module Unicode::DisplayWidth

def self.emoji_extra_width_of(string, ambiguous = 1, overwrite = {}, _ = {})
  require "unicode/emoji"
  extra_width = 0
  modifier_regex = /[#{ Unicode::Emoji::EMOJI_MODIFIERS.pack("U*") }]/
  zwj_regex = /(?<=#{ [Unicode::Emoji::ZWJ].pack("U") })./
  string.scan(Unicode::Emoji::REGEX){ |emoji|
    extra_width += 2 * emoji.scan(modifier_regex).size
    emoji.scan(zwj_regex){ |zwj_succ|
      extra_width += self.of(zwj_succ, ambiguous, overwrite)
    }
  }
  extra_width
end

def self.of(string, ambiguous = 1, overwrite = {}, options = {})
  res = string.codepoints.inject(0){ |total_width, codepoint|
    index_or_value = INDEX
    codepoint_depth_offset = codepoint
    DEPTHS.each{ |depth|
      index_or_value         = index_or_value[codepoint_depth_offset / depth]
      codepoint_depth_offset = codepoint_depth_offset % depth
      break unless index_or_value.is_a? Array
    }
    width = index_or_value.is_a?(Array) ? index_or_value[codepoint_depth_offset] : index_or_value
    width = ambiguous if width == :A
    total_width + (overwrite[codepoint] || width || 1)
  }
  res -= emoji_extra_width_of(string) if options[:emoji]
  res < 0 ? 0 : res
end