package org.apache.commons.jcs3.auxiliary.remote.server;
   
   /*
    * 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.
   */
  
  import java.io.IOException;
  import java.net.InetAddress;
  import java.net.MalformedURLException;
  import java.rmi.Naming;
  import java.rmi.NotBoundException;
  import java.rmi.Remote;
  import java.rmi.RemoteException;
  import java.rmi.registry.Registry;
  import java.rmi.server.RMISocketFactory;
  import java.rmi.server.UnicastRemoteObject;
  import java.util.Objects;
  import java.util.Properties;
  import java.util.concurrent.Executors;
  import java.util.concurrent.ScheduledExecutorService;
  import java.util.concurrent.TimeUnit;
  
  import org.apache.commons.jcs3.auxiliary.AuxiliaryCacheConfigurator;
  import org.apache.commons.jcs3.auxiliary.remote.RemoteUtils;
  import org.apache.commons.jcs3.auxiliary.remote.behavior.IRemoteCacheConstants;
  import org.apache.commons.jcs3.engine.behavior.ICacheServiceAdmin;
  import org.apache.commons.jcs3.engine.logging.behavior.ICacheEventLogger;
  import org.apache.commons.jcs3.log.Log;
  import org.apache.commons.jcs3.log.LogManager;
  import org.apache.commons.jcs3.utils.config.OptionConverter;
  import org.apache.commons.jcs3.utils.config.PropertySetter;
  import org.apache.commons.jcs3.utils.threadpool.DaemonThreadFactory;
  
  /**
   * Provides remote cache services. This creates remote cache servers and can proxy command line
   * requests to a running server.
   */
  public class RemoteCacheServerFactory
      implements IRemoteCacheConstants
  {
      /** The logger */
      private static final Log log = LogManager.getLog( RemoteCacheServerFactory.class );
  
      /** The single instance of the RemoteCacheServer object. */
      private static RemoteCacheServer<?, ?> remoteCacheServer;
  
      /** The name of the service. */
      private static String serviceName = IRemoteCacheConstants.REMOTE_CACHE_SERVICE_VAL;
  
      /** Executes the registry keep alive. */
      private static ScheduledExecutorService keepAliveDaemon;
  
      /** A reference to the registry. */
      private static Registry registry;
  
      /** Constructor for the RemoteCacheServerFactory object. */
      private RemoteCacheServerFactory()
      {
      }
  
      /**
       * This will allow you to get stats from the server, etc. Perhaps we should provide methods on
       * the factory to do this instead.
       * <p>
       * A remote cache is either a local cache or a cluster cache.
       * </p>
       * @return Returns the remoteCacheServer.
       */
      @SuppressWarnings("unchecked") // Need cast to specific RemoteCacheServer
      public static <K, V> RemoteCacheServer<K, V> getRemoteCacheServer()
      {
          return (RemoteCacheServer<K, V>)remoteCacheServer;
      }
  
      // ///////////////////// Startup/shutdown methods. //////////////////
      /**
       * Starts up the remote cache server on this JVM, and binds it to the registry on the given host
       * and port.
       * <p>
       * A remote cache is either a local cache or a cluster cache.
       * <p>
       * @param host
       * @param port
       * @param props
      * @throws IOException
      */
     public static void startup( String host, final int port, final Properties props)
         throws IOException
     {
         if ( remoteCacheServer != null )
         {
             throw new IllegalArgumentException( "Server already started." );
         }
 
         synchronized ( RemoteCacheServer.class )
         {
             if ( remoteCacheServer != null )
             {
                 return;
             }
 
             final RemoteCacheServerAttributes rcsa = configureRemoteCacheServerAttributes(props);
 
             // These should come from the file!
             rcsa.setRemoteLocation( Objects.toString(host, ""), port );
             log.info( "Creating server with these attributes: {0}", rcsa );
 
             setServiceName( rcsa.getRemoteServiceName() );
 
             final RMISocketFactory customRMISocketFactory = configureObjectSpecificCustomFactory( props );
 
             RemoteUtils.configureGlobalCustomSocketFactory( rcsa.getRmiSocketFactoryTimeoutMillis() );
 
             // CONFIGURE THE EVENT LOGGER
             final ICacheEventLogger cacheEventLogger = configureCacheEventLogger( props );
 
             // CREATE SERVER
             if ( customRMISocketFactory != null )
             {
                 remoteCacheServer = new RemoteCacheServer<>( rcsa, props, customRMISocketFactory );
             }
             else
             {
                 remoteCacheServer = new RemoteCacheServer<>( rcsa, props );
             }
 
             remoteCacheServer.setCacheEventLogger( cacheEventLogger );
 
             // START THE REGISTRY
         	registry = RemoteUtils.createRegistry(port);
 
             // REGISTER THE SERVER
             registerServer( serviceName, remoteCacheServer );
 
             // KEEP THE REGISTRY ALIVE
             if ( rcsa.isUseRegistryKeepAlive() )
             {
                 if ( keepAliveDaemon == null )
                 {
                     keepAliveDaemon = Executors.newScheduledThreadPool(1,
                             new DaemonThreadFactory("JCS-RemoteCacheServerFactory-"));
                 }
                 keepAliveDaemon.scheduleAtFixedRate(() -> keepAlive(host, port, cacheEventLogger),
                         0, rcsa.getRegistryKeepAliveDelayMillis(), TimeUnit.MILLISECONDS);
             }
         }
     }
 
     /**
      * Tries to lookup the server. If unsuccessful it will rebind the server using the factory
      * rebind method.
      *
      * @param registryHost - Hostname of the registry
      * @param registryPort - the port on which to start the registry
      * @param cacheEventLogger the event logger for error messages
      * @since 3.1
      */
     protected static void keepAlive(String registryHost, int registryPort, ICacheEventLogger cacheEventLogger)
     {
         String namingURL = RemoteUtils.getNamingURL(registryHost, registryPort, serviceName);
         log.debug( "looking up server {0}", namingURL );
 
         try
         {
             final Object obj = Naming.lookup( namingURL );
 
             // Successful connection to the remote server.
             final String message = "RMI registry looks fine.  Found [" + obj + "] in registry [" + namingURL + "]";
             if ( cacheEventLogger != null )
             {
                 cacheEventLogger.logApplicationEvent( "RegistryKeepAliveRunner", "Naming.lookup", message );
             }
             log.debug( message );
         }
         catch ( final Exception ex )
         {
             // Failed to connect to the remote server.
             final String message = "Problem finding server at [" + namingURL
                 + "].  Will attempt to start registry and rebind.";
             log.error( message, ex );
             if ( cacheEventLogger != null )
             {
                 cacheEventLogger.logError( "RegistryKeepAliveRunner", "Naming.lookup", message + ":" + ex.getMessage() );
             }
 
             registry = RemoteUtils.createRegistry(registryPort);
 
             if ( cacheEventLogger != null )
             {
                 if (registry != null)
                 {
                     cacheEventLogger.logApplicationEvent( "RegistryKeepAliveRunner", "createRegistry",
                             "Successfully created registry [" + serviceName + "]." );
                 }
                 else
                 {
                     cacheEventLogger.logError( "RegistryKeepAliveRunner", "createRegistry",
                             "Could not start registry [" + serviceName + "]." );
                 }
             }
         }
 
         try
         {
             registerServer(serviceName, remoteCacheServer);
 
             final String message = "Successfully rebound server to registry [" + serviceName + "].";
             if ( cacheEventLogger != null )
             {
                 cacheEventLogger.logApplicationEvent( "RegistryKeepAliveRunner", "registerServer", message );
             }
             log.info( message );
         }
         catch ( final RemoteException e )
         {
             final String message = "Could not rebind server to registry [" + serviceName + "].";
             log.error( message, e );
             if ( cacheEventLogger != null )
             {
                 cacheEventLogger.logError( "RegistryKeepAliveRunner", "registerServer", message + ":"
                     + e.getMessage() );
             }
         }
     }
 
     /**
      * Tries to get the event logger.
      * <p>
      * @param props configuration properties
      * @return ICacheEventLogger, may be null
      */
     protected static ICacheEventLogger configureCacheEventLogger( final Properties props )
     {
         return AuxiliaryCacheConfigurator
                 .parseCacheEventLogger( props, IRemoteCacheConstants.CACHE_SERVER_PREFIX );
     }
 
     /**
      * This configures an object specific custom factory. This will be configured for just this
      * object in the registry. This can be null.
      * <p>
      * @param props
      * @return RMISocketFactory
      */
     protected static RMISocketFactory configureObjectSpecificCustomFactory( final Properties props )
     {
         final RMISocketFactory customRMISocketFactory =
             OptionConverter.instantiateByKey( props, CUSTOM_RMI_SOCKET_FACTORY_PROPERTY_PREFIX, null );
 
         if ( customRMISocketFactory != null )
         {
             PropertySetter.setProperties( customRMISocketFactory, props, CUSTOM_RMI_SOCKET_FACTORY_PROPERTY_PREFIX
                 + "." );
             log.info( "Will use server specific custom socket factory. {0}",
                     customRMISocketFactory );
         }
         else
         {
             log.info( "No server specific custom socket factory defined." );
         }
         return customRMISocketFactory;
     }
 
     /**
      * Registers the server with the registry. I broke this off because we might want to have code
      * that will restart a dead registry. It will need to rebind the server.
      * <p>
      * @param serviceName the name of the service
      * @param server the server object to bind
      * @throws RemoteException
      */
     protected static void registerServer(final String serviceName, final Remote server )
         throws RemoteException
     {
         if ( server == null )
         {
             throw new RemoteException( "Cannot register the server until it is created." );
         }
 
         if ( registry == null )
         {
             throw new RemoteException( "Cannot register the server: Registry is null." );
         }
 
         log.info( "Binding server to {0}", serviceName );
 
         registry.rebind( serviceName, server );
     }
 
     /**
      * Configure.
      * <p>
      * jcs.remotecache.serverattributes.ATTRIBUTENAME=ATTRIBUTEVALUE
      * <p>
      * @param prop
      * @return RemoteCacheServerAttributesconfigureRemoteCacheServerAttributes
      */
     protected static RemoteCacheServerAttributes configureRemoteCacheServerAttributes( final Properties prop )
     {
         final RemoteCacheServerAttributes rcsa = new RemoteCacheServerAttributes();
 
         // configure automatically
         PropertySetter.setProperties( rcsa, prop, CACHE_SERVER_ATTRIBUTES_PROPERTY_PREFIX + "." );
 
         return rcsa;
     }
 
     /**
      * Unbinds the remote server.
      * <p>
      * @param host
      * @param port
      * @throws IOException
      */
     static void shutdownImpl( final String host, final int port )
         throws IOException
     {
         synchronized ( RemoteCacheServer.class )
         {
             if ( remoteCacheServer == null )
             {
                 return;
             }
             log.info( "Unbinding host={0}, port={1}, serviceName={2}",
                     host, port, getServiceName() );
             try
             {
                 Naming.unbind( RemoteUtils.getNamingURL(host, port, getServiceName()) );
             }
             catch ( final MalformedURLException ex )
             {
                 // impossible case.
                 throw new IllegalArgumentException( ex.getMessage() + "; host=" + host + ", port=" + port
                     + ", serviceName=" + getServiceName() );
             }
             catch ( final NotBoundException ex )
             {
                 // ignore.
             }
             remoteCacheServer.release();
             remoteCacheServer = null;
 
             // Shut down keepalive scheduler
             if ( keepAliveDaemon != null )
             {
                 keepAliveDaemon.shutdownNow();
                 keepAliveDaemon = null;
             }
 
             // Try to release registry
             if (registry != null)
             {
             	UnicastRemoteObject.unexportObject(registry, true);
             	registry = null;
             }
         }
     }
 
     /**
      * Creates an local RMI registry on the default port, starts up the remote cache server, and
      * binds it to the registry.
      * <p>
      * A remote cache is either a local cache or a cluster cache.
      * <p>
      * @param args The command line arguments
      * @throws Exception
      */
     public static void main( final String[] args )
         throws Exception
     {
         final Properties prop = args.length > 0 ? RemoteUtils.loadProps( args[args.length - 1] ) : new Properties();
 
         int port;
         try
         {
             port = Integer.parseInt( prop.getProperty( "registry.port" ) );
         }
         catch ( final NumberFormatException ex )
         {
             port = Registry.REGISTRY_PORT;
         }
 
         // shutdown
         if ( args.length > 0 && args[0].toLowerCase().indexOf( "-shutdown" ) != -1 )
         {
             try
             {
                 final ICacheServiceAdmin admin = lookupCacheServiceAdmin(prop, port);
                 admin.shutdown();
             }
             catch ( final Exception ex )
             {
                 log.error( "Problem calling shutdown.", ex );
             }
             log.debug( "done." );
             System.exit( 0 );
         }
 
         // STATS
         if ( args.length > 0 && args[0].toLowerCase().indexOf( "-stats" ) != -1 )
         {
             log.debug( "getting cache stats" );
 
             try
             {
                 final ICacheServiceAdmin admin = lookupCacheServiceAdmin(prop, port);
 
                 try
                 {
 //                    System.out.println( admin.getStats().toString() );
                     log.debug( admin.getStats() );
                 }
                 catch ( final IOException es )
                 {
                     log.error( es );
                 }
             }
             catch ( final Exception ex )
             {
                 log.error( "Problem getting stats.", ex );
             }
             log.debug( "done." );
             System.exit( 0 );
         }
 
         // startup.
         final String hostName = prop.getProperty( "registry.host" );
         final InetAddress host = InetAddress.getByName(hostName);
 
         if (host.isLoopbackAddress())
         {
             log.debug( "main> creating registry on the localhost" );
             RemoteUtils.createRegistry( port );
         }
         log.debug( "main> starting up RemoteCacheServer" );
         startup( host.getHostName(), port, prop);
         log.debug( "main> done" );
     }
 
     /**
      * Look up the remote cache service admin instance
      *
      * @param config the configuration properties
      * @param port the local port
      * @return the admin object instance
      *
      * @throws Exception if lookup fails
      */
     private static ICacheServiceAdmin lookupCacheServiceAdmin(final Properties config, final int port) throws Exception
     {
         final String remoteServiceName = config.getProperty( REMOTE_CACHE_SERVICE_NAME, REMOTE_CACHE_SERVICE_VAL ).trim();
         final String registry = RemoteUtils.getNamingURL("", port, remoteServiceName);
 
         log.debug( "looking up server {0}", registry );
         final Object obj = Naming.lookup( registry );
         log.debug( "server found" );
 
         return (ICacheServiceAdmin) obj;
     }
 
     /**
      * @param serviceName the serviceName to set
      */
     protected static void setServiceName( final String serviceName )
     {
         RemoteCacheServerFactory.serviceName = serviceName;
     }
 
     /**
      * @return the serviceName
      */
     protected static String getServiceName()
     {
         return serviceName;
     }
 }