1 """

     2 Kuwait-specific Form helpers

     3 """

     4 import re

     5 from datetime import date

     6 

     7 from django.core.validators import EMPTY_VALUES

     8 from django.forms import ValidationError

     9 from django.forms.fields import Field, RegexField

    10 from django.utils.translation import gettext as _

    11 

    12 id_re = re.compile(r'^(?P<initial>\d{1})(?P<yy>\d\d)(?P<mm>\d\d)(?P<dd>\d\d)(?P<mid>\d{4})(?P<checksum>\d{1})')

    13 

    14 class KWCivilIDNumberField(Field):

    15     """

    16     Kuwaiti Civil ID numbers are 12 digits, second to seventh digits

    17     represents the person's birthdate.

    18 

    19     Checks the following rules to determine the validty of the number:

    20         * The number consist of 12 digits.

    21         * The birthdate of the person is a valid date.

    22         * The calculated checksum equals to the last digit of the Civil ID.

    23     """

    24     default_error_messages = {

    25         'invalid': _('Enter a valid Kuwaiti Civil ID number'),

    26     }

    27 

    28     def has_valid_checksum(self, value):

    29         weight = (2, 1, 6, 3, 7, 9, 10, 5, 8, 4, 2)

    30         calculated_checksum = 0

    31         for i in range(11):

    32             calculated_checksum += int(value[i]) * weight[i]

    33 

    34         remainder = calculated_checksum % 11

    35         checkdigit = 11 - remainder

    36         if checkdigit != int(value[11]):

    37             return False

    38         return True

    39 

    40     def clean(self, value):

    41         super(KWCivilIDNumberField, self).clean(value)

    42         if value in EMPTY_VALUES:

    43             return u''

    44 

    45         if not re.match(r'^\d{12}$', value):

    46             raise ValidationError(self.error_messages['invalid'])

    47 

    48         match = re.match(id_re, value)

    49 

    50         if not match:

    51             raise ValidationError(self.error_messages['invalid'])

    52 

    53         gd = match.groupdict()

    54 

    55         try:

    56             d = date(int(gd['yy']), int(gd['mm']), int(gd['dd']))

    57         except ValueError:

    58             raise ValidationError(self.error_messages['invalid'])

    59 

    60         if not self.has_valid_checksum(value):

    61             raise ValidationError(self.error_messages['invalid'])

    62 

    63         return value