module CouchPillow

  module RenameDirective

    RESERVED_KEYS = %i[_id _type _created_at _updated_at]

    # Rename keys from one to another
    #
    def rename map
      map.each do |k, v|
        raise ArgumentError, "Cannot rename reserved keys" if
          RESERVED_KEYS.include?(k) || RESERVED_KEYS.include?(v)
      end

      smap = CouchPillow.symbolize(map)

      rename_keys.merge!(smap)
    end


    def rename_keys
      @rename_keys ||= {}
    end

  end
end