class Roda
  module RodaPlugins
    # The delegate plugin allows you to easily setup instance methods in
    # the scope of the route block that call methods on the related
    # request, response, or class which may offer a simpler API in some cases.
    # Roda doesn't automatically setup such delegate methods because
    # it pollutes the application's method namespace, but this plugin
    # allows the user to do so.
    #
    # Here's an example based on the README's initial example, using the
    # request_delegate method to simplify the DSL:
    #
    #   plugin :delegate
    #   request_delegate :root, :on, :is, :get, :post, :redirect
    #
    #   route do |r|
    #     # GET / request
    #     root do
    #       redirect "/hello"
    #     end
    #
    #     # /hello branch
    #     on "hello" do
    #       # GET /hello/world request
    #       get "world" do
    #         "Hello world!"
    #       end
    #
    #       # /hello request
    #       is do
    #         # GET /hello request
    #         get do
    #           "Hello!"
    #         end
    #
    #         # POST /hello request
    #         post do
    #           puts "Someone said hello!"
    #           redirect
    #         end
    #       end
    #     end
    #   end
    module Delegate
      module ClassMethods
        # Delegate the given methods to the class
        def class_delegate(*meths)
          meths.each do |meth|
            define_method(meth){|*a, &block| self.class.send(meth, *a, &block)}
          end
        end

        # Delegate the given methods to the request
        def request_delegate(*meths)
          meths.each do |meth|
            define_method(meth){|*a, &block| @_request.send(meth, *a, &block)}
          end
        end

        # Delegate the given methods to the response
        def response_delegate(*meths)
          meths.each do |meth|
            define_method(meth){|*a, &block| @_response.send(meth, *a, &block)}
          end
        end
      end
    end

    register_plugin(:delegate, Delegate)
  end
end