/*

 * 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);

    }

}