/**

 * 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));

            }

        }

    }

}