/**
* Class to build inputs for the appmean interface
* Maintains input history for calculating diffs between
* pair sets
*/
import java.util.*;
import edu.neu.ccs.satsolver.*;

public class InputGen {
	Set<Pair> oldPairs;
	PolynomialI oldPoly;

   /** Make an initial appmean input with current Pairs */
	public OutputI initial(Set<Pair> pairs) {
		oldPairs = pairs;
		OutputI result = SATSolverUtil.calculateBias(new InputInitial(pairs));
		oldPoly = result.getPolynomial();
		return result;
	}

	/** Make an update appmean input with current pairs and prev pairs */
	public OutputI update(Set<Pair> pairs) {
		// calculate diffs
		HashSet<Pair> added = new HashSet(pairs);
		added.removeAll(oldPairs);
		HashSet<Pair> removed = new HashSet(oldPairs);
		removed.removeAll(pairs);

		OutputI result = SATSolverUtil.updateBias(new InputUpdate(added, removed, oldPoly));
		oldPoly = result.getPolynomial();
		oldPairs.removeAll(removed);
		oldPairs.addAll(added);

		return result;
	}
}