ama-team / ruby-entity-mapper

require_relative 'errors'

module AMA

  module Entity

    class Mapper

      module Mixin

        # Collection of common methods twiddling with object internals

        module Reflection

          include Errors

          rescue StandardError => e

            message = "Failed to set attribute #{name} on #{object.class}, " \

              "this is most likely due to `#{method}` method not following " \

              'accessor conventions'

            mapping_error(message, parent: e)

          end

          # @param [Object] object

          def object_variables(object)

            intermediate = object.instance_variables.map do |variable|

              [variable[1..-1].to_sym, object.instance_variable_get(variable)]

            end

            Hash[intermediate]

          end

          # @param [Object] object

          # @param [String, Symbol] name

          def object_variable(object, name)

            name = "@#{name}" unless name[0] == '@'

            object.instance_variable_get(name)

          end

          def object_variable_exists(object, name)

            object.instance_variables.include?("@#{name}".to_sym)

          end

          def install_object_method(object, name, handler)

            compliance_error('Handler not provided') unless handler

            object.define_singleton_method(name, &handler)

            object

          end

          def method_object(method, to_s: nil, &handler)

            object = install_object_method(Object.new, method, handler)

            unless to_s

              to_s = "Wrapper object for proc #{handler} " \

                "(installed as method :#{method})"

            end

            object.define_singleton_method(:to_s) do

              to_s

            end

            object

          end

        end

      end

    end

  end

end