ama-team / ruby-entity-mapper

require_relative '../../../../lib/mapper/mixin/reflection'

require_relative '../../../../lib/mapper/mixin/errors'

module AMA

  module Entity

    class Mapper

      class Engine

        class Denormalizer

          # Standard-interface entity denormalizer

          class Entity

            include ::AMA::Entity::Mapper::Mixin::Reflection

            include ::AMA::Entity::Mapper::Mixin::Errors

            def initialize(registry)

              @registry = registry

            end

            # @param [AMA::Entity::Mapper::Type::Concrete] type

            # @param [Object] value

            # @param [AMA::Entity::Mapper::Engine::Context] context

            # @param [AMA::Entity::Mapper::Type::Concrete] target_type

            def denormalize(value, context, target_type)

              return value if value.is_a?(target_type.type)

              denormalizer = target_type.denormalizer

              unless denormalizer

                return denormalize_entity(value, context, target_type)

              end

              denormalizer.call(value, context, target_type) do |processed|

                denormalize_entity(processed, context, target_type)

              end

            end

            private

            def denormalize_entity(structure, context, target_type)

              unless structure.is_a?(Hash)

                message = "Can't denormalize #{target_type} from " \

                  "anything but hash (#{structure.class} supplied)"

                mapping_error(message, context: context)

              end

              entity = target_type.factory.create(context, structure)

              attributes = target_type.attributes.values

              attributes = filter_attributes(attributes, structure)

              extracted_attributes = extract_attributes(structure, attributes)

              # TODO: use acceptor

              set_object_attributes(entity, extracted_attributes)

            end

            def filter_attributes(attributes, structure)

              attributes.reject do |attribute|

                next true if attribute.virtual

                name = attribute.name

                !structure.key?(name) && !structure.key?(name.to_s)

              end

            end

            def extract_attributes(structure, attributes)

              # TODO: add attribute denormalizer support

              intermediate = attributes.map do |attribute|

                name = attribute.name

                value = structure.fetch(name, nil)

                value ||= structure.fetch(name.to_s, nil)

                [name, value]

              end

              Hash[intermediate]

            end

          end

        end

      end

    end

  end

end