/*
 * BioJava development code This code may be freely distributed and modified
 * under the terms of the GNU Lesser General Public Licence. This should be
 * distributed with the code. If you do not have a copy, see:
 * http://www.gnu.org/copyleft/lesser.html Copyright for this code is held
 * jointly by the individual authors. These should be listed in @author doc
 * comments. For more information on the BioJava project and its aims, or to
 * join the biojava-l mailing list, visit the home page at:
 * http://www.biojava.org/
 */

package org.biojavax.ga.impl;

import java.util.Iterator;

import org.biojava.utils.AbstractChangeable;
import org.biojava.utils.ChangeEvent;
import org.biojava.utils.ChangeSupport;
import org.biojava.utils.ChangeVetoException;
import org.biojavax.ga.GeneticAlgorithm;
import org.biojavax.ga.Organism;
import org.biojavax.ga.Population;
import org.biojavax.ga.functions.CrossOverFunction;
import org.biojavax.ga.functions.FitnessFunction;
import org.biojavax.ga.functions.MutationFunction;
import org.biojavax.ga.functions.SelectionFunction;

/**
 * Base class from which most implementations of GeneticAlgorithm will inherit.
 *
 * @author Mark Schreiber
 * @author Susanne Merz
 * @author Andreas Dräger
 * @version 1.1
 * @since 1.5
 */

public abstract class AbstractGeneticAlgorithm extends AbstractChangeable
    implements GeneticAlgorithm {

	protected Population	    population;

	private CrossOverFunction	crossF;

	private SelectionFunction	selectF;

	private MutationFunction	mutF;

	private FitnessFunction	  fit;

	protected AbstractGeneticAlgorithm() {
		population = new SimplePopulation();
	}

	public final CrossOverFunction getCrossOverFunction() {
		return crossF;
	}

	/*
	 * (non-Javadoc)
	 *
	 * @see org.biojavax.ga.GeneticAlgorithm#getFitnessFunction()
	 */
	public FitnessFunction getFitnessFunction() {
		return fit;
	}

	public final MutationFunction getMutationFunction() {
		return mutF;
	}

	public final Population getPopulation() {
		return population;
	}

	public final SelectionFunction getSelectionFunction() {
		return selectF;
	}

	/**
	 * Assigns a fitness value to each organism within the population according to
	 * the currently set fitness function. If no population or no fitness function
	 * is set, nothing will happen.
	 */
	public void initPopulation() {
		if ((population != null) && (fit != null))
		  for (Iterator i = population.getOrganisms().iterator(); i.hasNext();) {
			  Organism o = (Organism) i.next();
			  o.setFitness(fit.fitness(o, population, this));
		  }
	}

	public final void setCrossOverFunction(CrossOverFunction function)
	    throws ChangeVetoException {
		if (!hasListeners()) {
			this.crossF = function;
		} else {
			ChangeEvent ce = new ChangeEvent(this, GeneticAlgorithm.POPULATION,
			    function, this.crossF);
			ChangeSupport changeSupport = super
			    .getChangeSupport(GeneticAlgorithm.POPULATION);
			synchronized (changeSupport) {
				changeSupport.firePreChangeEvent(ce);
				this.crossF = function;
				changeSupport.firePostChangeEvent(ce);
			}
		}
	}

	/*
	 * (non-Javadoc)
	 *
	 * @see org.biojavax.ga.GeneticAlgorithm#setFitnessFunction(org.biojavax.ga.functions.FitnessFunction)
	 */
	public final void setFitnessFunction(FitnessFunction func)
	    throws ChangeVetoException {
		if (!hasListeners()) {
			fit = func;
			initPopulation();
		} else {
			ChangeEvent ce = new ChangeEvent(this, GeneticAlgorithm.FITNESS_FUNCTION,
			    func, fit);
			ChangeSupport changeSupport = super
			    .getChangeSupport(GeneticAlgorithm.FITNESS_FUNCTION);
			synchronized (changeSupport) {
				changeSupport.firePreChangeEvent(ce);
				fit = func;
				changeSupport.firePostChangeEvent(ce);
			}
		}
	}

	public final void setMutationFunction(MutationFunction function)
	    throws ChangeVetoException {
		if (!hasListeners()) {
			this.mutF = function;
		} else {
			ChangeEvent ce = new ChangeEvent(this, GeneticAlgorithm.POPULATION,
			    function, this.mutF);
			ChangeSupport changeSupport = super
			    .getChangeSupport(GeneticAlgorithm.POPULATION);
			synchronized (changeSupport) {
				changeSupport.firePreChangeEvent(ce);
				this.mutF = function;
				changeSupport.firePostChangeEvent(ce);
			}
		}
	}

	public final void setPopulation(Population pop) throws ChangeVetoException {
		if (!hasListeners()) {
			population = pop;
			initPopulation();
		} else {
			ChangeEvent ce = new ChangeEvent(this, GeneticAlgorithm.POPULATION, pop,
			    this.population);
			ChangeSupport changeSupport = super
			    .getChangeSupport(GeneticAlgorithm.POPULATION);
			synchronized (changeSupport) {
				changeSupport.firePreChangeEvent(ce);
				population = pop;
				changeSupport.firePostChangeEvent(ce);
			}
		}
	}

	public final void setSelectionFunction(SelectionFunction function)
	    throws ChangeVetoException {
		if (!hasListeners()) {
			this.selectF = function;
		} else {
			ChangeEvent ce = new ChangeEvent(this, GeneticAlgorithm.POPULATION,
			    function, this.selectF);
			ChangeSupport changeSupport = super
			    .getChangeSupport(GeneticAlgorithm.POPULATION);
			synchronized (changeSupport) {
				changeSupport.firePreChangeEvent(ce);
				this.selectF = function;
				changeSupport.firePostChangeEvent(ce);
			}
		}
	}
}