/*
 * 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.test;

import static com.oracle.graal.truffle.TruffleCompilerOptions.*;

import java.util.*;
import java.util.concurrent.*;

import org.junit.*;

import com.oracle.graal.api.code.*;
import com.oracle.graal.compiler.test.*;
import com.oracle.graal.debug.*;
import com.oracle.graal.java.*;
import com.oracle.graal.loop.*;
import com.oracle.graal.nodes.*;
import com.oracle.graal.nodes.java.*;
import com.oracle.graal.nodes.spi.Lowerable.LoweringType;
import com.oracle.graal.phases.*;
import com.oracle.graal.phases.PhasePlan.PhasePosition;
import com.oracle.graal.phases.common.*;
import com.oracle.graal.phases.tiers.*;
import com.oracle.graal.printer.*;
import com.oracle.graal.truffle.*;
import com.oracle.graal.truffle.printer.*;
import com.oracle.graal.virtual.phases.ea.*;
import com.oracle.truffle.api.*;
import com.oracle.truffle.api.frame.*;
import com.oracle.truffle.api.nodes.*;

public class PartialEvaluationTest extends GraalCompilerTest {

    private static final long UNROLL_LIMIT = 100;
    private final PartialEvaluator partialEvaluator;

    public PartialEvaluationTest() {
        // Make sure Truffle runtime is initialized.
        Assert.assertTrue(Truffle.getRuntime() instanceof GraalTruffleRuntime);
        this.partialEvaluator = new PartialEvaluator(runtime, ((GraalTruffleRuntime) Truffle.getRuntime()).getReplacements());

        DebugEnvironment.initialize(System.out);
    }

    protected InstalledCode assertPartialEvalEquals(String methodName, RootNode root, FrameDescriptor descriptor) {
        return assertPartialEvalEquals(methodName, root, descriptor, Arguments.EMPTY_ARGUMENTS);
    }

    protected InstalledCode assertPartialEvalEquals(String methodName, RootNode root, FrameDescriptor descriptor, Arguments arguments) {
        Assumptions assumptions = new Assumptions(true);
        StructuredGraph actual = partialEval(root, descriptor, arguments, assumptions, true);
        InstalledCode result = new TruffleCompilerImpl().compileMethodHelper(actual, GraphBuilderConfiguration.getDefault(), assumptions);
        StructuredGraph expected = parseForComparison(methodName);
        removeFrameStates(actual);
        Assert.assertEquals(getCanonicalGraphString(expected, true), getCanonicalGraphString(actual, true));
        return result;
    }

    protected void assertPartialEvalNoInvokes(RootNode root, FrameDescriptor descriptor) {
        assertPartialEvalNoInvokes(root, descriptor, Arguments.EMPTY_ARGUMENTS);
    }

    protected void assertPartialEvalNoInvokes(RootNode root, FrameDescriptor descriptor, Arguments arguments) {
        Assumptions assumptions = new Assumptions(true);
        StructuredGraph actual = partialEval(root, descriptor, arguments, assumptions, true);
        removeFrameStates(actual);
        for (MethodCallTargetNode node : actual.getNodes(MethodCallTargetNode.class)) {
            Assert.fail("Found invalid method call target node: " + node);
        }
    }

    protected StructuredGraph partialEval(RootNode root, FrameDescriptor descriptor, Arguments arguments, final Assumptions assumptions, final boolean canonicalizeReads) {
        final OptimizedCallTarget compilable = (OptimizedCallTarget) Truffle.getRuntime().createCallTarget(root, descriptor);

        // Executed AST so that all classes are loaded and initialized.
        do {
            compilable.call(null, arguments);
            compilable.call(null, arguments);
            compilable.call(null, arguments);
        } while (compilable.inline());

        StructuredGraph graph = Debug.scope("Truffle", new DebugDumpScope("Truffle: " + compilable), new Callable<StructuredGraph>() {

            @Override
            public StructuredGraph call() {
                StructuredGraph resultGraph = partialEvaluator.createGraph(compilable, assumptions);
                CanonicalizerPhase canonicalizer = new CanonicalizerPhase(canonicalizeReads);
                HighTierContext context = new HighTierContext(runtime, assumptions, replacements);

                if (resultGraph.hasLoops()) {
                    boolean unrolled;
                    do {
                        unrolled = false;
                        LoopsData loopsData = new LoopsData(resultGraph);
                        loopsData.detectedCountedLoops();
                        for (LoopEx ex : innerLoopsFirst(loopsData.countedLoops())) {
                            if (ex.counted().isConstantMaxTripCount()) {
                                long constant = ex.counted().constantMaxTripCount();
                                if (constant <= UNROLL_LIMIT) {
                                    LoopTransformations.fullUnroll(ex, runtime, assumptions, canonicalizeReads);
                                    Debug.dump(resultGraph, "After loop unrolling %d times", constant);

                                    canonicalizer.apply(resultGraph, context);
                                    unrolled = true;
                                    break;
                                }
                            }
                        }
                    } while (unrolled);
                }

                new DeadCodeEliminationPhase().apply(resultGraph);
                new PartialEscapePhase(true, canonicalizer).apply(resultGraph, context);

                if (TruffleInlinePrinter.getValue()) {
                    InlinePrinterProcessor.printTree();
                }

                return resultGraph;
            }

            private List<LoopEx> innerLoopsFirst(Collection<LoopEx> loops) {
                ArrayList<LoopEx> sortedLoops = new ArrayList<>(loops);
                Collections.sort(sortedLoops, new Comparator<LoopEx>() {

                    @Override
                    public int compare(LoopEx o1, LoopEx o2) {
                        return o2.lirLoop().depth - o1.lirLoop().depth;
                    }
                });
                return sortedLoops;
            }
        });

        return graph;
    }

    protected void removeFrameStates(StructuredGraph graph) {
        for (FrameState frameState : graph.getNodes(FrameState.class)) {
            frameState.replaceAtUsages(null);
            frameState.safeDelete();
        }
        new CanonicalizerPhase.Instance(runtime, new Assumptions(false), true).apply(graph);
        new DeadCodeEliminationPhase().apply(graph);
    }

    protected StructuredGraph parseForComparison(final String methodName) {

        StructuredGraph graphResult = Debug.scope("Truffle", new DebugDumpScope("Comparison: " + methodName), new Callable<StructuredGraph>() {

            public StructuredGraph call() {
                Assumptions assumptions = new Assumptions(false);
                StructuredGraph graph = parse(methodName);
                CanonicalizerPhase.Instance canonicalizerPhase = new CanonicalizerPhase.Instance(runtime, assumptions, true);
                canonicalizerPhase.apply(graph);

                // Additional inlining.
                final PhasePlan plan = new PhasePlan();
                GraphBuilderPhase graphBuilderPhase = new GraphBuilderPhase(runtime, GraphBuilderConfiguration.getEagerDefault(), TruffleCompilerImpl.Optimizations);
                plan.addPhase(PhasePosition.AFTER_PARSING, graphBuilderPhase);
                plan.addPhase(PhasePosition.AFTER_PARSING, canonicalizerPhase);
                plan.addPhase(PhasePosition.AFTER_PARSING, new DeadCodeEliminationPhase());

                new ConvertDeoptimizeToGuardPhase().apply(graph);
                canonicalizerPhase.apply(graph);
                new DeadCodeEliminationPhase().apply(graph);

                InliningPhase inliningPhase = new InliningPhase(runtime, null, replacements, assumptions, null, plan, OptimisticOptimizations.NONE);
                inliningPhase.apply(graph);
                removeFrameStates(graph);

                new ConvertDeoptimizeToGuardPhase().apply(graph);
                canonicalizerPhase.apply(graph);
                new DeadCodeEliminationPhase().apply(graph);

                new LoweringPhase(LoweringType.BEFORE_GUARDS).apply(graph, new PhaseContext(runtime, assumptions, replacements));
                canonicalizerPhase.apply(graph);
                new DeadCodeEliminationPhase().apply(graph);
                return graph;
            }
        });
        return graphResult;
    }
}