/*

 * 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 org.graalvm.compiler.replacements.nodes;

import static org.graalvm.compiler.nodeinfo.NodeSize.SIZE_8;

import java.util.Collections;

import org.graalvm.compiler.core.common.type.ObjectStamp;

import org.graalvm.compiler.core.common.type.Stamp;

import org.graalvm.compiler.core.common.type.StampFactory;

import org.graalvm.compiler.core.common.type.StampPair;

import org.graalvm.compiler.graph.NodeClass;

import org.graalvm.compiler.nodeinfo.NodeCycles;

import org.graalvm.compiler.nodeinfo.NodeInfo;

import org.graalvm.compiler.nodes.CallTargetNode.InvokeKind;

import org.graalvm.compiler.nodes.NodeView;

import org.graalvm.compiler.nodes.ValueNode;

import org.graalvm.compiler.nodes.java.LoadFieldNode;

import org.graalvm.compiler.nodes.java.MonitorIdNode;

import org.graalvm.compiler.nodes.spi.ArrayLengthProvider;

import org.graalvm.compiler.nodes.spi.VirtualizableAllocation;

import org.graalvm.compiler.nodes.spi.VirtualizerTool;

import org.graalvm.compiler.nodes.util.GraphUtil;

import org.graalvm.compiler.nodes.virtual.VirtualInstanceNode;

import org.graalvm.compiler.nodes.virtual.VirtualObjectNode;

import jdk.vm.ci.meta.Assumptions;

import jdk.vm.ci.meta.ResolvedJavaField;

import jdk.vm.ci.meta.ResolvedJavaMethod;

import jdk.vm.ci.meta.ResolvedJavaType;

@NodeInfo(cycles = NodeCycles.CYCLES_UNKNOWN, size = SIZE_8)

public abstract class BasicObjectCloneNode extends MacroStateSplitNode implements VirtualizableAllocation, ArrayLengthProvider {

    public static final NodeClass<BasicObjectCloneNode> TYPE = NodeClass.create(BasicObjectCloneNode.class);

    public BasicObjectCloneNode(NodeClass<? extends MacroNode> c, InvokeKind invokeKind, ResolvedJavaMethod targetMethod, int bci, StampPair returnStamp, ValueNode... arguments) {

        super(c, invokeKind, targetMethod, bci, returnStamp, arguments);

        updateStamp(computeStamp(getObject()));

    }

    @Override

    public boolean inferStamp() {

    }

    protected Stamp computeStamp(ValueNode object) {

        Stamp objectStamp = object.stamp(NodeView.DEFAULT);

        if (objectStamp instanceof ObjectStamp) {

            objectStamp = objectStamp.join(StampFactory.objectNonNull());

        }

        return objectStamp;

    }

    public ValueNode getObject() {

        return arguments.get(0);

    }

    /*

     * Looks at the given stamp and determines if it is an exact type (or can be assumed to be an

     * exact type) and if it is a cloneable type.

     *

     * If yes, then the exact type is returned, otherwise it returns null.

     */

    protected ResolvedJavaType getConcreteType(Stamp forStamp) {

        if (!(forStamp instanceof ObjectStamp)) {

            return null;

        }

        ObjectStamp objectStamp = (ObjectStamp) forStamp;

        if (objectStamp.type() == null) {

            return null;

        } else if (objectStamp.isExactType()) {

            return objectStamp.type().isCloneableWithAllocation() ? objectStamp.type() : null;

        } else if (objectStamp.type().isArray()) {

            return objectStamp.type();

        }

        return null;

    }

    protected LoadFieldNode genLoadFieldNode(Assumptions assumptions, ValueNode originalAlias, ResolvedJavaField field) {

        return LoadFieldNode.create(assumptions, originalAlias, field);

    }

    @Override

    public void virtualize(VirtualizerTool tool) {

        ValueNode originalAlias = tool.getAlias(getObject());

        if (originalAlias instanceof VirtualObjectNode) {

            VirtualObjectNode originalVirtual = (VirtualObjectNode) originalAlias;

            if (originalVirtual.type().isCloneableWithAllocation()) {

                ValueNode[] newEntryState = new ValueNode[originalVirtual.entryCount()];

                for (int i = 0; i < newEntryState.length; i++) {

                    newEntryState[i] = tool.getEntry(originalVirtual, i);

                }

                VirtualObjectNode newVirtual = originalVirtual.duplicate();

                tool.createVirtualObject(newVirtual, newEntryState, Collections.<MonitorIdNode> emptyList(), false);

                tool.replaceWithVirtual(newVirtual);

            }

        } else {

            ResolvedJavaType type = getConcreteType(originalAlias.stamp(NodeView.DEFAULT));

            if (type != null && !type.isArray()) {

                VirtualInstanceNode newVirtual = createVirtualInstanceNode(type, true);

                ResolvedJavaField[] fields = newVirtual.getFields();

                ValueNode[] state = new ValueNode[fields.length];

                final LoadFieldNode[] loads = new LoadFieldNode[fields.length];

                for (int i = 0; i < fields.length; i++) {

                    state[i] = loads[i] = genLoadFieldNode(graph().getAssumptions(), originalAlias, fields[i]);

                    tool.addNode(loads[i]);

                }

                tool.createVirtualObject(newVirtual, state, Collections.<MonitorIdNode> emptyList(), false);

                tool.replaceWithVirtual(newVirtual);

            }

        }

    }

    protected VirtualInstanceNode createVirtualInstanceNode(ResolvedJavaType type, boolean hasIdentity) {

        return new VirtualInstanceNode(type, hasIdentity);

    }

    @Override

    public ValueNode length() {

        return GraphUtil.arrayLength(getObject());

    }

}