# frozen_string_literal: true

module Notare
  module WidthParser
    TWIPS_PER_INCH = 1440
    TWIPS_PER_CM = 567
    PCT_MULTIPLIER = 50

    ParsedWidth = Struct.new(:value, :type, keyword_init: true)

    def self.parse(value)
      case value
      when :auto, nil
        ParsedWidth.new(value: 0, type: "auto")
      when Integer
        ParsedWidth.new(value: value, type: "dxa")
      when /\A(\d+(?:\.\d+)?)\s*in\z/i
        twips = (::Regexp.last_match(1).to_f * TWIPS_PER_INCH).to_i
        ParsedWidth.new(value: twips, type: "dxa")
      when /\A(\d+(?:\.\d+)?)\s*cm\z/i
        twips = (::Regexp.last_match(1).to_f * TWIPS_PER_CM).to_i
        ParsedWidth.new(value: twips, type: "dxa")
      when /\A(\d+(?:\.\d+)?)\s*%\z/
        pct = (::Regexp.last_match(1).to_f * PCT_MULTIPLIER).to_i
        ParsedWidth.new(value: pct, type: "pct")
      else
        raise ArgumentError, "Invalid width: #{value}. Use '2in', '5cm', '50%', :auto, or integer twips."
      end
    end
  end
end