/*
 * This file is part of the LibreOffice project.
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * This file incorporates work covered by the following license notice:
 *
 *   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 .
 */

package org.openoffice.xmerge.util;

import org.w3c.dom.Node;
import org.w3c.dom.Document;
import org.w3c.dom.NodeList;
import org.w3c.dom.Element;
import org.w3c.dom.NamedNodeMap;

/**
 * Class containing static utility methods for handling XML trees.
 */
public final class XmlUtil {

    /**
     * Perform a deep clone of certain {@code Node} which will base on the
     * document {@code Node} of the old {@code Node}.
     *
     * @param   oldNode  The {@code Document} of this {@code Node} is used to
     *                   clone the {@code Node}.
     * @param   newNode  The <code>Node</code> to clone.
     *
     * @return  The cloned {@code Node}.
     */
    public static Node deepClone(Node oldNode, Node newNode) {
        Document docNode = oldNode.getOwnerDocument();

        // clone the starting node
        Node clonedNode = cloneNode(docNode, newNode);

        if (clonedNode != null) {
            // then clone the sub-tree recursively
            cloneTree(docNode, clonedNode, newNode);
        }

        return clonedNode;
    }

    /**
     * Clone the sub-tree under certain given {@code Node}.
     *
     * @param  docNode  The {@code Document} used to clone the {@code Node}.
     * @param  oldNode  The {@code Node} to clone.
     * @param  newNode  The destination {@code Node}.
     */
    private static void cloneTree(Document docNode, Node oldNode, Node newNode) {

        NodeList nodeList = newNode.getChildNodes();
        int nodeListLen = nodeList.getLength();

        for (int i = 0; i < nodeListLen; i++) {
            Node newClonedChild = cloneNode(docNode, nodeList.item(i));
            if (newClonedChild != null) {
                oldNode.appendChild(newClonedChild);
                cloneTree(docNode, newClonedChild, nodeList.item(i));
            }
        }
    }

    /**
     * Clone a {@code Node} (either text or element).
     *
     * @param   docNode  The {@code Document} used to clone the {@code Node}.
     * @param   newNode  The {@code Node}to clone.
     *
     * @return  The cloned {@code Node}.
     */
    private static Node cloneNode(Document docNode, Node newNode) {

        Node clonedNode = null;

        // only support text node and element node (will copy the attributes)
        switch (newNode.getNodeType()) {
            case Node.TEXT_NODE:
                String textStr = newNode.getNodeValue();
                clonedNode = docNode.createTextNode(textStr);
                break;
            case Node.ELEMENT_NODE:
                Element oldElem = (Element)newNode;
                String tagName  = newNode.getNodeName();
                Element newElem = docNode.createElement(tagName);

                // copy the attributes
                NamedNodeMap attrs = oldElem.getAttributes();

                for (int i = 0; i < attrs.getLength(); i++) {
                    newElem.setAttribute(attrs.item(i).getNodeName(),
                                         attrs.item(i).getNodeValue());
                }
                clonedNode = newElem;
                break;
        }
        return clonedNode;
    }

    /**
     * Returns the name and type of an XML DOM {@code Node}.
     *
     * @param   node  {@code Node} to query.
     *
     * @return  Name and type of XML DOM {@code Node}.
     */
    public static String getNodeInfo(Node node) {

        String str = null;
        switch (node.getNodeType()) {

            case Node.ELEMENT_NODE:
                str = "ELEMENT";
                break;
            case Node.ATTRIBUTE_NODE:
                str = "ATTRIBUTE";
                break;
            case Node.TEXT_NODE:
                str = "TEXT";
                break;
            case Node.CDATA_SECTION_NODE:
                str = "CDATA_SECTION";
                break;
            case Node.ENTITY_REFERENCE_NODE:
                str = "ENTITY_REFERENCE";
                break;
            case Node.ENTITY_NODE:
                str = "ENTITY";
                break;
            case Node.PROCESSING_INSTRUCTION_NODE:
                str = "PROCESSING_INSTRUCTION";
                break;
            case Node.COMMENT_NODE:
                str = "COMMENT";
                break;
            case Node.DOCUMENT_NODE:
                str = "DOCUMENT";
                break;
            case Node.DOCUMENT_TYPE_NODE:
                str = "DOCUMENT_TYPE";
                break;
            case Node.DOCUMENT_FRAGMENT_NODE:
                str = "DOCUMENT_FRAGMENT";
                break;
            case Node.NOTATION_NODE:
                str = "NOTATION";
                break;
        }

        StringBuffer buffer = new StringBuffer("name=\"");
        buffer.append(node.getNodeName());
        buffer.append("\"  type=\"");
        buffer.append(str);
        buffer.append("\"");

        return buffer.toString();
    }
}
