import os, sys
from functools import partial
if 'DJANGO_SETTINGS_MODULE' not in os.environ:
    sys.path.append('.')
    os.environ['DJANGO_SETTINGS_MODULE'] = 'settings'
from django.conf import settings
from django.test.client import Client
from django.test.utils import setup_test_environment, teardown_test_environment
from django.core.management import call_command
from django.core import mail

from django.contrib.auth.models import User


def pytest_funcarg__django_client(request):
    '''py.test funcargs are awesome. This ugly function basically creates a
    test environment with an empty database every time you write a test
    function that accepts an argument named 'django_client.' Most of the time
    you won't use this, you'll use the 'client' funcarg below instead. This
    funcarg is only reset once per test session. The 'client' funcarg empties
    the database after each test to ensure a clean slate.'''
    old_name = settings.DATABASE_NAME
    def setup():
        setup_test_environment()
        if not hasattr(settings, 'DEBUG'):
            settings.DEBUG = False
        if 'south' in settings.INSTALLED_APPS:
            from south.management.commands import patch_for_test_db_setup
            patch_for_test_db_setup()
        from django.db import connection
        connection.creation.create_test_db(1, True)
        return Client()
    def teardown(client):
        teardown_test_environment()
        from django.db import connection
        connection.creation.destroy_test_db(old_name, 1)
    return request.cached_setup(setup, teardown, "session")

def pytest_funcarg__client(request):
    '''Creates a test environment using the 'django_client' funcarg above, but
    also ensures the database is flushed after running each test.'''
    def setup():
        return request.getfuncargvalue('django_client')
    def teardown(client):
        call_command('flush', verbosity=0, interactive=False)
        mail.outbox = []
    return request.cached_setup(setup, teardown, "function")

def user_creator(name, email, **extra):
    '''Creates a user.'''
    # Note: I make test usernames and passwords identical for easy login
    user = User.objects.create_user(username=name,
                                    password=name,
                                    email=email)
    for attr, value in extra.iteritems():
        setattr(user, attr, value)
        user.save()
    return user

def pytest_funcarg__user(request):
    '''Create a user with no special permissions.'''
    return request.cached_setup(partial(user_creator,
                                        "user",
                                        "user@example.com"),
                                lambda user: user.delete(),
                                "session")

def pytest_funcarg__admin(request):
    '''Create an admin user with all permissions.'''
    return request.cached_setup(partial(user_creator,
                                        "admin",
                                        "admin@example.com",
                                        is_superuser=True,
                                        is_staff=True),
                                lambda user: user.delete(),
                                "session")