routing.rb

class Routing
  include Rails.application.routes.url_helpers
  attr_reader :uri, :host, :port

  def initialize(args={})
    if args[:url]
      parsed = URI.parse(args[:url])
      configure({
        host: parsed.host,
        port: parsed.port,
        ssl: !!(parsed.scheme =~ /https/)
      })
    else
      configure(args)
    end
  end

  def ssl?
    !!@ssl
  end

  def configure(args={})
    @ssl  = args.fetch(:ssl, true)
    @port = args.fetch(:port, nil)
    @host = args.fetch(:host, nil)

    if @ssl
      @uri = URI::HTTPS.build({
        host: @host,
        port: @port
      })
    else
      @uri = URI::HTTP.build({
        host: @host,
        port: @port
      })
    end
  end

  def default_url_options
    {
      protocol: @ssl ? 'https' : 'http',
      host: @host,
      port: @port
    }
  end

  def host_with_port
    if @port
      '%s:%s' % [@host, @port]
    else
      @host
    end
  end

  def url_for_path(path)
    opts = default_url_options
    base = "#{opts[:protocol]}://#{host_with_port}"

    URI.join(base, path).to_s
  end
end