source: src/main/java/parties/in4010/q12015/group15/OMStrategy.java@ 148

package parties.in4010.q12015.group15;

import java.util.ArrayList;
import java.util.List;

import genius.core.Bid;
import genius.core.bidding.BidDetails;
import genius.core.utility.AdditiveUtilitySpace;

/**
 * This strategy uses Opponent Modeling to find a best bid out of a range of
 * bids. It tries to find the bid closest to the utility for the opponents from
 * their last offers but also with good utility for us. Our utility is valued
 * more important than the utility of our opponents.
 *
 */
public class OMStrategy {

        private OpponentModel om;
        private AdditiveUtilitySpace utilitySpace;
        private List<Bid> bidsOffered = new ArrayList<>();

        public OMStrategy(OpponentModel om, AdditiveUtilitySpace utilitySpace) {
                this.om = om;
                this.utilitySpace = utilitySpace;
        }

        /**
         * @param a
         *            range of bids to choose from
         * @return the best bid out of the list of bids
         */
        public Bid getBestBid(List<BidDetails> bids) {
                System.out.println("----- OMS -----");
                double highestEvaluation = Integer.MIN_VALUE;
                Bid bestBid = null;
                for (BidDetails bid : bids) {
                        System.out.println("OMS bid: " + bid.getBid());
                        if (bidsOffered.contains(bid.getBid())) { // Don't offer same bid
                                                                                                                // twice
                                System.out.println("Has offered bid before: " + bid.getBid());
                                continue;
                        }

                        double evaluation = 0;
                        try {
                                double totalWeights = 0;
                                for (String opponent : om.getOpponents()) {
                                        double opponentUtilityForBid = om.getBidEvaluation(
                                                        opponent, bid.getBid());
                                        double lastUtilityFromOpponentBid = om
                                                        .getLastBidEvaluation(opponent);
                                        double utilDiff = Math.abs(opponentUtilityForBid
                                                        - lastUtilityFromOpponentBid);

                                        double weight = 1 + om
                                                        .getAverageBidUtilityChangeForAgent(opponent); // Put
                                                                                                                                                        // higher
                                                                                                                                                        // weights
                                                                                                                                                        // to
                                                                                                                                                        // non-conceders
                                        totalWeights += weight;
                                        evaluation -= weight * utilDiff;
                                }
                                evaluation += totalWeights
                                                * utilitySpace.getUtility(bid.getBid()); // Add our
                                                                                                                                        // utility
                                if (evaluation > highestEvaluation) {
                                        highestEvaluation = evaluation;
                                        bestBid = bid.getBid();
                                }
                        } catch (Exception e) {
                                System.out
                                                .println("OMS Could not calculate highest evaluation from OM");
                                e.printStackTrace();
                        }

                }

                System.out.println("Highest bid evaluation: " + highestEvaluation);
                System.out.println("for bid: " + bestBid);
                bidsOffered.add(bestBid);
                return bestBid;
        }
}