EDIT

// $Id$

/**

 * Copyright (C) 2014 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.taxeditor.httpinvoker;

import java.io.BufferedReader;

import java.io.IOException;

import java.io.InputStreamReader;

import java.net.Socket;

import javax.sql.DataSource;

import org.apache.log4j.Level;

import org.apache.log4j.Logger;

import org.springframework.core.io.ClassPathResource;

import org.springframework.core.io.Resource;

import org.unitils.database.annotations.TestDataSource;

import org.unitils.spring.annotation.SpringApplicationContext;

import eu.etaxonomy.taxeditor.exception.CDMServerException;

import eu.etaxonomy.taxeditor.remoting.source.CdmRemoteSourceBase;

/**

 *

 * (Singleton) Server instance which manages a compatible cdmlib-webapp-war.

 * This is done by launching a jetty instance (using jetty-runner) as an

 * executed process. The choice of the external process over a more

 * preferable 'embedded jetty' instance is due to problems arising from the

 * class loading of classes (e.g. from hibernate core) which are needed

 * for both the webapp as well as the remoting client.

 *

 * @author cmathew

 * @date 23 Sep 2014

 *

 */

public class CDMServer {

    public static final Logger logger = Logger.getLogger(CDMServer.class);

    @TestDataSource

    protected DataSource dataSource;

    private final String name = "default";

    private final String host = "127.0.0.1";

    private final int port = 9090;

    private final int stopPort = 9191;

    private final String stopKey = "jetty-cdm-server";

    private final String contextPath = "";

    private boolean keepServerRunning = false;

    public static final Resource DEFAULT_CDM_WEBAPP_RESOURCE =

            new ClassPathResource("/etc/jetty/cdmlib-remote-webapp.war");

    public static final Resource DEFAULT_JETTY_CONFIG_RESOURCE =

            new ClassPathResource("/etc/jetty/jetty.xml");

    public static final Resource DEFAULT_JETTY_TEMP_RESOURCE =

            new ClassPathResource("/etc/jetty/temp");

    public static final Resource DEFAULT_JETTY_TEMP_WAR_LIB_RESOURCE =

            new ClassPathResource("/etc/jetty/temp/webapp/WEB-INF/lib");

    public static final Resource DEFAULT_DATASOURCE_FILE =

            new ClassPathResource("datasources.xml");

    public static final Resource DEFAULT_JETTY_RUNNER_RESOURCE =

            new ClassPathResource("/etc/jetty/jetty-runner-9.2.3.v20140905.jar");

    public static final Resource DEFAULT_JETTY_RESOURCE =

            new ClassPathResource("/etc/jetty/start-9.2.3.v20140905.jar");

    private static CDMServer cdmServer = null;

    private static CDMServerException cdmse = null;

    private void CDMServer() {

        logger.setLevel(Level.INFO);

    }

    public static CDMServer getInstance() {

        if(cdmServer == null) {

            cdmServer = new CDMServer();

        }

        return cdmServer;

    }

    public String getName() {

        return name;

    }

    public String getHost() {

        return host;

    }

    public int getPort() {

        return port;

    }

    public String getContextPath() {

        return contextPath;

    }

    public boolean getKeepServerRunning() {

        return keepServerRunning;

    }

    public void setKeepServerRunning(boolean keepServerRunning) {

        this.keepServerRunning = keepServerRunning;

    }

    public static boolean isRunningInEclipse() {

        return (System.getProperty("sun.java.command") != null &&

                System.getProperty("sun.java.command").startsWith("org.eclipse.jdt.internal.junit.runner.RemoteTestRunner"));

    }

    private String getVMArgs() throws IOException {

        StringBuilder sb = new StringBuilder();

        sb.append(" -Dspring.profiles.active=remoting");

        sb.append(" -Dcdm.beanDefinitionFile=" + DEFAULT_DATASOURCE_FILE.getFile().getAbsolutePath());

        sb.append(" -Dcdm.datasource=cdmTest");

        return sb.toString();

    }

    private String getStartServerArgs() {

        StringBuilder sb = new StringBuilder();

        sb.append(" --port ");

        sb.append(port);

        return sb.toString();

    }

    private String getStopServerSettings() {

        StringBuilder sb = new StringBuilder();

        sb.append(" --stop-port ");

        sb.append(stopPort);

        sb.append(" --stop-key ");

        sb.append(stopKey);

        return sb.toString();

    }

    private String getStopServerArgs() {

        StringBuilder sb = new StringBuilder();

        sb.append(" STOP.PORT=");

        sb.append(stopPort);

        sb.append(" STOP.KEY=");

        sb.append(stopKey);

        return sb.toString();

    }

    public void start() throws CDMServerException {

        /**

         * First check if the CDM server responds to a service request, which implies that

         * the server has started properly. If no response is received then check if the

         * server is listening on specific host / port, which implies that the server

         * has started but incorrectly, in which case we try to force stop it (if we can)

         * and start a new server.

         */

        if(isRunning(1)) {

            logger.info("[CDM-Server] Server already running @ " + host + ":" + port );

            return;

        } else if (isAvailable(1)){

            logger.info("[CDM-Server] Server available, but not started correctly @ " + host + ":" + port );

            logger.info("[CDM-Server] .... trying to force stop server @ " + host + ":" + port );

            try {

                stop(true);

            } catch (Exception e) {

                throw new CDMServerException("CDM Server could not be stopped : " + e.getMessage());

            }

        }

        Thread t = new Thread() {

            @Override

            public void run() {

                StringBuffer output = new StringBuffer();

                try{

                    Process p;

                    String command = "java "

                            + getVMArgs()

                            + " -jar "

                            + DEFAULT_JETTY_RUNNER_RESOURCE.getFile().getAbsolutePath()

                            + getStartServerArgs()

                            + getStopServerSettings()

                            + " "

                            + DEFAULT_CDM_WEBAPP_RESOURCE.getFile().getAbsolutePath();

                    logger.info("[CDM-Server] Starting server with Command : " + command);

                    p = Runtime.getRuntime().exec(command);

                    BufferedReader reader =

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

                    String line = "";

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

                        logger.info("[CDM-Server] Start : " + line);

                    }

                } catch (Exception e) {

                    e.printStackTrace();

                    cdmse = new CDMServerException(e);

                }

            }

        };

        t.setDaemon(true);

        cdmse = null;

        t.start();

        if(isRunning(50)) {

            logger.info("[CDM-Server] Started Server @ " + host + ":" + port );

        } else {

            logger.info("[CDM-Server] Server not started within given interval");

            // making sure to kill server if it is not started correctly

            try {

                stop(true);

            } catch (Exception e) {

                throw new CDMServerException("CDM Server could not be stopped : " + e.getMessage());

            }

            throw new CDMServerException("CDM Server not started : ");

        }

    }

    public boolean isAvailable(int checkingIntervals) throws CDMServerException {

        int intervalsCount = 0;

        do {

            try {

                Socket s = new Socket(host, port);

                logger.info("[CDM-Server] Available @ " + host + ":" + port );

                return true;

            } catch (IOException ioe) {

            }

            try {

                Thread.sleep(1000);

            } catch (InterruptedException ie) {

                throw new CDMServerException("Error checking CDM Server status", ie);

            }

            intervalsCount++;

        } while (intervalsCount < checkingIntervals);

        return false;

    }

    public boolean isStopped(int checkingIntervals) throws CDMServerException {

        int intervalsCount = 0;

        do {

            try {

                Socket s = new Socket(host, port);

            } catch (IOException ioe) {               

                return true;

            }

            try {

                Thread.sleep(1000);

            } catch (InterruptedException ie) {

                throw new CDMServerException("Error checking CDM Server status", ie);

            }

            intervalsCount++;

        } while (intervalsCount < checkingIntervals);

        return false;

    }

    public boolean isRunning(int checkingIntervals) throws CDMServerException  {

        CdmRemoteSourceBase crsb = new CdmRemoteSourceBase("local-cdm-server",

                host,

                port,

                contextPath,

                null);

        int intervalsCount = 0;

        do {

            try {

                if(cdmse != null) {

                    return false;

                }

                if(crsb.checkConnection()) {

                    logger.info("[CDM-Server] Running @ " + host + ":" + port );

                    return true;

                }

            } catch (Exception e) {

            }

            try {

                Thread.sleep(1000);

            } catch (InterruptedException ie) {

                throw new CDMServerException("Error checking CDM Server status", ie);

            }

            intervalsCount++;

        } while (intervalsCount < checkingIntervals);

        return false;

    }

    public void stop() throws Exception {

        stop(false);

    }

    public void stop(boolean force) throws Exception {

        if(!force) {

            if(!getInstance().isAvailable(1)) {

                logger.info("[CDM-Server] Server already stopped @ " + host + ":" + port );

                return;

            }

            if(getInstance().getKeepServerRunning()) {

                logger.info("[CDM-Server] Server @ " + host + ":" + port + " is set to keep running");

                return;

            }

        }

        Thread t = new Thread() {

            @Override

            public void run() {

                StringBuffer output = new StringBuffer();

                try{

                    Process p;

                    String command = "java -jar " + DEFAULT_JETTY_RESOURCE.getFile().getAbsolutePath()

                            + getStopServerArgs() + " --stop ";

                    logger.info("[CDM-Server] Stop Command : " + command);

                    p = Runtime.getRuntime().exec(command);

                    p.waitFor();

                    BufferedReader reader =

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

                    String line = "";

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

                        logger.info("CDM-Server Stop : " + line + "\n");

                    }

                } catch (Exception e) {

                    e.printStackTrace();

                }

            }

        };

        t.setDaemon(true);

        t.start();

        if(isStopped(5)) {

            logger.info("[CDM-Server] Stopped Server @ " + host + ":" + port );

        } else {

            logger.info("[CDM-Server] Could not stop @ " + host + ":" + port + ". Please kill it manually");

        }

    }

}