/*
 * Copyright (c) 2013, 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.truffle;

import com.oracle.truffle.api.*;
import com.oracle.truffle.api.CompilerDirectives.CompilationFinal;
import com.oracle.truffle.api.frame.FrameInstance.FrameAccess;
import com.oracle.truffle.api.frame.*;
import com.oracle.truffle.api.nodes.*;

/**
 * A call node with a constant {@link CallTarget} that can be optimized by Graal.
 */
@NodeInfo
public final class OptimizedDirectCallNode extends DirectCallNode implements MaterializedFrameNotify {

    private int callCount;
    private boolean inliningForced;

    @CompilationFinal private boolean inlined;
    @CompilationFinal private OptimizedCallTarget splitCallTarget;
    @CompilationFinal private FrameAccess outsideFrameAccess = FrameAccess.NONE;

    private final TruffleSplittingStrategy splittingStrategy;

    public OptimizedDirectCallNode(OptimizedCallTarget target) {
        super(target);
        if (TruffleCompilerOptions.TruffleSplittingNew.getValue()) {
            this.splittingStrategy = new DefaultTruffleSplittingStrategyNew(this);
        } else {
            this.splittingStrategy = new DefaultTruffleSplittingStrategy(this);
        }
    }

    @Override
    public Object call(VirtualFrame frame, Object[] arguments) {
        if (CompilerDirectives.inInterpreter()) {
            onInterpreterCall(arguments);
        }
        Object result = callProxy(this, getCurrentCallTarget(), frame, arguments, inlined, true);

        if (CompilerDirectives.inInterpreter()) {
            afterInterpreterCall(result);
        }
        return result;
    }

    private void afterInterpreterCall(Object result) {
        splittingStrategy.afterCall(result);
        // propagateInliningInvalidations();
    }

    public static Object callProxy(MaterializedFrameNotify notify, CallTarget callTarget, VirtualFrame frame, Object[] arguments, boolean inlined, boolean direct) {
        try {
            if (notify.getOutsideFrameAccess() != FrameAccess.NONE) {
                CompilerDirectives.materialize(frame);
            }
            if (inlined) {
                return ((OptimizedCallTarget) callTarget).callInlined(arguments);
            } else if (direct) {
                return ((OptimizedCallTarget) callTarget).callDirect(arguments);
            } else {
                return callTarget.call(arguments);
            }
        } finally {
            // this assertion is needed to keep the values from being cleared as non-live locals
            assert notify != null & callTarget != null & frame != null;
        }
    }

    public void resetInlining() {
        CompilerAsserts.neverPartOfCompilation();
        if (inlined && !inliningForced) {
            inlined = false;
        }
    }

    @Override
    public boolean isInlinable() {
        return true;
    }

    @Override
    public void forceInlining() {
        inliningForced = true;
    }

    @Override
    public boolean isInliningForced() {
        return inliningForced;
    }

    @Override
    public FrameAccess getOutsideFrameAccess() {
        return outsideFrameAccess;
    }

    @Override
    public void setOutsideFrameAccess(FrameAccess outsideFrameAccess) {
        this.outsideFrameAccess = outsideFrameAccess;
    }

    @Override
    public boolean isSplittable() {
        return getCallTarget().getRootNode().isSplittable();
    }

    @Override
    public OptimizedCallTarget getCallTarget() {
        return (OptimizedCallTarget) super.getCallTarget();
    }

    public int getCallCount() {
        return callCount;
    }

    @Override
    public OptimizedCallTarget getCurrentCallTarget() {
        return (OptimizedCallTarget) super.getCurrentCallTarget();
    }

    @Override
    public OptimizedCallTarget getSplitCallTarget() {
        return splitCallTarget;
    }

    private void onInterpreterCall(Object[] arguments) {
        int calls = ++callCount;
        if (calls == 1) {
            getCurrentCallTarget().incrementKnownCallSites();
        }
        splittingStrategy.beforeCall(arguments);
        // propagateInliningInvalidations();
    }

    /** Used by the splitting strategy to install new targets. */
    public void installSplitCallTarget(OptimizedCallTarget newTarget) {
        CompilerAsserts.neverPartOfCompilation();

        OptimizedCallTarget currentTarget = getCurrentCallTarget();
        if (currentTarget == newTarget) {
            return;
        }

        if (callCount >= 1) {
            currentTarget.decrementKnownCallSites();
        }
        newTarget.incrementKnownCallSites();

        // dummy replace to report the split
        replace(this, "Split call " + newTarget.toString());

        if (newTarget.getSplitSource() == null) {
            splitCallTarget = null;
        } else {
            splitCallTarget = newTarget;
        }
    }

    @SuppressWarnings("unused")
    private void propagateInliningInvalidations() {
        if (isInlined() && !getCurrentCallTarget().inliningPerformed) {
            replace(this, "Propagate invalid inlining from " + getCurrentCallTarget().toString());
        }
    }

    /* Called by the runtime system if this CallNode is really going to be inlined. */
    void inline() {
        inlined = true;
    }

    @Override
    public boolean isInlined() {
        return inlined;
    }

    @Override
    public boolean split() {
        splittingStrategy.forceSplitting();
        return true;
    }
}