/*
 * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
 */
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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
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/**
 * 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.xpath.internal.functions;

import javax.xml.transform.TransformerException;
import org.w3c.dom.Document;
import org.w3c.dom.Node;
import com.sun.org.apache.xml.internal.dtm.DTM;
import com.sun.org.apache.xpath.internal.NodeSetDTM;
import com.sun.org.apache.xpath.internal.XPathContext;
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;

Execute the XML Signature here() function.
/**
 * Execute the XML Signature here() function.
 */
public final class FuncHere extends Function {

    private static final long serialVersionUID = 4328660760070034592L;

    @Override
    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 (docContext == DTM.NULL) {
            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 = getOwnerDocument(dtm.getNode(currentNode));
        Document xpathOwnerDoc = getOwnerDocument(xpathOwnerNode);

        if (currentDoc != xpathOwnerDoc) {
            throw new TransformerException("Owner documents differ");
        }

        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;
    }

    private static Document getOwnerDocument(Node node) {
        if (node.getNodeType() == Node.DOCUMENT_NODE) {
            return (Document)node;
        }
        return node.getOwnerDocument();
    }

    @Override
    public void fixupVariables(java.util.Vector vars, int globalsSize) { }
}