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  * 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;

 import java.security.CodeSource;

 import java.security.Permission;

 import java.security.PermissionCollection;

 import java.security.Policy;

 import java.util.Collection;

 import java.util.Collections;

 import java.util.Enumeration;

 import junit.framework.TestCase;

 import junit.framework.*;

 /** This file contains the APIFest quest for day 2. Simply, turn the 

  * boolean circuit into circuit that can compute with double values from 0 to 1.

  * <p>

  * This means that where ever a boolean was used to represent input or 

  * output values, one can now use any double number from >= 0 and <= 1.

  * Still, to support backward compatibility, the operations with booleans

  * has to be kept available and have to work. In fact False shall be 

  * treated as 0 and True as 1.

  * <p>

  * The basic elements has to be modified to work on doubles in the following

  * way:

  * <ul>

  *   <li>negation - neg(x) = 1 - x, this is correct extension as neg(false)=neg(0)=1-0=1=true

  *   <li>and - and(x,y) = x * y, again this is fine as and(true,true)=1*1=true and also

  *             and(false,true)=0*1=0=false

  *   <li>or - or(x,y) = 1 - (1 - x) * (1 - y) and this is also ok as

  *             or(false,false) = 1 - (1 - 0) * (1 - 0) = 1 - 1 = 0 = false

  *             or(true,false) = 1 - (1 - 1) * (1 - 0) = 1 - 0 * 1 = 1 = true

  * </ul>

  * <p>

  * However as the circuits with doubles are more rich than plain boolean circuits,

  * there is additional requirement to allow any user of your API to write its 

  * own "element" type. This is all going to be exercise in the tests bellow

  * which you are supposed to implement.

  */

 public class RealTest extends TestCase {

     static {

         // your code shall run without any permissions

     }

     public RealTest(String testName) {

         super(testName);

     }

     protected void setUp() throws Exception {

     }

     protected void tearDown() throws Exception {

     }

     /** First of all create a circuit which will evaluate

      * expression (X1 and X2) or not(x1). Hold the circuit

      * in some variable.

      *

      * Feed this circuit with x1=true, x2=false, assert result is false

      *

      * Feed the same circuit with x1=false, x2=true, assert result is true

      *

      * Feed the same circuit with x1=0.0, x2=1.0, assert result is 1.0

      *

      * Feed the same circuit with x1=0.5, x2=0.5, assert result is 0.625

      *

      * Feed the same circuit with x1=0.0, x2=2.0, make sure it throws an exception

      */

     public void testX1andX2orNotX1() throws Exception {

         boolean fired = false;

         Circuit c = Circuit.construct(

             Element.createOr(

                 Element.createAnd(

                     Element.createInput(0),

                     Element.createInput(1)

                 ),

                 Element.createNot(Element.createInput(0))

             )

         );

         assertFalse ("false", c.evaluate(true, false));

         assertTrue ("true", c.evaluate(false, true));

         assertEquals ("1.0", 1.0, c.evaluate(0.0, 1.0));

         assertEquals ("0.625", 0.625, c.evaluate(0.5, 0.5));

         try {

             c.evaluate(0.0, 2.0);

         } catch (Exception exc) {

             fired = true;

         }

         assertTrue ("Fired an exception for wrong input", fired);

     }

     /** Ensure that one variable cannot be filled with two different values.

      * Create a circuit for x1 and x1. Make sure that for any usage of your

      * API that would not lead to x1 * x1 result, an exception is thrown.

      * For example if there was a way to feed the circuit with two different 

      * values 0.3 and 0.5 an exception is thrown indicating that this is 

      * improper use of the circuit.

      */

     public void testImproperUseOfTheCircuit() throws Exception {

         final double[] inputs = new double[] {1.0};

         // Cheating a little bit with one more gate, but the same effect

         // could be obtained with (hard to achieve) thread race condition.

         Circuit evil = Circuit.construct(

             Element.createAnd(

                 Element.createGate(

                     Element.createInput(0),

                     Element.createInput(0),

                     new Function() {

                         public double evaluate(double input1, double input2) {

                             inputs[0] = 0.0;

                             return input1*input2;

                         }

                     }

                 ),

                 Element.createInput(0)

             )

         );

         assertEquals ("1 and 1 'and' 1 = 1", 1.0, evil.evaluate(inputs));

     }

     /** Write your own element type called "gte" that will have two inputs and one output.

      * The output value will be 1 if x1 >= x2 and 0 otherwise. 

      * 

      * Create 

      * circuit for following expression: (x1 and not(x1)) gte x1

      *

      * Feed the circuit with 0.5 and verify the result is 0

      *

      * Feed the same circuit with 1 and verify the result is 0

      *

      * Feed the same circuit with 0 and verify the result is 1

      */

     public void testGreaterThanEqualElement() throws Exception {

         Circuit c = Circuit.construct(

             Element.createGate(

                 Element.createAnd(

                     Element.createInput(0),

                     Element.createNot(Element.createInput(0))

                 ),

                 Element.createInput(0),

                 new Function() {

                     public double evaluate(double input1, double input2) {

                         return input1 >= input2 ? 1.0 : 0.0;

                     }

                 }

             )

         );

         assertEquals ("0.0", 0.0, c.evaluate(0.5));

         assertEquals ("0.0", 0.0, c.evaluate(1.0));

         assertEquals ("1.0", 1.0, c.evaluate(0.0));

     }

 }