/*

 * Copyright (c) 2019, 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 jdk.internal.vm.compiler.libgraal;

import jdk.vm.ci.hotspot.HotSpotJVMCIRuntime;

import jdk.vm.ci.services.Services;

/**

 * JDK13+ version of {@code LibGraal}.

 */

public class LibGraal {

    public static boolean isAvailable() {

        return isCurrentRuntime() || libgraalIsolate != 0L;

    }

    public static boolean isCurrentRuntime() {

        return Services.IS_IN_NATIVE_IMAGE;

    }

    public static long getIsolate() {

        if (isCurrentRuntime() || !isAvailable()) {

            throw new IllegalStateException();

        }

        return libgraalIsolate;

    }

    public static long getIsolateThread() {

        if (isCurrentRuntime()) {

            throw new IllegalStateException();

        }

        return CURRENT_ISOLATE_THREAD.get();

    }

    @SuppressWarnings("unused")

    public static long[] registerNativeMethods(HotSpotJVMCIRuntime runtime, Class<?> clazz) {

        if (clazz.isPrimitive()) {

            throw new IllegalArgumentException();

        }

        if (isCurrentRuntime() || !isAvailable()) {

            throw new IllegalStateException();

        }

        // Waiting for https://bugs.openjdk.java.net/browse/JDK-8220623

        // return runtime.registerNativeMethods(clazz);

        throw new IllegalStateException("Requires JDK-8220623");

    }

    @SuppressWarnings("unused")

    public static long translate(HotSpotJVMCIRuntime runtime, Object obj) {

        if (!isAvailable()) {

            throw new IllegalStateException();

        }

        // return runtime.translate(obj);

        throw new IllegalStateException("Requires JDK-8220623");

    }

    @SuppressWarnings("unused")

    public static <T> T unhand(HotSpotJVMCIRuntime runtime, Class<T> type, long handle) {

        if (!isAvailable()) {

            throw new IllegalStateException();

        }

        // return runtime.unhand(type, handle);

        throw new IllegalStateException("Requires JDK-8220623");

    }

    private static final ThreadLocal<Long> CURRENT_ISOLATE_THREAD = new ThreadLocal<>() {

        @Override

        protected Long initialValue() {

            return attachThread(libgraalIsolate);

        }

    };

    private static final long libgraalIsolate = Services.IS_BUILDING_NATIVE_IMAGE ? 0L : initializeLibgraal();

    private static long initializeLibgraal() {

        try {

            // Initialize JVMCI to ensure JVMCI opens its packages to

            // Graal otherwise the call to HotSpotJVMCIRuntime.runtime()

            // below will fail on JDK13+.

            Services.initializeJVMCI();

            // Waiting for https://bugs.openjdk.java.net/browse/JDK-8220623

            // HotSpotJVMCIRuntime runtime = HotSpotJVMCIRuntime.runtime();

            // long[] nativeInterface = runtime.registerNativeMethods(LibGraal.class);

            // return nativeInterface[1];

            return 0L;

        } catch (UnsupportedOperationException e) {

            return 0L;

        }

    }

    /**

     * Attaches the current thread to a thread in {@code isolate}.

     *

     * @param isolate

     */

    private static native long attachThread(long isolate);

}