require 'active_model/validations/shared/luhn_checker'

module ActiveModel
  module Validations

    class CreditCardValidator < EachValidator
      def validate_each(record, attribute, value)
        type = options.fetch(:type, :any)
        record.errors.add(attribute) if value.blank? || !Luhn.valid?(type, sanitize_card(value))
      end

      def sanitize_card(value)
        value.tr('- ','')
      end

      class Luhn
        def self.valid?(card_type,number)
          if card_type == :any
            LuhnChecker.valid?(number)
          else
            self.send("#{card_type.to_s}?", number)
          end
        end

        def self.mastercard?(number)
          LuhnChecker.valid?(number) and !(number !~ /^5[1-5].{14}/)
        end

        class << self
          alias :master_card? :mastercard?
        end

        def self.visa?(number)
          LuhnChecker.valid?(number) and !(number !~ /^4.{15}/)
        end

        def self.amex?(number)
          LuhnChecker.valid?(number) and !(number !~ /^3[47].{13}/)
        end

        [:diners_club, :en_route, :discover, :jcb, :carte_blanche, :switch,
          :solo, :laser].each do |card_type|
          class_eval <<-VALIDATOR, __FILE__, __LINE__ + 1
          def self.#{card_type}?(number)
            LuhnChecker.valid?(number)
          end
          VALIDATOR
        end
      end
    end

  end
end