/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 org.apache.commons.math.genetics;

import java.util.ArrayList;
import java.util.List;

/**
 * Chromosome represented by a vector of 0s and 1s.
 * 
 * @version $Revision:$ $Date:$
 * @since 2.0
 */
public abstract class BinaryChromosome extends AbstractListChromosome<Integer> {

	/**
	 * Constructor.
	 * 
	 * @param representation
	 *            list of {0,1} values representing the chromosome
	 */
	public BinaryChromosome(List<Integer> representation) {
		super(representation);
	}

	/**
	 * Constructor.
	 * 
	 * @param representation
	 *            array of {0,1} values representing the chromosome
	 */
	public BinaryChromosome(Integer[] representation) {
		super(representation);
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	protected void checkValidity(List<Integer> representation) throws InvalidRepresentationException {
		for (int i : representation) {
			if (i < 0 || i > 1)
				throw new InvalidRepresentationException("Elements can be only 0 or 1.");
		}
	}

	/**
	 * Returns a representation of a random binary array of length
	 * <code>length</code>.
	 * 
	 * @param length
	 *            length of the array
	 * @return a random binary array of length <code>length</code>
	 */
	public static List<Integer> randomBinaryRepresentation(int length) {
		// random binary list
		List<Integer> rList = new ArrayList<Integer>(length);
		for (int j = 0; j < length; j++) {
			rList.add(GeneticAlgorithm.getRandomGenerator().nextInt(2));
		}
		return rList;
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	protected boolean isSame(Chromosome another) {
		// type check
		if (!(another instanceof BinaryChromosome))
			return false;
		BinaryChromosome anotherBc = (BinaryChromosome) another;
		// size check
		if (getLength() != anotherBc.getLength())
			return false;

		for (int i = 0; i < getRepresentation().size(); i++) {
			if (!(getRepresentation().get(i).equals(anotherBc.getRepresentation().get(i))))
				return false;
		}
		// all is ok
		return true;
	}
}
