source: src/main/java/agents/anac/y2011/TheNegotiator/BidsCollection.java

package agents.anac.y2011.TheNegotiator;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Random;

import genius.core.Bid;
import genius.core.bidding.BidDetails;
import genius.core.bidding.BidDetailsStrictSorterUtility;

/**
 * The BidsCollection class stores the bids of the partner and all possible bids.
 * 
 * @author Alex Dirkzwager, Mark Hendrikx, Julian de Ruiter
 */
public class BidsCollection {

        // bids done by partner
        private ArrayList<BidDetails> partnerBids;
        // all possible bids (for us) which do not violate the constraints
        private ArrayList<BidDetails> possibleBids;
        private Random random200;
        private final boolean TEST_EQUIVALENCE = false;

        /**
         * Creates a BidsCollection-object which stores the partner bids and all possible
         * bids.
         */
        public BidsCollection() {
                partnerBids = new ArrayList<BidDetails>();
                possibleBids  = new ArrayList<BidDetails>();
                if (TEST_EQUIVALENCE) {
                        random200 = new Random(200);
                } else {
                        random200 = new Random(200);
                }
        }

        /**
         * @return the partnerBids
         */
        public ArrayList<BidDetails> getPartnerBids() {
                return partnerBids;
        }

        /**
         * @return the possibleBids
         */
        public ArrayList<BidDetails> getPossibleBids() {
                return possibleBids;
        }

        /**
         * Add a partner bid to the history. Bids are stored at the front
         * to preserve the timeline.
         * 
         * @param bid made by partner in the current turn
         * @param utility of the bid
         */
        public void addPartnerBid(Bid bid, double utility, double time) {
                BidDetails utbid = new BidDetails(bid, utility, time);
                partnerBids.add(0, utbid);
        }
        
        /**
         * Add a possible bid to the list of possible bids. The given bid 
         * should not violate the constraints of the negotiation.
         * 
         * @param bid which is possible
         * @param utility of the bid
         */
        public void addPossibleBid(Bid bid, double utility) {
                BidDetails utbid = new BidDetails(bid, utility, -1.0);
                possibleBids.add(utbid);
        }
        
        /**
         * Sorts all possible bids in reverse natural order.
         */
        public void sortPossibleBids() {
                if (TEST_EQUIVALENCE) {
                        Collections.sort(possibleBids, new BidDetailsStrictSorterUtility());
                } else {
                        Collections.sort(possibleBids);
                }
        }
                
        /**
         * Get a partner bid.
         * 
         * @param i 
         * @return the i'th bid in the timeline
         */
        public Bid getPartnerBid(int i) {
                Bid bid = null;
                
                if (i < partnerBids.size()) {
                        bid = partnerBids.get(i).getBid();
                } else {
                        ErrorLogger.log("BIDSCOLLECTION: Out of bounds");
                }
                return bid;
        }

        /**
         * Get a partner bid which has a utility of at least a certain
         * value. Null is returned if no such bid exists.
         * 
         * @param threshold
         * @return bid with utility > threshold if exists
         */
        public Bid getBestPartnerBids(double threshold) {
                ArrayList<BidDetails> temp = partnerBids;
                if (TEST_EQUIVALENCE) {
                        Collections.sort(temp, new BidDetailsStrictSorterUtility());
                } else {
                        Collections.sort(temp);
                }
                Bid bid = null;

                int count = 0;
                while (count < temp.size() && temp.get(count).getMyUndiscountedUtil() >= threshold) {
                        count++;
                }
                
                if (count > 0) {
                        bid = temp.get(random200.nextInt(count)).getBid();
                }
                return bid;
        }

        public Bid getOwnBidBetween(double lowerThres, double upperThres) {
                return getOwnBidBetween(lowerThres, upperThres, 0);
        }
        
        /**
         * Get a random bid between two given thresholds.
         * 
         * @param lowerThres lowerbound threshold
         * @param upperThres upperbound threshold
         * @return random bid between thresholds
         */
        public Bid getOwnBidBetween(double lowerThres, double upperThres, int counter) {
                int lB = 0;
                int uB = 0;
                Bid bid = null;

                // determine upperbound and lowerbound by visiting all points
                for (int i = 0; i < possibleBids.size(); i++) {
                        double util = possibleBids.get(i).getMyUndiscountedUtil();
                        if (util > upperThres) {
                                uB++;
                        }
                        if (util >= lowerThres) {
                                lB++;
                        }
                }
                // if there are no points between the bounds
                if (lB == uB) {
                        if (counter == 1) {
                                return possibleBids.get(0).getBid(); // safe fallback value
                        }
                        // ignore upper threshold
                        bid = getOwnBidBetween(lowerThres, 1.1, 1);
                } else {
                        // decrement upper- and lowerbound to get the correct index
                        // (count counts from 1, while arrays are indexed from 0)
                        if (lB > 0) {
                                lB--;
                        }
                        if ((uB + 1) <= lB) {
                                uB++;
                        }
                        // calculate a random bid index
                        int result = uB + (int) ( random200.nextDouble() * (lB - uB) + 0.5);
                        bid = possibleBids.get(result).getBid();
                }
                return bid;
        }

        /**
         * Calculate the upperthreshold based on the lowerthreshold and a given percentage.
         * @param threshold
         * @param percentage
         * @return
         */
        public double getUpperThreshold(double threshold, double percentage) {
                int boundary = 0;
                while (boundary < possibleBids.size() && possibleBids.get(boundary).getMyUndiscountedUtil() >= threshold) {
                        boundary++;
                }
                if (boundary > 0)
                        boundary--;
                int index = boundary - (int) Math.ceil(percentage * boundary);
        
                double utility = possibleBids.get(index).getMyUndiscountedUtil();
                return utility;
        }
}