source: src/main/java/negotiator/boaframework/acceptanceconditions/other/AC_Gap.java

package negotiator.boaframework.acceptanceconditions.other;

import java.util.HashSet;
import java.util.Map;
import java.util.Set;

import genius.core.boaframework.AcceptanceStrategy;
import genius.core.boaframework.Actions;
import genius.core.boaframework.BOAparameter;
import genius.core.boaframework.NegotiationSession;
import genius.core.boaframework.OfferingStrategy;
import genius.core.boaframework.OpponentModel;

/**
 * This is the decoupled Acceptance Conditions Based on Tim Baarslag's paper on
 * Acceptance Conditions: "Acceptance Conditions in Automated Negotiation"
 * 
 * This Acceptance Condition accepts a bid if the utility of the opponent's bid
 * plus a constant (the gap) is higher than the utility of the next bid. The
 * acceptance condition is a restricted version of AC_next.
 * 
 * Decoupling Negotiating Agents to Explore the Space of Negotiation Strategies
 * T. Baarslag, K. Hindriks, M. Hendrikx, A. Dirkzwager, C.M. Jonker
 * 
 * @author Alex Dirkzwager
 */
public class AC_Gap extends AcceptanceStrategy {

        private double constant;

        /**
         * Empty constructor for the BOA framework.
         */
        public AC_Gap() {
        }

        public AC_Gap(NegotiationSession negoSession, double c) {
                this.negotiationSession = negoSession;
                this.constant = c;
        }

        @Override
        public void init(NegotiationSession negoSession, OfferingStrategy strat, OpponentModel opponentModel,
                        Map<String, Double> parameters) throws Exception {
                this.negotiationSession = negoSession;
                if (parameters.get("c") != null) {
                        constant = parameters.get("c");
                } else {
                        throw new Exception("Constant \"c\" for the threshold was not set.");
                }
        }

        @Override
        public String printParameters() {
                return "[c: " + constant + "]";
        }

        @Override
        public Actions determineAcceptability() {
                if (!negotiationSession.getOwnBidHistory().getHistory().isEmpty()) {
                        double opponentBidUtil = negotiationSession.getOpponentBidHistory().getLastBidDetails()
                                        .getMyUndiscountedUtil();
                        double prevMyBidUtil = negotiationSession.getOwnBidHistory().getLastBidDetails().getMyUndiscountedUtil();

                        if (opponentBidUtil + constant >= prevMyBidUtil) {
                                return Actions.Accept;
                        }
                }
                return Actions.Reject;
        }

        @Override
        public Set<BOAparameter> getParameterSpec() {
                Set<BOAparameter> set = new HashSet<BOAparameter>();
                set.add(new BOAparameter("c", 0.01,
                                "Accept when opponent's bid utility plus constant c is greater than utility of previous offer"));
                return set;
        }

        @Override
        public String getName() {
                return "Other - Gap";
        }
}