from __future__ import unicode_literals

import os
import sys

from django.apps import app_cache
from django.core.management import call_command
from django.test import TestCase, TransactionTestCase
from django.utils._os import upath

from .models import (ConcreteModel, ConcreteModelSubclass,
    ConcreteModelSubclassProxy)


class ProxyModelInheritanceTests(TransactionTestCase):
    """
    Proxy model inheritance across apps can result in migrate not creating the table
    for the proxied model (as described in #12286).  This test creates two dummy
    apps and calls migrate, then verifies that the table has been created.
    """
    available_apps = []

    def setUp(self):
        self.old_sys_path = sys.path[:]
        sys.path.append(os.path.dirname(os.path.abspath(upath(__file__))))

    def tearDown(self):
        sys.path = self.old_sys_path

    def test_table_exists(self):
        with app_cache._with_app('app1'), app_cache._with_app('app2'):
            call_command('migrate', verbosity=0)
            from .app1.models import ProxyModel
            from .app2.models import NiceModel
            self.assertEqual(NiceModel.objects.all().count(), 0)
            self.assertEqual(ProxyModel.objects.all().count(), 0)


class MultiTableInheritanceProxyTest(TestCase):

    def test_model_subclass_proxy(self):
        """
        Deleting an instance of a model proxying a multi-table inherited
        subclass should cascade delete down the whole inheritance chain (see
        #18083).
        """
        instance = ConcreteModelSubclassProxy.objects.create()
        instance.delete()
        self.assertEqual(0, ConcreteModelSubclassProxy.objects.count())
        self.assertEqual(0, ConcreteModelSubclass.objects.count())
        self.assertEqual(0, ConcreteModel.objects.count())