/*
 * Copyright (C) 2003-2011 eXo Platform SAS.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */
package org.etk.kernel.container.configuration;

import java.util.HashSet;
import java.util.Set;

import org.xml.sax.Attributes;
import org.xml.sax.ContentHandler;
import org.xml.sax.Locator;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.AttributesImpl;
import org.xml.sax.helpers.DefaultHandler;

/**
 * Removes kernel namespace declaration from the document to not confuse the
 * jibx thing. It also filters the active profiles from the XML stream.
 * 
 */
class NoKernelNamespaceSAXFilter extends DefaultHandler {
  /** . */
  private static final String XSI_URI = "http://www.w3.org/2001/XMLSchema-instance";

  /** . */
  private ContentHandler      contentHandler;

  /** . */
  private final Set<String>   blackListedPrefixes;

  NoKernelNamespaceSAXFilter(ContentHandler contentHandler) {
    this.contentHandler = contentHandler;
    this.blackListedPrefixes = new HashSet<String>();
  }

  public void setDocumentLocator(Locator locator) {
    contentHandler.setDocumentLocator(locator);
  }

  public void startDocument() throws SAXException {
    contentHandler.startDocument();
  }

  public void endDocument() throws SAXException {
    contentHandler.endDocument();
  }

  public void startPrefixMapping(String prefix, String uri) throws SAXException {
    if (Namespaces.isKernelNamespace(uri) || XSI_URI.equals(uri)) {
      blackListedPrefixes.add(prefix);
    } else {
      contentHandler.startPrefixMapping(prefix, uri);
      
    }
  }

  public void endPrefixMapping(String prefix) throws SAXException {
    if (!blackListedPrefixes.remove(prefix)) {
     
      contentHandler.endPrefixMapping(prefix);
    } else {
     
    }
  }

  public void startElement(String uri, String localName, String qName, Attributes atts) throws SAXException {
    AttributesImpl noNSAtts = new AttributesImpl();
    for (int i = 0; i < atts.getLength(); i++) {
      String attQName = atts.getQName(i);
      if ((attQName.equals("xmlns")) && blackListedPrefixes.contains("")) {
        
      } else if (attQName.startsWith("xmlns:")
          && blackListedPrefixes.contains(attQName.substring(6))) {
        
      } else {
        String attURI = atts.getURI(i);
        String attLocalName = atts.getLocalName(i);
        String attType = atts.getType(i);
        String attValue = atts.getValue(i);

        //
        if (XSI_URI.equals(attURI)) {
          continue;
        } else if (Namespaces.isKernelNamespace(attURI)) {
          attURI = null;
          attQName = localName;
        }

        //
        noNSAtts.addAttribute(attURI, attLocalName, attQName, attType, attValue);
      }
    }

    //
    if (Namespaces.isKernelNamespace(uri)) {
      qName = localName;
      uri = null;
    }

    //
    contentHandler.startElement(uri, localName, qName, noNSAtts);
  }

  public void endElement(String uri, String localName, String qName) throws SAXException {
    if (Namespaces.isKernelNamespace(uri)) {
      qName = localName;
      uri = null;
    }
    contentHandler.endElement(uri, localName, qName);
  }

  public void characters(char[] ch, int start, int length) throws SAXException {
    contentHandler.characters(ch, start, length);
  }

  public void ignorableWhitespace(char[] ch, int start, int length) throws SAXException {
    contentHandler.ignorableWhitespace(ch, start, length);
  }

  public void processingInstruction(String target, String data) throws SAXException {
    contentHandler.processingInstruction(target, data);
  }

  public void skippedEntity(String name) throws SAXException {
    contentHandler.skippedEntity(name);
  }
}