//
   //  ========================================================================
   //  Copyright (c) 1995-2013 Mort Bay Consulting Pty. Ltd.
   //  ------------------------------------------------------------------------
   //  All rights reserved. This program and the accompanying materials
   //  are made available under the terms of the Eclipse Public License v1.0
   //  and Apache License v2.0 which accompanies this distribution.
   //
   //      The Eclipse Public License is available at
  //      http://www.eclipse.org/legal/epl-v10.html
  //
  //      The Apache License v2.0 is available at
  //      http://www.opensource.org/licenses/apache2.0.php
  //
  //  You may elect to redistribute this code under either of these licenses.
  //  ========================================================================
  //
  
  package org.eclipse.jetty.osgi.boot.internal.serverfactory;
  
  import java.util.HashMap;
  import java.util.Map;
  import java.util.Properties;
  
  import org.eclipse.jetty.osgi.boot.OSGiServerConstants;
  import org.eclipse.jetty.server.Server;
  import org.eclipse.jetty.util.log.Log;
  import org.eclipse.jetty.util.log.Logger;
  import org.osgi.framework.Bundle;
  import org.osgi.framework.ServiceEvent;
  import org.osgi.framework.ServiceListener;
  import org.osgi.framework.ServiceReference;
  
  /**
   * JettyServerServiceTracker
   * 
   * Tracks instances of Jetty Servers, and configures them so that they can deploy 
   * webapps or ContextHandlers discovered from the OSGi environment.
   * 
   */
  public class JettyServerServiceTracker implements ServiceListener, IManagedJettyServerRegistry
  {
      private static Logger LOG = Log.getLogger(JettyServerServiceTracker.class.getName());
  
      /**
       * Servers indexed by PIDs. PIDs are generated by the ConfigurationAdmin
       * service.
       */
      private Map<String, ServerInstanceWrapper> _serversIndexedByName = new HashMap<String, ServerInstanceWrapper>();
  
      /** The context-handler to deactivate indexed by ServerInstanceWrapper */
      private Map<ServiceReference, ServerInstanceWrapper> _indexByServiceReference = new HashMap<ServiceReference, ServerInstanceWrapper>();
  
      /**
       * Stops each one of the registered servers.
       */
      public void stop()
      {
          // not sure that this is really useful but here we go.
          for (ServerInstanceWrapper wrapper : _serversIndexedByName.values())
          {
              try
              {
                  wrapper.stop();
              }
              catch (Throwable t)
              {
                  LOG.warn(t);
              }
          }
      }
  
      /**
       * Receives notification that a service has had a lifecycle change.
       * 
       * @param ev The <code>ServiceEvent</code> object.
       */
      public void serviceChanged(ServiceEvent ev)
      {
          ServiceReference sr = ev.getServiceReference();
          switch (ev.getType())
          {
              case ServiceEvent.MODIFIED:
              case ServiceEvent.UNREGISTERING:
              {
                  ServerInstanceWrapper instance = unregisterInIndex(ev.getServiceReference());
                  if (instance != null)
                  {
                      try
                      {
                          instance.stop();
                      }
                      catch (Exception e)
                      {
                          LOG.warn(e);
                      }
                  }
  
                  if (ev.getType() == ServiceEvent.UNREGISTERING)
                 {
                     break;
                 }
                 else
                 {
                     // modified, meaning: we reload it. now that we stopped it;
                     // we can register it.
                 }
             }
             case ServiceEvent.REGISTERED:
             {
                 try
                 {
                     Bundle contributor = sr.getBundle();
                     Server server = (Server) contributor.getBundleContext().getService(sr);
                     ServerInstanceWrapper wrapper = registerInIndex(server, sr);
                     Properties props = new Properties();
                     for (String key : sr.getPropertyKeys())
                     {
                         Object value = sr.getProperty(key);
                         props.put(key, value);
                     }
                     wrapper.start(server, props);
                 }
                 catch (Exception e)
                 {
                     LOG.warn(e);
                 }
                 break;
             }
         }
     }
 
     private ServerInstanceWrapper registerInIndex(Server server, ServiceReference sr)
     {
         String name = (String) sr.getProperty(OSGiServerConstants.MANAGED_JETTY_SERVER_NAME);
         if (name == null) { throw new IllegalArgumentException("The property " + OSGiServerConstants.MANAGED_JETTY_SERVER_NAME + " is mandatory"); }
         ServerInstanceWrapper wrapper = new ServerInstanceWrapper(name);
         _indexByServiceReference.put(sr, wrapper);
         _serversIndexedByName.put(name, wrapper);
         return wrapper;
     }
 
     /**
      * Returns the ContextHandler to stop.
      * 
      * @param reg
      * @return the ContextHandler to stop.
      */
     private ServerInstanceWrapper unregisterInIndex(ServiceReference sr)
     {
         ServerInstanceWrapper handler = _indexByServiceReference.remove(sr);
         if (handler == null)
         {
             // a warning?
             return null;
         }
         String name = handler.getManagedServerName();
         if (name != null)
         {
             _serversIndexedByName.remove(name);
         }
         return handler;
     }
 
     /**
      * @param managedServerName The server name
      * @return the corresponding jetty server wrapped with its deployment
      *         properties.
      */
     public ServerInstanceWrapper getServerInstanceWrapper(String managedServerName)
     {
         return _serversIndexedByName.get(managedServerName == null ? OSGiServerConstants.MANAGED_JETTY_SERVER_DEFAULT_NAME : managedServerName);
     }
 
 }