/*
 *  RapidMiner
 *
 *  Copyright (C) 2001-2014 by RapidMiner and the contributors
 *
 *  Complete list of developers available at our web site:
 *
 *       http://rapidminer.com
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU Affero General Public License as published by
 *  the Free Software Foundation, either version 3 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 Affero General Public License for more details.
 *
 *  You should have received a copy of the GNU Affero General Public License
 *  along with this program.  If not, see http://www.gnu.org/licenses/.
 */
package com.rapidminer.operator.validation;

import java.util.List;

import com.rapidminer.operator.IOObject;
import com.rapidminer.operator.OperatorChain;
import com.rapidminer.operator.OperatorDescription;
import com.rapidminer.operator.OperatorException;
import com.rapidminer.operator.ValueDouble;
import com.rapidminer.operator.performance.PerformanceCriterion;
import com.rapidminer.operator.performance.PerformanceVector;
import com.rapidminer.operator.ports.PortPairExtender;
import com.rapidminer.operator.ports.metadata.MetaData;
import com.rapidminer.operator.ports.metadata.SubprocessTransformRule;
import com.rapidminer.parameter.ParameterType;
import com.rapidminer.parameter.ParameterTypeBoolean;
import com.rapidminer.parameter.ParameterTypeInt;
import com.rapidminer.tools.math.AverageVector;


/**
 * This operator chain performs the inner operators the given number of times.
 * The inner operators must provide a PerformanceVector. These are averaged and
 * returned as result.
 * 
 * @author Ingo Mierswa
 */
public class IteratingPerformanceAverage extends OperatorChain {
    
	public static final String PARAMETER_ITERATIONS = "iterations";
	
	public static final String PARAMETER_AVERAGE_PERFORMANCES_ONLY = "average_performances_only";
	
	private PerformanceCriterion lastPerformance;
    
	private PortPairExtender inExtender = new PortPairExtender("in", getInputPorts(), getSubprocess(0).getInnerSources());
	private final PortPairExtender performancePortExtender = new PortPairExtender("averagable", getSubprocess(0).getInnerSinks(), getOutputPorts(), new MetaData(AverageVector.class));
	
	public IteratingPerformanceAverage(OperatorDescription description) {
		super(description, "Subprocess");
		
		inExtender.start();
		performancePortExtender.start();
		getTransformer().addRule(inExtender.makePassThroughRule());
		getTransformer().addRule(new SubprocessTransformRule(getSubprocess(0)));
		getTransformer().addRule(performancePortExtender.makePassThroughRule());
		
        addValue(new ValueDouble("performance", "The last performance average (main criterion).") {
            @Override
			public double getDoubleValue() {
                if (lastPerformance != null)
                    return lastPerformance.getAverage();
                else
                    return Double.NaN;
            }
        });
	}

	@Override
	public void doWork() throws OperatorException {
		int numberOfIterations = getParameterAsInt(PARAMETER_ITERATIONS);	
				
		for (int i = 0; i < numberOfIterations; i++) {
			evaluate();			
			inApplyLoop();
		}

        // set last result for plotting purposes. This is an average value and
        // actually not the last performance value!
		boolean success = false;
		for (IOObject result : performancePortExtender.getData(IOObject.class)) {
			if (result instanceof PerformanceVector) {
				lastPerformance = ((PerformanceVector)result).getMainCriterion();				
				success = true;
			}
		}
		if (!success) {
			lastPerformance = null;
			getLogger().warning("No performance vector found among averagable results. Performance will not be loggable.");
		}       
	}

	/** Applies the inner operator on a clone of the input. */
	private void evaluate() throws OperatorException {
		inExtender.passCloneThrough();
		getSubprocess(0).execute();
		Tools.buildAverages(performancePortExtender);
	}
	
	@Override
	public List<ParameterType> getParameterTypes() {
		List<ParameterType> types = super.getParameterTypes();
		ParameterType type = new ParameterTypeInt(PARAMETER_ITERATIONS, "The number of iterations.", 1, Integer.MAX_VALUE, 10);
		type.setExpert(false);
		types.add(type);
		types.add(new ParameterTypeBoolean(PARAMETER_AVERAGE_PERFORMANCES_ONLY, "Indicates if only performance vectors should be averaged or all types of averagable result vectors.", true));
		return types;
	}
}