/*

 * Copyright (c) 2013, 2016, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

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

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package org.graalvm.compiler.core.test;

import static org.graalvm.compiler.core.common.CompilationIdentifier.INVALID_COMPILATION_ID;

import static org.graalvm.compiler.nodes.StructuredGraph.NO_PROFILING_INFO;

import java.io.ByteArrayOutputStream;

import java.io.IOException;

import java.io.InputStream;

import java.lang.reflect.Constructor;

import java.util.HashMap;

import jdk.vm.ci.meta.Assumptions;

import jdk.vm.ci.meta.Assumptions.Assumption;

import jdk.vm.ci.meta.Assumptions.LeafType;

import jdk.vm.ci.meta.Assumptions.NoFinalizableSubclass;

import jdk.vm.ci.meta.ResolvedJavaMethod;

import org.junit.Assert;

import org.junit.Test;

import org.graalvm.compiler.debug.Debug;

import org.graalvm.compiler.java.GraphBuilderPhase;

import org.graalvm.compiler.nodes.StructuredGraph;

import org.graalvm.compiler.nodes.StructuredGraph.AllowAssumptions;

import org.graalvm.compiler.nodes.graphbuilderconf.GraphBuilderConfiguration;

import org.graalvm.compiler.nodes.java.RegisterFinalizerNode;

import org.graalvm.compiler.phases.OptimisticOptimizations;

import org.graalvm.compiler.phases.common.CanonicalizerPhase;

import org.graalvm.compiler.phases.common.inlining.InliningPhase;

import org.graalvm.compiler.phases.tiers.HighTierContext;

public class FinalizableSubclassTest extends GraalCompilerTest {

    /**

     * used as template to generate class files at runtime.

     */

    public static class NoFinalizerEverAAAA {

    }

    public static class NoFinalizerYetAAAA {

    }

    public static final class WithFinalizerAAAA extends NoFinalizerYetAAAA {

        @Override

        protected void finalize() throws Throwable {

            super.finalize();

        }

    }

    private StructuredGraph parseAndProcess(Class<?> cl, AllowAssumptions allowAssumptions) {

        Constructor<?>[] constructors = cl.getConstructors();

        Assert.assertTrue(constructors.length == 1);

        final ResolvedJavaMethod javaMethod = getMetaAccess().lookupJavaMethod(constructors[0]);

        StructuredGraph graph = new StructuredGraph(javaMethod, allowAssumptions, NO_PROFILING_INFO, INVALID_COMPILATION_ID);

        GraphBuilderConfiguration conf = GraphBuilderConfiguration.getSnippetDefault(getDefaultGraphBuilderPlugins());

        new GraphBuilderPhase.Instance(getMetaAccess(), getProviders().getStampProvider(), getProviders().getConstantReflection(), getProviders().getConstantFieldProvider(), conf,

                        OptimisticOptimizations.ALL, null).apply(graph);

        HighTierContext context = new HighTierContext(getProviders(), getDefaultGraphBuilderSuite(), OptimisticOptimizations.ALL);

        new InliningPhase(new CanonicalizerPhase()).apply(graph, context);

        new CanonicalizerPhase().apply(graph, context);

        return graph;

    }

    private void checkForRegisterFinalizeNode(Class<?> cl, boolean shouldContainFinalizer, AllowAssumptions allowAssumptions) {

        StructuredGraph graph = parseAndProcess(cl, allowAssumptions);

        Assert.assertTrue(graph.getNodes().filter(RegisterFinalizerNode.class).count() == (shouldContainFinalizer ? 1 : 0));

        int noFinalizerAssumption = 0;

        Assumptions assumptions = graph.getAssumptions();

        if (assumptions != null) {

            for (Assumption a : assumptions) {

                if (a instanceof NoFinalizableSubclass) {

                    noFinalizerAssumption++;

                } else if (a instanceof LeafType) {

                    // Need to also allow leaf type assumption instead of no finalizable subclass

                    // assumption.

                    noFinalizerAssumption++;

                }

            }

        }

        Assert.assertTrue(noFinalizerAssumption == (shouldContainFinalizer ? 0 : 1));

    }

    /**

     * Use a custom class loader to generate classes, to make sure the given classes are loaded in

     * correct order.

     */

    @Test

    public void test1() throws ClassNotFoundException {

        for (int i = 0; i < 2; i++) {

            ClassTemplateLoader loader = new ClassTemplateLoader();

            checkForRegisterFinalizeNode(loader.findClass("NoFinalizerEverAAAA"), true, AllowAssumptions.NO);

            checkForRegisterFinalizeNode(loader.findClass("NoFinalizerEverAAAA"), false, AllowAssumptions.YES);

            checkForRegisterFinalizeNode(loader.findClass("NoFinalizerYetAAAA"), false, AllowAssumptions.YES);

            checkForRegisterFinalizeNode(loader.findClass("WithFinalizerAAAA"), true, AllowAssumptions.YES);

            checkForRegisterFinalizeNode(loader.findClass("NoFinalizerYetAAAA"), true, AllowAssumptions.YES);

        }

    }

    private static class ClassTemplateLoader extends ClassLoader {

        private static int loaderInstance = 0;

        private final String replaceTo;

        private HashMap<String, Class<?>> cache = new HashMap<>();

        ClassTemplateLoader() {

            loaderInstance++;

            replaceTo = String.format("%04d", loaderInstance);

        }

        @Override

        protected Class<?> findClass(final String name) throws ClassNotFoundException {

            String nameReplaced = name.replaceAll("AAAA", replaceTo);

            if (cache.containsKey(nameReplaced)) {

                return cache.get(nameReplaced);

            }

            // copy classfile to byte array

            byte[] classData = null;

            try {

                InputStream is = FinalizableSubclassTest.class.getResourceAsStream("FinalizableSubclassTest$" + name + ".class");

                assert is != null;

                ByteArrayOutputStream baos = new ByteArrayOutputStream();

                byte[] buf = new byte[1024];

                int size;

                while ((size = is.read(buf, 0, buf.length)) != -1) {

                    baos.write(buf, 0, size);

                }

                baos.flush();

                classData = baos.toByteArray();

            } catch (IOException e) {

                Assert.fail("can't access class: " + name);

            }

            dumpStringsInByteArray(classData);

            // replace all occurrences of "AAAA" in classfile

            int index = -1;

            while ((index = indexOfAAAA(classData, index + 1)) != -1) {

                replaceAAAA(classData, index, replaceTo);

            }

            dumpStringsInByteArray(classData);

            Class<?> c = defineClass(null, classData, 0, classData.length);

            cache.put(nameReplaced, c);

            return c;

        }

        private static int indexOfAAAA(byte[] b, int index) {

            for (int i = index; i < b.length; i++) {

                boolean match = true;

                for (int j = i; j < i + 4; j++) {

                    if (b[j] != (byte) 'A') {

                        match = false;

                        break;

                    }

                }

                if (match) {

                    return i;

                }

            }

            return -1;

        }

        private static void replaceAAAA(byte[] b, int index, String replacer) {

            assert replacer.length() == 4;

            for (int i = index; i < index + 4; i++) {

                b[i] = (byte) replacer.charAt(i - index);

            }

        }

        private static void dumpStringsInByteArray(byte[] b) {

            boolean wasChar = true;

            StringBuilder sb = new StringBuilder();

            for (Byte x : b) {

                // check for [a-zA-Z0-9]

                if ((x >= 0x41 && x <= 0x7a) || (x >= 0x30 && x <= 0x39)) {

                    if (!wasChar) {

                        Debug.log(sb + "");

                        sb.setLength(0);

                    }

                    sb.append(String.format("%c", x));

                    wasChar = true;

                } else {

                    wasChar = false;

                }

            }

            Debug.log(sb + "");

        }

    }

}