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.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.WEBAPP;

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

import java.io.File;

import java.io.FileNotFoundException;

import java.io.FileOutputStream;

import java.io.IOException;

import java.io.InputStream;

import java.io.OutputStream;

import java.lang.management.ManagementFactory;

import java.lang.reflect.InvocationTargetException;

import java.net.URL;

import java.sql.Connection;

import java.sql.SQLException;

import java.util.Set;

import javax.naming.NamingException;

import javax.sql.DataSource;

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.server.Server;

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

import org.eclipse.jetty.util.component.LifeCycle;

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

import org.eclipse.jetty.webapp.WebAppClassLoader;

import org.eclipse.jetty.webapp.WebAppContext;

import eu.etaxonomy.cdm.server.CdmInstanceProperties.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 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 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 CDM_WEBAPP_WAR_NAME = "cdmserver";

    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 + CDM_WEBAPP_WAR_NAME);

    private static final String ATTRIBUTE_JDBC_JNDI_NAME = "cdm.jdbcJndiName";

    private static final String CDM_LOGFILE = "cdm.logfile";

    // memory requirements

    private static final long MB = 1024 * 1024;

    private static final long PERM_GEN_SPACE_PER_INSTANCE = 64 * MB;

    private static final long HEAP_PER_INSTANCE = 300 * MB;

    private static final int KB = 1024;

    private Set<CdmInstanceProperties> configAndStatus = null;

    public Set<CdmInstanceProperties> getConfigAndStatus() {

		return configAndStatus;

	}

	private File webappFile = null;

    private File defaultWebAppFile = null;

    private Server server = null;

    private ContextHandlerCollection contexts = new ContextHandlerCollection();

    private CommandLine cmdLine;

    /* thread save singleton implementation */

	private static Bootloader instance = new Bootloader();

    private Bootloader() {}

    public synchronized static Bootloader getBootloader(){

    	return instance;

    }

    /* end of singleton implementation */

    private Set<CdmInstanceProperties> loadDataSources(){

    	if(configAndStatus == null){

    		File datasourcesFile = new File(USERHOME_CDM_LIBRARY_PATH, DATASOURCE_BEANDEF_FILE); 

    		configAndStatus = DataSourcePropertyParser.parseDataSourceConfigs(datasourcesFile);

        	logger.info("cdm server instance names loaded: "+ configAndStatus.toString());

    	}

    	return configAndStatus;

    }

    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;

    }

	private boolean bindJndiDataSource(CdmInstanceProperties conf) {

		try {

			Class<DataSource> dsCass = (Class<DataSource>) Thread.currentThread().getContextClassLoader().loadClass("com.mchange.v2.c3p0.ComboPooledDataSource");

			DataSource datasource = dsCass.newInstance();

			dsCass.getMethod("setDriverClass", new Class[] {String.class}).invoke(datasource, new Object[] {conf.getDriverClass()});

			dsCass.getMethod("setJdbcUrl", new Class[] {String.class}).invoke(datasource, new Object[] {conf.getUrl()});

			dsCass.getMethod("setUser", new Class[] {String.class}).invoke(datasource, new Object[] {conf.getUsername()});

			dsCass.getMethod("setPassword", new Class[] {String.class}).invoke(datasource, new Object[] {conf.getPassword()});

			Connection connection = null;

			String sqlerror = null;

			try {

				connection = datasource.getConnection();

				connection.close();

			} catch (SQLException e) {

				sqlerror = e.getMessage() + "["+ e.getSQLState() + "]";

				conf.getProblems().add(sqlerror);

				if(connection !=  null){

					try {connection.close();} catch (SQLException e1) { /* IGNORE */ }

				}

				logger.error(conf.toString() + " has problem : "+ sqlerror );

			}

			if(!conf.hasProblems()){

				logger.info("binding jndi datasource at " + conf.getJdbcJndiName() + " with "+conf.getUsername() +"@"+ conf.getUrl());

				org.eclipse.jetty.plus.jndi.Resource jdbcResource = new org.eclipse.jetty.plus.jndi.Resource(conf.getJdbcJndiName(), datasource);

				return true;				

			}

		} catch (IllegalArgumentException e) {

			logger.error(e);

			e.printStackTrace();

		} catch (SecurityException e) {

			logger.error(e);

		} catch (ClassNotFoundException e) {

			logger.error(e);

		} catch (InstantiationException e) {

			logger.error(e);

		} catch (IllegalAccessException e) {

			logger.error(e);

		} catch (InvocationTargetException e) {

			logger.error(e);

		} catch (NoSuchMethodException e) {

			logger.error(e);

		} catch (NamingException e) {

			logger.error(e);

		}

		return false;

	}

	private 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.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;

    	URL resource = classLoader.getResource(warFileName);

    	if (resource == null) {

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

    		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();

    }

	private void startServer() throws IOException,

			FileNotFoundException, Exception, InterruptedException {

		//assure LOG_PATH exists

		File logPath = new File(LOG_PATH);

		if(!logPath.exists()){

			FileUtils.forceMkdir(new File(LOG_PATH));

		}

		//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;

    	 // WARFILE

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

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

    		 if(webappFile.isDirectory()){

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

    		 } else {

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

    		 }

    		 if(isRunningFromSource()){

    			 //FIXME check if all local paths are valid !!!!

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

    	     } else {

    	    	//defaultWebAppFile = extractWar(DEFAULT_WEBAPP_WAR_NAME);

    	     }

    	 } else {    	 

    		 webappFile = extractWar(CDM_WEBAPP_WAR_NAME);

    		 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())){

    		 logger.error(DATASOURCES_FILE.getOpt() + " NOT JET IMPLEMENTED!!!");

    	 }

    	loadDataSources();

    	verifyMemoryRequirements();

		server = new Server(httpPort);

		// 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 servelet contexts

		//

		// 1. default context

		//

		logger.info("preparing default WebAppContext");

    	WebAppContext defaultWebappContext = new WebAppContext();

    	setWebApp(defaultWebappContext, defaultWebAppFile);

        defaultWebappContext.setContextPath("/");

        defaultWebappContext.setTempDirectory(DEFAULT_WEBAPP_TEMP_FOLDER);

        // 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);

    	//

		// 2. cdm server contexts

    	//

    	server.addLifeCycleListener(new LifeCycle.Listener(){

			@Override

			public void lifeCycleFailure(LifeCycle event, Throwable cause) {

			}

			@Override

			public void lifeCycleStarted(LifeCycle event) {

				logger.info("cdmserver has started, now adding CDM server contexts");

				try {

					addCdmServerContexts(true);

				} catch (IOException e1) {

					logger.error(e1);

				}		

			}

			@Override

			public void lifeCycleStarting(LifeCycle event) {

			}

			@Override

			public void lifeCycleStopped(LifeCycle event) {

			}

			@Override

			public void lifeCycleStopping(LifeCycle event) {

			}

			});

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

        server.setHandler(contexts);

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

        	logger.info("jetty is waiting to be started as win32 service");

        } else {

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

	        server.start();

	        server.join();

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

	    	System.exit(0);

        }

	}

	/**

	 * 

	 */

	private void verifyMemoryRequirements() {

		verifyMemoryRequirement("PermGenSpace", PERM_GEN_SPACE_PER_INSTANCE, JvmManager.getPermGenSpaceUsage().getMax());

		verifyMemoryRequirement("HeapSpace", HEAP_PER_INSTANCE, JvmManager.getHeapMemoryUsage().getMax());

	}

	private void verifyMemoryRequirement(String memoryName, long requiredSpacePerIntance, long availableSpace) {

		long requiredSpace = configAndStatus.size() * requiredSpacePerIntance;

		if(requiredSpace > availableSpace){

			String message = memoryName + " (" 

				+ (availableSpace / MB)  

				+ "MB) insufficient for " 

				+ configAndStatus.size()

				+ " instances. Increase " + memoryName + " by " 

				+ ((requiredSpace - availableSpace)/MB) 

				+ "MB";

				;

			logger.error(message + " => disabling some instances!!!");

			// disabling some instances 

			int i=0;

			for(CdmInstanceProperties instanceProps : configAndStatus){

				i++;

				if(i * requiredSpacePerIntance > availableSpace){

					instanceProps.setStatus(Status.disabled);

					instanceProps.getProblems().add("Disbled due to: " + message);

				}

			}

		}

	}

	/**

	 * 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 = LOG_PATH + 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);

		}

	}

	private void addCdmServerContexts(boolean austostart) throws IOException {

		for(CdmInstanceProperties conf : configAndStatus){

			if(!conf.isEnabled()){

				logger.info(conf.getDataSourceName() + " is disabled => skipping");

				continue;

			}

			conf.setStatus(CdmInstanceProperties.Status.initializing);

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

        	WebAppContext cdmWebappContext = new WebAppContext();

	        cdmWebappContext.setContextPath("/"+conf.getDataSourceName());

	        cdmWebappContext.setTempDirectory(CDM_WEBAPP_TEMP_FOLDER);

            if(!bindJndiDataSource(conf)){

            	// a problem with the datasource occurred skip this webapp

            	cdmWebappContext = null;

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

				conf.setStatus(CdmInstanceProperties.Status.error);

            	continue;

            }

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

	        setWebApp(cdmWebappContext, webappFile);

			cdmWebappContext.setAttribute(CDM_LOGFILE,

					LOG_PATH + File.separator + "cdm-"

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

	        if(webappFile.isDirectory() && 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.

				 */

        		logger.info("Running webapp from source folder, thus adding java.class.path to WebAppClassLoader");

        		WebAppClassLoader classLoader = new WebAppClassLoader(cdmWebappContext);

	        	String classPath = System.getProperty("java.class.path");

	        	classLoader.addClassPath(classPath);

	        	cdmWebappContext.setClassLoader(classLoader);

        	}

	        contexts.addHandler(cdmWebappContext);  

	        if(austostart){

		        try {

		        	conf.setStatus(CdmInstanceProperties.Status.starting);

					cdmWebappContext.start();

					conf.setStatus(CdmInstanceProperties.Status.started);

				} catch (Exception e) {

					logger.error("Could not start " + cdmWebappContext.getContextPath());

					conf.setStatus(CdmInstanceProperties.Status.error);

				}

	        }

        }

	}

	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 boolean isRunningFromSource() {

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

		return webappPathNormalized.endsWith("src/main/webapp") || webappPathNormalized.endsWith("cdmlib-remote/target/cdmserver");

	}

}