package org.lsst.ccs.bus;
   
   import org.lsst.ccs.bootstrap.resources.BootstrapResourceUtils;
   
   import java.util.Collections;
   import java.util.List;
   
   /**
    * Messaging factory, insulating the application from the messaging middleware
   * (JMS or other)
   *
   * @author aubourg
   */
  
  public abstract class MessagingFactory {
      protected volatile static MessagingFactory instance;
  
      //@TODO: should be getInstance( String subsystemName)
      public static synchronized MessagingFactory getInstance() {
          if (instance == null) {
              instanciate();
          }
          return instance;
      }
  
      protected static void instanciate() {
          String clazz = BootstrapResourceUtils.getBootstrapSystemProperties().getProperty("org.lsst.ccs.messaging.factory", "org.lsst.ccs.bus.BusMessagingFactory");
          try {
              instance = (MessagingFactory) Class.forName(clazz).newInstance();
          } catch (InstantiationException e) {
              throw new RuntimeException(e);
          } catch (IllegalAccessException e) {
              throw new RuntimeException(e);
          } catch (ClassNotFoundException e) {
              throw new RuntimeException(e);
          } catch (Exception e) { //@modified (bamade) : for other crashes
              throw new RuntimeException(e);
          }
      }
      
      //todo: change that (added by bamade)
      
      private String subsystemName;
  
      public  MessagingFactory forSubsystem(String subsystemName) {
  	this.subsystemName=subsystemName;
          return this ;
      }
  
      public String getSubsystemName() {
  	return subsystemName;
      }
  
      public abstract void addCommandListener(CommandListener l);
      public abstract void removeCommandListener(CommandListener l);
  
      public abstract void addStatusListener(StatusListens l);
      public abstract void removeStatusListener(StatusListens l);
  
      public abstract void addLogListener(LogListener l);
      public abstract void removeLogListener(LogListener l);
  
      public abstract void addCommandListener(CommandListener l, String selector);
      public abstract void addStatusListener(StatusListens l, String selector);
      public abstract void addLogListener(LogListener l, String selector);
      
      public abstract void addMembershipListener(BusMembershipListener l);
      public abstract void removeMembershipListener(BusMembershipListener l);
  
      public abstract void sendCommand(Command cmd);
  
      // TODO sendCommandSync qui retourne un Reply
  
      public abstract void sendStatus(Status status);
  
      public abstract void sendLogEvent(LogEvent evt);
  
      public abstract String getToken();
  
      /* has to be called on the same thread as the command */
      public abstract void reply(CommandAckOrReply cmd);
  
      public boolean isReplyRequested() {
          return false;
      }
  
      public abstract void noAutoReply();
      //@modified (bamade) -> @TODO: add a close() method to stop listening threads!
      public void shutdownBusAccess() {
  
      }
      public List<String> connectedToCommand() {
          return Collections.EMPTY_LIST ;
      }
  
  }