package com.nailabs.abac.process;

import com.nailabs.abac.trust.*;
import com.nailabs.abac.test.*;
import java.util.*;

/**
 * An implication edge represents an edge in a trust target graph 
 * (<CODE>TTG</CODE>) with accompanying evidence. An implication edge 
 * is proved by a set of credentials (i.e. a chain).
 */
public class ImplicationEdge extends EdgeOperation {
    
    /** Jared: Added this method to make XML processing easier */
    public ImplicationEdge() {
        super();
        type = new String("Implication");
    }
    
    /** 
     * Default constructor 
     * @param parent an upcast StandardTTNode
     * @param child an upcast TargetNode
     */
    public ImplicationEdge(Goal parent, Goal child, ProcessingState state,
			   HashSet evidence) {
	super(parent, child, state, evidence);
	type = new String("Implication");
	debug("edge", "state = " + state );
    }

    public void performAdditional(TTG graph) {
	StandardTTNode parent=(StandardTTNode)graph.getNodeByHash(getParent());
	TargetNode child = (TargetNode)graph.getNode(getChild());
	debug("perform", "performing " + toString(parent, child));
	parent.addImplicationChild(child);
	child.addImplicationParent(parent);
	//propagate satisfaction for all nodes
	int satisfaction = child.getSatisfactionValue();
	debug("perform",  "child is satified =  " + 
			   (satisfaction == SatisfactionState.SATISFIED));
	//if(child instanceof TrivialTTNode)
	//parent.receive((TrustTarget)child.getGoal(),
	//new SatisfactionState(satisfaction)); 
    }

    public void performNewAdditional(TTG graph) {
	TTGNode child = graph.getNodeByHash(getChild());
	if(child == null) {
	    child = TTGNode.createNode(getChild());
	    debug("newop", performNewInfo());
	    // set processing if necessary here
	    if(state != null) {
		child.getProcessingState().update(state);
	    } else {
		debug("newop", "warning perform new additional has no state");
	    }
	    graph.putNodeByHash(child);
	}
	performAdditional(graph);
    }
    
    /** Friendly debugging convenience method */
    protected void debug(String level, String message) {
	StringBuffer buff = new StringBuffer("ImplicationEdge: ");
	buff.append(message);
	Debug.debug(level, buff.toString());
    }


    public String toString(StandardTTNode parent, TargetNode child) {
	StringBuffer buff = new StringBuffer("[ImplicationEdge  ");
	buff.append(parent).append(" <<=== ");
	buff.append(child);
	return buff.toString();
    }

    public String toString() {
	StringBuffer buff = new StringBuffer("[ImplicationEdge  ");
	buff.append(getParent()).append(" <<=== ");
	buff.append(getChild()).append(", state = ");
	buff.append(state).append(", evidence = ");
    buff.append(getEvidence());
	return buff.toString();
    }

}