'.format(n))


class ImageFactory(factory.Factory):
    FACTORY_FOR = Image

    image = factory.LazyAttribute(lambda a: File(open(TEST_IMAGE_PATH)))


class PinFactory(factory.Factory):
    FACTORY_FOR = Pin

    submitter = factory.SubFactory(UserFactory)
    image = factory.SubFactory(ImageFactory)

    @factory.post_generation(extract_prefix='tags')
    def add_tags(self, create, extracted, **kwargs):
        if isinstance(extracted, Tag):
            self.tags.add(extracted)
        elif isinstance(extracted, list):
            self.tags.add(*extracted)
        elif isinstance(extracted, QuerySet):
            self.tags = extracted
        else:
            self.tags.add(TagFactory())


class PinFactoryTest(TestCase):
    def test_default_tags(self):
        self.assertTrue(PinFactory().tags.get(pk=1).name.startswith('tag_'))

    def test_custom_tag(self):
        custom = 'custom_tag'
        self.assertEqual(PinFactory(tags=Tag.objects.create(name=custom)).tags.get(pk=1).name, custom)

    def test_custom_tags_list(self):
        tags = TagFactory.create_batch(2)
        PinFactory(tags=tags)
        self.assertEqual(Tag.objects.count(), 2)

    def test_custom_tags_queryset(self):
        TagFactory.create_batch(2)
        tags = Tag.objects.all()
        PinFactory(tags=tags)
        self.assertEqual(Tag.objects.count(), 2)

    def test_empty_tags(self):
        PinFactory(tags=[])
        self.assertEqual(Tag.objects.count(), 0)