/*******************************************************************************
*   Copyright 2012 Analog Devices, Inc.
*
*   Licensed under the Apache License, Version 2.0 (the "License");
*   you may not use this file except in compliance with the License.
*   You may obtain a copy of the License at
*
*       http://www.apache.org/licenses/LICENSE-2.0
*
*   Unless required by applicable law or agreed to in writing, software
*   distributed under the License is distributed on an "AS IS" BASIS,
*   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
*   See the License for the specific language governing permissions and
*   limitations under the License.
********************************************************************************/

package com.analog.lyric.dimple.schedulers;

import java.util.Map;

import com.analog.lyric.dimple.model.core.FactorGraph;
import com.analog.lyric.dimple.model.variables.Variable;
import com.analog.lyric.dimple.schedulers.schedule.FixedSchedule;
import com.analog.lyric.dimple.schedulers.schedule.IGibbsSchedule;
import com.analog.lyric.dimple.schedulers.scheduleEntry.NodeScheduleEntry;


/**
 * @author jeffb
 * 
 *         This class generates a sequential schedule on a graph specifically
 *         suited for the Gibbs solver. This schedule updates each variable
 *         sequentially.  In the Gibbs solver, factors do not need to be explicitly
 *         updated in the schedule.
 * 
 *         WARNING: This schedule DOES NOT respect any existing sub-graph
 *         scheduler associations. That is, if any sub-graph already has an
 *         associated scheduler, that scheduler is ignored in creating this
 *         schedule. I believe this is a necessary limitation for Gibbs sampling
 *         to operate properly.
 */
public class GibbsSequentialScanScheduler extends GibbsSchedulerBase
{
	private static final long serialVersionUID = 1L;

	/*-------------
	 * Constructor
	 */
	
	public GibbsSequentialScanScheduler()
	{
		super();
	}
	
	protected GibbsSequentialScanScheduler(GibbsSequentialScanScheduler other, Map<Object,Object> old2NewMap,
		boolean copyToRoot)
	{
		super(other, old2NewMap, copyToRoot);
	}
	
	/*------------
	 * IScheduler
	 */
	
	@Override
	public IScheduler copy(Map<Object, Object> old2NewMap, boolean copyToRoot)
	{
		return new GibbsSequentialScanScheduler(this, old2NewMap, copyToRoot);
	}
	
	@Override
	public IGibbsSchedule createSchedule(FactorGraph g)
	{
		FixedSchedule schedule = new FixedSchedule(this, g);

		// Update all owned variables
		for (Variable v : g.getVariablesFlat())
			schedule.add(new NodeScheduleEntry(v));

		return addBlockEntries(schedule);
	}
}