/**

  * Back 2 Browser Bytecode Translator

  * Copyright (C) 2012-2015 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 java.lang.annotation.Annotation;

 import org.apidesign.bck2brwsr.vmtest.*;

 import java.lang.reflect.Method;

 import java.util.ArrayList;

 import java.util.HashSet;

 import java.util.List;

 import java.util.Set;

 import org.apidesign.bck2brwsr.launcher.Launcher;

 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 final double slowdown;

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

         this.first = first;

         this.second = second;

         this.m = m;

         this.slowdown = slowdown;

     }

     /** 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(String[] brwsr, Class[] classes, Class<? extends Annotation> brwsrTest) {

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

         final LaunchSetup l = LaunchSetup.INSTANCE;

         ret.add(l);

         {

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

             if (p != null) {

                 brwsr = p.split(",");

             }

         }

         for (Class clazz : classes) {

             Method[] arr = clazz.getMethods();

             for (Method m : arr) {

                 registerCompareCases(m, l, ret, brwsr);

                 registerBrwsrCases(brwsrTest, m, l, ret, brwsr);

             }

         }

         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 instanceof Integer || v1 instanceof Long || v1 instanceof Byte || v1 instanceof Short) {

             try {

                 v1 = Long.parseLong(v1.toString());

             } catch (NumberFormatException nfe) {

                 v1 = "Can't parse " + v1.toString();

             }

             try {

                 v2 = Long.parseLong(v2.toString());

             } catch (NullPointerException | NumberFormatException nfe) {

                 v2 = "Can't parse " + v2.toString();

             }

         } else if (v1 instanceof Number) {

             try {

                 v1 = Double.parseDouble(v1.toString());

             } catch (NullPointerException | NumberFormatException nfe) {

                 v1 = "Can't parse " + v1.toString();

             }

             try {

                 v2 = Double.parseDouble(v2.toString());

             } catch (NullPointerException | NumberFormatException nfe) {

                 v2 = "Can't parse " + v2.toString();

             }

         } else {

             if (v1 != null) {

                 v1 = v1.toString();

             } else {

                 v1 = "null";

             }

         }

         try {

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

         } catch (AssertionError e) {

             StringBuilder sb = new StringBuilder();

             sb.append(e.getMessage());

             Bck2BrwsrCase.dumpJS(sb, second);

             throw new AssertionError(sb.toString());

         }

         if (slowdown > 0.0) {

             Bck2BrwsrCase slow;

             Bck2BrwsrCase fast;

             if (first.time >= second.time) {

                 slow = second;

                 fast = first;

             } else {

                 fast = second;

                 slow = first;

             }

             if (slow.time * slowdown < fast.time) {

                 Assert.fail("Too slow " + slow.getTestName() + " took " + slow.time + " ms vs. " + fast.time + " ms of " + fast.getTestName());

             }

         }

     }

     /** Test name.

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

      */

     @Override

     public String getTestName() {

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

     }

     private static void registerCompareCases(Method m, final LaunchSetup l, List<Object> ret, String[] brwsr) {

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

         if (c == null) {

             return;

         }

         String slowdownOverride = System.getProperty("vmtest.slowdown");

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

         ret.add(real);

         double slowdown = c.slowdown();

         if (slowdown > 0.0 && slowdownOverride != null) {

             slowdown = Double.parseDouble(slowdownOverride);

         }

         Set<Launcher> unique = new HashSet<>();

         for (String b : brwsr) {

             final Launcher s = l.brwsr(b);

             ret.add(s);

             unique.add(s);

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

             ret.add(cse);

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

         }

         if (c.scripting()) {

             final Launcher jsLauncher = l.javaScript();

             if (unique.add(jsLauncher)) {

                 final Bck2BrwsrCase js = new Bck2BrwsrCase(m, "JavaScript", jsLauncher, false, null, null);

                 ret.add(js);

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

             }

         }

     }

     private static void registerBrwsrCases(Class<? extends Annotation> brwsrTest, Method m, final LaunchSetup l, List<Object> ret, String[] brwsr) {

         Object c = m.getAnnotation(brwsrTest);

         if (c == null) {

             return;

         }

         HtmlFragment f = m.getAnnotation(HtmlFragment.class);

         if (f == null) {

             f = m.getDeclaringClass().getAnnotation(HtmlFragment.class);

         }

         Http.Resource[] r = {};

         Http h = m.getAnnotation(Http.class);

         if (h == null) {

             h = m.getDeclaringClass().getAnnotation(Http.class);

             if (h != null) {

                 r = h.value();

             }

         } else {

             r = h.value();

         }

         if (brwsr.length == 0) {

             final Launcher s = l.brwsr(null);

             ret.add(s);

             ret.add(new Bck2BrwsrCase(m, "Brwsr", s, true, f, r));

         } else {

             for (String b : brwsr) {

                 final Launcher s = l.brwsr(b);

                 ret.add(s);

                 ret.add(new Bck2BrwsrCase(m, b, s, true, f, r));

             }

         }

     }

 }