/**

  * Back 2 Browser Bytecode Translator

  * Copyright (C) 2012 Jaroslav Tulach <jaroslav.tulach@apidesign.org>

  *

  * This program is free software: you can redistribute it and/or modify

  * it under the terms of the GNU General Public License as published by

  * the Free Software Foundation, version 2 of the License.

  *

  * This program is distributed in the hope that it will be useful,

  * but WITHOUT ANY WARRANTY; without even the implied warranty of

  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

  * GNU General Public License for more details.

  *

  * You should have received a copy of the GNU General Public License

  * along with this program. Look for COPYING file in the top folder.

  * If not, see http://opensource.org/licenses/GPL-2.0.

  */

 package org.apidesign.bck2brwsr.vmtest.impl;

 import org.apidesign.bck2brwsr.vmtest.*;

 import java.io.File;

 import java.io.FileWriter;

 import java.io.IOException;

 import java.lang.reflect.Method;

 import java.util.ArrayList;

 import java.util.List;

 import org.testng.Assert;

 import org.testng.ITest;

 import org.testng.annotations.Factory;

 import org.testng.annotations.Test;

 /** A TestNG {@link Factory} that seeks for {@link Compare} annotations

  * in provided class and builds set of tests that compare the computations

  * in real as well as JavaScript virtual machines. Use as:<pre>

  * {@code @}{@link Factory} public static create() {

  *   return @{link VMTest}.{@link #create(YourClass.class);

  * }</pre>

  *

  * @author Jaroslav Tulach <jtulach@netbeans.org>

  */

 public final class CompareCase implements ITest {

     private final Bck2BrwsrCase first, second;

     private final Method m;

     private CompareCase(Method m, Bck2BrwsrCase first, Bck2BrwsrCase second) {

         this.first = first;

         this.second = second;

         this.m = m;

     }

     /** Inspects <code>clazz</code> and for each {@lik Compare} method creates

      * instances of tests. Each instance runs the test in different virtual

      * machine and at the end they compare the results.

      * 

      * @param clazz the class to inspect

      * @return the set of created tests

      */

     public static Object[] create(Class<?> clazz) {

         Method[] arr = clazz.getMethods();

         List<Object> ret = new ArrayList<>();

         final LaunchSetup l = LaunchSetup.javaScript();

         ret.add(l);

         String[] brwsr;

         {

             String p = System.getProperty("vmtest.brwsrs");

             if (p != null) {

                 brwsr = p.split(",");

             } else {

                 brwsr = new String[0];

             }

         }

         for (Method m : arr) {

             Compare c = m.getAnnotation(Compare.class);

             if (c == null) {

                 continue;

             }

             final Bck2BrwsrCase real = new Bck2BrwsrCase(m, "Java", null);

             final Bck2BrwsrCase js = new Bck2BrwsrCase(m, "JavaScript", l);

             ret.add(real);

             ret.add(js);

             ret.add(new CompareCase(m, real, js));

             for (String b : brwsr) {

                 final LaunchSetup s = LaunchSetup.brwsr(b);

                 ret.add(s);

                 final Bck2BrwsrCase cse = new Bck2BrwsrCase(m, b, s);

                 ret.add(cse);

                 ret.add(new CompareCase(m, real, cse));

             }

         }

         return ret.toArray();

     }

     /** Test that compares the previous results.

      * @throws Throwable 

      */

     @Test(dependsOnGroups = "run") public void compareResults() throws Throwable {

         Object v1 = first.value;

         Object v2 = second.value;

         if (v1 != null) {

             v1 = v1.toString();

         } else {

             v1 = "null";

         }

         Assert.assertEquals(v2, v1, "Comparing results");

     }

     /** Test name.

      * @return name of the tested method followed by a suffix

      */

     @Override

     public String getTestName() {

         return m.getName() + "[Compare " + second.typeName() + "]";

     }

     static StringBuilder dumpJS(CharSequence sb) throws IOException {

         File f = File.createTempFile("execution", ".js");

         try (FileWriter w = new FileWriter(f)) {

             w.append(sb);

         }

         return new StringBuilder(f.getPath());

     }

 }