/*
 * The Apache Software License, Version 1.1
 *
 *
 * Copyright (c) 1999 The Apache Software Foundation.  All rights 
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer. 
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:  
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Xalan" and "Apache Software Foundation" must
 *    not be used to endorse or promote products derived from this
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 *
 * 5. Products derived from this software may not be called "Apache",
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 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
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 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation and was
 * originally based on software copyright (c) 1999, Lotus
 * Development Corporation., http://www.lotus.com.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */
package org.apache.xpath.patterns;

import org.apache.xpath.Expression;
import org.apache.xpath.objects.XObject;
import org.apache.xpath.XPathContext;
import org.apache.xml.utils.PrefixResolver;
import org.apache.xpath.axes.LocPathIterator;

import org.w3c.dom.Node;
import org.w3c.dom.traversal.NodeIterator;

/**
 * <meta name="usage" content="advanced"/>
 * Implements a match pattern step that tests an ancestor.
 */
public class AncestorStepPattern extends StepPattern
{

  /**
   * Construct an AncestorStepPattern that tests for namespaces and node names.
   *
   *
   * @param whatToShow Bit set defined mainly by {@link org.w3c.dom.traversal.NodeFilter}.
   * @param namespace The namespace to be tested.
   * @param name The local name to be tested.
   */
  public AncestorStepPattern(int whatToShow, String namespace, String name)
  {
    super(whatToShow, namespace, name);
  }

  /**
   * Construct an AncestorStepPattern that doesn't test for node names.
   *
   *
   * @param whatToShow Bit set defined mainly by {@link org.w3c.dom.traversal.NodeFilter}.
   */
  public AncestorStepPattern(int whatToShow)
  {
    super(whatToShow);
  }

  /**
   * Static calc of match score.
   */
  protected final void calcScore()
  {

    m_score = SCORE_OTHER;

    if (null == m_targetString)
      calcTargetString();
  }

  /**
   * Overide the super method so that we can handle
   * match patterns starting with a function such as id()/
   *
   * @param xctxt XPath runtime context.
   *
   * @return {@link org.apache.xpath.patterns.NodeTest#SCORE_NODETEST}, 
   *         {@link org.apache.xpath.patterns.NodeTest#SCORE_NONE}, 
   *         {@link org.apache.xpath.patterns.NodeTest#SCORE_NSWILD}, 
   *         {@link org.apache.xpath.patterns.NodeTest#SCORE_QNAME}, or
   *         {@link org.apache.xpath.patterns.NodeTest#SCORE_OTHER}.
   *
   * @throws javax.xml.transform.TransformerException
   */
  public XObject execute(XPathContext xctxt) throws javax.xml.transform.TransformerException
  {

    int whatToShow = getWhatToShow();

    if (whatToShow == NodeTest.SHOW_BYFUNCTION)
    {
      XObject score = NodeTest.SCORE_NONE;

      if (null != m_relativePathPattern)
      {
        score = m_relativePathPattern.execute(xctxt);
      }

      return score;
    }
    else
      return super.execute(xctxt);
  }

  /**
   * Execute the match pattern step relative to another step.
   *
   *
   * @param xctxt The XPath runtime context.
   *
   * @return {@link org.apache.xpath.patterns.NodeTest#SCORE_NODETEST}, 
   *         {@link org.apache.xpath.patterns.NodeTest#SCORE_NONE}, 
   *         {@link org.apache.xpath.patterns.NodeTest#SCORE_NSWILD}, 
   *         {@link org.apache.xpath.patterns.NodeTest#SCORE_QNAME}, or
   *         {@link org.apache.xpath.patterns.NodeTest#SCORE_OTHER}.
   *
   * @throws javax.xml.transform.TransformerException
   */
  public XObject executeRelativePathPattern(XPathContext xctxt)
          throws javax.xml.transform.TransformerException
  {

    XObject score = NodeTest.SCORE_NONE;
    Node parent = xctxt.getCurrentNode();

    while (null != (parent = xctxt.getDOMHelper().getParentOfNode(parent)))
    {
      try
      {
        xctxt.pushCurrentNode(parent);

        score = execute(xctxt);

        if (score != NodeTest.SCORE_NONE)
        {
          score = SCORE_OTHER;

          break;
        }
      }
      finally
      {
        xctxt.popCurrentNode();
      }
    }

    return score;
  }
}