package com.nailabs.abac.process;

import com.nailabs.abac.trust.*;
import com.nailabs.abac.test.*;
import edu.stanford.peer.rbtm.credential.Entity;

/**
 * This class is a concrete negotiator implementation isolated from the 
 * underlying communications transport mechanism.
 */
public class StaticNegotiator {
    /**
     * The peer with which this instance negotiates.
     */
    protected StaticNegotiator peer;

    /** 
     * The context for the current negotiation, including a trust target graph,
     * strategy, and frontier manager instances.
     */
    protected NegotiationContext context;

    /**
     * Default constructor for the client-side negotiatior. This negotiator
     * is requesting access to a resource.
     */
    public StaticNegotiator(NegotiationContext nc) { 
	context = nc;
    }

    /**
     * Constructor for the server-side negotiator. This negotiator has a 
     * resource that needs protection. 
     */
    public StaticNegotiator(TargetNode root, StaticNegotiator peer) {
        setPeer(peer); 
    } 
    
    public Entity getSelf() 
    {
        return context.getSelf();
    }

    /**
     * initial a new root node and start the negotiation process. 
     */
    public boolean negotiate() {
	TTG graph = context.getGraph();
	Strategy s = context.getStrategy();
	SatisfactionState state;
	int i = 0;
	debug("pre-processing locally...");
	//perform strategy once
	s.iterate();
	Message changes = graph.getChanges();
	graph.reset();
	do {
	    debug("processing cycle = " + ++i);
	    debug("sending message " + changes);
            System.out.println("Sending message: ");
            System.out.println(changes.toXML());
        try {
            Message updates = peer.receive(changes);
            debug("receiving message " + updates);
            changes = receive(updates);
        }
        catch(Exception ex) {
            Debug.rbtmStop();
            ex.printStackTrace();
            return false;
        }
	    state = new SatisfactionState(context.getStrategy().getSatisfactionState());
	    debug("StaticNegotiator:  primary trust target  is " + state);
	}while(state.getState() == SatisfactionState.UNKNOWN && i <= 100);
	// out of the loop so we need to return success or failure
	return (state.getState() == SatisfactionState.SATISFIED);
    }


    /** set the other negotiator dynamically */
    public void setPeer(StaticNegotiator peer) {
	this.peer = peer;
    }

    public void setRoot(TrustTarget tt) {
	context.getGraph().setRoot(tt);
	//TargetNode node = (TargetNode)context.getGraph().getNodeByHash(tt);
	//context.getStrategy().addToWorklist(node);
    }
    

    /** 
     * Synchronously receive a message which can contain multiple operations 
     * from an peer and then return the updates to the originating 
     * peer.
     */
    public Message receive(Message msg) throws Exception {
	Strategy strategy = context.getStrategy();
	TTG graph = context.getGraph();
	Message results = null;

	//for(int i = 0, max = msg.getOperationsCount(); i < max; i++) {
	//    System.out.println("max = " + max);
	//   try {
	//	Operation op = msg.getNextOperation();
	//	op.perform(graph);
	//    }
	//    catch(Exception ex) {
	//	ex.printStackTrace();
	//    }
	//}
	debug("begin receive");
	graph.update(msg);
	debug("graph has been updated");
	strategy.process(msg);
	debug("strategy has processed the work list");
	results = graph.getChanges();
	debug("grabbing the delta list = " + results);
	graph.reset();

	debug("end receive");	
	return results;
    }
    
    /** convenience method for printing messages */
    public void debug(String message) {
	StringBuffer buff = new StringBuffer("StaticNegotiator[");
	buff.append(context.getSelf()).append("]: ").append(message);
	//System.out.println(buff);
	Debug.debug("negotiate", buff.toString());
    }
}