source: src/main/java/agents/rlboa/AverageTitForTatOfferingGamma2.java

package agents.rlboa;

import genius.core.Bid;
import genius.core.BidHistory;
import genius.core.bidding.BidDetails;
import genius.core.boaframework.*;
import genius.core.utility.AbstractUtilitySpace;
import genius.core.utility.UtilitySpace;

import java.util.Collections;
import java.util.List;

public class AverageTitForTatOfferingGamma2 extends OfferingStrategy {

        private int gamma = 2;
        private int k = 0;
        private List<BidDetails> allBids;

        private double minUtil;
        private double maxUtil;

        public AverageTitForTatOfferingGamma2(NegotiationSession negotiationSession, OpponentModel opponentModel, OMStrategy omStrategy) {
                super.init(negotiationSession, null);

                OutcomeSpace sortedOutcomeSpace = new SortedOutcomeSpace(this.negotiationSession.getUtilitySpace());
                this.negotiationSession.setOutcomeSpace(sortedOutcomeSpace);
                allBids = sortedOutcomeSpace.getAllOutcomes();

                // get min/max utility obtainable
                try {
                        AbstractUtilitySpace utilitySpace = this.negotiationSession.getUtilitySpace();
                        Bid maxUtilBid = utilitySpace.getMaxUtilityBid();
                        Bid minUtilBid = utilitySpace.getMinUtilityBid();
                        maxUtil = utilitySpace.getUtility(maxUtilBid);
                        minUtil = utilitySpace.getUtility(minUtilBid);
                        minUtil = Math.max(minUtil, utilitySpace.getReservationValueUndiscounted());
                } catch (Exception e) {
                        // exception is thrown by getMaxUtilityBid if there are no bids in the outcomespace
                        // but I guess that's pretty rare. Default to 0.0 - 1.0 to prevent crashes.
                        maxUtil = 1.0;
                        minUtil = 0.0;
                }
        }
        
        @Override
        public BidDetails determineOpeningBid() {
                BidDetails openingsBid = allBids.get(k);
                k++;
                return openingsBid;
        }

        @Override
        public BidDetails determineNextBid() {
                int opponentWindowSize = this.negotiationSession.getOpponentBidHistory().size();
                BidDetails nextBid = null;

                // in the paper, the condition of applicability is t_n > 2*gamma; but because
                // we keep track of opponent/own bids seperately we have devide the threshold by 2
                // we can use averageTitForTat if the number of bids made by the opponent is larger
                // than the window we average over
                if (opponentWindowSize > gamma) {
                        double targetUtility = this.averageTitForTat();
                        nextBid = this.negotiationSession.getOutcomeSpace().getBidNearUtility(targetUtility);
                } else {
                        nextBid = this.determineOpeningBid();
                }

                return nextBid;
        }

        private double averageTitForTat() {

                // determine relative change of opponent bid
                int tOpp = this.negotiationSession.getOpponentBidHistory().size() - 1;
                List<BidDetails> opponentHistory = this.negotiationSession.getOpponentBidHistory().getHistory();

                double opponentLastBid = opponentHistory.get(tOpp).getMyUndiscountedUtil();
                double opponentFirstBidInWindow = opponentHistory.get(tOpp - gamma).getMyUndiscountedUtil();
                double relativeChangeOpponent = opponentFirstBidInWindow / opponentLastBid;

                // target utility is the same change applied to our last bid
                double myLastBid = this.negotiationSession.getOwnBidHistory().getLastBidDetails().getMyUndiscountedUtil();
                double targetUtil = relativeChangeOpponent * myLastBid;

                return Math.min(Math.max(targetUtil, minUtil), maxUtil);
        }

        @Override
        public String getName() {
                return "AverageTitForTat2 offering";
        }

}