/*
 *  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.performance;

import java.util.List;

import com.rapidminer.operator.Operator;
import com.rapidminer.operator.OperatorDescription;
import com.rapidminer.operator.OperatorException;
import com.rapidminer.operator.ports.InputPort;
import com.rapidminer.operator.ports.OutputPort;
import com.rapidminer.parameter.ParameterType;
import com.rapidminer.parameter.ParameterTypeDouble;


/**
 * Wraps a {@link MinMaxCriterion} around each performance criterion of type
 * MeasuredPerformance. This criterion uses the minimum fitness achieved instead
 * of the average fitness or arbitrary weightings of both. Please note that the
 * average values stay the same and only the fitness values change.
 * 
 * @author Ingo Mierswa
 */
public class MinMaxWrapper extends Operator {

	/** The parameter name for "Defines the weight for the minimum fitness agains the average fitness" */
	public static final String PARAMETER_MINIMUM_WEIGHT = "minimum_weight";

	private InputPort performanceInput = getInputPorts().createPort("performance vector", PerformanceVector.class);
	private OutputPort performanceOutput = getOutputPorts().createPort("performance vector");
	
	public MinMaxWrapper(OperatorDescription description) {
		super(description);
		
		getTransformer().addPassThroughRule(performanceInput, performanceOutput);
	}

	@Override
	public void doWork() throws OperatorException {
		PerformanceVector performanceVector = performanceInput.getData(PerformanceVector.class);
		PerformanceVector result = new PerformanceVector();
		for (int i = 0; i < performanceVector.size(); i++) {
			PerformanceCriterion crit = performanceVector.getCriterion(i);
			if (crit instanceof MeasuredPerformance)
				result.addCriterion(new MinMaxCriterion((MeasuredPerformance) crit, getParameterAsDouble(PARAMETER_MINIMUM_WEIGHT)));
		}
		result.setMainCriterionName(performanceVector.getMainCriterion().getName());
		performanceOutput.deliver(result);
	}

	@Override
	public List<ParameterType> getParameterTypes() {
		List<ParameterType> types = super.getParameterTypes();
		ParameterType type = new ParameterTypeDouble(PARAMETER_MINIMUM_WEIGHT, "Defines the weight for the minimum fitness agains the average fitness", 0.0d, 1.0d, 1.0d);
		type.setExpert(false);
		types.add(type);
		return types;
	}
}