/*
 * Copyright (c) 1998-2002 Caucho Technology -- all rights reserved
 *
 * This file is part of Resin(R) Open Source
 *
 * Each copy or derived work must preserve the copyright notice and this
 * notice unmodified.
 *
 * Resin Open Source is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * Resin Open Source is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, or any warranty
 * of NON-INFRINGEMENT.  See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Resin Open Source; if not, write to the
 *   Free SoftwareFoundation, Inc.
 *   59 Temple Place, Suite 330
 *   Boston, MA 02111-1307  USA
 *
 * @author Scott Ferguson
 */

package com.caucho.jmx;

import java.lang.reflect.Method;
import java.lang.reflect.InvocationTargetException;

import java.util.TimerTask;

/**
 * Abstract implementation for an MBeanServer factory.
 */
public class JobManager {
  private static Method _queueAbsolute;
  private static Method _queueRelative;
  private static Method _dequeue;
  private static Method _getCurrentTime;
  
  private JobManager() {}

  /**
   * Returns the current time.
   */
  public static long getCurrentTime()
  {
    try {
      Long value = (Long) _getCurrentTime.invoke(null, null);

      if (value == null)
	return 0;
      else
	return value.longValue();
    } catch (IllegalAccessException e) {
      throw new RuntimeException(e);
    } catch (InvocationTargetException e) {
      throw (RuntimeException) e.getCause();
    }
  }

  /**
   * Queues a job.
   */
  public static void queueAbsolute(TimerTask job, long time)
  {
    try {
      _queueAbsolute.invoke(null, new Object[] { job, new Long(time) });
    } catch (IllegalAccessException e) {
      throw new RuntimeException(e);
    } catch (InvocationTargetException e) {
      throw (RuntimeException) e.getCause();
    }
  }

  /**
   * Queues a job.
   */
  public static void queueRelative(TimerTask job, long time)
  {
    try {
      _queueRelative.invoke(null, new Object[] { job, new Long(time) });
    } catch (IllegalAccessException e) {
      throw new RuntimeException(e);
    } catch (InvocationTargetException e) {
      throw (RuntimeException) e.getCause();
    }
  }

  /**
   * Queues a job.
   */
  public static void dequeue(TimerTask job)
  {
    try {
      _dequeue.invoke(null, new Object[] { job });
    } catch (IllegalAccessException e) {
      throw new RuntimeException(e);
    } catch (InvocationTargetException e) {
      throw (RuntimeException) e.getCause();
    }
  }

  static {
    try {
      Class jmx = Class.forName("com.caucho.jmx.Jmx");

      _queueAbsolute = jmx.getMethod("queueAbsolute",
				     new Class[] { TimerTask.class,
						   long.class });
      _queueRelative = jmx.getMethod("queueRelative",
				     new Class[] { TimerTask.class,
						   long.class });
      _dequeue = jmx.getMethod("dequeue", new Class[] { TimerTask.class });
      
      Class alarm = Class.forName("com.caucho.util.Alarm");
      
      _getCurrentTime = alarm.getMethod("getCurrentTime", new Class[] { });
    } catch (Throwable e) {
      e.printStackTrace();
    }
  }
}
