/*
 *  RapidMiner
 *
 *  Copyright (C) 2001-2011 by Rapid-I and the contributors
 *
 *  Complete list of developers available at our web site:
 *
 *       http://rapid-i.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.learner.local;

import java.io.Serializable;
import java.util.Collection;
import java.util.Collections;
import java.util.List;

import com.rapidminer.parameter.ParameterHandler;
import com.rapidminer.parameter.ParameterType;
import com.rapidminer.parameter.ParameterTypeInt;
import com.rapidminer.parameter.UndefinedParameterError;
import com.rapidminer.tools.container.Tupel;
import com.rapidminer.tools.math.container.GeometricDataCollection;

/**
 * @author Sebastian Land
 *
 */
public class NearestNeighborNeighborhood implements Neighborhood {

	private static final long serialVersionUID = 3449482421551746223L;

	public static final String PARAMETER_K = "k";
	
	private int k = 1;
	
	@Override
	public <T extends Serializable> Collection<Tupel<Double, T>> getNeighbourhood(GeometricDataCollection<T> samples, double[] probePoint) {
		return samples.getNearestValueDistances(k, probePoint);
	}

	@Override
	public List<ParameterType> getParameterTypes(ParameterHandler handler) {
		ParameterType type = new ParameterTypeInt(PARAMETER_K, "Specifies the number of neighbors in the neighborhood. Regardless of the local density, always that much samples are returned.", 1, Integer.MAX_VALUE, 5);
		type.setExpert(false);
		return Collections.singletonList(type);
	}

	@Override
	public void init(ParameterHandler handler) throws UndefinedParameterError {
		this.k = handler.getParameterAsInt(PARAMETER_K);
	}

	@Override
	public String toString() {
		return "Nearest Neighbor";
	}
}