gregbell/active_admin

# frozen_string_literal: true
module ActiveAdmin
  class ResourceController < BaseController
    module Decorators

      protected

      def apply_decorator(resource)
        decorate? ? decorator_class.new(resource) : resource
      end

      def apply_collection_decorator(collection)
        if decorate?
          collection_decorator.decorate collection, with: decorator_class
        else
          collection
        end
      end

      def self.undecorate(resource)
        if resource.respond_to?(:decorated?) && resource.decorated?
          resource.model
        else
          resource
        end
      end

      private

      def decorate?
        case action_name
        when "new", "edit", "create", "update"
          form = active_admin_config.get_page_presenter :form
          form && form.options[:decorate] && decorator_class.present?
        else
          decorator_class.present?
        end
      end

      def decorator_class
        active_admin_config.decorator_class
      end

      # When using Draper, we wrap the collection draper in a new class that
      # correctly delegates methods that Active Admin depends on.
      def collection_decorator
        if decorator_class
          Wrapper.wrap decorator_class
        end
      end

      class Wrapper
        @cache = {}

        def self.wrap(decorator)
          collection_decorator = find_collection_decorator(decorator)
          name = "#{collection_decorator.name} of #{decorator} + ActiveAdmin"
          @cache[name] ||= wrap! collection_decorator, name
        end

        def self.wrap!(parent, name)
          ::Class.new parent do
            delegate :reorder, :page, :current_page, :total_pages, :limit_value,
                     :total_count, :total_pages, :offset, :to_key, :group_values,
                     :except, :find_each, :ransack, to: :object

            define_singleton_method(:name) { name }
          end
        end

        def self.find_collection_decorator(decorator)
          if decorator.respond_to?(:collection_decorator_class)
            decorator.collection_decorator_class
          else
            CollectionDecorator
          end
        end
      end
    end
  end
end