package cecj.fitness;

import java.util.Arrays;
import java.util.List;

import cecj.interaction.InteractionResult;

import ec.EvolutionState;
import ec.Individual;
import ec.simple.SimpleFitness;

public class SimpleSumFitness implements FitnessAggregateMethod {

	private float[] fitnesses;

	public void prepareToAggregate(EvolutionState state, int subpop) {
		fitnesses = new float[state.population.subpops[subpop].individuals.length];
		Arrays.fill(fitnesses, 0.0f);
	}

	public void addToAggregate(EvolutionState state, int subpop,
			List<List<InteractionResult>> subpopulationResults, int weight) {

		Individual[] inds = state.population.subpops[subpop].individuals;
		if (subpopulationResults.size() != inds.length) {
			throw new IllegalArgumentException(
				"Results list's size must be equal to subpopulation size.");
		}

		for (int ind = 0; ind < inds.length; ind++) {
			float fitness = 0;
			for (InteractionResult result : subpopulationResults.get(ind)) {
				fitness += result.getNumericValue();
			}
			fitnesses[ind] += fitness * weight;
		}
	}

	public void assignFitness(EvolutionState state, int subpop) {
		Individual[] inds = state.population.subpops[subpop].individuals;
		for (int ind = 0; ind < inds.length; ind++) {
			((SimpleFitness) inds[ind].fitness).setFitness(state, fitnesses[ind], false);
		}
	}
}