class Reline::Unicode

def self.vi_forward_end_word(line, byte_pointer)
  if (line.bytesize - 1) > byte_pointer
    size = get_next_mbchar_size(line, byte_pointer)
    mbchar = line.byteslice(byte_pointer, size)
    if mbchar =~ /\w/
      started_by = :word
    elsif mbchar =~ /\s/
      started_by = :space
    else
      started_by = :non_word_printable
    end
    width = get_mbchar_width(mbchar)
    byte_size = size
  else
    return [0, 0]
  end
  if (line.bytesize - 1) > (byte_pointer + byte_size)
    size = get_next_mbchar_size(line, byte_pointer + byte_size)
    mbchar = line.byteslice(byte_pointer + byte_size, size)
    if mbchar =~ /\w/
      second = :word
    elsif mbchar =~ /\s/
      second = :space
    else
      second = :non_word_printable
    end
    second_width = get_mbchar_width(mbchar)
    second_byte_size = size
  else
    return [byte_size, width]
  end
  if second == :space
    width += second_width
    byte_size += second_byte_size
    while (line.bytesize - 1) > (byte_pointer + byte_size)
      size = get_next_mbchar_size(line, byte_pointer + byte_size)
      mbchar = line.byteslice(byte_pointer + byte_size, size)
      if mbchar =~ /\S/
        if mbchar =~ /\w/
          started_by = :word
        else
          started_by = :non_word_printable
        end
        break
      end
      width += get_mbchar_width(mbchar)
      byte_size += size
    end
  else
    case [started_by, second]
    when [:word, :non_word_printable], [:non_word_printable, :word]
      started_by = second
    else
      width += second_width
      byte_size += second_byte_size
      started_by = second
    end
  end
  prev_width = width
  prev_byte_size = byte_size
  while line.bytesize > (byte_pointer + byte_size)
    size = get_next_mbchar_size(line, byte_pointer + byte_size)
    mbchar = line.byteslice(byte_pointer + byte_size, size)
    case started_by
    when :word
      break if mbchar =~ /\W/
    when :non_word_printable
      break if mbchar =~ /[\w\s]/
    end
    prev_width = width
    prev_byte_size = byte_size
    width += get_mbchar_width(mbchar)
    byte_size += size
  end
  [prev_byte_size, prev_width]
end