/**
    * This file Copyright (c) 2003-2015 Magnolia International
    * Ltd.  (http://www.magnolia-cms.com). All rights reserved.
    *
    *
    * This file is dual-licensed under both the Magnolia
    * Network Agreement and the GNU General Public License.
    * You may elect to use one or the other of these licenses.
    *
   * This file is distributed in the hope that it will be
   * useful, but AS-IS and WITHOUT ANY WARRANTY; without even the
   * implied warranty of MERCHANTABILITY or FITNESS FOR A
   * PARTICULAR PURPOSE, TITLE, or NONINFRINGEMENT.
   * Redistribution, except as permitted by whichever of the GPL
   * or MNA you select, is prohibited.
   *
   * 1. For the GPL license (GPL), you can redistribute and/or
   * modify this file under the terms of the GNU General
   * Public License, Version 3, as published by the Free Software
   * Foundation.  You should have received a copy of the GNU
   * General Public License, Version 3 along with this program;
   * if not, write to the Free Software Foundation, Inc., 51
   * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * 2. For the Magnolia Network Agreement (MNA), this file
   * and the accompanying materials are made available under the
   * terms of the MNA which accompanies this distribution, and
   * is available at http://www.magnolia-cms.com/mna.html
   *
   * Any modifications to this file must keep this entire header
   * intact.
   *
   */
  package info.magnolia.importexport.filters;
  
  import org.xml.sax.Attributes;
  import org.xml.sax.SAXException;
  import org.xml.sax.XMLReader;
  import org.xml.sax.helpers.AttributesImpl;
  import org.xml.sax.helpers.XMLFilterImpl;
  
  /**
   * SAX filter, strips version information from a JCR XML (system view).
   */
  public class MagnoliaV2Filter extends XMLFilterImpl {
  
      /**
       * if != 0 we are in the middle of a filtered element.
       */
      private int inMetadataElement;
  
      private boolean skipNode;
  
      private boolean skipProperty;
  
      private boolean skipWs;
  
      /**
       * Instantiates a new version filter.
       *
       * @param parent wrapped XMLReader
       */
      public MagnoliaV2Filter(XMLReader parent) {
          super(parent);
      }
  
      /**
       * @see org.xml.sax.helpers.XMLFilterImpl#endElement(String, String, String)
       */
      @Override
      public void endElement(String uri, String localName, String qName) throws SAXException {
  
          if (inMetadataElement > 0) {
              inMetadataElement--;
          }
  
          if (skipNode && "sv:node".equals(qName)) {
              skipNode = false;
              skipWs = true; // skip additional whitespace after skipped tag
              return;
          }
  
          if (skipProperty) {
              if ("sv:property".equals(qName)) {
                  skipProperty = false;
                  skipWs = true; // skip additional whitespace after skipped tag
              }
              return;
          }
  
          super.endElement(uri, localName, qName);
      }
  
      /**
       * @see org.xml.sax.helpers.XMLFilterImpl#characters(char[], int, int)
       */
      @Override
      public void characters(char[] ch, int start, int length) throws SAXException {
          // do not emit text inside of skipped elements
         if (!(skipNode || skipProperty)) {
             while (skipWs && length > 0
                     && Character.isWhitespace(ch[start])) {
                 start++;
                 length--;
             }
             if (length > 0) {
                 super.characters(ch, start, length);
             }
         }
         skipWs = false;
     }
 
     /**
      * @see org.xml.sax.helpers.XMLFilterImpl#startElement(String, String, String, Attributes)
      */
     @Override
     public void startElement(String uri, String localName, String qName, Attributes atts) throws SAXException {
 
         if (inMetadataElement > 0) {
             inMetadataElement++;
         }
 
         String svname = atts.getValue("sv:name");
 
         if ("sv:node".equals(qName) && "MetaData".equals(svname)) {
             inMetadataElement++;
         }
 
         if (inMetadataElement > 0) {
             // MAGNOILA-2653 skip nested elements (sv:value)
             if (skipProperty) {
                 return;
             }
             // remove
             // <sv:node sv:name="jcr:content">
             if ("sv:node".equals(qName) && "jcr:content".equals(svname)) {
                 skipNode = true;
                 return;
             }
             if ("sv:property".equals(qName)
                     && ("sequenceposition".equals(svname) || "jcr:primaryType".equals(svname) || "jcr:isCheckedOut"
                     .equals(svname))) {
                 skipProperty = true;
                 return;
             }
             if ("sv:property".equals(qName)
                     && ("Data".equals(svname) || "template".equals(svname) || "authorid".equals(svname) || "title"
                     .equals(svname))) {
                 atts = new AttributesImpl();
                 ((AttributesImpl) atts).addAttribute(uri, "name", "sv:name", uri, "mgnl:" + svname);
                 ((AttributesImpl) atts).addAttribute(uri, "type", "sv:type", uri, "String");
             } else if ("sv:property".equals(qName) && ("creationdate".equals(svname) || "lastmodified".equals(svname))) {
                 atts = new AttributesImpl();
                 ((AttributesImpl) atts).addAttribute(uri, "name", "sv:name", uri, "mgnl:" + svname);
                 ((AttributesImpl) atts).addAttribute(uri, "type", "sv:type", uri, "Date");
             }
 
         }
 
         super.startElement(uri, localName, qName, atts);
 
         if ("sv:node".equals(qName) && "MetaData".equals(svname)) {
 
             // add:
             // <sv:property sv:name="jcr:primaryType" sv:type="Name">
             // <sv:value>nt:unstructured</sv:value>
             // </sv:property>
 
             String atturi = atts.getURI(0);
             AttributesImpl atts2 = new AttributesImpl();
             atts2.addAttribute(uri, "name", "sv:name", atturi, "jcr:primaryType");
             atts2.addAttribute(uri, "type", "sv:type", atturi, "Name");
 
             super.startElement(uri, "property", "sv:property", atts2);
             super.startElement(uri, "value", "sv:value", new AttributesImpl());
             super.characters(new char[]{'m', 'g', 'n', 'l', ':', 'm', 'e', 't', 'a', 'D', 'a', 't', 'a'}, 0, 13);
             super.endElement(uri, "value", "sv:value");
             super.endElement(uri, "property", "sv:property");
         }
     }
 }