EDIT

// $Id$

/**

 * Copyright (C) 2009 EDIT

 * European Distributed Institute of Taxonomy

 * http://www.e-taxonomy.eu

 *

 * The contents of this file are subject to the Mozilla Public License Version 1.1

 * See LICENSE.TXT at the top of this package for the full license terms.

 */

package eu.etaxonomy.cdm.server;

import static eu.etaxonomy.cdm.server.AssumedMemoryRequirements.KB;

import static eu.etaxonomy.cdm.server.CommandOptions.DATASOURCES_FILE;

import static eu.etaxonomy.cdm.server.CommandOptions.HELP;

import static eu.etaxonomy.cdm.server.CommandOptions.HTTP_PORT;

import static eu.etaxonomy.cdm.server.CommandOptions.JMX;

import static eu.etaxonomy.cdm.server.CommandOptions.LOG_DIR;

import static eu.etaxonomy.cdm.server.CommandOptions.WEBAPP;

import static eu.etaxonomy.cdm.server.CommandOptions.WEBAPP_CLASSPATH;

import static eu.etaxonomy.cdm.server.CommandOptions.WIN32SERVICE;

import java.io.BufferedReader;

import java.io.File;

import java.io.FileNotFoundException;

import java.io.FileOutputStream;

import java.io.IOException;

import java.io.InputStream;

import java.io.InputStreamReader;

import java.io.OutputStream;

import java.lang.management.ManagementFactory;

import java.net.URL;

import java.util.List;

import java.util.Properties;

import org.apache.commons.cli.CommandLine;

import org.apache.commons.cli.CommandLineParser;

import org.apache.commons.cli.GnuParser;

import org.apache.commons.cli.HelpFormatter;

import org.apache.commons.cli.ParseException;

import org.apache.commons.io.FileUtils;

import org.apache.log4j.Logger;

import org.apache.log4j.PatternLayout;

import org.apache.log4j.RollingFileAppender;

import org.eclipse.jetty.jmx.MBeanContainer;

import org.eclipse.jetty.security.HashLoginService;

import org.eclipse.jetty.server.Handler;

import org.eclipse.jetty.server.Server;

import org.eclipse.jetty.server.handler.ContextHandler;

import org.eclipse.jetty.server.handler.ContextHandlerCollection;

import org.eclipse.jetty.util.log.Log;

import org.eclipse.jetty.webapp.WebAppClassLoader;

import org.eclipse.jetty.webapp.WebAppContext;

import eu.etaxonomy.cdm.server.instance.CdmInstance;

import eu.etaxonomy.cdm.server.instance.Configuration;

import eu.etaxonomy.cdm.server.instance.InstanceManager;

import eu.etaxonomy.cdm.server.instance.SharedAttributes;

import eu.etaxonomy.cdm.server.instance.Status;

import eu.etaxonomy.cdm.server.win32service.Win32Service;

/**

 * A bootstrap class for starting Jetty Runner using an embedded war.

 *

 * Recommended start options for the java virtual machine:

 * <pre>

 * -Xmx1024M

 *

 * -XX:PermSize=128m

 * -XX:MaxPermSize=192m

 *

 * -XX:+UseConcMarkSweepGC

 * -XX:+CMSClassUnloadingEnabled

 * -XX:+CMSPermGenSweepingEnabled

 * </pre>

 *

 * @version $Revision$

 */

public final class Bootloader {

    /**

     *

     */

    private static final String VERSION_PROPERTIES_FILE = "version.properties";

    //private static final String DEFAULT_WARFILE = "target/";

    private static final Logger logger = Logger.getLogger(Bootloader.class);

    private static final String DATASOURCE_BEANDEF_FILE = "datasources.xml";

    private static final String REALM_PROPERTIES_FILE = "cdm-server-realm.properties";

    private static final String USERHOME_CDM_LIBRARY_PATH = System.getProperty("user.home")+File.separator+".cdmLibrary"+File.separator;

    private static final String TMP_PATH = USERHOME_CDM_LIBRARY_PATH + "server" + File.separator;

    private static final String LOG_PATH = USERHOME_CDM_LIBRARY_PATH + "log" + File.separator;

    private static final String APPLICATION_NAME = "CDM Server";

    private static final String WAR_POSTFIX = ".war";

    private static final String CDMLIB_REMOTE_WEBAPP = "cdmlib-remote-webapp";

    private static final String CDMLIB_REMOTE_WEBAPP_VERSION = "cdmlib-remote-webapp.version";

    private static final String DEFAULT_WEBAPP_WAR_NAME = "default-webapp";

    private static final File DEFAULT_WEBAPP_TEMP_FOLDER = new File(TMP_PATH + DEFAULT_WEBAPP_WAR_NAME);

    private static final File CDM_WEBAPP_TEMP_FOLDER = new File(TMP_PATH + CDMLIB_REMOTE_WEBAPP);

    private final InstanceManager instanceManager = new InstanceManager(new File(USERHOME_CDM_LIBRARY_PATH, DATASOURCE_BEANDEF_FILE));

    public List<CdmInstance> getCdmInstances() {

        return instanceManager.getInstances();

    }

    public InstanceManager getInstanceManager(){

        return instanceManager;

    }

    private File cdmRemoteWebAppFile = null;

    private File defaultWebAppFile = null;

    private String logPath = null;

    private String webAppClassPath = null;

    private Server server = null;

    private final ContextHandlerCollection contexts = new ContextHandlerCollection();

    private CommandLine cmdLine;

    private boolean isRunningFromSource;

    private boolean isRunningfromTargetFolder;

    private boolean isRunningFromWarFile;

    /* thread save singleton implementation */

    private static Bootloader bootloader = new Bootloader();

    private Bootloader() {}

    /**

     * @return the thread save singleton instance of the Bootloader

     */

    public synchronized static Bootloader getBootloader(){

        return bootloader;

    }

    /* end of singleton implementation */

    /**

     * @param input

     * @param output

     * @param bufferSize

     * @return

     * @throws IOException

     */

    public int writeStreamTo(final InputStream input, final OutputStream output, int bufferSize) throws IOException {

        int available = Math.min(input.available(), 256 * KB);

        byte[] buffer = new byte[Math.max(bufferSize, available)];

        int answer = 0;

        int count = input.read(buffer);

        while (count >= 0) {

            output.write(buffer, 0, count);

            answer += count;

            count = input.read(buffer);

        }

        return answer;

    }

    public void parseCommandOptions(String[] args) throws ParseException {

        CommandLineParser parser = new GnuParser();

        cmdLine = parser.parse( CommandOptions.getOptions(), args );

         // print the help message

         if(cmdLine.hasOption(HELP.getOpt())){

             HelpFormatter formatter = new HelpFormatter();

             formatter.setWidth(200);

             formatter.printHelp( "java .. ", CommandOptions.getOptions() );

             System.exit(0);

         }

    }

    private File extractWar(String warName) throws IOException, FileNotFoundException {

        ClassLoader classLoader = Thread.currentThread().getContextClassLoader();

        String warFileName = warName + WAR_POSTFIX;

        // 1. find in classpath

        URL resource = classLoader.getResource(warFileName);

        if (resource == null) {

            logger.error("Could not find the " + warFileName + " on classpath!");

            File pomxml = new File("pom.xml");

            if(pomxml.exists()){

                // 2. try finding in target folder of maven project

                File warFile = new File("target" + File.separator + warFileName);

                logger.debug("looking for war file at " + warFile.getAbsolutePath());

                if (warFile.canRead()) {

                    resource = warFile.toURI().toURL();

                } else {

                    logger.error("Also could not find the " + warFileName + " in maven project, try excuting 'mvn install'");

                }

            }

        }

        if (resource == null) {

            // no way finding the war file :-(

            System.exit(1);

        }

        File warFile = new File(TMP_PATH, warName + "-" + WAR_POSTFIX);

        logger.info("Extracting " + warFileName + " to " + warFile + " ...");

        writeStreamTo(resource.openStream(), new FileOutputStream(warFile), 8 * KB);

        logger.info("Extracted " + warFileName);

        return warFile;

    }

    /**

     * MAIN METHOD

     *

     * @param args

     * @throws Exception

     */

    public static void main(String[] args) throws Exception {

        Bootloader bootloader = Bootloader.getBootloader();

        bootloader.parseCommandOptions(args);

        bootloader.startServer();

    }

    public void startServer() throws IOException,

            FileNotFoundException, Exception, InterruptedException {

        if(cmdLine.hasOption(LOG_DIR.getOpt())){

            logPath = cmdLine.getOptionValue(LOG_DIR.getOpt());

        } else {

            logPath = LOG_PATH;

        }

        //assure LOG_PATH exists

        File logPathFile = new File(logPath);

        if(!logPathFile.exists()){

            FileUtils.forceMkdir(new File(logPath));

        }

        //append logger

        configureFileLogger();

        logger.info("Starting "+APPLICATION_NAME);

        logger.info("Using  " + System.getProperty("user.home") + " as home directory. Can be specified by -Duser.home=<FOLDER>");

        //assure TMP_PATH exists and clean it up

        File tempDir = new File(TMP_PATH);

        if(!tempDir.exists() && !tempDir.mkdirs()){

            logger.error("Error creating temporary directory for webapplications " + tempDir.getAbsolutePath());

            System.exit(-1);

        } else {

            if(FileUtils.deleteQuietly(tempDir)){

                tempDir.mkdirs();

                logger.info("Old webapplications successfully cleared");

            }

        }

        tempDir = null;

        // WEBAPP options

        //   prepare web application files to run either from war files (production mode)

        //   or from source (development mode)

        if(cmdLine.hasOption(WEBAPP.getOpt())){

            cdmRemoteWebAppFile = new File(cmdLine.getOptionValue(WEBAPP.getOpt()));

            if(cdmRemoteWebAppFile.isDirectory()){

                logger.info("using user defined web application folder: " + cdmRemoteWebAppFile.getAbsolutePath());

            } else {

                logger.info("using user defined warfile: " + cdmRemoteWebAppFile.getAbsolutePath());

            }

            updateServerRunMode();

            // load the default-web-application from source if running in development mode mode

            if(isRunningFromWarFile){

                defaultWebAppFile = extractWar(DEFAULT_WEBAPP_WAR_NAME);

            } else {

                defaultWebAppFile = new File("./src/main/webapp");

            }

            if(isRunningFromSource){

                if(cmdLine.hasOption(WEBAPP_CLASSPATH.getOpt())){

                    String classPathOption = cmdLine.getOptionValue(WEBAPP_CLASSPATH.getOpt());

                    normalizeClasspath(classPathOption);

                }

            }

        } else {

            // read version number

            String version = readCdmRemoteVersion();

            cdmRemoteWebAppFile = extractWar(CDMLIB_REMOTE_WEBAPP + "-" + version);

            defaultWebAppFile = extractWar(DEFAULT_WEBAPP_WAR_NAME);

        }

        // HTTP Port

        int httpPort = 8080;

        if(cmdLine.hasOption(HTTP_PORT.getOpt())){

            try {

               httpPort = Integer.parseInt(cmdLine.getOptionValue(HTTP_PORT.getOpt()));

               logger.info(HTTP_PORT.getOpt()+" set to "+cmdLine.getOptionValue(HTTP_PORT.getOpt()));

           } catch (NumberFormatException e) {

               logger.error("Supplied portnumber is not an integer");

               System.exit(-1);

           }

        }

         if(cmdLine.hasOption(DATASOURCES_FILE.getOpt())){

             File datasourcesFile = new File(cmdLine.getOptionValue(DATASOURCES_FILE.getOpt()));

             if(datasourcesFile.canRead()) {

                instanceManager.setDatasourcesFile(datasourcesFile);

            } else {

                logger.error("File set as " + DATASOURCES_FILE.getOpt()

                        + " (" + cmdLine.getOptionValue(DATASOURCES_FILE.getOpt())

                        + ") is not readable.");

            }

         }

        verifySystemResources();

         // load the configured instances for the first time

        instanceManager.reLoadInstanceConfigurations();

        server = new Server(httpPort);

        server.addLifeCycleListener(instanceManager);

        // JMX support

        if(cmdLine.hasOption(JMX.getOpt())){

            logger.info("adding JMX support ...");

            MBeanContainer mBeanContainer = new MBeanContainer(ManagementFactory.getPlatformMBeanServer());

            server.getContainer().addEventListener(mBeanContainer);

            mBeanContainer.addBean(Log.getLog());

            mBeanContainer.start();

        }

        if(cmdLine.hasOption(WIN32SERVICE.getOpt())){

            Win32Service win32Service = new Win32Service();

            win32Service.setServer(server);

            server.setStopAtShutdown(true);

            server.addBean(win32Service);

        }

        // add default servlet context

        logger.info("preparing default WebAppContext");

        WebAppContext defaultWebappContext = new WebAppContext();

        setWebApp(defaultWebappContext, defaultWebAppFile);

        defaultWebappContext.setContextPath("/");

        defaultWebappContext.setTempDirectory(DEFAULT_WEBAPP_TEMP_FOLDER);

        // configure security context

        // see for reference * http://docs.codehaus.org/display/JETTY/Realms

        //                   * http://wiki.eclipse.org/Jetty/Starting/Porting_to_Jetty_7

        HashLoginService loginService = new HashLoginService();

        loginService.setConfig(USERHOME_CDM_LIBRARY_PATH + REALM_PROPERTIES_FILE);

        defaultWebappContext.getSecurityHandler().setLoginService(loginService);

        // Important:

        // the defaultWebappContext MUST USE the super classloader

        // otherwise the status page (index.jsp) might not work

        defaultWebappContext.setClassLoader(this.getClass().getClassLoader());

        contexts.addHandler(defaultWebappContext);

        logger.info("setting contexts ...");

        server.setHandler(contexts);

        logger.info("starting jetty ...");

//        try {

            server.start();

//        } catch(org.springframework.beans.BeansException e){

//        	Throwable rootCause = null;

//        	while(e.getCause() != null){

//        		rootCause = e.getCause();

//        	}

//        	if(rootCause != null && rootCause.getClass().getSimpleName().equals("InvalidCdmVersionException")){

//

//        		logger.error("rootCause ----------->" + rootCause.getMessage());

////        		for(CdmInstanceProperties props : configAndStatus){

////        			if(props.getDataSourceName())

////        		}

//        	}

//        }

        if(cmdLine.hasOption(WIN32SERVICE.getOpt())){

            logger.info("jetty has started as win32 service");

        } else {

            server.join();

            logger.info(APPLICATION_NAME+" stopped.");

            System.exit(0);

        }

    }

    /**

     * @param classpath

     */

    private void normalizeClasspath(String classpath) {

        StringBuilder classPathBuilder = new StringBuilder((int) (classpath.length() * 1.2));

        String[] cpEntries = classpath.split("[\\:]");

        for(String cpEntry : cpEntries){

            classPathBuilder.append(',');

//            if(cpEntry.endsWith(".jar")){

//                classPathBuilder.append("jar:");

//            }

            classPathBuilder.append(cpEntry);

        }

        webAppClassPath = classPathBuilder.toString();

    }

    public String readCdmRemoteVersion() throws IOException {

        String version = "cdmlib version unreadable";

        InputStream versionInStream = Bootloader.class.getClassLoader().getResourceAsStream(VERSION_PROPERTIES_FILE);

        if (versionInStream != null){

            Properties versionProperties = new Properties();

            versionProperties.load(versionInStream);

            version = versionProperties.getProperty(CDMLIB_REMOTE_WEBAPP_VERSION, version);

        }

        return version;

    }

    private void verifySystemResources() {

        OsChecker osChecker = new OsChecker();

        if(osChecker.isLinux()){

            try {

                Process p = Runtime.getRuntime().exec(new String[] { "bash", "-c", "ulimit -n" });

                BufferedReader in = new BufferedReader(new InputStreamReader(p.getInputStream()));

                String line;

                StringBuilder response = new StringBuilder();

                     while ((line = in.readLine()) != null) {

                         response.append(line);

                     }

               logger.info("OS Limit (Linux): maximum number of open files: " + response);

            } catch (IOException e) {

                // TODO Auto-generated catch block

                e.printStackTrace();

            }

        } else {

            logger.info("verifySystemResources only implemented for linux");

        }

    }

    /**

     * Configures and adds a {@link RollingFileAppender} to the root logger

     *

     * The log files of the cdm-remote instances are configured by the

     * {@link eu.etaxonomy.cdm.remote.config.LoggingConfigurer}

     */

    private void configureFileLogger() {

        PatternLayout layout = new PatternLayout("%d %p [%c] - %m%n");

        try {

            String logFile = logPath + File.separator + "cdmserver.log";

            RollingFileAppender appender = new RollingFileAppender(layout, logFile);

            appender.setMaxBackupIndex(3);

            appender.setMaxFileSize("2MB");

            Logger.getRootLogger().addAppender(appender);

            logger.info("logging to :" + logFile);

        } catch (IOException e) {

            logger.error("Creating RollingFileAppender failed:", e);

        }

    }

    /**

     * Adds a new WebAppContext to the contexts of the running jetty instance.

     * <ol>

     * <li>Initialize WebAppContext:

     * <ol>

     * <li>set context path</li>

     * <li>set tmp directory</li>

     * <li>bind JndiDataSource</li>

     * <li>set web app context attributes</li>

     * <li>create and setup individual classloader for the instance</li>

     * </ol>

     * </li>

     * <li>

     * finally add the new webappcontext to the contexts of the jetty instance</li>

     * </ol>

     *

     * @param instance

     * @return the instance given as parameter of null in case the instance has

     *         {@link Status.#disabled} or if it is already added.

     * @throws IOException

     */

    public WebAppContext addCdmInstanceContext(CdmInstance instance) throws IOException {

        Configuration conf = instance.getConfiguration();

        if(!instance.isEnabled()){

            logger.info(conf.getInstanceName() + " is disabled, possibly due to JVM memory limitations");

            return null;

        }

        if(getContextFor(conf) != null){

            logger.info(conf.getInstanceName() + " is alreaddy added to the contexts - skipping");

            return null;

        }

        instance.setStatus(Status.initializing);

        logger.info("preparing WebAppContext for '"+ conf.getInstanceName() + "'");

        WebAppContext cdmWebappContext = new WebAppContext();

        cdmWebappContext.setContextPath(constructContextPath(conf));

        cdmWebappContext.setTempDirectory(CDM_WEBAPP_TEMP_FOLDER);

        if(!instance.bindJndiDataSource()){

            // a problem with the datasource occurred skip this webapp

            cdmWebappContext = null;

            logger.error("a problem with the datasource occurred -> skipping /" + conf.getInstanceName());

            instance.setStatus(Status.error);

            return cdmWebappContext;

        }

        cdmWebappContext.setAttribute(SharedAttributes.ATTRIBUTE_DATASOURCE_NAME, conf.getInstanceName());

        cdmWebappContext.setAttribute(SharedAttributes.ATTRIBUTE_JDBC_JNDI_NAME, conf.getJdbcJndiName());

        setWebApp(cdmWebappContext, getCdmRemoteWebAppFile());

        cdmWebappContext.setAttribute(SharedAttributes.ATTRIBUTE_CDM_LOGFILE,

                logPath + File.separator + "cdm-"

                        + conf.getInstanceName() + ".log");

        if( isRunningFromSource ){

            /*

             * when running the webapp from {projectpath} src/main/webapp we

             * must assure that each web application is using it's own

             * classloader thus we tell the WebAppClassLoader where the

             * dependencies of the webapplication can be found. Otherwise

             * the system classloader would load these resources.

             */

            WebAppClassLoader classLoader = new WebAppClassLoader(cdmWebappContext);

            if(webAppClassPath != null){

                logger.info("Running cdmlib-remote-webapp from source folder: Adding class path supplied by option '-" +  WEBAPP_CLASSPATH.getOpt() +" =" + webAppClassPath +"'  to WebAppClassLoader");

                classLoader.addClassPath(webAppClassPath);

            } else {

                throw new RuntimeException("Classpath cdmlib-remote-webapp for missing while running cdmlib-remote-webapp from source folder. Please supplied cdm-server option '-" +  WEBAPP_CLASSPATH.getOpt() +"");

            }

            cdmWebappContext.setClassLoader(classLoader);

        }

        contexts.addHandler(cdmWebappContext);

        instance.setWebAppContext(cdmWebappContext);

        cdmWebappContext.addLifeCycleListener(instance);

        instance.setStatus(Status.stopped);

        return cdmWebappContext;

    }

    /**

     * @param conf

     * @return

     */

    private String constructContextPath(Configuration conf) {

        return "/" + conf.getInstanceName();

    }

    /**

     * Removes the given instance from the contexts. If the instance is running

     * at the time of calling this method it will be stopped first.

     * The JndiDataSource and the webapplicationContext will be released and removed.

     *

     * @param instance the instance to be removed

     *

     * @throws Exception in case stopping the instance fails

     */

    public void removeCdmInstanceContext(CdmInstance instance) throws Exception {

        if(instance.getWebAppContext() != null){

            if(instance.getWebAppContext().isRunning()){

                try {

                    instance.getWebAppContext().stop();

                } catch (Exception e) {

                    instance.getProblems().add("Error while stopping instance: " + e.getMessage());

                    throw e;

                }

            }

            contexts.removeHandler(instance.getWebAppContext());

            instance.releaseWebAppContext();

        } else  {

            // maybe something went wrong before, try to find the potentially lost

            // contexts directly in the server

            ContextHandler handler = getContextFor(instance.getConfiguration());

            if(handler != null){

                contexts.removeHandler(handler);

            }

        }

        instance.unbindJndiDataSource();

    }

    /**

     * Sets the webapp specified by the <code>webApplicationResource</code> to

     * the given <code>context</code>.

     *

     * @param context

     * @param webApplicationResource the resource can either be a directory containing

     * a Java web application or *.war file.

     *

     */

    private void setWebApp(WebAppContext context, File webApplicationResource) {

        if(webApplicationResource.isDirectory()){

            context.setResourceBase(webApplicationResource.getAbsolutePath());

            logger.debug("setting directory " + webApplicationResource.getAbsolutePath() + " as webapplication");

        } else {

            context.setWar(webApplicationResource.getAbsolutePath());

            logger.debug("setting war file " + webApplicationResource.getAbsolutePath() + " as webapplication");

        }

    }

    private void updateServerRunMode() {

        String webappPathNormalized = cdmRemoteWebAppFile.getAbsolutePath().replace('\\', '/');

        isRunningFromSource =  webappPathNormalized.endsWith("src/main/webapp");

        isRunningfromTargetFolder = webappPathNormalized.endsWith("cdmlib-remote-webapp/target/cdmserver");

        isRunningFromWarFile = !(isRunningFromSource || isRunningfromTargetFolder);

    }

    public Server getServer() {

        return server;

    }

    public ContextHandler getContextFor(Configuration conf) {

        return getContextFor(constructContextPath(conf));

    }

    public ContextHandler getContextFor(String contextPath) {

        for( Handler handler : contexts.getHandlers()){

            if(handler instanceof ContextHandler){

                if(((ContextHandler)handler).getContextPath().equals(contextPath)){

                    return (ContextHandler)handler;

                }

            }

        }

        return null;

    }

    public ContextHandlerCollection getContexts() {

        return contexts;

    }

    /**

     * @return a File object pointing to the location of the cdmlib-remote-webapp

     */

    public File getCdmRemoteWebAppFile(){

        if(cdmRemoteWebAppFile == null){

            throw new RuntimeException("Invalid order of action. Server not yet started. The startServer() method must be called first. ");

        }

        return cdmRemoteWebAppFile;

    }

}