/*
 * Copyright (c) 1997, 2018 Oracle and/or its affiliates. All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0, which is available at
 * http://www.eclipse.org/legal/epl-2.0.
 *
 * This Source Code may also be made available under the following Secondary
 * Licenses when the conditions for such availability set forth in the
 * Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
 * version 2 with the GNU Classpath Exception, which is available at
 * https://www.gnu.org/software/classpath/license.html.
 *
 * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
 */

package com.sun.enterprise.v3.common;

import java.io.OutputStream;
import java.util.Map;
import javax.xml.parsers.*;
import javax.xml.transform.*;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.jvnet.hk2.annotations.Service;

import org.glassfish.hk2.api.PerLookup;

/**
 * Represents the action report as XML like this:
 * <br>
 * <!--
 *     Apologies for the formatting - it's necessary for the JavaDoc to be readable
 *     If you are using NetBeans, for example, click anywhere in this comment area to see
 *     the document example clearly in the JavaDoc preview
 * -->
 * <code>
 * <br>&lt;action-report description="xxx" exit-code="xxx" [failure-cause="xxx"]>
 * <br>&nbsp;&nbsp;&lt;message-part message="">
 * <br>&nbsp;&nbsp;&nbsp;&nbsp;&lt;property name="xxx" value="xxx"/>
 * <br>&nbsp;&nbsp;&nbsp;&nbsp;...
 * <br>&nbsp;&nbsp;&nbsp;&nbsp;&lt;<i>child-type</i> <i>property</i>="value"/>
 * <br>&nbsp;&nbsp;&nbsp;&nbsp;...
 * <br>&nbsp;&nbsp;&nbsp;&nbsp;&lt;/<i>child-type</i>>
 * <br>&nbsp;&nbsp;&nbsp;&nbsp;&lt;/message-part>
 * <br>&nbsp;&nbsp;&lt/message-part>
 * <br>&lt;/action-report>
 * </code>
 *
 * Currently this is used to return the metadata for a command, although
 * it could be used more generally to return XML content.  In the general
 * case the action-report and message-part elements ought to be removed.
 *
 * @author tjquinn
 * @author Bill Shannon
 */
@Service(name="metadata")   // XXX - need a better mapping
@PerLookup
public class XMLContentActionReporter extends ActionReporter {

    public void writeReport(OutputStream os)  {
        try {
            DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
            DocumentBuilder db = dbf.newDocumentBuilder();

            Document d = db.newDocument();

            d.appendChild(writeActionReport(d, this));
            writeXML(d, os);
        } catch (ParserConfigurationException pex) {
            throw new RuntimeException(pex);
        } catch (TransformerException e) {
            throw new RuntimeException(e);
        }
    }

    /**
     * Creates a new Element representing the XML content describing an
     * action report.  Invokes itself recursively to capture information
     * about any subactions.
     * @param owningDocument Document which will own all generated XML content
     * @param report the ActionReporter to convert to XML content
     * @return Element for the specified ActionReporter (and any sub-reports)
     */
    private Element writeActionReport(Document owningDocument,
            ActionReporter report) {
        Element result = owningDocument.createElement("action-report");
        result.setAttribute("description", report.actionDescription);
        result.setAttribute("exit-code", report.getActionExitCode().name());
        if (exception != null) {
            result.setAttribute("failure-cause",
                exception.getLocalizedMessage());
        }

        writePart(result, report.getTopMessagePart(), null);
        for (ActionReporter subReport : report.subActions) {
            result.appendChild(writeActionReport(owningDocument, subReport));
        }
        return result;
    }

    @Override
    public String getContentType() {
        return "text/xml";
    }

    private void writePart(Element actionReport, MessagePart part,
            String childType) {
        Document d = actionReport.getOwnerDocument();
        Element messagePart = d.createElement("message-part");
        actionReport.appendChild(messagePart);
        if (childType != null) {
            messagePart.setAttribute("type", childType);
        }

        for (Map.Entry prop : part.getProps().entrySet()) {
            Element p = d.createElement("property");
            messagePart.appendChild(p);
            p.setAttribute("name", prop.getKey().toString());
            p.setAttribute("value", prop.getValue().toString());
        }
        messagePart.setAttribute("message", part.getMessage());

        for (MessagePart subPart : part.getChildren())
            writeSubPart(messagePart, subPart, subPart.getChildrenType());
    }

    /**
     * Write out all the sub-parts as XML elements where the
     * "childType" is the name of the XML element and the properties
     * are attributes of the element.  Recurse for any subparts.
     */
    private void writeSubPart(Element actionReport, MessagePart part,
            String childType) {
        Document d = actionReport.getOwnerDocument();
        Element messagePart = d.createElement(childType);
        actionReport.appendChild(messagePart);

        for (Map.Entry prop : part.getProps().entrySet()) {
            messagePart.setAttribute(prop.getKey().toString(),
                prop.getValue().toString());
        }
        for (MessagePart subPart : part.getChildren())
            writeSubPart(messagePart, subPart, subPart.getChildrenType());
    }

    /**
     * Write the XML document to the output stream.
     *
     * @param doc   the XML document
     * @param os    the output stream
     * @throws TransformerException if anything goes wrong
     */
    private void writeXML(Document doc, OutputStream os)
            throws TransformerException {
        Source source = new DOMSource(doc);

        Result result = new StreamResult(os);

        Transformer xformer = TransformerFactory.newInstance().newTransformer();
        xformer.transform(source, result);
    }
}