/*
  Copyright 2006 by Sean Luke and George Mason University
  Licensed under the Academic Free License version 3.0
  See the file "LICENSE" for more information
*/

package ec.spatial;

import ec.Initializer;
import ec.Individual;
import ec.BreedingPipeline;
import ec.Breeder;
import ec.simple.*;
import ec.EvolutionState;
import ec.Population;
import ec.util.Parameter;
import ec.util.*;

/* 
 * SpatialBreeder.java
 * 
 * By: Liviu Panait
 */

/**
 * A slight modification of the simple breeder for spatially-embedded EAs.
 
 * Breeds each subpopulation separately, with no inter-population exchange,
 * and using a generational approach.  A SpatialBreeder may have multiple
 * threads; it divvys up a subpopulation into chunks and hands one chunk
 * to each thread to populate.  One array of BreedingPipelines is obtained
 * from a population's Species for each operating breeding thread.
 *
 *
 *
 *
 * @author Liviu Panait
 * @version 1.0 
 */

public class SpatialBreeder extends SimpleBreeder
    {
    public void setup(final EvolutionState state, final Parameter base)
        {
        super.setup(state, base);
                
        // check for elitism and warn about it
        for(int i = 0 ; i < elite.length; i++)
            if (elite[i] > 0)
                {
                state.output.warning("You're using elitism with SpatialBreeder.  This is unwise as elitism is done by moving individuals around in the population, thus messing up the spatial nature of breeding.",
                    base.push(P_ELITE).push(""+i));
                break;
                }
        }
                
    protected void breedPopChunk(Population newpop, EvolutionState state,
        int[] numinds, int[] from, int threadnum) 
        {
        for(int subpop=0;subpop<newpop.subpops.length;subpop++)
            {
            BreedingPipeline bp = (BreedingPipeline)newpop.subpops[subpop].
                species.pipe_prototype.clone();
                                
            if (!(state.population.subpops[subpop] instanceof Space))
                state.output.fatal("Subpopulation " + subpop + " does not implement the Space interface.");
            Space space = (Space)(state.population.subpops[subpop]);
                        
            // check to make sure that the breeding pipeline produces
            // the right kind of individuals.  Don't want a mistake there! :-)
            if (!bp.produces(state,newpop,subpop,threadnum))
                state.output.fatal("The Breeding Pipeline of subpopulation " + subpop + " does not produce individuals of the expected species " + newpop.subpops[subpop].species.getClass().getName() + " or fitness " + newpop.subpops[subpop].species.f_prototype );
            bp.prepareToProduce(state,subpop,threadnum);
                        
            // start breedin'!
            for(int x = from[subpop]; x < from[subpop] + numinds[subpop]; x++)
                {
                space.setIndex(threadnum, x);
                if (bp.produce(1, 1, x, subpop, newpop.subpops[subpop].individuals, state, threadnum) != 1)
                    state.output.fatal( "The pipelines should produce one individual at a time!" );
                }
                                
            bp.finishProducing(state,subpop,threadnum);
            }
        }

    }