module RestfulScaffold
  def self.included(controller)
    controller.extend ClassMethods
  end

  module ClassMethods
    def gen_rest_methods(table_name, *args)
      model = table_name.to_s.classify.constantize
      singular = table_name.to_s.singularize
      plural = table_name.to_s

      define_method :standard_respond_to do |instance_variable|
        respond_to do |format|
          format.html
          format.xml { render :xml => self.instance_variable_get("@#{instance_variable}") }
        end
      end

      define_method :index do
        self.instance_variable_set("@#{plural}", model.find(:all))
        standard_respond_to(plural)
      end

      define_method :show do
        self.instance_variable_set("@#{singular}", model.find(params[:id]))
        standard_respond_to(singular)
      end

      define_method :new do
        self.instance_variable_set("@#{singular}", model.new)
        standard_respond_to(singular)
      end

      define_method :edit do
        self.instance_variable_set("@#{singular}", model.find(params[:id]))
      end

      define_method :create do
        self.instance_variable_set("@#{singular}", model.new(params["#{singular}"]))
        respond_to do |format|
          if self.instance_variable_get("@#{singular}").save
            flash[:notice] = "#{model} was successfully created."
            format.html { redirect_to(self.instance_variable_get("@#{singular}")) }
            format.xml  { render :xml => self.instance_variable_get("@#{singular}"),
                                 :status => :created,
                                 :location => self.instance_variable_get("@#{singular}") }
          else
            format.html { render :action => "new" }
            format.xml  { render :xml => self.instance_variable_get("@#{singular}").errors, :status => :unprocessable_entity }
          end
        end
      end

      define_method :update do
        self.instance_variable_set("@#{singular}", model.find(params[:id]))
        respond_to do |format|
          if self.instance_variable_get("@#{singular}").update_attributes(params["#{singular}"])
            flash[:notice] = "#{model.humanize} was successfully updated."
            format.html { redirect_to(self.instance_variable_get("@#{singular}")) }
            format.xml  { head :ok }
          else
            format.html { render :action => "edit" }
            format.xml  { render :xml => self.instance_variable_get("@#{singular}").errors, :status => :unprocessable_entity }
          end
        end
      end

      define_method :destroy do
        self.instance_variable_set("@#{singular}", model.find(params[:id]))
        self.instance_variable_get("@#{singular}").destroy

        respond_to do |format|
          format.html { redirect_to(eval("#{plural}_url")) }
          format.xml  { head :ok }
        end
      end

    end
  end
end