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.webapp;

import java.io.File;

import java.io.IOException;

import java.net.ServerSocket;

import java.net.URI;

import java.net.URISyntaxException;

import java.net.URL;

import javax.management.InstanceNotFoundException;

import javax.management.MBeanException;

import javax.management.MBeanServerConnection;

import javax.management.MalformedObjectNameException;

import javax.management.ObjectName;

import javax.management.ReflectionException;

import javax.management.remote.JMXConnector;

import javax.management.remote.JMXConnectorFactory;

import javax.management.remote.JMXServiceURL;

import org.apache.log4j.Logger;

import org.eclipse.core.runtime.FileLocator;

import org.eclipse.core.runtime.Platform;

import org.eclipse.jetty.server.Server;

import org.eclipse.jetty.util.StringUtil;

import org.eclipse.jetty.util.preventers.AppContextLeakPreventer;

import org.eclipse.jetty.webapp.WebAppContext;

import org.osgi.framework.Bundle;

/**

 *

 * (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);

    private final String dataSourceName;

    private final String host = "127.0.0.1";

    private int httpPort = 9090;

    private final String contextPath = "/";

    private File warFile;

    private Server server;

    public CDMServer(String dataSourceName, File dataSourcesFile) throws CDMEmbeddedServerException {

        if(StringUtil.isBlank(dataSourceName)) {

            throw new CDMEmbeddedServerException("DataSource name is not valid");

        }

        if(dataSourcesFile == null || !dataSourcesFile.exists()) {

            throw new CDMEmbeddedServerException("DataSource config file does not exist");

        }

        this.dataSourceName = dataSourceName;

        Bundle bundle = Platform.getBundle("eu.etaxonomy.taxeditor.webapp");

        URL warURL = bundle.getEntry("lib/cdmlib-remote-webapp.war");

        try {

            URL resolvedWarURL = FileLocator.toFileURL(warURL);

            // We need to use the 3-arg constructor of URI in order to properly escape file system chars

            URI resolvedURI = new URI(resolvedWarURL.getProtocol(), resolvedWarURL.getPath(), null);

            warFile = new File(resolvedURI);

            System.out.println("war url : " + warFile.getAbsolutePath());

            if(warFile == null || !warFile.exists()) {

                throw new CDMEmbeddedServerException("Cdmlib War file does not exist");

            }

        } catch (URISyntaxException use) {

            throw new CDMEmbeddedServerException(use);

        } catch (IOException ioe) {

            throw new CDMEmbeddedServerException(ioe);

        }

        System.setProperty("spring.profiles.active", "remoting");

        System.setProperty("cdm.beanDefinitionFile", dataSourcesFile.getAbsolutePath());

        System.setProperty("cdm.datasource", dataSourceName);

        httpPort = findFreePort();

        logger.warn("Starting server on port : " + httpPort);

        server = new Server(httpPort);

        server.addBean(new AppContextLeakPreventer());

        WebAppContext webapp = new WebAppContext();

        webapp.setContextPath(contextPath);

        webapp.setWar(warFile.getAbsolutePath());

        webapp.setThrowUnavailableOnStartupException(true);

        server.setHandler(webapp);

    }

    public String getDataSourceName() {

        return dataSourceName;

    }

    public String getHost() {

        return host;

    }

    public int getPort() {

        return httpPort;

    }

    public String getContextPath() {

        return contextPath;

    }

    private static int findFreePort() throws CDMEmbeddedServerException {

        ServerSocket socket = null;

        try {

            socket = new ServerSocket(0);

            socket.setReuseAddress(true);

            int port = socket.getLocalPort();

            try {

                socket.close();

            } catch (IOException e) {

            }

            return port;

        } catch (IOException e) {

        } finally {

            if (socket != null) {

                try {

                    socket.close();

                } catch (IOException e) {

                }

            }

        }

        throw new CDMEmbeddedServerException("Could not find a free TCP/IP port to start embedded Jetty HTTP Server on");

    }

    public void start(ICDMServerError cdmServerError) throws CDMEmbeddedServerException {

        start(true, cdmServerError);

    }

    public void start(boolean wait, final ICDMServerError cdmServerError) throws CDMEmbeddedServerException {

        if(server == null) {

            throw new CDMEmbeddedServerException("Server is already disposed");

        }

        if(server.isStarting()) {

            throw new CDMEmbeddedServerException("Server is starting");

        }

        if(server.isStarted()) {

            throw new CDMEmbeddedServerException("Server has started");

        }

        if(server.isRunning()) {

            throw new CDMEmbeddedServerException("Server is running");

        }

        if(server.isStopping()) {

            throw new CDMEmbeddedServerException("Server is currently stopping. Please re-try in about 10 seconds");

        }

        Thread serverThread = new Thread() {

            @Override

            public void run() {

                try {

                    server.start();

                    server.join();

                } catch (Throwable t) {

                    //wait for 1sec to get the right order of login dialog and error

                    //message when connection fails

                    try {

                        Thread.sleep(1000);

                    } catch (InterruptedException e) {

                    }

                    cdmServerError.handleError(new RuntimeException("Error during CDM server startup", t));

                }

            }

        };

        serverThread.start();

        if(wait) {

            while(!server.isStarted()) {}

        }

    }

    public boolean isAlive()  {

        return server.isRunning() || server.isStarting() || server.isStarted();

    }

    public boolean isStarted() {

        return server.isStarted();

    }

    public boolean isFailed() {

        return server.isFailed();

    }

    public void stop() throws Exception {

        server.stop();

        server.destroy();

        server = null;

    }

    public static void stopServerViaJMX(int jmxPort) throws CDMEmbeddedServerException  {

        String JMX_URL = "service:jmx:rmi:///jndi/rmi://localhost:" + jmxPort + "/jmxrmi";

        logger.warn("Shutting down Jetty instance ... ");

        try {

            JMXConnector connector = JMXConnectorFactory.connect(new JMXServiceURL(JMX_URL), null);

            connector.connect(null);

            MBeanServerConnection connection = connector.getMBeanServerConnection();

            ObjectName objectName = new ObjectName("org.eclipse.jetty.server:type=server,id=0");

            connection.invoke(objectName, "stop", null, null);

            logger.warn("Shutdown command sent");

        } catch (InstanceNotFoundException e) {

            throw new CDMEmbeddedServerException(e);

        } catch (MBeanException e) {

            throw new CDMEmbeddedServerException(e);

        } catch (ReflectionException e) {

            throw new CDMEmbeddedServerException(e);

        } catch (IOException e) {

            throw new CDMEmbeddedServerException(e);

        } catch (MalformedObjectNameException e) {

            throw new CDMEmbeddedServerException(e);

        }

    }

}