/*
 * Copyright (C) 2018 JetBrains s.r.o.
 *
 * This program is free software; you can redistribute and/or modify it under
 * the terms of the GNU General Public License v2 with Classpath Exception.
 * The text of the license is available in the file LICENSE.TXT.
 *
 * 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 LICENSE.TXT for more details.
 *
 * You may contact JetBrains s.r.o. at Na Hřebenech II 1718/10, 140 00 Prague,
 * Czech Republic or at legal@jetbrains.com.
 */

package com.jetbrains.sa.jdi;

import sun.jvm.hotspot.debugger.Address;
import sun.jvm.hotspot.memory.SystemDictionary;
import sun.jvm.hotspot.oops.*;
import sun.jvm.hotspot.runtime.JavaThread;
import sun.jvm.hotspot.runtime.Threads;
import sun.jvm.hotspot.runtime.VM;
import sun.jvm.hotspot.utilities.KlassArray;

import java.util.ArrayList;
import java.util.List;

@SuppressWarnings("unused")
class CompatibilityHelper13 implements Compatibility {
    @Override
    public Address getAddress(Method method) {
        return method.getAddress();
    }

    @Override
    public Address getAddress(Klass klass) {
        return klass.getAddress();
    }

    @Override
    public Klass asKlass(Oop ref) {
        return java_lang_Class.asKlass(ref);
    }

    @Override
    public List<InstanceKlass> getTransitiveInterfaces(InstanceKlass saKlass) {
        List<InstanceKlass> res = new ArrayList<>();
        KlassArray interfaces = saKlass.getTransitiveInterfaces();
        int n = interfaces.length();
        for (int i = 0; i < n; i++) {
            res.add((InstanceKlass) interfaces.getAt(i));
        }
        return res;
    }

    @Override
    public String getSourceDebugExtension(InstanceKlass saKlass) {
        return saKlass.getSourceDebugExtension();
    }

    @Override
    public InstanceKlass getMethodHandleKlass() {
        return SystemDictionary.getMethodHandleKlass();
    }

    @Override
    public Klass getMethodHolder(Method method) {
        return method.getMethodHolder();
    }

    private static final long compressedKlassOffset;
    private static final long klassOffset;

    static {
        long coff = -1;
        long koff = -1;
        try {
            java.lang.reflect.Field field = Oop.class.getDeclaredField("klass");
            field.setAccessible(true);
            coff = ((MetadataField) field.get(null)).getOffset();
            java.lang.reflect.Field field1 = Oop.class.getDeclaredField("compressedKlass");
            field1.setAccessible(true);
            koff = ((MetadataField) field1.get(null)).getOffset();
        } catch (IllegalAccessException | NoSuchFieldException e) {
            e.printStackTrace();
        }
        compressedKlassOffset = coff;
        klassOffset = koff;
    }

    @Override
    public Address getKlassAddress(Oop oop) {
        if (VM.getVM().isCompressedKlassPointersEnabled()) {
            return oop.getHandle().getCompKlassAddressAt(compressedKlassOffset);
        } else {
            return oop.getHandle().getAddressAt(klassOffset);
        }
    }

    @Override
    public List<Klass> allClasses(SystemDictionary systemDictionary, VM vm) {
        List<Klass> saKlasses = new ArrayList<>();
        vm.getClassLoaderDataGraph().classesDo(k -> {
            // for non-array classes filter out un-prepared classes
            // refer to 'allClasses' in share/back/VirtualMachineImpl.c
            if (k instanceof ArrayKlass) {
                saKlasses.add(k);
            } else {
                int status = k.getClassStatus();
                if ((status & JVMDIClassStatus.PREPARED) != 0) {
                    saKlasses.add(k);
                }
            }
        });
        return saKlasses;
    }

    @Override
    public List<ReferenceTypeImpl> visibleClasses(final Oop ref, final VirtualMachineImpl vm) {
        List<ReferenceTypeImpl> res = new ArrayList<>();
        vm.saVM().getClassLoaderDataGraph().allEntriesDo((k, loader) -> {
            if (ref.equals(loader)) {
                res.add(vm.referenceType(k));
            }
        });
        return res;
    }

    @Override
    public List<JavaThread> getThreads(VM vm) {
        List<JavaThread> res = new ArrayList<>();
        Threads threads = vm.getThreads();
        for (int i = 0; i < threads.getNumberOfThreads(); i++) {
            res.add(threads.getJavaThreadAt(i));
        }
        return res;
    }
}