/*
 * Copyright (c) 2011, 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 com.oracle.graal.hotspot.meta;

import java.lang.annotation.*;
import java.lang.reflect.*;
import java.util.*;
import java.util.concurrent.*;

import com.oracle.graal.api.meta.*;
import com.oracle.graal.api.meta.ProfilingInfo.ExceptionSeen;
import com.oracle.graal.bytecode.*;
import com.oracle.graal.hotspot.*;
import com.oracle.graal.phases.*;

/**
 * Implementation of {@link JavaMethod} for resolved HotSpot methods.
 */
public final class HotSpotResolvedJavaMethod extends HotSpotMethod implements ResolvedJavaMethod {

    private static final long serialVersionUID = -5486975070147586588L;

    /** DO NOT USE IN JAVA CODE! */
    @SuppressWarnings("unused")
    @Deprecated
    private Object javaMirror;

    // cached values
    private final int codeSize;
    private final int accessFlags;
    private final int maxLocals;
    private final int maxStackSize;
    private Signature signature;
    private Boolean hasBalancedMonitors;
    private Map<Object, Object> compilerStorage;
    private ResolvedJavaType holder;
    private HotSpotMethodData methodData;
    private byte[] code;
    private boolean canBeInlined;
    private int compilationComplexity;

    private CompilationTask currentTask;

    private HotSpotResolvedJavaMethod() {
        throw new IllegalStateException("this constructor is never actually called, because the objects are allocated from within the VM");
    }

    @Override
    public ResolvedJavaType getDeclaringClass() {
        return holder;
    }

    @Override
    public int getModifiers() {
        return accessFlags;
    }

    @Override
    public boolean canBeStaticallyBound() {
        return (Modifier.isFinal(getModifiers()) || Modifier.isPrivate(getModifiers()) || Modifier.isStatic(getModifiers())) && !Modifier.isAbstract(getModifiers());
    }

    @Override
    public byte[] getCode() {
        if (code == null) {
            code = HotSpotGraalRuntime.getInstance().getCompilerToVM().JavaMethod_code(this);
            assert code.length == codeSize : "expected: " + codeSize + ", actual: " + code.length;
        }
        return code;
    }

    @Override
    public int getCodeSize() {
        return codeSize;
    }

    @Override
    public ExceptionHandler[] getExceptionHandlers() {
        return HotSpotGraalRuntime.getInstance().getCompilerToVM().JavaMethod_exceptionHandlers(this);
    }

    public boolean hasBalancedMonitors() {
        if (hasBalancedMonitors == null) {
            hasBalancedMonitors = HotSpotGraalRuntime.getInstance().getCompilerToVM().JavaMethod_hasBalancedMonitors(this);
        }
        return hasBalancedMonitors;
    }

    @Override
    public boolean isClassInitializer() {
        return "<clinit>".equals(name) && Modifier.isStatic(getModifiers());
    }

    @Override
    public boolean isConstructor() {
        return "<init>".equals(name) && !Modifier.isStatic(getModifiers());
    }

    @Override
    public int getMaxLocals() {
        return maxLocals;
    }

    @Override
    public int getMaxStackSize() {
        return maxStackSize;
    }

    @Override
    public StackTraceElement asStackTraceElement(int bci) {
        if (bci < 0 || bci >= codeSize) {
            // HotSpot code can only construct stack trace elements for valid bcis
            StackTraceElement ste = HotSpotGraalRuntime.getInstance().getCompilerToVM().JavaMethod_toStackTraceElement(this, 0);
            return new StackTraceElement(ste.getClassName(), ste.getMethodName(), ste.getFileName(), -1);
        }
        return HotSpotGraalRuntime.getInstance().getCompilerToVM().JavaMethod_toStackTraceElement(this, bci);
    }

    public ResolvedJavaMethod uniqueConcreteMethod() {
        return (ResolvedJavaMethod) HotSpotGraalRuntime.getInstance().getCompilerToVM().JavaMethod_uniqueConcreteMethod(this);
    }

    @Override
    public Signature getSignature() {
        if (signature == null) {
            signature = new HotSpotSignature(HotSpotGraalRuntime.getInstance().getCompilerToVM().JavaMethod_signature(this));
        }
        return signature;
    }

    @Override
    public String toString() {
        return "HotSpotMethod<" + MetaUtil.format("%h.%n", this) + ">";
    }

    public boolean hasCompiledCode() {
        return HotSpotGraalRuntime.getInstance().getCompilerToVM().JavaMethod_hasCompiledCode(this);
    }

    public int getCompiledCodeSize() {
        return HotSpotGraalRuntime.getInstance().getCompilerToVM().JavaMethod_getCompiledCodeSize(this);
    }

    public int invocationCount() {
        return HotSpotGraalRuntime.getInstance().getCompilerToVM().JavaMethod_invocationCount(this);
    }

    @Override
    public int getCompilationComplexity() {
        if (compilationComplexity <= 0 && getCodeSize() > 0) {
            BytecodeStream s = new BytecodeStream(getCode());
            int result = 0;
            int currentBC;
            while ((currentBC = s.currentBC()) != Bytecodes.END) {
                result += Bytecodes.compilationComplexity(currentBC);
                s.next();
            }
            assert result > 0;
            compilationComplexity = result;
        }
        return compilationComplexity;
    }

    @Override
    public ProfilingInfo getProfilingInfo() {
        ProfilingInfo info;

        if (GraalOptions.UseProfilingInformation && methodData == null) {
            methodData = HotSpotGraalRuntime.getInstance().getCompilerToVM().JavaMethod_methodData(this);
        }

        if (methodData == null || (!methodData.hasNormalData() && !methodData.hasExtraData())) {
            // Be optimistic and return false for exceptionSeen. A methodDataOop is allocated in case of a deoptimization.
            info = DefaultProfilingInfo.get(ExceptionSeen.FALSE);
        } else {
            info = new HotSpotProfilingInfo(methodData, codeSize);
        }
        return info;
    }

    @Override
    public Map<Object, Object> getCompilerStorage() {
        if (compilerStorage == null) {
            compilerStorage = new ConcurrentHashMap<>();
        }
        return compilerStorage;
    }

    @Override
    public ConstantPool getConstantPool() {
        return ((HotSpotResolvedJavaType) getDeclaringClass()).constantPool();
    }

    @Override
    public Annotation[][] getParameterAnnotations() {
        if (isConstructor()) {
            Constructor javaConstructor = toJavaConstructor();
            return javaConstructor == null ? null : javaConstructor.getParameterAnnotations();
        }
        Method javaMethod = toJava();
        return javaMethod == null ? null : javaMethod.getParameterAnnotations();
    }

    @Override
    public <T extends Annotation> T getAnnotation(Class<T> annotationClass) {
        if (isConstructor()) {
            Constructor<?> javaConstructor = toJavaConstructor();
            return javaConstructor == null ? null : javaConstructor.getAnnotation(annotationClass);
        }
        Method javaMethod = toJava();
        return javaMethod == null ? null : javaMethod.getAnnotation(annotationClass);
    }

    @Override
    public Type[] getGenericParameterTypes() {
        if (isConstructor()) {
            Constructor javaConstructor = toJavaConstructor();
            return javaConstructor == null ? null : javaConstructor.getGenericParameterTypes();
        }
        Method javaMethod = toJava();
        return javaMethod == null ? null : javaMethod.getGenericParameterTypes();
    }

    private Method toJava() {
        try {
            return holder.toJava().getDeclaredMethod(name, MetaUtil.signatureToTypes(getSignature(), holder));
        } catch (NoSuchMethodException e) {
            return null;
        }
    }

    private Constructor toJavaConstructor() {
        try {
            return holder.toJava().getDeclaredConstructor(MetaUtil.signatureToTypes(getSignature(), holder));
        } catch (NoSuchMethodException e) {
            return null;
        }
    }

    @Override
    public boolean canBeInlined() {
        return canBeInlined;
    }

    /**
     * Returns the offset of this method into the v-table.
     * If the holder is not initialized, returns -1
     * @return the offset of this method into the v-table
     */
    public int vtableEntryOffset() {
        if (!holder.isInitialized()) {
            return -1;
        }
        return HotSpotGraalRuntime.getInstance().getCompilerToVM().JavaMethod_vtableEntryOffset(this);
    }

    public void setCurrentTask(CompilationTask task) {
        currentTask = task;
    }

    public CompilationTask currentTask() {
        return currentTask;
    }
}