class Kramdown::Parser::Kramdown

def parse_link
  result = @src.scan(LINK_START)
  reset_pos = @src.pos
  link_type = (result =~ /^!/ ? :img : :a)
  # no nested links allowed
  if link_type == :a && (@tree.type == :img || @tree.type == :a || @stack.any? {|t,s| t && (t.type == :img || t.type == :a)})
    add_text(result)
    return
  end
  el = Element.new(link_type)
  stop_re = /\]|!?\[/
  count = 1
  found = parse_spans(el, stop_re) do
    case @src.matched
    when "[", "!["
      count += 1
    when "]"
      count -= 1
    end
    count - el.children.select {|c| c.type == :img}.size == 0
  end
  if !found || el.children.empty?
    @src.pos = reset_pos
    add_text(result)
    return
  end
  alt_text = extract_string(reset_pos...@src.pos)
  conv_link_id = alt_text.gsub(/(\s|\n)+/m, ' ').gsub(LINK_ID_NON_CHARS, '').downcase
  @src.scan(stop_re)
  # reference style link or no link url
  if @src.scan(LINK_INLINE_ID_RE) || !@src.check(/\(/)
    link_id = (@src[1] || conv_link_id).downcase
    if @doc.parse_infos[:link_defs].has_key?(link_id)
      add_link(el, @doc.parse_infos[:link_defs][link_id].first, @doc.parse_infos[:link_defs][link_id].last, alt_text)
    else
      warning("No link definition for link ID '#{link_id}' found")
      @src.pos = reset_pos
      add_text(result)
    end
    return
  end
  # link url in parentheses
  if @src.scan(/\(<(.*?)>/)
    link_url = @src[1]
    if @src.scan(/\)/)
      add_link(el, link_url, nil, alt_text)
      return
    end
  else
    link_url = ''
    re = /\(|\)|\s/
    nr_of_brackets = 0
    while temp = @src.scan_until(re)
      link_url += temp
      case @src.matched
      when /\s/
        break
      when '('
        nr_of_brackets += 1
      when ')'
        nr_of_brackets -= 1
        break if nr_of_brackets == 0
      end
    end
    link_url = link_url[1..-2]
    if nr_of_brackets == 0
      add_link(el, link_url, nil, alt_text)
      return
    end
  end
  if @src.scan(LINK_INLINE_TITLE_RE)
    add_link(el, link_url, @src[2], alt_text)
  else
    @src.pos = reset_pos
    add_text(result)
  end
end