source: src/main/java/parties/simplemediator/Annealer.java@ 127

package parties.simplemediator;

import java.util.List;

import genius.core.AgentID;
import genius.core.Bid;
import genius.core.Vote;
import genius.core.actions.Action;
import genius.core.actions.DefaultAction;
import genius.core.actions.InformVotingResult;
import genius.core.actions.VoteForOfferAcceptance;
import genius.core.parties.AbstractNegotiationParty;
import genius.core.protocol.DefaultMultilateralProtocol;
import genius.core.protocol.SimpleMediatorBasedProtocol;
import genius.core.timeline.Timeline.Type;

public class Annealer extends AbstractNegotiationParty {

        private double lastAcceptedBidUtility;
        private double lastReceivedBidUtility;
        private Vote currentVote;

        public Annealer() {
                super();
                lastAcceptedBidUtility = 0.0;
                lastReceivedBidUtility = 0.0;
        }

        @Override
        public void receiveMessage(AgentID sender, Action opponentAction) {

                if (opponentAction instanceof InformVotingResult) {
                        if (((InformVotingResult) opponentAction).getVotingResult() == Vote.ACCEPT)
                                /*
                                 * update the utility of last accepted bid by all
                                 */
                                lastAcceptedBidUtility = lastReceivedBidUtility;
                        return;
                }

                Bid receivedBid = DefaultAction.getBidFromAction(opponentAction);
                if (receivedBid == null)
                        return;

                if (getTimeLine().getType() == Type.Time)
                        lastReceivedBidUtility = getUtilityWithDiscount(receivedBid);
                else
                        lastReceivedBidUtility = getUtility(receivedBid);

                if (lastAcceptedBidUtility <= lastReceivedBidUtility)
                        currentVote = Vote.ACCEPT;
                else {

                        double T = getTimeLine().getTime();

                        double probability = Math.pow(Math.E, ((double) (lastReceivedBidUtility - lastAcceptedBidUtility) / T));

                        if (probability > Math.random())
                                currentVote = Vote.ACCEPT;
                        else
                                currentVote = Vote.REJECT;
                }

        }

        @Override
        public Action chooseAction(List<Class<? extends Action>> validActions) {
                return (new VoteForOfferAcceptance(getPartyId(), currentVote));
        }

        @Override
        public Class<? extends DefaultMultilateralProtocol> getProtocol() {
                return SimpleMediatorBasedProtocol.class;
        }

        @Override
        public String getDescription() {
                return "Annealer";
        }

}