Ruby random South African ID number generator

gistfile1.txt

def id_number(birthday, gender)
  gender          = (0..4).to_a.sample if gender == 'female'
  gender          = (5..9).to_a.sample if gender == 'male'
  random_sequence = rand.to_s[2..5]
  citizenship     = 0
  race            = 8

  id_number = [
    birthday.gsub('-', '')[2..-1],
    gender,
    random_sequence,
    citizenship,
    race
  ].join.split('').map(&:to_i)

  # Luhn digit
  luhn_total = 0
  luhn_count = 0

  id_number.each do |d, x|
    multiple    = (luhn_count % 2) + 1
    luhn_count += 1
    temp        = multiple * d
    luhn_total += (temp/10).floor + (temp % 10)
  end

  return id_number.push((luhn_total * 9) % 10).join
end

gistfile2.txt

class ZaIdNumberValidator < ActiveModel::EachValidator
  def validate_each(record, attribute, value)

    if value.length != 13
      record.errors[attribute] << (options[:message] || "Identification number is invalid")
    else
      id_number  = value.to_s.split('').map(&:to_i)
      luhn_check = id_number.last
      luhn_total = 0
      luhn_count = 0

      id_number.take(12).each do |d, x|
        multiple    = (luhn_count % 2) + 1
        luhn_count += 1
        temp        = multiple * d
        luhn_total += (temp/10).floor + (temp % 10)
      end

      if luhn_check != (luhn_total * 9) % 10
        record.errors[attribute] << (options[:message] || "Identification number is invalid")
      end
    end
  end
end

class Profile < ApplicationRecord
  validates :identification_number,
            presence: true,
            za_id_number: true
end