/*

 * 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.catalina.manager.host;

import java.io.File;

import java.io.FileInputStream;

import java.io.FileOutputStream;

import java.io.IOException;

import java.nio.channels.FileChannel;

import java.util.Date;

import javax.xml.parsers.DocumentBuilder;

import javax.xml.parsers.DocumentBuilderFactory;

import javax.xml.parsers.ParserConfigurationException;

import javax.xml.transform.OutputKeys;

import javax.xml.transform.Result;

import javax.xml.transform.Source;

import javax.xml.transform.Transformer;

import javax.xml.transform.TransformerConfigurationException;

import javax.xml.transform.TransformerException;

import javax.xml.transform.TransformerFactory;

import javax.xml.transform.TransformerFactoryConfigurationError;

import javax.xml.transform.dom.DOMSource;

import javax.xml.transform.stream.StreamResult;

import org.apache.catalina.Engine;

import org.apache.catalina.Host;

import org.apache.catalina.Service;

import org.apache.catalina.core.StandardHost;

import org.apache.catalina.startup.Catalina;

import org.w3c.dom.Comment;

import org.w3c.dom.Document;

import org.w3c.dom.Element;

import org.w3c.dom.NodeList;

import org.xml.sax.SAXException;

/**

 * Responsible for adding and removing hosts from server.xml.

 * 

 * @author Wesley

 * 

 */

public class HostXMLUpdater {

    /**

     * The directory where tomcat resides.

     */

    private String baseFileName;

    /**

     * The name of the configuration file that has the hosts defined in it. This

     * is usually conf/server.xml.

     */

    private String confFileName;

    /**

     * The name of the file where the contents will be initially written.

     */

    private String tempFileName;

    /**

     * The name of the file which will contain a backup of the old settings.

     */

    private String backupFileName;

    public HostXMLUpdater() {

        init();

    }

    synchronized private void init() {

        confFileName = System.getProperty(Catalina.CONFIG_FILE_PROPERTY);

        baseFileName = System.getProperty("catalina.base");

    }

    /**

     * Saves a host to the xml configuration file.

     * 

     * @param host

     *            The host to save as xml.

     */

    public void addHost(StandardHost host) {

        try {

            FileReferences ref = createBackupAndTempFiles();

            Document document = createDocumentFromFile(ref.getTempFile());

            HostParents hostParents = findParents(host);

            Element engineNode = findHostParentNode(hostParents, document);

            Element hostNode = createHostNode(document, host);

            engineNode.appendChild(hostNode);

            // Following is debug code

            Transformer aTransformer = createTransformer();

            writeToTempFile(ref, document, aTransformer);

            replaceCurrentConfFileWithTempFile(ref);

        } catch (Exception e) {

            // FIXME Need to decide what to do on a failure.

            e.printStackTrace();

        } finally {

            // FIXME cleanup files

        }

    }

    /**

     * Deletes the current file and replaces it with the temp file.

     * 

     * @param ref

     *            References to the temp and current files.

     */

    private void replaceCurrentConfFileWithTempFile(FileReferences ref) {

        ref.currentFile.delete();

        ref.tempFile.renameTo(ref.currentFile);

    }

    /**

     * Writes output to tempory file.

     * 

     * @param ref

     *            A reference to the current and temp and backup files.

     * @param document

     *            The document to be written to the temp file.

     * @param transformer

     *            The transformer which writes to the temp file.

     * @throws TransformerException

     *             If an unrecoverable error occurs during the course of the

     *             transformation.

     */

    private void writeToTempFile(FileReferences ref, Document document,

            Transformer transformer) throws TransformerException {

        Source src = new DOMSource(document);

        Result dest = new StreamResult(ref.tempFile);

        transformer.transform(src, dest);

    }

    /**

     * @return A Transformer to transform the document to file.

     * @throws TransformerFactoryConfigurationError

     *             Thrown if the TransformerFactory implementation is not

     *             available or cannot be instantiated.

     * @throws TransformerConfigurationException

     *             When it is not possible to create a transformer.

     */

    private Transformer createTransformer()

            throws TransformerFactoryConfigurationError,

            TransformerConfigurationException {

        TransformerFactory tranFactory = TransformerFactory.newInstance();

        Transformer transformer = tranFactory.newTransformer();

        transformer.setOutputProperty(OutputKeys.INDENT, "yes");

        return transformer;

    }

    /**

     * Removes a host from the configuration file.

     * 

     * @param host

     *            The host to remove.

     */

    public void removeHost(Host host) {

        try {

            FileReferences ref = createBackupAndTempFiles();

            Document document = createDocumentFromFile(ref.getTempFile());

            HostParents hostParents = findParents(host);

            Element engineNode = findHostParentNode(hostParents, document);

            deleteHostNode(document, engineNode, host);

            Transformer aTransformer = createTransformer();

            writeToTempFile(ref, document, aTransformer);

            replaceCurrentConfFileWithTempFile(ref);

        } catch (Exception e) {

            e.printStackTrace();

        } finally {

            // FIXME cleanup files

        }

    }

    /**

     * Finds a host by name and removes it from a document.

     * 

     * @param document

     *            The document to remove the host from.

     * @param engineNode

     *            The node to remove the host from.

     * @param hostThe

     *            host to remove.

     */

    private void deleteHostNode(Document document, Element engineNode, Host host) {

        NodeList hostNodes = engineNode.getElementsByTagName("Host");

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

            Element currentElement = (Element) hostNodes.item(i);

            String name = currentElement.getAttribute("name");

            if (name.equals(host.getName())) {

                engineNode.removeChild(currentElement);

            }

        }

    }

    /**

     * Creates a host node.

     * 

     * @param document

     *            The document to create the node on.

     * @param host

     *            The host to represent as XML.

     * @return A newly created XML element representing the host.

     */

    private Element createHostNode(Document document, StandardHost host) {

        Element hostNode = document.createElement("Host");

        hostNode.setAttribute("name", host.getName());

        hostNode.setAttribute("appBase", host.getAppBase());

        hostNode.setAttribute("autoDeploy", Boolean.toString(host

                .getAutoDeploy()));

        hostNode.setAttribute("deployOnStartup", Boolean.toString(host

                .getDeployOnStartup()));

        hostNode

                .setAttribute("deployXML", Boolean.toString(host.isDeployXML()));

        String[] aliases = host.getAliases();

        Comment creationComment = document

                .createComment("Automatically created host on "

                        + (new Date().toString()));

        hostNode.appendChild(creationComment);

        for (int i = 0; i < aliases.length; i++) {

            Element alias = document.createElement("Alias");

            alias.setTextContent(aliases[i]);

            hostNode.appendChild(alias);

        }

        return hostNode;

    }

    /**

     * Finds the parent nodes of a host node.

     * 

     * First finds the service by name then the engine.

     * 

     * @param hostParents

     *            The parents of the node to find.

     * @param document

     *            The document to find the XML representation of the parents on.

     * @return An element representing the engine the host is attached to.

     */

    private Element findHostParentNode(HostParents hostParents,

            Document document) {

        try {

            NodeList serviceNodeList = document.getElementsByTagName("Service");

            Element serviceNode = (Element) serviceNodeList.item(0);

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

                serviceNode = (Element) serviceNodeList.item(i);

                String name = serviceNode.getAttribute("name");

                if (name.equals(hostParents.getService().getName())) {

                    break;

                }

            }

            NodeList engineNodeList = serviceNode

                    .getElementsByTagName("Engine");

            if (engineNodeList.getLength() != 1) {

                throw new ServiceParseException(

                        "Unable to parse server.xml. There should only be one engine associated with a given service.");

            }

            return ((Element) engineNodeList.item(0));

        } catch (RuntimeException e) {

            throw new ServiceParseException(e);

        }

    }

    /**

     * Finds the service and engine associated with a host.

     * 

     * @param host

     *            The host which we need too find the parents of.

     * @return An object representing the service and the engine that parent the

     *         host.

     */

    private HostParents findParents(Host host) {

        Engine engine = (Engine) host.getParent();

        Service service = engine.getService();

        HostParents parents = new HostParents();

        parents.setEngine(engine);

        parents.setService(service);

        return parents;

    }

    private FileReferences createBackupAndTempFiles() throws IOException {

        FileReferences ref = createFileRefrences();

        copyFile(ref.getCurrentFile(), ref.getBackupFile());

        copyFile(ref.getCurrentFile(), ref.getTempFile());

        return ref;

    }

    /**

     * Creates a document from a file.

     * 

     * @param file

     *            The file to parse to create a document.

     * @return The document instance that is within the file.

     * @throws ParserConfigurationException

     *             if a DocumentBuilder cannot be created which satisfies the

     *             configuration requested.

     * @throws SAXException

     *             If there is an error parsing.

     * @throws IOException

     *             If there is any IO errors.

     */

    private Document createDocumentFromFile(File file)

            throws ParserConfigurationException, SAXException, IOException {

        DocumentBuilderFactory builderFactory = DocumentBuilderFactory

                .newInstance();

        DocumentBuilder parser = builderFactory.newDocumentBuilder();

        Document document = parser.parse(file);

        return document;

    }

    /**

     * Creates references to the current configuration file, the backup file and

     * a temporary file.

     * 

     * @return A reference to the temporary configuration file, the backup file

     *         and the current configuration file.

     */

    private FileReferences createFileRefrences() {

        File currentFile = createFileReference(confFileName);

        // Make two copies of the current file.

        String tempFileName = confFileName + ".tmp";

        File tempFile = createFileReference(tempFileName);

        String backupFileName = confFileName + ".bak";

        File backupFile = createFileReference(backupFileName);

        FileReferences ref = new FileReferences();

        ref.setBackupFile(backupFile);

        ref.setCurrentFile(currentFile);

        ref.setTempFile(tempFile);

        return ref;

    }

    /**

     * Creates a file reference representing the filename passed in. Creates all

     * directories that are needed to create the file.

     * 

     * @param fileName

     * @return

     */

    private File createFileReference(String fileName) {

        File currentFile = new File(fileName);

        if (!currentFile.isAbsolute()) {

            currentFile = new File(baseFileName, fileName);

        }

        currentFile.getParentFile().mkdirs();

        return currentFile;

    }

    /**

     * @param confFileName

     *            The name of the current configuration file. Usually

     *            "conf/server.xml".

     */

    public void setConfFileName(String confFileName) {

        this.confFileName = confFileName;

    }

    /**

     * @return The name of the current configuration file. Usually

     *         "conf/server.xml".

     */

    public String getConfFileName() {

        return confFileName;

    }

    /**

     * @param tempFileName

     *            The file where the temporary contents will be written before

     *            Overwriting the main configuration file.

     */

    public void setTempFileName(String tempFileName) {

        this.tempFileName = tempFileName;

    }

    /**

     * 

     * @return The file where the temporary contents will be written before

     *         Overwriting the main configuration file.

     */

    public String getTempFileName() {

        return tempFileName;

    }

    /**

     * @param backupFileName

     *            The name of the backup file.

     */

    public void setBackupFileName(String backupFileName) {

        this.backupFileName = backupFileName;

    }

    /**

     * @return The name of the backup file.

     */

    public String getBackupFileName() {

        return backupFileName;

    }

    /**

     * @param baseFileName

     *            The location of catalina.base.

     */

    public void setBaseFileName(String baseFileName) {

        this.baseFileName = baseFileName;

    }

    /**

     * @return The location of catalina.base.

     */

    public String getBaseFileName() {

        return baseFileName;

    }

    /**

     * Copies a file to another file.

     * 

     * @param sourceFile

     *            The file to copy.

     * @param destFile

     *            The file to write.

     * @throws IOException

     *             If sourceFile cannot be read or destFile cannot be written.

     * 

     * @see http://www.javalobby.org/java/forums/t17036.html

     */

    void copyFile(File sourceFile, File destFile) throws IOException {

        if (!destFile.exists()) {

            destFile.createNewFile();

        }

        FileChannel source = null;

        FileChannel destination = null;

        try {

            source = new FileInputStream(sourceFile).getChannel();

            destination = new FileOutputStream(destFile).getChannel();

            destination.transferFrom(source, 0, source.size());

        } finally {

            if (source != null) {

                source.close();

            }

        }

        if (destination != null) {

            destination.close();

        }

    }

    /**

     * Simply used as a private return value.

     * 

     * Represents the three files the current file, the backup file and a

     * Temporary file.

     * 

     * @author Wesley

     * 

     */

    private class FileReferences {

        private File currentFile;

        private File tempFile;

        private File backupFile;

        /**

         * Constructor

         */

        public FileReferences() {

        }

        /**

         * @return The current file.

         */

        public File getCurrentFile() {

            return currentFile;

        }

        /**

         * @param The current file.

         */

        public void setCurrentFile(File currentFile) {

            this.currentFile = currentFile;

        }

        /**

         * @return A temporary file that will be used to update the current file.

         */

        public File getTempFile() {

            return tempFile;

        }

        /**

         * @param tempFile A temporary file that will be used to update the current file.

         */

        public void setTempFile(File tempFile) {

            this.tempFile = tempFile;

        }

        /**

         * @return A backup file of the current file.

         */

        public File getBackupFile() {

            return backupFile;

        }

        /**

         * @param backupFile A backup file of the current file.

         */

        public void setBackupFile(File backupFile) {

            this.backupFile = backupFile;

        }

    }

    /**

     * Represents the service and engine associated with an individual host.

     * @author Wesley

     *

     */

    private class HostParents {

        private Engine engine;

        private Service service;

        /**

         * @return The engine associated with the host.

         */

        public Engine getEngine() {

            return engine;

        }

        /**

         * @param engine The engine associated with the host.

         */

        public void setEngine(Engine engine) {

            this.engine = engine;

        }

        /**

         * @return The service associated with the host.

         */

        public Service getService() {

            return service;

        }

        /**

         * @param service The service associated with the host.

         */

        public void setService(Service service) {

            this.service = service;

        }

    }

}

    private static final long serialVersionUID = -3386410077320670918L;

    protected static HostXMLUpdater xmlUpdater = new HostXMLUpdater();

            xmlUpdater.addHost(host);

            xmlUpdater.removeHost((StandardHost) child);

    public static final String CONFIG_FILE_PROPERTY = "catalina.configFileProperty";

        System.setProperty(CONFIG_FILE_PROPERTY, configFile);

    // ----------------------------------------------------------- Constructor

    public Catalina() {

        setConfigFile(configFile);

    }

/**

 * 

 */

package org.apache.catalina.manager.host;

/**

 * @author Wesley

 *

 */

public class ServiceUpdateException extends RuntimeException {

    private static final long serialVersionUID = 7282583481793836635L;

    /**

     * @see RuntimeException#RuntimeException()

     */

    public ServiceUpdateException() {

        super();

        // TODO Auto-generated constructor stub

    }

    /**

     * @see RuntimeException#RuntimeException(String, Throwable)

     */

    public ServiceUpdateException(String message, Throwable cause) {

        super(message, cause);

        // TODO Auto-generated constructor stub

    }

    /**

     * @see RuntimeException#RuntimeException(String)

     */

    public ServiceUpdateException(String message) {

        super(message);

        // TODO Auto-generated constructor stub

    }

    /**

     * @see RuntimeException#RuntimeException(Throwable)

     */

    public ServiceUpdateException(Throwable cause) {

        super(cause);

        // TODO Auto-generated constructor stub

    }

}

/**

 * 

 */

package org.apache.catalina.manager.host;

/**

 * @author Wesley

 *

 */

public class ServiceParseException extends ServiceUpdateException {

    private static final long serialVersionUID = -3951000538081277024L;

    /**

     * @see RuntimeException#RuntimeException()

     */

    public ServiceParseException() {

    }

    /**

     * @see RuntimeException#RuntimeException(String)

     */

    public ServiceParseException(String message) {

        super(message);

    }

    /**

     * @see RuntimeException#RuntimeException(Throwable)

     */

    public ServiceParseException(Throwable cause) {

        super(cause);

    }

    /**

     * @see RuntimeException#RuntimeException(String, Throwable)

     */

    public ServiceParseException(String message, Throwable cause) {

        super(message, cause);

    }

}