Workaround for Asciidoctor #858 (fix the HTML Ouptu)

WorkaroundAsciidoctor858.java

  //Workaround using JSoup to obtain the desired behavior described in #858 for the HTML output.
  //see https://github.com/asciidoctor/asciidoctor/issues/858

  static private Pattern pattern = Pattern.compile("Figure ([0-9]+)\\.");

  /**
   * Main method for the #858 workaround.
   *
   * @param doc
   *          JSoup document (type is {@link org.jsoup.nodes.Document})
   */
  public static void fixFigureLink(Document doc) {
    Elements elements = doc.getElementsByTag("a");
    for (Element link : elements) {
      String href = link.attr("href");
      if (href != null && href.startsWith("#")) {
        String id = href.substring(1);
        Element idElement = doc.getElementById(id);
        boolean fixedText = false;
        if (idElement != null && "imageblock".equals(idElement.attr("class"))) {
          fixedText = fixLink(link, idElement);
        }
        //Support for the multiple Images in one figure workaround (see Issue 1287)
        if (!fixedText && idElement != null) {
          Element container = idElement.parent();
          boolean checkNext = false;
          for (int i = 0; i < container.childNodeSize(); i++) {
            Node childNode = container.childNode(i);
            if (id.equals(childNode.attr("id")) && "imageblock".equals(childNode.attr("class"))) {
              checkNext = true;
            }
            if (!fixedText && checkNext) {
              if ("imageblock".equals(childNode.attr("class")) && childNode instanceof Element) {
                fixedText = fixLink(link, (Element) childNode);
              }
              else if (!(childNode instanceof Element)) {
                //do nothing.
              }
              else {
                //found an other element that does not correspond.
                checkNext = false;
              }
            }
          }
        }
      }
    }
  }

  private static boolean fixLink(Element link, Element element) {
    Element titleDiv = findTitleDiv(element);
    if (titleDiv != null) {
      Matcher matcher = pattern.matcher(titleDiv.text());
      if (matcher.find()) {
        link.text("Figure " + matcher.group(1));
        return true;
      }
    }
    return false;
  }

  private static Element findTitleDiv(Element element) {
    Elements elements = element.getElementsByTag("div");
    for (Element e : elements) {
      if ("imageblock".equals(e.attr("class"))) {
        return e;
      }
    }
    return null;
  }