package edu.stanford.peer.rbtm.engine;

import java.util.*;
import edu.stanford.peer.rbtm.credential.*;
/**
 * A proof node which respresents an entity in the credential graph.
 */
public class EntityProofNode extends AbstractProofNode
{
	/**
	 * A map for managing all the partial solutions per intersection that arrive
	 */
   static protected PartialSolutionMap partialSolutions = 
		 new PartialSolutionMap();

	/**
	 * Default constructor
	 */
   protected EntityProofNode(ProofGraph graph, Entity re, int trackType) {
		 super(graph, re, trackType);
	}
	
	public void additionalBackwardProcess() {
	    //backwardSolutionAdded(this, getRoleExp());
	}

	public void additionalForwardProcess() {
	    
	}
	 
	/**
	 * Adds a forward solution but propagating the solution backwards along
	 * the credential chain. If s is a partial solution and all k pieces have
	 * arrived, then add edge from this node to the intersection.
	 */
	public void forwardSolutionAdded(ProofNode s, ForwardSolution r) {
		 super.forwardSolutionAdded(s, r);
		 EntityExpression expr = s.getRoleExp();
		 System.out.println("Additional forward processing on " + getRoleExp() +
								  " where s = " + expr);
		 Iterator iCreds = getGraph().findCredentialsByPartialSubject(expr);
		 while(iCreds.hasNext()) { // if s is partial solution of intersection(s)
			  StaticCredential credential = (StaticCredential) iCreds.next();
			  Intersection i = (Intersection)credential.getSubject();				
			  System.out.println(getRoleExp() + " matches partial solution " + i);
			  if(partialSolutions.addPartialSolution(i, expr)) {
					ProofNode node = getGraph().addForwardNode(i);
					node.addParent(node, r);
			  }
		 } 
	}

	 
}