/*-
 * ============LICENSE_START=======================================================
 * ONAP CLAMP
 * ================================================================================
 * Copyright (C) 2019 Nokia. All rights
 *                             reserved.
 * ================================================================================
 * Licensed 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.
 * ============LICENSE_END============================================
 * ===================================================================
 *
 */

package org.onap.clamp.clds.util;

import java.io.StringWriter;
import javax.xml.XMLConstants;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import org.apache.batik.anim.dom.SVGDOMImplementation;
import org.apache.batik.dom.GenericDOMImplementation;
import org.apache.batik.util.SVGConstants;
import org.w3c.dom.DOMImplementation;
import org.w3c.dom.Document;

public class XmlTools {

    /**
     * Private constructor to avoid creating instances of util class.
     */
    private XmlTools(){
    }

    /**
     * Transforms document to XML string.
     *
     * @param doc XML document
     * @return XML string
     */
    public static String exportXmlDocumentAsString(Document doc) {
        try {
            TransformerFactory tf = TransformerFactory.newInstance();
            tf.setFeature(XMLConstants.FEATURE_SECURE_PROCESSING, true);
            Transformer transformer = tf.newTransformer();
            transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
            StringWriter writer = new StringWriter();
            transformer.transform(new DOMSource(doc), new StreamResult(writer));
            return writer.getBuffer().toString();
        } catch (TransformerException e) {
            throw new RuntimeException(e);
        }
    }

    /**
     * Creates empty svg document.
     *
     * @return Document
     */
    public static Document createEmptySvgDocument() {
        DOMImplementation domImplementation = GenericDOMImplementation.getDOMImplementation();
        String svgNs = SVGDOMImplementation.SVG_NAMESPACE_URI;
        return domImplementation.createDocument(svgNs, SVGConstants.SVG_SVG_TAG, null);
    }
}