package uk.ac.vamsas.client.simpleclient;

import org.apache.commons.logging.*;

import uk.ac.vamsas.client.picking.IMessageHandler;
import uk.ac.vamsas.client.picking.IPickManager;
import uk.ac.vamsas.client.picking.Message;
import uk.ac.vamsas.client.picking.SocketManager;
/**
 * Blocking message handler
 * @author
 *
 */
public class SimplePickManager implements IPickManager {
  private Log log = LogFactory.getLog(SimplePickManager.class);
  
  SocketManager manager=null;
  SimplePickManager(SocketManager manager) {
    this.manager=manager;
    final SimplePickManager me=this;
    /**
     * add a handler that calls the SimplePickManager message handler
     */
    manager.registerMessageHandler(new IMessageHandler() {
      public void handleMessage(Message message) {
        me.handleMessage(message);
      }
    });
    
  }
  /**
   * when false, messages are queued in a FIFO until thread can restart.
   */
  private boolean passThru=true;
  /**
   * internal flag - set to true to sleep until passThru is true before passing on a message
   */
  private boolean qUEUE=false;
  /**
   * the client apps message handler
   */
  IMessageHandler pickHandler=null;
  public void registerMessageHandler(IMessageHandler handler) {
    pickHandler=handler; 
    
  }

  public synchronized void sendMessage(Message message) {
    // throw away messages whilst we block
    if (passThru && manager!=null)
      manager.sendMessage(message);
  }
  /**
   * pass message onto the Apps handler, or wait until
   * passThru is true before passing message on.
   * @param message
   */
  protected synchronized void handleMessage(Message message) {
    if (qUEUE) {
     while (!passThru && manager!=null) {
      log.debug("Not passing through.");
      try {
        Thread.sleep(5);
      } catch (InterruptedException e) {};
    } 
    }
    if (passThru && manager!=null)
      pickHandler.handleMessage(message);
  }

  /**
   * @return true if messages are being passed to handlers
   */
  public boolean isPassThru() {
    return passThru;
  }

  /**
   * @param true to pass messages on to handlers, false to hold messages in queue
   */
  public void setPassThru(boolean passThru) {
    this.passThru = passThru;
  }
  /**
   * shutdown the pickmanager and remove all references to it
   */
  public void shutdown() {
    passThru=false;
    manager.registerMessageHandler(null);
    SocketManager dying = manager;
    manager=null;
  	dying.shutdown();
  }
}