# -*- coding: utf-8 -*-

"""

UY-specific form helpers.

"""

import re

from django.core.validators import EMPTY_VALUES

from django.forms.fields import Select, RegexField

from django.forms import ValidationError

from django.utils.translation import ugettext_lazy as _

from django.contrib.localflavor.uy.util import get_validation_digit

class UYDepartamentSelect(Select):

    """

    A Select widget that uses a list of Uruguayan departaments as its choices.

    """

    def __init__(self, attrs=None):

        from uy_departaments import DEPARTAMENT_CHOICES

        super(UYDepartamentSelect, self).__init__(attrs, choices=DEPARTAMENT_CHOICES)

class UYCIField(RegexField):

    """

    A field that validates Uruguayan 'Cedula de identidad' (CI) numbers.

    """

    default_error_messages = {

        'invalid': _("Enter a valid CI number in X.XXX.XXX-X,"

                     "XXXXXXX-X or XXXXXXXX format."),

        'invalid_validation_digit': _("Enter a valid CI number."),

    }

    def __init__(self, *args, **kwargs):

        super(UYCIField, self).__init__(r'(?P<num>(\d{6,7}|(\d\.)?\d{3}\.\d{3}))-?(?P<val>\d)',

                                        *args, **kwargs)

    def clean(self, value):

        """

        Validates format and validation digit.

        The official format is [X.]XXX.XXX-X but usually dots and/or slash are

        omitted so, when validating, those characters are ignored if found in

        the correct place. The three typically used formats are supported:

        [X]XXXXXXX, [X]XXXXXX-X and [X.]XXX.XXX-X.

        """

        value = super(UYCIField, self).clean(value)

        if value in EMPTY_VALUES:

            return u''

        match = self.regex.match(value)

        if not match:

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

        number = int(match.group('num').replace('.', ''))

        validation_digit = int(match.group('val'))

        if not validation_digit == get_validation_digit(number):

            raise ValidationError(self.error_messages['invalid_validation_digit'])

        return value