module Rack::App::SingletonMethods::Mounting

  def mount(api_class, mount_prop={})
    mount_to_path = ::Rack::App::Utils.deep_dup(mount_prop[:to])

    unless api_class.is_a?(Class) and api_class <= Rack::App
      raise(ArgumentError, 'Invalid class given for mount, must be a Rack::App')
    end

    duplication = ::Rack::App::Utils.deep_dup(api_class)

    duplication.on_mounted.each do |on_mount|
      duplication.class_exec(mount_prop,&on_mount)
    end

    merge_prop = {:namespaces => [@namespaces, mount_to_path].flatten}
    router.merge_router!(duplication.router, merge_prop)

    return nil
  end

  def mount_directory(directory_path, options={})

    directory_full_path = ::Rack::App::Utils.expand_path(directory_path)

    namespace options[:to] do

      Dir.glob(File.join(directory_full_path, '**', '*')).each do |file_path|

        request_path = file_path.sub(/^#{Regexp.escape(directory_full_path)}/, '')
        get(request_path) { serve_file(file_path) }
        options(request_path) { '' }

      end

    end
    nil

  end

  alias create_endpoints_for_files_in mount_directory

  def serve_files_from(file_path, options={})
    file_server = Rack::App::FileServer.new(Rack::App::Utils.expand_path(file_path))
    request_path = Rack::App::Utils.join(@namespaces, options[:to], '**', '*')
    router.register_endpoint!('GET', request_path, @last_description, file_server)
    @last_description = nil
  end

  def mount_rack_based_application(rack_based_app, options={})
    router.register_endpoint!(
        ::Rack::App::Constants::HTTP::ANY,
        Rack::App::Utils.join(@namespaces, options[:to], ::Rack::App::Constants::RACK_BASED_APPLICATION),
        @last_description,
        rack_based_app)

    @last_description = nil
  end

  alias mount_app mount_rack_based_application

  protected

  def on_mounted(&block)
    @on_mounted ||= []
    @on_mounted << block unless block.nil?
    @on_mounted
  end

  alias while_being_mounted on_mounted

end