/*

 * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package stream.XMLStreamWriterTest;

import java.io.IOException;

import java.io.InputStream;

import java.util.Iterator;

import javax.xml.XMLConstants;

import javax.xml.namespace.NamespaceContext;

import javax.xml.parsers.DocumentBuilder;

import javax.xml.parsers.DocumentBuilderFactory;

import javax.xml.parsers.FactoryConfigurationError;

import javax.xml.parsers.ParserConfigurationException;

import javax.xml.stream.XMLStreamException;

import javax.xml.stream.XMLStreamWriter;

import org.w3c.dom.Document;

import org.w3c.dom.Element;

import org.w3c.dom.NamedNodeMap;

import org.w3c.dom.Node;

import org.w3c.dom.NodeList;

import org.xml.sax.SAXException;

public class DOMUtil {

    private static DocumentBuilder db;

    private static String fixNull(String s) {

        if (s == null)

            return "";

        else

            return s;

    }

    /**

     * Creates a new DOM document.

     */

    public static Document createDom() {

        synchronized (DOMUtil.class) {

            if (db == null) {

                try {

                    DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();

                    dbf.setNamespaceAware(true);

                    db = dbf.newDocumentBuilder();

                } catch (ParserConfigurationException e) {

                    throw new FactoryConfigurationError(e);

                }

            }

            return db.newDocument();

        }

    }

    public static Node createDOMNode(InputStream inputStream) {

        DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();

        dbf.setNamespaceAware(true);

        dbf.setValidating(false);

        try {

            DocumentBuilder builder = dbf.newDocumentBuilder();

            try {

                return builder.parse(inputStream);

            } catch (SAXException e) {

                e.printStackTrace(); // To change body of catch statement use

                                     // File | Settings | File Templates.

            } catch (IOException e) {

                e.printStackTrace(); // To change body of catch statement use

                                     // File | Settings | File Templates.

            }

        } catch (ParserConfigurationException pce) {

            IllegalArgumentException iae = new IllegalArgumentException(pce.getMessage());

            iae.initCause(pce);

            throw iae;

        }

        return null;

    }

    public static void serializeNode(Element node, XMLStreamWriter writer) throws XMLStreamException {

        String nodePrefix = fixNull(node.getPrefix());

        String nodeNS = fixNull(node.getNamespaceURI());

        // See if nodePrefix:nodeNS is declared in writer's NamespaceContext

        // before writing start element

        // Writing start element puts nodeNS in NamespaceContext even though

        // namespace declaration not written

        boolean prefixDecl = isPrefixDeclared(writer, nodeNS, nodePrefix);

        writer.writeStartElement(nodePrefix, node.getLocalName(), nodeNS);

        if (node.hasAttributes()) {

            NamedNodeMap attrs = node.getAttributes();

            int numOfAttributes = attrs.getLength();

            // write namespace declarations first.

            // if we interleave this with attribue writing,

            // Zephyr will try to fix it and we end up getting inconsistent

            // namespace bindings.

            for (int i = 0; i < numOfAttributes; i++) {

                Node attr = attrs.item(i);

                String nsUri = fixNull(attr.getNamespaceURI());

                if (nsUri.equals(XMLConstants.XMLNS_ATTRIBUTE_NS_URI)) {

                    // handle default ns declarations

                    String local = attr.getLocalName().equals(XMLConstants.XMLNS_ATTRIBUTE) ? "" : attr.getLocalName();

                    if (local.equals(nodePrefix) && attr.getNodeValue().equals(nodeNS)) {

                        prefixDecl = true;

                    }

                    // this is a namespace declaration, not an attribute

                    writer.setPrefix(attr.getLocalName(), attr.getNodeValue());

                    writer.writeNamespace(attr.getLocalName(), attr.getNodeValue());

                }

            }

        }

        // node's namespace is not declared as attribute, but declared on

        // ancestor

        if (!prefixDecl) {

            writer.writeNamespace(nodePrefix, nodeNS);

        }

        // Write all other attributes which are not namespace decl.

        if (node.hasAttributes()) {

            NamedNodeMap attrs = node.getAttributes();

            int numOfAttributes = attrs.getLength();

            for (int i = 0; i < numOfAttributes; i++) {

                Node attr = attrs.item(i);

                String attrPrefix = fixNull(attr.getPrefix());

                String attrNS = fixNull(attr.getNamespaceURI());

                if (!attrNS.equals(XMLConstants.XMLNS_ATTRIBUTE_NS_URI)) {

                    String localName = attr.getLocalName();

                    if (localName == null) {

                        // TODO: this is really a bug in the caller for not

                        // creating proper DOM tree.

                        // will remove this workaround after plugfest

                        localName = attr.getNodeName();

                    }

                    boolean attrPrefixDecl = isPrefixDeclared(writer, attrNS, attrPrefix);

                    if (!attrPrefix.equals("") && !attrPrefixDecl) {

                        // attr has namespace but namespace decl is there in

                        // ancestor node

                        // So write the namespace decl before writing the attr

                        writer.setPrefix(attr.getLocalName(), attr.getNodeValue());

                        writer.writeNamespace(attrPrefix, attrNS);

                    }

                    writer.writeAttribute(attrPrefix, attrNS, localName, attr.getNodeValue());

                }

            }

        }

        if (node.hasChildNodes()) {

            NodeList children = node.getChildNodes();

            for (int i = 0; i < children.getLength(); i++) {

                Node child = children.item(i);

                switch (child.getNodeType()) {

                    case Node.PROCESSING_INSTRUCTION_NODE:

                        writer.writeProcessingInstruction(child.getNodeValue());

                    case Node.DOCUMENT_TYPE_NODE:

                        break;

                    case Node.CDATA_SECTION_NODE:

                        writer.writeCData(child.getNodeValue());

                        break;

                    case Node.COMMENT_NODE:

                        writer.writeComment(child.getNodeValue());

                        break;

                    case Node.TEXT_NODE:

                        writer.writeCharacters(child.getNodeValue());

                        break;

                    case Node.ELEMENT_NODE:

                        serializeNode((Element) child, writer);

                        break;

                }

            }

        }

        writer.writeEndElement();

    }

    private static boolean isPrefixDeclared(XMLStreamWriter writer, String nsUri, String prefix) {

        boolean prefixDecl = false;

        NamespaceContext nscontext = writer.getNamespaceContext();

        Iterator prefixItr = nscontext.getPrefixes(nsUri);

        while (prefixItr.hasNext()) {

            if (prefix.equals(prefixItr.next())) {

                prefixDecl = true;

                break;

            }

        }

        return prefixDecl;

    }

    /**

     * Gets the first child of the given name, or null.

     */

    public static Element getFirstChild(Element e, String nsUri, String local) {

        for (Node n = e.getFirstChild(); n != null; n = n.getNextSibling()) {

            if (n.getNodeType() == Node.ELEMENT_NODE) {

                Element c = (Element) n;

                if (c.getLocalName().equals(local) && c.getNamespaceURI().equals(nsUri))

                    return c;

            }

        }

        return null;

    }

}