/*

 * Copyright (c) 2015, 2017, Oracle and/or its affiliates. All rights reserved.

 */

/**

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

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.objects.XNodeSet;

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

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

import java.util.List;

import javax.xml.transform.TransformerException;

import org.w3c.dom.Document;

import org.w3c.dom.Node;

/**

 * Execute the XML Signature here() function.

 *

 * @LastModified: Oct 2017

 */

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(List<QName> vars, int globalsSize) { }

}