from django.core import validators
from django.utils import six
from django.utils.deconstruct import deconstructible
from django.utils.translation import ugettext_lazy as _

import re


@deconstructible
class CallUsernameValidator(validators.RegexValidator):
    #regex = r'^[\w.@+-]+$'
    regex = r'^(?:[A-Z]+/)?[A-Z]{1,2}[0-9][A-Z]{1,4}(?:/[A-Z])?$'
    message = _(
        'Enter a valid Callsign as Username, ALL UPPERCASE, if needed with /A /B,'
        'e.g. DL7BST, DN1BER/A, DL/OE1FOO'
    )
    flags = re.ASCII if six.PY3 else 0