class RestModel
  class Relation
    module Builder
      def relation(name, options = {})
        key Relation.new(name, options)
      end

      def has_one(name, options = {})
        options.merge!(many: false, has: true)
        relation(name, options)
      end

      def has_many(name, options = {})
        options.merge!(many: true, has: true)
        relation(name, options)
      end

      def belongs_to(name, options = {})
        options.merge!(many: false, has: false)
        relation(name, options)
        attr_accessor "#{name}_id"
      end
    end
  end
end