Initiator.java

package siebog.interaction.contractnet;

import java.util.ArrayList;
import java.util.List;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import siebog.agents.AID;
import siebog.agents.XjafAgent;
import siebog.interaction.ACLMessage;
import siebog.interaction.Performative;
import siebog.utils.ObjectFactory;

/**
 * 
 * @author <a href="jovanai.191@gmail.com">Jovana Ivkovic</a>
 */

public abstract class Initiator extends XjafAgent {
	private static final long serialVersionUID = 1L;
	private static final Logger LOG = LoggerFactory.getLogger(Initiator.class);
	private int pendingProposals;
	private Proposal bestProposal;
	private List<AID> rejectedAID = new ArrayList<AID>();

	private List<Proposal> proposals = new ArrayList<Proposal>();

	/*
	 * 1 - all proposals received 2 - acceptance sent, waiting for response 3 - all done
	 */
	private int status = 0;

	public void cfp(CallForProposal proposal) {
		status = 0;
		proposal.setInitiator(myAid);
		List<AID> participants = ObjectFactory.getAgentManager().getRunningAgents();
		ACLMessage msg = new ACLMessage(Performative.CALL_FOR_PROPOSAL);
		msg.receivers.addAll(participants);
		msg.contentObj = proposal;
		msg.sender = myAid;

		msg.replyBy = proposal.getReplyBy();
		msm().post(msg);
		pendingProposals = participants.size() - 1;
		LOG.info("A call for proposals is out!");
		// fault checking
		ACLMessage delayedMsg = new ACLMessage();
		delayedMsg.sender = myAid;
		delayedMsg.receivers.add(myAid);
		delayedMsg.content = "replyBy";
		msm().post(delayedMsg, proposal.getReplyBy() - System.currentTimeMillis());
	}

	public void rejectProposal() {

		ACLMessage msg = new ACLMessage(Performative.REJECT_PROPOSAL);
		msg.sender = myAid;
		msg.receivers = rejectedAID;
		msm().post(msg);
		rejectedAID.clear();
		bestProposal = null;
	}

	public void acceptProposal() {
		ACLMessage msg = new ACLMessage(Performative.ACCEPT_PROPOSAL);
		msg.sender = myAid;

		bestProposal = getOptimalProposal(proposals);
		proposals.remove(bestProposal);
		rejectedAID.remove(bestProposal.getParticipant());

		if (bestProposal != null) {
			msg.receivers.add(bestProposal.getParticipant());
			status = 2;
			msm().post(msg);

			// fault checking
			ACLMessage delayedMsg = new ACLMessage();
			delayedMsg.sender = myAid;
			delayedMsg.receivers.add(myAid);
			delayedMsg.content = "waiting";
			delayedMsg.contentObj = bestProposal.getParticipant();

			msm().post(delayedMsg, bestProposal.getTimeEstimate());

		} else {
			LOG.info("No proposals made");
		}
	}

	public void handleRefuse() {
		pendingProposals--;
		if (pendingProposals == 0) {
			acceptProposal();
		}
	}

	public void handlePropose(ACLMessage msg) {

		proposals.add((Proposal) msg.contentObj);
		rejectedAID.add(((Proposal) msg.contentObj).getParticipant());
		pendingProposals--;
		if (pendingProposals == 0) {
			acceptProposal();
		}
	}

	public abstract Proposal getOptimalProposal(List<Proposal> proposals);

	public abstract void failure();

	public abstract void success(Result result);

	public void handleFailure() {
		bestProposal = getOptimalProposal(proposals);

		if (bestProposal == null) {
			status = 3;
			failure();
		} else {
			proposals.remove(bestProposal);
			rejectedAID.remove(bestProposal.getParticipant());
			acceptProposal();
		}
	}

	public void handleDone(ACLMessage msg) {
		status = 3;
		rejectProposal();
		success((Result) msg.contentObj);
	}

	public abstract CallForProposal createCfp();

	@Override
	protected void onMessage(ACLMessage msg) {
		switch (msg.performative) {

		case REQUEST:
			CallForProposal cfp = createCfp();
			cfp(cfp);
			break;
		case PROPOSE:
			handlePropose(msg);
			break;
		case REFUSE:
			handleRefuse();
			break;
		case INFORM:
			handleDone(msg);
			break;
		case FAILURE:
			handleFailure();
			break;
		case CALL_FOR_PROPOSAL:
			break;
		default: // delayedMsg
			if (msg.content.equals("replyBy") && status < 1) {
				LOG.info("ReplyBy time has passed.");
				pendingProposals = 0;
				acceptProposal();

			} else if (msg.content.equals("waiting") && status > 1) {
				if (bestProposal != null
						&& ((AID) msg.contentObj).equals(bestProposal.getParticipant())) {
					LOG.info("Participant hasn't finished in time. {}", ((AID) msg.contentObj));
					handleFailure();
				}
			}
			break;
		}
	}

}