source: src/main/java/parties/in4010/q12015/group5/OpponentModel.java@ 127

package parties.in4010.q12015.group5;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

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

/**
 * This class represents a model of the issue and value weights of an Opponent.
 * This model is built using the Frequency analysis method.
 */
public class OpponentModel {

        /**
         * The history of bids this opponent has made
         */
        public List<Bid> bidHistory;

        /**
         * The domain we are negotiating in.
         */
        private Domain domain;

        /**
         * Map containing the modeled issue weight for each issue.
         */
        public Map<IssueDiscrete, Double> issueModel;

        /**
         * n used in the Frequency Analysis.
         */
        private final double n = 0.1;

        /**
         * Map containing the observed count every value has been bid.
         */
        public Map<IssueDiscrete, Map<ValueDiscrete, Integer>> valueCountModel;

        /**
         * Map containing the modeled value weight for each value in each issue.
         */
        public Map<IssueDiscrete, Map<ValueDiscrete, Double>> valueWeightModel;

        /**
         * Constructs an new OpponentModel based on the first bid.
         * 
         * @param domain
         *            The domain we are negotiating in.
         * @param bid
         *            The opponent's first bid.
         * @throws Exception
         */
        public OpponentModel(Domain domain, Bid bid) throws Exception {
                issueModel = new HashMap<IssueDiscrete, Double>();
                valueCountModel = new HashMap<IssueDiscrete, Map<ValueDiscrete, Integer>>();
                valueWeightModel = new HashMap<IssueDiscrete, Map<ValueDiscrete, Double>>();

                bidHistory = new ArrayList<Bid>();
                bidHistory.add(bid);
                this.domain = domain;

                List<Issue> issues = bid.getIssues();
                for (Issue issue : issues) {
                        // Initialize weights evenly
                        IssueDiscrete issueDiscrete = (IssueDiscrete) issue;
                        issueModel.put(issueDiscrete, 1. / issues.size());

                        List<ValueDiscrete> values = issueDiscrete.getValues();
                        HashMap<ValueDiscrete, Integer> valueCountMap = new HashMap<ValueDiscrete, Integer>();
                        HashMap<ValueDiscrete, Double> valueWeightMap = new HashMap<ValueDiscrete, Double>();
                        ValueDiscrete bidValue = (ValueDiscrete) bid.getValue(issueDiscrete
                                        .getNumber());
                        for (ValueDiscrete value : values) {
                                if (value.equals(bidValue)) {
                                        valueCountMap.put(value, 1);
                                        valueWeightMap.put(value, 1.);
                                } else {
                                        valueCountMap.put(value, 0);
                                        valueWeightMap.put(value, 0.);
                                }
                        }
                        valueCountModel.put(issueDiscrete, valueCountMap);
                        valueWeightModel.put(issueDiscrete, valueWeightMap);
                }
        }

        /**
         * @param percentage
         *            The percentage (between 0 and 1) of the list, starting from
         *            the end, that should be returned.
         * @return Returns the last few bids from this opponent, based on the
         *         percentage.
         */
        public List<Bid> getBidHistory(double percentage) {
                int historySize = bidHistory.size();
                int fromIndex = (int) Math.floor(historySize
                                - (historySize * percentage));
                List<Bid> newList = new ArrayList<Bid>(historySize - fromIndex);
                for (int i = fromIndex - 1; i < historySize; i++) { // Make sure to
                                                                                                                        // always return one
                        newList.add(bidHistory.get(fromIndex));
                }
                return newList;
        }

        /**
         * Generates an UtilitySpace that represents the modeled UtilitySpace of
         * this opponent.
         * 
         * @return An UtilitySpace that represents the modeled UtilitySpace of this
         *         opponent.
         * @throws Exception
         */
        public AdditiveUtilitySpace getUtilitySpace() throws Exception {
                Map<Objective, Evaluator> evaluatorMap = new HashMap<Objective, Evaluator>();
                for (IssueDiscrete issue : issueModel.keySet()) {
                        EvaluatorDiscrete evaluator = new EvaluatorDiscrete();
                        evaluator.setWeight(issueModel.get(issue));
                        Map<ValueDiscrete, Double> valueWeightMap = valueWeightModel
                                        .get(issue);
                        for (ValueDiscrete value : valueWeightMap.keySet()) {
                                evaluator.setEvaluationDouble(value, valueWeightMap.get(value));
                        }
                        evaluatorMap.put(issue, evaluator);
                }
                return new AdditiveUtilitySpace(domain, evaluatorMap);
        }

        /**
         * Normalizes the issue weights in the issueModel.
         */
        private void normalizeWeights() {
                double sum = 0;
                for (IssueDiscrete v : issueModel.keySet()) {
                        sum += issueModel.get(v);
                }

                // Divide every issue weight with the sum of the weights to obtain a sum
                // of 1.
                for (IssueDiscrete v : issueModel.keySet()) {
                        double issueWeight = issueModel.get(v);
                        issueModel.put(v, issueWeight / sum);
                }
        }

        /*
         * (non-Javadoc)
         * 
         * @see java.lang.Object#toString()
         */
        @Override
        public String toString() {
                String ret = "";
                for (Issue issue : valueWeightModel.keySet()) {
                        ret += "Issue: " + issue.getName() + " - weight: "
                                        + issueModel.get(issue) + "\n";
                        for (Value value : valueWeightModel.get(issue).keySet()) {
                                ret += "Value: " + value.toString();
                                ret += " - weight: " + valueWeightModel.get(issue).get(value)
                                                + " (" + valueCountModel.get(issue).get(value) + ")\n";
                        }
                }

                return ret;
        }

        /**
         * Updates the model with a new bid that has been received.
         * 
         * @param bid
         *            The newest bid of our opponent.
         * @throws Exception
         */
        public void updateModel(Bid bid) throws Exception {
                Bid lastBid = bidHistory.get(bidHistory.size() - 1);
                for (Issue issue : issueModel.keySet()) {
                        // Increase the issue weight if its value didn't change.
                        ValueDiscrete newValue = (ValueDiscrete) bid.getValue(issue
                                        .getNumber());
                        ValueDiscrete oldValue = (ValueDiscrete) lastBid.getValue(issue
                                        .getNumber());
                        if (newValue.equals(oldValue)) {
                                double issueWeight = issueModel.get(issue);
                                issueModel.put((IssueDiscrete) issue, issueWeight + n);
                        }

                        // Increase the count for the values that have been bid.
                        Map<ValueDiscrete, Integer> valueCountMap = valueCountModel
                                        .get(issue);
                        int valueCount = valueCountMap.get(newValue);
                        valueCountMap.put(newValue, valueCount + 1);

                        // Recalculate the weights based on the counts.
                        updateValueWeights((IssueDiscrete) issue);
                }

                // Normalize the weights again so the sum is again 1.
                normalizeWeights();
                bidHistory.add(bid);
        }

        /**
         * Updates the valueWeightModel based on the valueCountModel for the given
         * issue.
         * 
         * @param issue
         *            The issue for which the value weights should be updated.
         */
        private void updateValueWeights(IssueDiscrete issue) {
                Map<ValueDiscrete, Integer> valueCountMap = valueCountModel.get(issue);
                Map<ValueDiscrete, Double> valueWeightMap = valueWeightModel.get(issue);

                int max = 0;
                for (ValueDiscrete v : valueCountMap.keySet()) {
                        int valueCount = valueCountMap.get(v);
                        if (valueCount > max)
                                max = valueCount;
                }

                // Divide every value count with the maximum count to obtain values
                // between 0 and 1.
                for (ValueDiscrete v : valueCountMap.keySet()) {
                        int valueCount = valueCountMap.get(v);
                        double valueWeight = valueCount / (double) max;
                        valueWeightMap.put(v, valueWeight);
                }
        }
}