module Gds
  module Props
    def self.included(base)
      base.extend ClassMethods
    end

    module ClassMethods
      def props(*args)
        @props ||= []
        @props += args

        args.each do |prop|
          class_eval %{
            def self.#{prop}(value)
              @#{prop} = value
            end
          }
        end

        @props
      end
    end
  end

  class Base
    include Props
    props :schema, :host

    def to_url
      # UGLY
      @schema = self.class.instance_variable_get(:@schema)
      @host   = self.class.instance_variable_get(:@host)

      "#{@schema}://#{@host}"
    end

  end

  class Example < Base
    schema 'http'
    host   'localhost'
  end

  class Other < Base
    schema 'https'
    host   'google.com'
  end
end

e = Gds::Example.new
puts "#{e.to_url}"

e = Gds::Other.new
puts "#{e.to_url}"