/*

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 * 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

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 */

import java.lang.invoke.MethodHandle;

import java.lang.invoke.MethodHandleInfo;

import java.lang.invoke.MethodHandles;

import java.lang.invoke.MethodType;

import java.lang.invoke.VarHandle;

import java.lang.invoke.WrongMethodTypeException;

import java.lang.reflect.Method;

import java.nio.ReadOnlyBufferException;

import java.util.EnumMap;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

import java.util.stream.Stream;

import static java.util.stream.Collectors.toList;

import static org.testng.Assert.*;

abstract class VarHandleBaseTest {

    static final int ITERS = Integer.getInteger("iters", 1);

    static final int WEAK_ATTEMPTS = Integer.getInteger("weakAttempts", 10);

    interface ThrowingRunnable {

        void run() throws Throwable;

    }

    static void checkUOE(ThrowingRunnable r) {

        checkWithThrowable(UnsupportedOperationException.class, null, r);

    }

    static void checkUOE(Object message, ThrowingRunnable r) {

        checkWithThrowable(UnsupportedOperationException.class, message, r);

    }

    static void checkROBE(ThrowingRunnable r) {

        checkWithThrowable(ReadOnlyBufferException.class, null, r);

    }

    static void checkROBE(Object message, ThrowingRunnable r) {

        checkWithThrowable(ReadOnlyBufferException.class, message, r);

    }

    static void checkIOOBE(ThrowingRunnable r) {

        checkWithThrowable(IndexOutOfBoundsException.class, null, r);

    }

    static void checkIOOBE(Object message, ThrowingRunnable r) {

        checkWithThrowable(IndexOutOfBoundsException.class, message, r);

    }

    static void checkISE(ThrowingRunnable r) {

        checkWithThrowable(IllegalStateException.class, null, r);

    }

    static void checkISE(Object message, ThrowingRunnable r) {

        checkWithThrowable(IllegalStateException.class, message, r);

    }

    static void checkIAE(ThrowingRunnable r) {

        checkWithThrowable(IllegalAccessException.class, null, r);

    }

    static void checkIAE(Object message, ThrowingRunnable r) {

        checkWithThrowable(IllegalAccessException.class, message, r);

    }

    static void checkWMTE(ThrowingRunnable r) {

        checkWithThrowable(WrongMethodTypeException.class, null, r);

    }

    static void checkWMTE(Object message, ThrowingRunnable r) {

        checkWithThrowable(WrongMethodTypeException.class, message, r);

    }

    static void checkCCE(ThrowingRunnable r) {

        checkWithThrowable(ClassCastException.class, null, r);

    }

    static void checkCCE(Object message, ThrowingRunnable r) {

        checkWithThrowable(ClassCastException.class, message, r);

    }

    static void checkNPE(ThrowingRunnable r) {

        checkWithThrowable(NullPointerException.class, null, r);

    }

    static void checkNPE(Object message, ThrowingRunnable r) {

        checkWithThrowable(NullPointerException.class, message, r);

    }

    static void checkWithThrowable(Class<? extends Throwable> re,

                                   Object message,

                                   ThrowingRunnable r) {

        Throwable _e = null;

        try {

            r.run();

        }

        catch (Throwable e) {

            _e = e;

        }

        message = message == null ? "" : message + ". ";

        assertNotNull(_e, String.format("%sNo throwable thrown. Expected %s", message, re));

        assertTrue(re.isInstance(_e), String.format("%sIncorrect throwable thrown, %s. Expected %s", message, _e, re));

    }

    enum TestAccessType {

        GET,

        SET,

        COMPARE_AND_SET,

        COMPARE_AND_EXCHANGE,

        GET_AND_SET,

        GET_AND_ADD;

    }

    enum TestAccessMode {

        GET(TestAccessType.GET),

        SET(TestAccessType.SET),

        GET_VOLATILE(TestAccessType.GET),

        SET_VOLATILE(TestAccessType.SET),

        GET_ACQUIRE(TestAccessType.GET),

        SET_RELEASE(TestAccessType.SET),

        GET_OPAQUE(TestAccessType.GET),

        SET_OPAQUE(TestAccessType.SET),

        COMPARE_AND_SET(TestAccessType.COMPARE_AND_SET),

        COMPARE_AND_EXCHANGE_VOLATILE(TestAccessType.COMPARE_AND_EXCHANGE),

        COMPARE_AND_EXCHANGE_ACQUIRE(TestAccessType.COMPARE_AND_EXCHANGE),

        COMPARE_AND_EXCHANGE_RELEASE(TestAccessType.COMPARE_AND_EXCHANGE),

        WEAK_COMPARE_AND_SET(TestAccessType.COMPARE_AND_SET),

        WEAK_COMPARE_AND_SET_VOLATILE(TestAccessType.COMPARE_AND_SET),

        WEAK_COMPARE_AND_SET_ACQUIRE(TestAccessType.COMPARE_AND_SET),

        WEAK_COMPARE_AND_SET_RELEASE(TestAccessType.COMPARE_AND_SET),

        GET_AND_SET(TestAccessType.GET_AND_SET),

        GET_AND_ADD(TestAccessType.GET_AND_ADD),

        ADD_AND_GET(TestAccessType.GET_AND_ADD),;

        final TestAccessType at;

        final boolean isPolyMorphicInReturnType;

        final Class<?> returnType;

        TestAccessMode(TestAccessType at) {

            this.at = at;

            try {

                VarHandle.AccessMode vh_am = toAccessMode();

                Method m = VarHandle.class.getMethod(vh_am.methodName(), Object[].class);

                this.returnType = m.getReturnType();

                isPolyMorphicInReturnType = returnType != Object.class;

            }

            catch (Exception e) {

                throw new Error(e);

            }

        }

        boolean isOfType(TestAccessType at) {

            return this.at == at;

        }

        VarHandle.AccessMode toAccessMode() {

            return VarHandle.AccessMode.valueOf(name());

        }

    }

    static List<TestAccessMode> testAccessModes() {

        return Stream.of(TestAccessMode.values()).collect(toList());

    }

    static List<TestAccessMode> testAccessModesOfType(TestAccessType... ats) {

        Stream<TestAccessMode> s = Stream.of(TestAccessMode.values());

        for (TestAccessType at : ats) {

            s = s.filter(e -> e.isOfType(at));

        }

        return s.collect(toList());

    }

    static List<VarHandle.AccessMode> accessModes() {

        return Stream.of(VarHandle.AccessMode.values()).collect(toList());

    }

    static List<VarHandle.AccessMode> accessModesOfType(TestAccessType... ats) {

        Stream<TestAccessMode> s = Stream.of(TestAccessMode.values());

        for (TestAccessType at : ats) {

            s = s.filter(e -> e.isOfType(at));

        }

        return s.map(TestAccessMode::toAccessMode).collect(toList());

    }

    static MethodHandle toMethodHandle(VarHandle vh, TestAccessMode tam, MethodType mt) {

        return vh.toMethodHandle(tam.toAccessMode());

    }

    static MethodHandle findVirtual(VarHandle vh, TestAccessMode tam, MethodType mt) {

        mt = vh.accessModeType(tam.toAccessMode());

        MethodHandle mh;

        try {

            mh = MethodHandles.publicLookup().

                    findVirtual(VarHandle.class,

                                tam.toAccessMode().methodName(),

                                mt);

        } catch (Exception e) {

            throw new RuntimeException(e);

        }

        return bind(vh, tam, mh, mt);

    }

    static MethodHandle varHandleInvokerWithAccessModeType(VarHandle vh, TestAccessMode tam, MethodType mt) {

        mt = vh.accessModeType(tam.toAccessMode());

        MethodHandle mh = MethodHandles.varHandleInvoker(

                tam.toAccessMode(),

                mt);

        return bind(vh, tam, mh, mt);

    }

    static MethodHandle varHandleInvokerWithSymbolicTypeDescriptor(VarHandle vh, TestAccessMode tam, MethodType mt) {

        MethodHandle mh = MethodHandles.varHandleInvoker(

                tam.toAccessMode(),

                mt);

        return bind(vh, tam, mh, mt);

    }

    static MethodHandle varHandleExactInvokerWithAccessModeType(VarHandle vh, TestAccessMode tam, MethodType mt) {

        mt = vh.accessModeType(tam.toAccessMode());

        MethodHandle mh = MethodHandles.varHandleExactInvoker(

                tam.toAccessMode(),

                mt);

        return bind(vh, tam, mh, mt);

    }

    private static MethodHandle bind(VarHandle vh, TestAccessMode testAccessMode, MethodHandle mh, MethodType emt) {

        assertEquals(mh.type(), emt.insertParameterTypes(0, VarHandle.class),

                     "MethodHandle type differs from access mode type");

        MethodHandleInfo info = MethodHandles.lookup().revealDirect(mh);

        assertEquals(info.getMethodType(), emt,

                     "MethodHandleInfo method type differs from access mode type");

        return mh.bindTo(vh);

    }

    private interface TriFunction<T, U, V, R> {

        R apply(T t, U u, V v);

    }

    enum VarHandleToMethodHandle {

        VAR_HANDLE_TO_METHOD_HANDLE(

                "VarHandle.toMethodHandle",

                VarHandleBaseTest::toMethodHandle),

        METHOD_HANDLES_LOOKUP_FIND_VIRTUAL(

                "Lookup.findVirtual",

                VarHandleBaseTest::findVirtual),

        METHOD_HANDLES_VAR_HANDLE_INVOKER_WITH_ACCESS_MODE_TYPE(

                "MethodHandles.varHandleInvoker(accessModeType)",

                VarHandleBaseTest::varHandleInvokerWithAccessModeType),

        METHOD_HANDLES_VAR_HANDLE_INVOKER_WITH_SYMBOLIC_TYPE_DESCRIPTOR(

                "MethodHandles.varHandleInvoker(symbolicTypeDescriptor)",

                VarHandleBaseTest::varHandleInvokerWithSymbolicTypeDescriptor),

        METHOD_HANDLES_VAR_HANDLE_EXACT_INVOKER_WITH_ACCESS_MODE_TYPE(

                "MethodHandles.varHandleExactInvoker(accessModeType)",

                VarHandleBaseTest::varHandleExactInvokerWithAccessModeType);

        final String desc;

        final TriFunction<VarHandle, TestAccessMode, MethodType, MethodHandle> f;

        final boolean exact;

        VarHandleToMethodHandle(String desc, TriFunction<VarHandle, TestAccessMode, MethodType, MethodHandle> f) {

            this(desc, f, false);

        }

        VarHandleToMethodHandle(String desc, TriFunction<VarHandle, TestAccessMode, MethodType, MethodHandle> f,

                                boolean exact) {

            this.desc = desc;

            this.f = f;

            this.exact = exact;

        }

        MethodHandle apply(VarHandle vh, TestAccessMode am, MethodType mt) {

            return f.apply(vh, am, mt);

        }

        @Override

        public String toString() {

            return desc;

        }

    }

    static class Handles {

        static class AccessModeAndType {

            final TestAccessMode tam;

            final MethodType t;

            public AccessModeAndType(TestAccessMode tam, MethodType t) {

                this.tam = tam;

                this.t = t;

            }

            @Override

            public boolean equals(Object o) {

                if (this == o) return true;

                if (o == null || getClass() != o.getClass()) return false;

                AccessModeAndType x = (AccessModeAndType) o;

                if (tam != x.tam) return false;

                if (t != null ? !t.equals(x.t) : x.t != null) return false;

                return true;

            }

            @Override

            public int hashCode() {

                int result = tam != null ? tam.hashCode() : 0;

                result = 31 * result + (t != null ? t.hashCode() : 0);

                return result;

            }

        }

        final VarHandle vh;

        final VarHandleToMethodHandle f;

        final EnumMap<TestAccessMode, MethodType> amToType;

        final Map<AccessModeAndType, MethodHandle> amToHandle;

        Handles(VarHandle vh, VarHandleToMethodHandle f) throws Exception {

            this.vh = vh;

            this.f = f;

            this.amToHandle = new HashMap<>();

            amToType = new EnumMap<>(TestAccessMode.class);

            for (TestAccessMode am : testAccessModes()) {

                amToType.put(am, vh.accessModeType(am.toAccessMode()));

            }

        }

        MethodHandle get(TestAccessMode am) {

            return get(am, amToType.get(am));

        }

        MethodHandle get(TestAccessMode am, MethodType mt) {

            AccessModeAndType amt = new AccessModeAndType(am, mt);

            return amToHandle.computeIfAbsent(

                    amt, k -> f.apply(vh, am, mt));

        }

    }

    interface AccessTestAction<T> {

        void action(T t) throws Throwable;

    }

    static abstract class AccessTestCase<T> {

        final String desc;

        final AccessTestAction<T> ata;

        final boolean loop;

        AccessTestCase(String desc, AccessTestAction<T> ata, boolean loop) {

            this.desc = desc;

            this.ata = ata;

            this.loop = loop;

        }

        boolean requiresLoop() {

            return loop;

        }

        abstract T get() throws Exception;

        void testAccess(T t) throws Throwable {

            ata.action(t);

        }

        @Override

        public String toString() {

            return desc;

        }

    }

    static class VarHandleAccessTestCase extends AccessTestCase<VarHandle> {

        final VarHandle vh;

        VarHandleAccessTestCase(String desc, VarHandle vh, AccessTestAction<VarHandle> ata) {

            this(desc, vh, ata, true);

        }

        VarHandleAccessTestCase(String desc, VarHandle vh, AccessTestAction<VarHandle> ata, boolean loop) {

            super("VarHandle -> " + desc, ata, loop);

            this.vh = vh;

        }

        @Override

        VarHandle get() {

            return vh;

        }

    }

    static class MethodHandleAccessTestCase extends AccessTestCase<Handles> {

        final VarHandle vh;

        final VarHandleToMethodHandle f;

        MethodHandleAccessTestCase(String desc, VarHandle vh, VarHandleToMethodHandle f, AccessTestAction<Handles> ata) {

            this(desc, vh, f, ata, true);

        }

        MethodHandleAccessTestCase(String desc, VarHandle vh, VarHandleToMethodHandle f, AccessTestAction<Handles> ata, boolean loop) {

            super("VarHandle -> " + f.toString() + " -> " + desc, ata, loop);

            this.vh = vh;

            this.f = f;

        }

        @Override

        Handles get() throws Exception {

            return new Handles(vh, f);

        }

    }

    static void testTypes(VarHandle vh) {

        List<Class<?>> pts = vh.coordinateTypes();

        for (TestAccessMode accessMode : testAccessModes()) {

            MethodType amt = vh.accessModeType(accessMode.toAccessMode());

            assertEquals(amt.parameterList().subList(0, pts.size()), pts);

        }

        for (TestAccessMode testAccessMode : testAccessModesOfType(TestAccessType.GET)) {

            MethodType mt = vh.accessModeType(testAccessMode.toAccessMode());

            assertEquals(mt.returnType(), vh.varType());

            assertEquals(mt.parameterList(), pts);

        }

        for (TestAccessMode testAccessMode : testAccessModesOfType(TestAccessType.SET)) {

            MethodType mt = vh.accessModeType(testAccessMode.toAccessMode());

            assertEquals(mt.returnType(), void.class);

            assertEquals(mt.parameterType(mt.parameterCount() - 1), vh.varType());

        }

        for (TestAccessMode testAccessMode : testAccessModesOfType(TestAccessType.COMPARE_AND_SET)) {

            MethodType mt = vh.accessModeType(testAccessMode.toAccessMode());

            assertEquals(mt.returnType(), boolean.class);

            assertEquals(mt.parameterType(mt.parameterCount() - 1), vh.varType());

            assertEquals(mt.parameterType(mt.parameterCount() - 2), vh.varType());

        }

        for (TestAccessMode testAccessMode : testAccessModesOfType(TestAccessType.COMPARE_AND_EXCHANGE)) {

            MethodType mt = vh.accessModeType(testAccessMode.toAccessMode());

            assertEquals(mt.returnType(), vh.varType());

            assertEquals(mt.parameterType(mt.parameterCount() - 1), vh.varType());

            assertEquals(mt.parameterType(mt.parameterCount() - 2), vh.varType());

        }

        for (TestAccessMode testAccessMode : testAccessModesOfType(TestAccessType.GET_AND_SET, TestAccessType.GET_AND_ADD)) {

            MethodType mt = vh.accessModeType(testAccessMode.toAccessMode());

            assertEquals(mt.returnType(), vh.varType());

            assertEquals(mt.parameterType(mt.parameterCount() - 1), vh.varType());

        }

    }

}