module Rocx
  module Properties
    class Spacing
      include AttributeBuilder

      VALID_LINE_RULES = %i(atLeast auto exact)

      attribute :after, expects: :positive_integer
      attribute :after_auto, expects: :on_or_off, displays_as: :afterAutospacing
      attribute :after_lines, expects: :integer, displays_as: :afterLines
      attribute :before, expects: :positive_integer
      attribute :before_auto, expects: :on_or_off, displays_as: :beforeAutospacing
      attribute :before_lines, expects: :integer, displays_as: :beforeLines
      attribute :line, expects: :integer
      attribute :line_rule, expects: :valid_line_rule, displays_as: :lineRule

      def name
        "spacing"
      end

      def tag
        :spacing
      end

      def to_xml(xml)
        return if xml_attributes.empty?
        xml["w"].public_send(tag, xml_attributes)
      end

    private

      def valid_line_rule(value)
        valid_in? value, VALID_LINE_RULES
      end

    end
  end
end