/*

 * Copyright (c) 2012, 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

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 */

package org.graalvm.compiler.virtual.phases.ea;

import java.util.ArrayList;

import org.graalvm.compiler.debug.DebugCloseable;

import org.graalvm.compiler.debug.DebugContext;

import org.graalvm.compiler.graph.Node;

import org.graalvm.compiler.nodes.ControlSinkNode;

import org.graalvm.compiler.nodes.FixedNode;

import org.graalvm.compiler.nodes.FixedWithNextNode;

import org.graalvm.compiler.nodes.FrameState;

import org.graalvm.compiler.nodes.IfNode;

import org.graalvm.compiler.nodes.NodeView;

import org.graalvm.compiler.nodes.PhiNode;

import org.graalvm.compiler.nodes.PiNode;

import org.graalvm.compiler.nodes.StructuredGraph;

import org.graalvm.compiler.nodes.ValueNode;

import org.graalvm.compiler.nodes.debug.DynamicCounterNode;

import org.graalvm.compiler.nodes.debug.WeakCounterNode;

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

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

import org.graalvm.compiler.phases.common.DeadCodeEliminationPhase;

public final class GraphEffectList extends EffectList {

    public GraphEffectList(DebugContext debug) {

        super(debug);

    }

    /**

     * Determines how many objects are virtualized (positive) or materialized (negative) by this

     * effect.

     */

    private int virtualizationDelta;

    @Override

    public void clear() {

        super.clear();

        virtualizationDelta = 0;

    }

    public void addCounterBefore(String group, String name, int increment, boolean addContext, FixedNode position) {

        add("add counter", graph -> DynamicCounterNode.addCounterBefore(group, name, increment, addContext, position));

    }

    public void addCounterAfter(String group, String name, int increment, boolean addContext, FixedWithNextNode position) {

        FixedNode nextPosition = position.next();

        add("add counter after", graph -> DynamicCounterNode.addCounterBefore(group, name, increment, addContext, nextPosition));

    }

    public void addWeakCounterCounterBefore(String group, String name, int increment, boolean addContext, ValueNode checkedValue, FixedNode position) {

        add("add weak counter", graph -> WeakCounterNode.addCounterBefore(group, name, increment, addContext, checkedValue, position));

    }

    /**

     * Adds the given fixed node to the graph's control flow, before position (so that the original

     * predecessor of position will then be node's predecessor).

     *

     * @param node The fixed node to be added to the graph.

     * @param position The fixed node before which the node should be added.

     */

    public void addFixedNodeBefore(FixedWithNextNode node, FixedNode position) {

        add("add fixed node", graph -> {

            assert !node.isAlive() && !node.isDeleted() && position.isAlive();

            graph.addBeforeFixed(position, graph.add(node));

        });

    }

    public void ensureAdded(ValueNode node, FixedNode position) {

        add("ensure added", graph -> {

            assert position.isAlive();

            assert node instanceof FixedNode;

            if (!node.isAlive()) {

                graph.addOrUniqueWithInputs(node);

                if (node instanceof FixedWithNextNode) {

                    graph.addBeforeFixed(position, (FixedWithNextNode) node);

                }

            }

        });

    }

    public void addVirtualizationDelta(int delta) {

        virtualizationDelta += delta;

    }

    public int getVirtualizationDelta() {

        return virtualizationDelta;

    }

    /**

     * Add the given floating node to the graph.

     *

     * @param node The floating node to be added.

     */

    public void addFloatingNode(ValueNode node, @SuppressWarnings("unused") String cause) {

        add("add floating node", graph -> {

            graph.addWithoutUniqueWithInputs(node);

        });

    }

    /**

     * Sets the phi node's input at the given index to the given value, adding new phi inputs as

     * needed.

     *

     * @param node The phi node whose input should be changed.

     * @param index The index of the phi input to be changed.

     * @param value The new value for the phi input.

     */

    public void initializePhiInput(PhiNode node, int index, ValueNode value) {

        add("set phi input", (graph, obsoleteNodes) -> {

            assert node.isAlive() && index >= 0 : node;

            node.initializeValueAt(index, graph.addOrUniqueWithInputs(value));

        });

    }

    /**

     * Adds a virtual object's state to the given frame state. If the given reusedVirtualObjects set

     * contains the virtual object then old states for this object will be removed.

     *

     * @param node The frame state to which the state should be added.

     * @param state The virtual object state to add.

     */

    public void addVirtualMapping(FrameState node, EscapeObjectState state) {

        add("add virtual mapping", new Effect() {

            @Override

            public void apply(StructuredGraph graph, ArrayList<Node> obsoleteNodes) {

                if (node.isAlive()) {

                    assert !state.isDeleted();

                    FrameState stateAfter = node;

                    for (int i = 0; i < stateAfter.virtualObjectMappingCount(); i++) {

                        if (stateAfter.virtualObjectMappingAt(i).object() == state.object()) {

                            stateAfter.virtualObjectMappings().remove(i);

                        }

                    }

                    stateAfter.addVirtualObjectMapping(graph.addOrUniqueWithInputs(state));

                }

            }

            @Override

            public boolean isVisible() {

                return false;

            }

        });

    }

    /**

     * Removes the given fixed node from the control flow and deletes it.

     *

     * @param node The fixed node that should be deleted.

     */

    public void deleteNode(Node node) {

        add("delete fixed node", (graph, obsoleteNodes) -> {

            if (node instanceof FixedWithNextNode) {

                GraphUtil.unlinkFixedNode((FixedWithNextNode) node);

            }

            obsoleteNodes.add(node);

        });

    }

    public void killIfBranch(IfNode ifNode, boolean constantCondition) {

        add("kill if branch", new Effect() {

            @Override

            public void apply(StructuredGraph graph, ArrayList<Node> obsoleteNodes) {

                graph.removeSplitPropagate(ifNode, ifNode.getSuccessor(constantCondition));

            }

            @Override

            public boolean isCfgKill() {

                return true;

            }

        });

    }

    public void replaceWithSink(FixedWithNextNode node, ControlSinkNode sink) {

        add("kill if branch", new Effect() {

            @SuppressWarnings("try")

            @Override

            public void apply(StructuredGraph graph, ArrayList<Node> obsoleteNodes) {

                try (DebugCloseable position = graph.withNodeSourcePosition(node)) {

                    graph.addWithoutUnique(sink);

                    node.replaceAtPredecessor(sink);

                    GraphUtil.killCFG(node);

                }

            }

            @Override

            public boolean isCfgKill() {

                return true;

            }

        });

    }

    /**

     * Replaces the given node at its usages without deleting it. If the current node is a fixed

     * node it will be disconnected from the control flow, so that it will be deleted by a

     * subsequent {@link DeadCodeEliminationPhase}

     *

     * @param node The node to be replaced.

     * @param replacement The node that should replace the original value. If the replacement is a

     *            non-connected {@link FixedWithNextNode} it will be added to the control flow.

     * @param insertBefore

     *

     */

    @SuppressWarnings("try")

    public void replaceAtUsages(ValueNode node, ValueNode replacement, FixedNode insertBefore) {

        assert node != null && replacement != null : node + " " + replacement;

        assert !node.hasUsages() || node.stamp(NodeView.DEFAULT).isCompatible(replacement.stamp(NodeView.DEFAULT)) : "Replacement node stamp not compatible " + node.stamp(NodeView.DEFAULT) + " vs " +

                        replacement.stamp(NodeView.DEFAULT);

        add("replace at usages", (graph, obsoleteNodes) -> {

            try (DebugCloseable position = graph.withNodeSourcePosition(node)) {

                assert node.isAlive();

                ValueNode replacementNode = graph.addOrUniqueWithInputs(replacement);

                assert replacementNode.isAlive();

                assert insertBefore != null;

                if (replacementNode instanceof FixedWithNextNode && ((FixedWithNextNode) replacementNode).next() == null) {

                    graph.addBeforeFixed(insertBefore, (FixedWithNextNode) replacementNode);

                }

                /*

                 * Keep the (better) stamp information when replacing a node with another one if the

                 * replacement has a less precise stamp than the original node. This can happen for

                 * example in the context of read nodes and unguarded pi nodes where the pi will be

                 * used to improve the stamp information of the read. Such a read might later be

                 * replaced with a read with a less precise stamp.

                 */

                if (node.hasUsages() && !node.stamp(NodeView.DEFAULT).equals(replacementNode.stamp(NodeView.DEFAULT))) {

                    replacementNode = graph.unique(new PiNode(replacementNode, node.stamp(NodeView.DEFAULT)));

                }

                node.replaceAtUsages(replacementNode);

                if (node instanceof FixedWithNextNode) {

                    GraphUtil.unlinkFixedNode((FixedWithNextNode) node);

                }

                obsoleteNodes.add(node);

            }

        });

    }

    /**

     * Replaces the first occurrence of oldInput in node with newInput.

     *

     * @param node The node whose input should be changed.

     * @param oldInput The value to look for.

     * @param newInput The value to replace with.

     */

    public void replaceFirstInput(Node node, Node oldInput, Node newInput) {

        assert node.isAlive() && oldInput.isAlive() && !newInput.isDeleted();

        add("replace first input", new Effect() {

            @Override

            public void apply(StructuredGraph graph, ArrayList<Node> obsoleteNodes) {

                if (node.isAlive()) {

                    assert oldInput.isAlive() && newInput.isAlive();

                    node.replaceFirstInput(oldInput, newInput);

                }

            }

            @Override

            public boolean isVisible() {

                return !(node instanceof FrameState);

            }

        });

    }

}