package boaexample;

import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Map.Entry;

import genius.core.Bid;
import genius.core.bidding.BidDetails;
import genius.core.boaframework.BOAparameter;
import genius.core.boaframework.NegotiationSession;
import genius.core.boaframework.OpponentModel;
import genius.core.issue.Issue;
import genius.core.issue.IssueDiscrete;
import genius.core.issue.Objective;
import genius.core.issue.ValueDiscrete;
import genius.core.utility.AdditiveUtilitySpace;
import genius.core.utility.Evaluator;
import genius.core.utility.EvaluatorDiscrete;

import java.util.Set;

/**
 * BOA framework implementation of the HardHeaded Frequecy Model. My main
 * contribution to this model is that I fixed a bug in the mainbranch which
 * resulted in an equal preference of each bid in the ANAC 2011 competition.
 * Effectively, the corrupt model resulted in the offering of a random bid in
 * the ANAC 2011.
 * 
 * Default: learning coef l = 0.2; learnValueAddition v = 1.0
 * 
 * Adapted by Mark Hendrikx to be compatible with the BOA framework.
 * 
 * Tim Baarslag, Koen Hindriks, Mark Hendrikx, Alex Dirkzwager and Catholijn M.
 * Jonker. Decoupling Negotiating Agents to Explore the Space of Negotiation
 * Strategies
 * 
 */
public class HardHeadedFrequencyModel extends OpponentModel {

	// the learning coefficient is the weight that is added each turn to the
	// issue weights
	// which changed. It's a trade-off between concession speed and accuracy.
	private double learnCoef;
	// value which is added to a value if it is found. Determines how fast
	// the value weights converge.
	private int learnValueAddition;
	private int amountOfIssues;

	/**
	 * Initializes the utility space of the opponent such that all value issue
	 * weights are equal.
	 */
	@Override
	public void init(NegotiationSession negotiationSession, Map<String, Double> parameters) {
		super.init(negotiationSession, parameters);
		this.negotiationSession = negotiationSession;
		if (parameters != null && parameters.get("l") != null) {
			learnCoef = parameters.get("l");
		} else {
			learnCoef = 0.2;
		}
		learnValueAddition = 1;
		initializeModel();
	}

	private void initializeModel() {
		opponentUtilitySpace = new AdditiveUtilitySpace(negotiationSession.getDomain());
		amountOfIssues = opponentUtilitySpace.getDomain().getIssues().size();
		double commonWeight = 1D / (double) amountOfIssues;

		// initialize the weights
		for (Entry<Objective, Evaluator> e : opponentUtilitySpace.getEvaluators()) {
			// set the issue weights
			opponentUtilitySpace.unlock(e.getKey());
			e.getValue().setWeight(commonWeight);
			try {
				// set all value weights to one (they are normalized when
				// calculating the utility)
				for (ValueDiscrete vd : ((IssueDiscrete) e.getKey()).getValues())
					((EvaluatorDiscrete) e.getValue()).setEvaluation(vd, 1);
			} catch (Exception ex) {
				ex.printStackTrace();
			}
		}
	}

	/**
	 * Determines the difference between bids. For each issue, it is determined
	 * if the value changed. If this is the case, a 1 is stored in a hashmap for
	 * that issue, else a 0.
	 * 
	 * @param a
	 *            bid of the opponent
	 * @param another
	 *            bid
	 * @return
	 */
	private HashMap<Integer, Integer> determineDifference(BidDetails first, BidDetails second) {

		HashMap<Integer, Integer> diff = new HashMap<Integer, Integer>();
		try {
			for (Issue i : opponentUtilitySpace.getDomain().getIssues()) {
				diff.put(i.getNumber(), (((ValueDiscrete) first.getBid().getValue(i.getNumber()))
						.equals((ValueDiscrete) second.getBid().getValue(i.getNumber()))) ? 0 : 1);
			}
		} catch (Exception ex) {
			ex.printStackTrace();
		}

		return diff;
	}

	/**
	 * Updates the opponent model given a bid.
	 */
	@Override
	public void updateModel(Bid opponentBid, double time) {
		if (negotiationSession.getOpponentBidHistory().size() < 2) {
			return;
		}
		int numberOfUnchanged = 0;
		BidDetails oppBid = negotiationSession.getOpponentBidHistory().getHistory()
				.get(negotiationSession.getOpponentBidHistory().size() - 1);
		BidDetails prevOppBid = negotiationSession.getOpponentBidHistory().getHistory()
				.get(negotiationSession.getOpponentBidHistory().size() - 2);
		HashMap<Integer, Integer> lastDiffSet = determineDifference(prevOppBid, oppBid);

		// count the number of changes in value
		for (Integer i : lastDiffSet.keySet()) {
			if (lastDiffSet.get(i) == 0)
				numberOfUnchanged++;
		}

		// This is the value to be added to weights of unchanged issues before
		// normalization.
		// Also the value that is taken as the minimum possible weight,
		// (therefore defining the maximum possible also).
		double goldenValue = learnCoef / (double) amountOfIssues;
		// The total sum of weights before normalization.
		double totalSum = 1D + goldenValue * (double) numberOfUnchanged;
		// The maximum possible weight
		double maximumWeight = 1D - ((double) amountOfIssues) * goldenValue / totalSum;

		// re-weighing issues while making sure that the sum remains 1
		for (Integer i : lastDiffSet.keySet()) {
			if (lastDiffSet.get(i) == 0 && opponentUtilitySpace.getWeight(i) < maximumWeight)
				opponentUtilitySpace.setWeight(opponentUtilitySpace.getDomain().getObjectives().get(i),
						(opponentUtilitySpace.getWeight(i) + goldenValue) / totalSum);
			else
				opponentUtilitySpace.setWeight(opponentUtilitySpace.getDomain().getObjectives().get(i),
						opponentUtilitySpace.getWeight(i) / totalSum);
		}

		// Then for each issue value that has been offered last time, a constant
		// value is added to its corresponding ValueDiscrete.
		try {
			for (Entry<Objective, Evaluator> e : opponentUtilitySpace.getEvaluators()) {
				// cast issue to discrete and retrieve value. Next, add constant
				// learnValueAddition to the current preference of the value to
				// make
				// it more important
				((EvaluatorDiscrete) e.getValue()).setEvaluation(
						oppBid.getBid().getValue(((IssueDiscrete) e.getKey()).getNumber()),
						(learnValueAddition + ((EvaluatorDiscrete) e.getValue()).getEvaluationNotNormalized(
								((ValueDiscrete) oppBid.getBid().getValue(((IssueDiscrete) e.getKey()).getNumber())))));
			}
		} catch (Exception ex) {
			ex.printStackTrace();
		}
	}

	@Override
	public double getBidEvaluation(Bid bid) {
		double result = 0;
		try {
			result = opponentUtilitySpace.getUtility(bid);
		} catch (Exception e) {
			e.printStackTrace();
		}
		return result;
	}

	@Override
	public String getName() {
		return "HardHeaded Frequency Model example";
	}

	@Override
	public Set<BOAparameter> getParameterSpec() {
		Set<BOAparameter> set = new HashSet<BOAparameter>();
		set.add(new BOAparameter("l", 0.2,
				"The learning coefficient determines how quickly the issue weights are learned"));
		return set;
	}
}