/*

 * reserved comment block

 * DO NOT REMOVE OR ALTER!

 */

/**

 * Licensed to the Apache Software Foundation (ASF) under one

 * or more contributor license agreements. See the NOTICE file

 * distributed with this work for additional information

 * regarding copyright ownership. The ASF licenses this file

 * to you under the Apache License, Version 2.0 (the

 * "License"); you may not use this file except in compliance

 * with the License. You may obtain a copy of the License at

 *

 * http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing,

 * software distributed under the License is distributed on an

 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY

 * KIND, either express or implied. See the License for the

 * specific language governing permissions and limitations

 * under the License.

 */

package com.sun.org.apache.xml.internal.security.transforms.implementations;

import javax.xml.transform.TransformerException;

import com.sun.org.apache.xml.internal.dtm.DTM;

import com.sun.org.apache.xml.internal.security.utils.I18n;

import com.sun.org.apache.xml.internal.security.utils.XMLUtils;

import com.sun.org.apache.xml.internal.utils.QName;

import com.sun.org.apache.xpath.internal.NodeSetDTM;

import com.sun.org.apache.xpath.internal.XPathContext;

import com.sun.org.apache.xpath.internal.functions.Function;

import com.sun.org.apache.xpath.internal.objects.XNodeSet;

import com.sun.org.apache.xpath.internal.objects.XObject;

import com.sun.org.apache.xpath.internal.res.XPATHErrorResources;

import org.w3c.dom.Document;

import org.w3c.dom.Node;

import java.util.List;

/**

 * The 'here()' function returns a node-set containing the attribute or

 * processing instruction node or the parent element of the text node

 * that directly bears the XPath expression.  This expression results

 * in an error if the containing XPath expression does not appear in the

 * same XML document against which the XPath expression is being evaluated.

 *

 * Mainpart is stolen from FuncId.java

 *

 * This does crash under Xalan2.2.D7 and works under Xalan2.2.D9

 *

 * To get this baby to work, a special trick has to be used. The function needs

 * access to the Node where the XPath expression has been defined. This is done

 * by constructing a {@link FuncHere} which has this Node as 'owner'.

 *

 * @see "http://www.w3.org/Signature/Drafts/xmldsig-core/Overview.html#function-here"

 */

public class FuncHere extends Function {

    /**

     *

     */

    private static final long serialVersionUID = 1L;

    /**

     * The here function returns a node-set containing the attribute or

     * processing instruction node or the parent element of the text node

     * that directly bears the XPath expression.  This expression results

     * in an error if the containing XPath expression does not appear in the

     * same XML document against which the XPath expression is being evaluated.

     *

     * @param xctxt

     * @return the xobject

     * @throws javax.xml.transform.TransformerException

     */

    public XObject execute(XPathContext xctxt) throws TransformerException {

        Node xpathOwnerNode = (Node) xctxt.getOwnerObject();

        if (xpathOwnerNode == null) {

            return null;

        }

        int xpathOwnerNodeDTM = xctxt.getDTMHandleFromNode(xpathOwnerNode);

        int currentNode = xctxt.getCurrentNode();

        DTM dtm = xctxt.getDTM(currentNode);

        int docContext = dtm.getDocument();

        if (DTM.NULL == docContext) {

            error(xctxt, XPATHErrorResources.ER_CONTEXT_HAS_NO_OWNERDOC, null);

        }

        {

            // check whether currentNode and the node containing the XPath expression

            // are in the same document

            Document currentDoc =

                XMLUtils.getOwnerDocument(dtm.getNode(currentNode));

            Document xpathOwnerDoc = XMLUtils.getOwnerDocument(xpathOwnerNode);

            if (currentDoc != xpathOwnerDoc) {

                throw new TransformerException(I18n.translate("xpath.funcHere.documentsDiffer"));

            }

        }

        XNodeSet nodes = new XNodeSet(xctxt.getDTMManager());

        NodeSetDTM nodeSet = nodes.mutableNodeset();

        {

            int hereNode = DTM.NULL;

            switch (dtm.getNodeType(xpathOwnerNodeDTM)) {

            case Node.ATTRIBUTE_NODE :

            case Node.PROCESSING_INSTRUCTION_NODE : {

                // returns a node-set containing the attribute /  processing instruction node

                hereNode = xpathOwnerNodeDTM;

                nodeSet.addNode(hereNode);

                break;

            }

            case Node.TEXT_NODE : {

                // returns a node-set containing the parent element of the

                // text node that directly bears the XPath expression

                hereNode = dtm.getParent(xpathOwnerNodeDTM);

                nodeSet.addNode(hereNode);

                break;

            }

            default :

                break;

            }

        }

        /** $todo$ Do I have to do this detach() call? */

        nodeSet.detach();

        return nodes;

    }

    /**

     * No arguments to process, so this does nothing.

     * @param vars

     * @param globalsSize

     */

    public void fixupVariables(List<QName> vars, int globalsSize) {

        // do nothing

    }

}