/*

  * The contents of this file are subject to the terms of the Common Development

  * and Distribution License (the License). You may not use this file except in

  * compliance with the License.

  *

  * You can obtain a copy of the License at http://www.netbeans.org/cddl.html

  * or http://www.netbeans.org/cddl.txt.

  *

  * When distributing Covered Code, include this CDDL Header Notice in each file

  * and include the License file at http://www.netbeans.org/cddl.txt.

  * If applicable, add the following below the CDDL Header, with the fields

  * enclosed by brackets [] replaced by your own identifying information:

  * "Portions Copyrighted [year] [name of copyright owner]"

  *

  * The Original Software is NetBeans. The Initial Developer of the Original

  * Software is Sun Microsystems, Inc. Portions Copyright 1997-2006 Sun

  * Microsystems, Inc. All Rights Reserved.

  */

 package org.netbeans.apifest.boolcircuit;

 /**

  * A representation of a logic circuit.

  * It can only be constructed from an element net.

  * Usage:

  * <pre>

  *  Circuit c = Circuit.construct(

  *      Element.createOr(

  *          Element.createAnd(

  *              Element.createInput(0),

  *              Element.createInput(1)

  *          ),

  *          Element.createInput(2)

  *      )

  *  );

  *            

  *  boolean val = c.evaluate(false, true, false));

  * </pre>

  */

 public class Circuit {

     Element root;

     int pins;

     private Circuit(Element elem) {

         root = elem;

         pins = 1 + root.maxInput();

     }

     /**

      * Evaluate output of the circuit for given inputs.

      * For general 

      */

     public boolean evaluate(Boolean ... inputs) throws UnstableException {

         if (inputs.length != pins) throw new IllegalArgumentException("Wrong number of inputs, " + pins + " expected.");

         double[] inp = new double[pins];

         for (int i=0; i<pins; i++) inp[i] = inputs[i] ? 1 : 0;

         double res = root.evaluate(inp);

         return res > 0.5;

     }

     public double evaluate(double ... inputs) throws UnstableException {

         if (inputs.length != pins) throw new IllegalArgumentException("Wrong number of inputs, " + pins + " expected.");

         double[] inp = new double[pins]; // defensive copy with a check

         for (int i=0; i<inputs.length; i++) {

             if (inputs[i] < 0.0 || inputs[i] > 1.0) {

                 throw new IllegalArgumentException("Out of range, pin " + i + ", value=" + inputs[i]);

             }

             inp[i] = inputs[i];

         }

         return root.evaluate(inp);

     }

     /**

      * Creates a circuit from a preconstructed element net.

      *

      * @param a top-level element representing the logic net.

      * @return a circuit prepared for evaluating result for given inputs.

      * 

      */

     public static Circuit construct(Element elem) {

         return new Circuit(elem);

     }

 }