module Happy
  module Resources
    module ControllerExtensions
      def resource(klass, options = {}, &blk)
        invoke Happy::Resources::ResourceMounter, options.merge(:class => klass), &blk
      end
    end

    class ResourceMounter < Happy::Controller
      def render_resource_template(name)
        render "#{options[:plural_name]}/#{name}.html.haml"
      end

      def resource
        options[:class]
      end

      def resource_with_permission_scope(*args)
        context.permissions.scoped_model(*args, options[:class])
      end

      def require_permission!(*args)
        raise "not allowed" unless can?(*args, options[:class])
      end

      def set_plural_variable(v)
        context.instance_variable_set "@#{options[:plural_name]}", v
      end

      def plural_variable
        context.instance_variable_get "@#{options[:plural_name]}"
      end

      def set_singular_variable(v)
        context.instance_variable_set "@#{options[:singular_name]}", v
      end

      def singular_variable
        context.instance_variable_get "@#{options[:singular_name]}"
      end

      def do_index
        require_permission! :index
        set_plural_variable resource_with_permission_scope(:index).all
        render_resource_template 'index'
      end

      def do_show
        require_permission! :show
        set_singular_variable resource_with_permission_scope(:show).find(params['id'])
        render_resource_template 'show'
      end

      def do_new
        require_permission! :new
        set_singular_variable resource_with_permission_scope(:new).new(params[options[:singular_name]], :as => options[:role])
        render_resource_template 'new'
      end

      def do_create
        require_permission! :create
        set_singular_variable resource_with_permission_scope(:create).new(params[options[:singular_name]], :as => options[:role])

        if singular_variable.save
          redirect! singular_variable
        else
          render_resource_template 'new'
        end
      end

      def do_edit
        require_permission! :edit
        set_singular_variable resource_with_permission_scope(:edit).find(params['id'])
        render_resource_template 'edit'
      end

      def do_update
        require_permission! :update
        set_singular_variable resource_with_permission_scope(:update).find(params['id'])
        singular_variable.assign_attributes params[options[:singular_name]], :as => options[:role]

        if singular_variable.save
          redirect! singular_variable
        else
          render_resource_template 'edit'
        end
      end

      def route
        @options = {
          singular_name: options[:class].to_s.tableize.singularize,
          plural_name:   options[:class].to_s.tableize.pluralize
        }.merge(@options)

        path options[:plural_name] do
          get('new') { do_new }

          path :id do
            get         { do_show }
            post        { do_update }
            get('edit') { do_edit }
          end

          post { do_create }
          get  { do_index }
        end
      end
    end
  end
end

Happy::Controller.send(:include, Happy::Resources::ControllerExtensions)