import unittest
import argparse


def email(string):
    """ check that email is correct"""
    import re
    # this ia a copy of the regex from django
    regex = re.compile(
        r"(^[-!#$%&'*+/=?^_`{}|~0-9A-Z]+(\.[-!#$%&'*+/=?^_`{}|~0-9A-Z]+)*"  # dot-atom
        r'|^"([\001-\010\013\014\016-\037!#-\[\]-\177]|\\[\001-011\013\014\016-\177])*"'  # quoted-string
        r')@(?:[A-Z0-9](?:[A-Z0-9-]{0,61}[A-Z0-9])?\.)+[A-Z]{2,6}\.?$', re.IGNORECASE)  # domain
    if not re.fullmatch(regex, string):
        raise argparse.ArgumentTypeError(f'{string} is not a correct email')
    return string


class tests_email_argument(unittest.TestCase):

    def setUp(self):
        self.parser = argparse.ArgumentParser(description=' test of email parsing')
        self.parser.add_argument('email',
                                 help='your user mail',
                                 type=email,)

    def test1_email_incorrect(self):
        with self.assertRaises(argparse.ArgumentError):
            args = self.parser.parse_args(('odile.toto',))