dvmonroe/sanity-ruby

# frozen_string_literal: true

module Sanity
  # Attributable is responsible for setting the appropriate attributes
  # on an object in memory
  #
  # The attribute marco is used to define the available attributes and
  # the default return value if applicable
  #
  # @example provides getter and setter methods for `_id` and sets the default value to an empty string
  #   attribute :_id, default: ""
  #
  module Attributable
    class << self
      def included(base)
        base.extend(ClassMethods)
      end
    end

    module ClassMethods
      def attributes
        @attributes ||= []
      end

      def default_attributes
        @defaults ||= {}
      end

      private

      def attribute(name, default: nil)
        attributes << name
        default_attributes.merge!("#{name}": default)
      end
    end

    attr_reader :attributes

    def initialize(**args)
      self.class.default_attributes.merge(args).then do |attrs|
        attrs.each do |key, val|
          define_singleton_method(:"#{key}=") do |val|
            args[key] = val
            attributes[key] = val
          end

          define_singleton_method(key) { args[key] }
        end

        instance_variable_set(:@attributes, attrs)
      end
    end

    def inspect
      attributes.keys.map { |key| "#{key}: #{attributes[key].inspect}" }.join(", ").then do |attrs|
        attrs.empty? ? "#<#{_instance}>" : "#<#{_instance} #{attrs}>"
      end
    end

    private

    def _instance
      "#{self.class}:0x#{object_id}"
    end
  end
end