/*
 *  eXist Scheduler Module Extension ResumeSheduledJob
 *  Copyright (C) 2006-09 Adam Retter <adam.retter@devon.gov.uk>
 *  www.adamretter.co.uk
 *  
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public License
 *  as published by the Free Software Foundation; either version 2
 *  of the License, or (at your option) any later version.
 *
 *  This program 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.  See the
 *  GNU Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public License
 *  along with this program; if not, write to the Free Software Foundation
 *  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *  
 *  $Id$
 */

package org.exist.xquery.modules.scheduler;

import org.exist.dom.QName;
import org.exist.security.User;
import org.exist.scheduler.Scheduler;
import org.exist.scheduler.UserJob;
import org.exist.xquery.BasicFunction;
import org.exist.xquery.Cardinality;
import org.exist.xquery.FunctionSignature;
import org.exist.xquery.XPathException;
import org.exist.xquery.XQueryContext;
import org.exist.xquery.value.BooleanValue;
import org.exist.xquery.value.FunctionParameterSequenceType;
import org.exist.xquery.value.FunctionReturnSequenceType;
import org.exist.xquery.value.Sequence;
import org.exist.xquery.value.SequenceType;
import org.exist.xquery.value.Type;

/**
 * eXist Scheduler Module Extension ResumeScheduledJob
 * 
 * Resumes a Job with the Scheduler
 * 
 * @author Adam Retter <adam.retter@devon.gov.uk>
 * @serial 2006-11-15
 * @version 1.0
 *
 * @see org.exist.xquery.BasicFunction#BasicFunction(org.exist.xquery.XQueryContext, org.exist.xquery.FunctionSignature)
 */
public class ResumeScheduledJob extends BasicFunction
{	
	private Scheduler scheduler = null;
	
	public final static FunctionSignature signature =
		new FunctionSignature(
			new QName("resume-scheduled-job", SchedulerModule.NAMESPACE_URI, SchedulerModule.PREFIX),
			"Resumes the named job in the scheduler. Will only resume user scheduled jobs!",
			new SequenceType[]
			{
				new FunctionParameterSequenceType("job-name", Type.STRING, Cardinality.EXACTLY_ONE, "The name of the job to resume.")
			},
			new FunctionReturnSequenceType(Type.BOOLEAN, Cardinality.EXACTLY_ONE, "the indicator of successful resumption"));
	
	/**
	 * ResumeScheduledJob Constructor
	 * 
	 * @param context	The Context of the calling XQuery
	 */
	public ResumeScheduledJob(XQueryContext context, FunctionSignature signature)
	{
		super(context, signature);
		
		scheduler = context.getBroker().getBrokerPool().getScheduler();
    }

	/**
	 * evaluate the call to the xquery function,
	 * it is really the main entry point of this class
	 * 
	 * @param args		arguments from the  function call
	 * @param contextSequence	the Context Sequence to operate on (not used here internally!)
	 * @return		A sequence representing the result of the function call
	 * 
	 * @see org.exist.xquery.BasicFunction#eval(org.exist.xquery.value.Sequence[], org.exist.xquery.value.Sequence)
	 */
	public Sequence eval(Sequence[] args, Sequence contextSequence) throws XPathException
	{
		String jobName = args[0].getStringValue();
		
		User user = context.getUser();
		
		//Check if the user is a DBA
		if(!user.hasDbaRole())
		{
			return(BooleanValue.FALSE);
		}
		
		return BooleanValue.valueOf(scheduler.resumeJob(jobName, UserJob.JOB_GROUP));
	}
}