/*
 * LiteralNode.java
 * Copyright (C) 2004 The Free Software Foundation
 * 
 * This file is part of GNU JAXP, a library.
 *
 * GNU JAXP is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 * 
 * GNU JAXP 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 General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * Linking this library statically or dynamically with other modules is
 * making a combined work based on this library.  Thus, the terms and
 * conditions of the GNU General Public License cover the whole
 * combination.
 *
 * As a special exception, the copyright holders of this library give you
 * permission to link this library with independent modules to produce an
 * executable, regardless of the license terms of these independent
 * modules, and to copy and distribute the resulting executable under
 * terms of your choice, provided that you also meet, for each linked
 * independent module, the terms and conditions of the license of that
 * module.  An independent module is a module which is not derived from
 * or based on this library.  If you modify this library, you may extend
 * this exception to your version of the library, but you are not
 * obliged to do so.  If you do not wish to do so, delete this
 * exception statement from your version. 
 */

package gnu.xml.transform;

import java.util.Collection;
import java.util.Collections;
import java.util.HashSet;
import java.util.StringTokenizer;
import javax.xml.namespace.QName;
import javax.xml.transform.TransformerException;
import org.w3c.dom.Document;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;

/**
 * A template node that copies a DOM node in the template to the result
 * tree.
 *
 * @author <a href='mailto:dog@gnu.org'>Chris Burdess</a>
 */
final class LiteralNode
  extends TemplateNode
{

  /**
   * The source node in the XSL template.
   */
  final Node source;

  final Collection elementExcludeResultPrefixes;

  LiteralNode(TemplateNode children, TemplateNode next, Node source)
  {
    super(children, next);
    this.source = source;
    if (source.getNodeType() == Node.ELEMENT_NODE)
      {
        NamedNodeMap attrs = source.getAttributes();
        Node attr = attrs.getNamedItemNS(Stylesheet.XSL_NS,
                                         "exclude-result-prefixes");
        if (attr != null)
          {
            elementExcludeResultPrefixes = new HashSet();
            StringTokenizer st = new StringTokenizer(attr.getNodeValue());
            while (st.hasMoreTokens())
              {
                elementExcludeResultPrefixes.add(st.nextToken());
              }
          }
        else
          {
            elementExcludeResultPrefixes = Collections.EMPTY_SET;
          }
      }
    else
      {
        elementExcludeResultPrefixes = null;
      }
  }

  TemplateNode clone(Stylesheet stylesheet)
  {
    return new LiteralNode((children == null) ? null :
                           children.clone(stylesheet),
                           (next == null) ? null :
                           next.clone(stylesheet),
                           source);
  }

  void doApply(Stylesheet stylesheet, QName mode,
             Node context, int pos, int len,
             Node parent, Node nextSibling)
    throws TransformerException
  {
    Node result = null;
    Document doc = (parent instanceof Document) ? (Document) parent :
      parent.getOwnerDocument();
    short nodeType = source.getNodeType();
    if (nodeType == Node.ATTRIBUTE_NODE &&
        parent.getFirstChild() != null)
      {
        // Ignore attributes added after child elements
      }
    else
      {
        // Namespace aliasing
        if (nodeType == Node.ELEMENT_NODE)
          {
            String prefix = source.getPrefix();
            if (prefix == null)
              {
                prefix = "#default";
              }
            String resultPrefix =
              (String) stylesheet.namespaceAliases.get(prefix);
            if (resultPrefix != null)
              {
                if ("#default".equals(resultPrefix))
                  {
                    resultPrefix = null;
                  }
                String uri = source.lookupNamespaceURI(resultPrefix);
                String name = source.getNodeName();
                // Create a new element node in the result document
                result = doc.createElementNS(uri, name);
                // copy attributes
                NamedNodeMap srcAttrs = source.getAttributes();
                NamedNodeMap dstAttrs = result.getAttributes();
                int l = srcAttrs.getLength();
                for (int i = 0; i < l; i++)
                  {
                    Node attr = srcAttrs.item(i);
                    if (!Stylesheet.XSL_NS.equals(attr.getNamespaceURI()))
                      {
                        attr = attr.cloneNode(true);
                        attr = doc.adoptNode(attr);
                        dstAttrs.setNamedItemNS(attr);
                      }
                  }
              }
          }
        if (result == null)
          {
            // Create result node
            result = source.cloneNode(false);
            // Remove any XSL attributes
            NamedNodeMap attrs = result.getAttributes();
            if (attrs != null)
              {
                int l = attrs.getLength();
                for (int i = 0; i < l; i++)
                  {
                    Node attr = attrs.item(i);
                    if (Stylesheet.XSL_NS.equals(attr.getNamespaceURI()))
                      {
                        attrs.removeNamedItem(attr.getNodeName());
                        i--;
                        l--;
                      }
                  }
              }
            result = doc.adoptNode(result);
            if (result == null)
              {
                String msg = "Error adopting node to result tree";
                DOMSourceLocator l = new DOMSourceLocator(context);
                throw new TransformerException(msg, l);
              }
          }
        if (nextSibling != null)
          {
            parent.insertBefore(result, nextSibling);
          }
        else
          {
            parent.appendChild(result);
          }
        if (nodeType == Node.ELEMENT_NODE)
          {
            stylesheet.addNamespaceNodes(source, result, doc,
                                         elementExcludeResultPrefixes);
          }
        // children
        if (children != null)
          {
            children.apply(stylesheet, mode,
                           context, pos, len,
                           result, null);
          }
      }
    // next sibling
    if (next != null)
      {
        next.apply(stylesheet, mode,
                   context, pos, len,
                   parent, nextSibling);
      }
  }

  public String toString()
  {
    StringBuffer buf = new StringBuffer(getClass().getName());
    buf.append('[');
    buf.append("source=");
    buf.append(source);
    buf.append(']');
    return buf.toString();
  }
  
}
