source: src/main/java/agents/anac/y2015/pnegotiator/BayesLogic.java

package agents.anac.y2015.pnegotiator;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Iterator;
import java.util.List;
import java.util.Random;
import java.util.TreeSet;

import genius.core.Bid;
import genius.core.Domain;
import genius.core.issue.Issue;
import genius.core.issue.IssueDiscrete;
import genius.core.issue.ValueDiscrete;
import genius.core.utility.AdditiveUtilitySpace;
import genius.core.utility.EvaluatorDiscrete;

/**
 * Created by chad on 2/28/15.
 */
public class BayesLogic {
        private AdditiveUtilitySpace utilitySpace;
        private ArrayList<TreeSet<ValueFrequency>> valueFrequencies;
        private ArrayList<ValueFrequency>[] vFreqs;
        public int T = 1;
        int totalBids = 0;
        int P;
        public int V = 1;

        public BayesLogic(AdditiveUtilitySpace utilitySpace, int P)
                        throws Exception {
                Domain domain = utilitySpace.getDomain();
                List<Issue> issues = domain.getIssues();
                this.P = P;

                this.utilitySpace = utilitySpace;
                valueFrequencies = new ArrayList<TreeSet<ValueFrequency>>(
                                issues.size() - 1);
                vFreqs = new ArrayList[issues.size() - 1];
                for (int i = 0; i < issues.size() - 1; ++i) {
                        // System.out.println("Adding TreeSet<ValueFrequency> vfs[" + (i) +
                        // "]");
                        valueFrequencies.add(i, new TreeSet<ValueFrequency>(new VFComp()));
                        vFreqs[i] = new ArrayList<ValueFrequency>();
                        IssueDiscrete di = (IssueDiscrete) domain.getIssues().get(i);
                        EvaluatorDiscrete ed = (EvaluatorDiscrete) utilitySpace
                                        .getEvaluator(i + 1);
                        for (ValueDiscrete v : di.getValues()) {
                                // System.out.println("\tAdding ValueFrequency element[" +
                                // v.value + ", " + (ed.getEvaluation(v) * ed.getWeight()) +
                                // "]");
                                ValueFrequency v1 = new ValueFrequency(v, ed.getEvaluation(v),
                                                P);
                                valueFrequencies.get(i).add(v1);
                                vFreqs[i].add(v1);
                        }
                }

        }

        public Bid bayesBid(Bid bestBid) {
                Bid b = new Bid(bestBid);
                for (int i = 0; i < valueFrequencies.size(); ++i) {
                        Iterator<ValueFrequency> itr = valueFrequencies.get(i)
                                        .descendingIterator();
                        ValueDiscrete highestExpectedUtilVal = null;
                        double highestExpectedUtil = -1.0;
                        // System.out.format("Issue: %d\n", i);
                        while (itr.hasNext()) {
                                ValueFrequency vfr = itr.next();
                                double FP = 1;
                                for (int p = 0; p < P; p++)
                                        FP *= vfr.opponentFrequency[p];
                                // Math.pow(totalBids,P)
                                double EU = FP * Math.pow(vfr.utility, V);
                                // System.out.format("  Choice: %10s, U = %6.4f, E[U]: %10.2f,  Frequencies: %s\n",
                                // vfr.value, vfr.utility, EU,
                                // Arrays.toString(vfr.opponentFrequency));
                                if (EU > highestExpectedUtil) {
                                        highestExpectedUtilVal = vfr.value;
                                        highestExpectedUtil = EU;
                                }
                        }
                        // ValueDiscrete highestExpectedUtilVal =
                        // (ValueDiscrete)(lastBid.getValue(i + 1));
                        // while(itr.hasNext()) {
                        // ValueFrequency vfr = itr.next();
                        // if((((double)vfr.opponentFrequency)/(double)totalBids) *
                        // vfr.utility >= highestExpectedUtil) {
                        // highestExpectedUtil =
                        // ((double)vfr.opponentFrequency/(double)totalBids * vfr.utility);
                        // highestExpectedUtilVal = vfr.value;
                        // }
                        // }
                        b = b.putValue(i + 1, highestExpectedUtilVal);
                }
                return b;
        }

        private Bid asBid(ValueFrequency[] b) throws Exception {
                Bid b1 = utilitySpace.getMaxUtilityBid();
                for (int i = 0; i < b.length; i++) {
                        b1 = b1.putValue(i + 1, b[i].value);
                }
                return b1;
        }

        private double EU2(ValueFrequency[] b) throws Exception {
                double EU = utilitySpace.getUtility(asBid(b));
                for (int p = 1; p < P; p++) {
                        for (int v = 0; v < b.length; v++)
                                EU *= b[v].opponentFrequency[p];
                }
                return EU;
        }

        /**
         * Approximates bid value
         * 
         * @return
         */
        public Bid bayesBid2(Random rand) throws Exception {
                ValueFrequency[] b = new ValueFrequency[valueFrequencies.size()];
                for (int i = 0; i < valueFrequencies.size(); i++)
                        b[i] = valueFrequencies.get(i).last();
                double T = 1, Tmin = 0.2, alpha = 0.9;
                int K = 10;
                double EU = EU2(b);
                do {
                        System.out.println(T);
                        for (int k = 0; k < K; k++) {
                                ValueFrequency[] nb = Arrays.copyOf(b, b.length);

                                int ri = rand.nextInt(nb.length);
                                nb[ri] = vFreqs[ri].get(rand.nextInt(vFreqs[ri].size()));

                                double nEU = EU2(nb);
                                double p = Math.exp((EU - nEU) / T);
                                if (p > rand.nextDouble()) {
                                        b = nb;
                                        EU = nEU;
                                }
                        }
                        T *= alpha;
                } while (T > Tmin);
                return asBid(b);
        }

        // Update the frequency of our proposed values based on a bid we're about to
        // make
        public void updateOurFrequency(Bid bid) throws Exception {
                for (int i = 0; i < valueFrequencies.size(); ++i) {
                        Iterator<ValueFrequency> itr = valueFrequencies.get(i)
                                        .descendingIterator();
                        while (itr.hasNext()) {
                                ValueFrequency vfr = itr.next();
                                if (vfr.value.toString().compareTo(
                                                ((ValueDiscrete) bid.getValue(i + 1)).toString()) == 0) {
                                        vfr.ourFrequency++;
                                }
                                break;
                        }
                }
        }

        // Update the frequency of opponents' proposed values based on a bid an
        // opponent just made
        public void updateOpponentFrequency(Bid bid, int P) throws Exception {
                ++totalBids;
                for (int i = 0; i < valueFrequencies.size(); ++i) {
                        Iterator<ValueFrequency> itr = valueFrequencies.get(i)
                                        .descendingIterator();
                        while (itr.hasNext()) {
                                ValueFrequency vfr = itr.next();
                                // if(vfr.value.toString().compareTo(((ValueDiscrete)bid.getValue(i+1)).toString())
                                // == 0) {
                                // System.out.println(vfr + " " + bid);
                                if (vfr.value.toString().equals(bid.getValue(i + 1).toString())) {
                                        vfr.opponentFrequency[P] += T;
                                        break;
                                }
                        }
                }
        }
}