package org.apache.turbine.services.schedule;

/* ====================================================================
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2001-2003 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Apache" and "Apache Software Foundation" and
 *    "Apache Turbine" must not be used to endorse or promote products
 *    derived from this software without prior written permission. For
 *    written permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache",
 *    "Apache Turbine", nor may "Apache" appear in their name, without
 *    prior written permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */

import java.util.List;

import org.apache.turbine.services.TurbineServices;
import org.apache.turbine.util.TurbineException;

/**
 * This is a fascade class to provide easy access to the Scheduler
 * service.  All access methods are static and act upon the current
 * instance of the scheduler service.
 *
 * @author <a href="mailto:quintonm@bellsouth.net">Quinton McCombs</a>
 * @version $Id$
 * @see org.apache.turbine.services.schedule.ScheduleService
 */
public abstract class TurbineScheduler
{
    /**
     * Get a specific Job from Storage.
     *
     * @param oid The int id for the job.
     * @return A JobEntry.
     * @exception TurbineException job could not be retrieved
     */
    public static JobEntry getJob(int oid)
            throws TurbineException
    {
        return getService().getJob(oid);
    }

    /**
     * Add a new job to the queue.
     *
     * @param je A JobEntry with the job to add.
     * @exception TurbineException job could not be added
     */
    public static void addJob(JobEntry je)
            throws TurbineException
    {
        getService().addJob(je);
    }

    /**
     * Add or update a job
     *
     * @param je A JobEntry with the job to modify
     * @exception TurbineException job could not be updated
     */
    public static void updateJob(JobEntry je)
            throws TurbineException
    {
        getService().updateJob(je);
    }

    /**
     * Remove a job from the queue.
     *
     * @param je A JobEntry with the job to remove.
     * @exception TurbineException job could not be removed
     */
    public static void removeJob(JobEntry je)
            throws TurbineException
    {
        getService().removeJob(je);
    }

    /**
     * List jobs in the queue.  This is used by the scheduler UI.
     *
     * @return A Vector of jobs.
     */
    public static List listJobs()
    {
        return getService().listJobs();
    }

    /**
     * Determines if the scheduler service is currently active.
     *
     * @return Status of the scheduler service.
     */
    public static boolean isEnabled()
    {
        return getService().isEnabled();
    }

    /**
     * Starts the scheduler if not already running.
     */
    public static void startScheduler()
    {
        getService().startScheduler();
    }

    /**
     * Stops the scheduler if ti is currently running.
     */
    public static void stopScheduler()
    {
        getService().stopScheduler();
    }

    /**
     * Utility method for accessing the service
     * implementation
     *
     * @return a ScheduleService implementation instance
     */
    private static ScheduleService getService()
    {
        return (ScheduleService) TurbineServices
                .getInstance().getService(ScheduleService.SERVICE_NAME);
    }

}