/**
 * 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 org.apache.cxf.ws.transfer.validationtransformation;

import java.util.logging.Logger;

import javax.annotation.Resource;
import javax.xml.XMLConstants;
import javax.xml.transform.Source;
import javax.xml.transform.Templates;
import javax.xml.transform.TransformerConfigurationException;
import javax.xml.transform.TransformerFactory;
import javax.xml.ws.WebServiceContext;

import org.w3c.dom.Document;
import org.w3c.dom.Node;

import org.apache.cxf.binding.soap.SoapFault;
import org.apache.cxf.binding.soap.SoapMessage;
import org.apache.cxf.binding.soap.SoapVersion;
import org.apache.cxf.common.logging.LogUtils;
import org.apache.cxf.feature.transform.XSLTUtils;
import org.apache.cxf.helpers.DOMUtils;
import org.apache.cxf.jaxws.context.WrappedMessageContext;
import org.apache.cxf.ws.transfer.Representation;

/**
 * Implementation of the ResourceTransformer for the XSL transformation.
 */
public class XSLTResourceTransformer implements ResourceTransformer {

    private static final Logger LOG = LogUtils.getL7dLogger(XSLTResourceTransformer.class);

    protected Templates templates;

    protected ResourceValidator validator;

    @Resource
    private WebServiceContext context;

    public XSLTResourceTransformer(Source xsl) {
        this(xsl, null);
    }

    public XSLTResourceTransformer(Source xsl, ResourceValidator validator) {
        this.validator = validator;
        try {
            final TransformerFactory transformerFactory = TransformerFactory.newInstance();
            try {
                transformerFactory.setAttribute(XMLConstants.ACCESS_EXTERNAL_DTD, "");
                transformerFactory.setAttribute(XMLConstants.ACCESS_EXTERNAL_STYLESHEET, "");
            } catch (IllegalArgumentException ex) {
                // ignore
            }
            transformerFactory.setFeature(XMLConstants.FEATURE_SECURE_PROCESSING, Boolean.TRUE);
            templates = transformerFactory.newTemplates(xsl);
        } catch (TransformerConfigurationException e) {
            LOG.severe(e.getLocalizedMessage());
            throw new SoapFault("Internal error", getSoapVersion().getReceiver());
        }
    }

    @Override
    public ResourceValidator transform(Representation newRepresentation, Representation oldRepresentation) {
        Document doc = DOMUtils.createDocument();
        Node representation = (Node) newRepresentation.getAny();
        Node importedNode = doc.importNode(representation, true);
        doc.appendChild(importedNode);
        Document result = XSLTUtils.transform(templates, doc);
        newRepresentation.setAny(result.getDocumentElement());
        return validator;
    }

    private SoapVersion getSoapVersion() {
        WrappedMessageContext wmc = (WrappedMessageContext) context.getMessageContext();
        SoapMessage message = (SoapMessage) wmc.getWrappedMessage();
        return message.getVersion();
    }

}
