/*
 * Copyright (c) 2011, 2018, 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.core.test;

import java.io.BufferedInputStream;
import java.io.ByteArrayInputStream;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;

import org.graalvm.compiler.debug.DebugContext;
import org.graalvm.compiler.debug.TTY;
import org.graalvm.compiler.graph.Node;
import org.graalvm.compiler.nodeinfo.Verbosity;
import org.graalvm.compiler.nodes.AbstractMergeNode;
import org.graalvm.compiler.nodes.PhiNode;
import org.graalvm.compiler.nodes.StructuredGraph;
import org.graalvm.compiler.nodes.StructuredGraph.AllowAssumptions;
import org.graalvm.compiler.nodes.StructuredGraph.ScheduleResult;
import org.graalvm.compiler.nodes.cfg.Block;
import org.graalvm.compiler.nodes.java.InstanceOfNode;
import org.graalvm.compiler.phases.common.CanonicalizerPhase;
import org.graalvm.compiler.phases.common.ConditionalEliminationPhase;
import org.graalvm.compiler.phases.schedule.SchedulePhase;
import org.graalvm.compiler.phases.tiers.PhaseContext;
import org.junit.Assert;
import org.junit.Ignore;
import org.junit.Test;

/**
 * In the following tests, the scalar type system of the compiler should be complete enough to see
 * the relation between the different conditions.
 */
public class TypeSystemTest extends GraalCompilerTest {

    @Test
    public void test3() {
        test("test3Snippet", "referenceSnippet3");
    }

    public static int referenceSnippet3(Object o) {
        if (o == null) {
            return 1;
        } else {
            return 2;
        }
    }

    @SuppressWarnings("unused")
    public static int test3Snippet(Object o) {
        if (o == null) {
            if (o != null) {
                return 3;
            } else {
                return 1;
            }
        } else {
            return 2;
        }
    }

    @Test
    public void test4() {
        test("test4Snippet", "referenceSnippet3");
    }

    @SuppressWarnings("unused")
    public static int test4Snippet(Object o) {
        if (o == null) {
            Object o2 = Integer.class;
            if (o == o2) {
                return 3;
            } else {
                return 1;
            }
        } else {
            return 2;
        }
    }

    @Test
    @Ignore
    public void test5() {
        test("test5Snippet", "referenceSnippet5");
    }

    public static int referenceSnippet5(Object o, Object a) {
        if (o == null) {
            if (a == Integer.class) {
                return 1;
            }
        } else {
            if (a == Double.class) {
                return 11;
            }
        }
        if (a == Integer.class) {
            return 3;
        }
        return 5;
    }

    @SuppressWarnings("unused")
    public static int test5Snippet(Object o, Object a) {
        if (o == null) {
            if (a == Integer.class) {
                if (a == null) {
                    return 10;
                }
                return 1;
            }
        } else {
            if (a == Double.class) {
                if (a != null) {
                    return 11;
                }
                return 2;
            }
        }
        if (a == Integer.class) {
            return 3;
        }
        return 5;
    }

    @Test
    public void test6() {
        testHelper("test6Snippet", InstanceOfNode.class);
    }

    public static int test6Snippet(int i) throws IOException {
        Object o = null;

        if (i == 5) {
            o = new FileInputStream("asdf");
        }
        if (i < 10) {
            o = new ByteArrayInputStream(new byte[]{1, 2, 3});
        }
        if (i > 0) {
            o = new BufferedInputStream(null);
        }

        return ((InputStream) o).available();
    }

    @Test
    public void test7() {
        test("test7Snippet", "referenceSnippet7");
    }

    public static int test7Snippet(int x) {
        return ((x & 0xff) << 10) == ((x & 0x1f) + 1) ? 0 : x;
    }

    public static int referenceSnippet7(int x) {
        return x;
    }

    private void test(String snippet, String referenceSnippet) {
        StructuredGraph graph = parseEager(snippet, AllowAssumptions.NO);
        DebugContext debug = graph.getDebug();
        debug.dump(DebugContext.BASIC_LEVEL, graph, "Graph");
        /*
         * When using FlowSensitiveReductionPhase instead of ConditionalEliminationPhase,
         * tail-duplication gets activated thus resulting in a graph with more nodes than the
         * reference graph.
         */
        new ConditionalEliminationPhase(false).apply(graph, new PhaseContext(getProviders()));
        new CanonicalizerPhase().apply(graph, new PhaseContext(getProviders()));
        // a second canonicalizer is needed to process nested MaterializeNodes
        new CanonicalizerPhase().apply(graph, new PhaseContext(getProviders()));
        StructuredGraph referenceGraph = parseEager(referenceSnippet, AllowAssumptions.NO);
        new ConditionalEliminationPhase(false).apply(referenceGraph, new PhaseContext(getProviders()));
        new CanonicalizerPhase().apply(referenceGraph, new PhaseContext(getProviders()));
        new CanonicalizerPhase().apply(referenceGraph, new PhaseContext(getProviders()));
        assertEquals(referenceGraph, graph);
    }

    @Override
    protected void assertEquals(StructuredGraph expected, StructuredGraph graph) {
        DebugContext debug = graph.getDebug();
        if (getNodeCountExcludingUnusedConstants(expected) != getNodeCountExcludingUnusedConstants(graph)) {
            debug.dump(DebugContext.BASIC_LEVEL, expected, "expected (node count)");
            debug.dump(DebugContext.BASIC_LEVEL, graph, "graph (node count)");
            Assert.fail("Graphs do not have the same number of nodes: " + expected.getNodeCount() + " vs. " + graph.getNodeCount());
        }
    }

    public static void outputGraph(StructuredGraph graph, String message) {
        TTY.println("========================= " + message);
        SchedulePhase schedulePhase = new SchedulePhase(graph.getOptions());
        schedulePhase.apply(graph);
        ScheduleResult schedule = graph.getLastSchedule();
        for (Block block : schedule.getCFG().getBlocks()) {
            TTY.print("Block " + block + " ");
            if (block == schedule.getCFG().getStartBlock()) {
                TTY.print("* ");
            }
            TTY.print("-> ");
            for (Block succ : block.getSuccessors()) {
                TTY.print(succ + " ");
            }
            TTY.println();
            for (Node node : schedule.getBlockToNodesMap().get(block)) {
                outputNode(node);
            }
        }
    }

    private static void outputNode(Node node) {
        TTY.print("  " + node + "    (usage count: " + node.getUsageCount() + ") (inputs:");
        for (Node input : node.inputs()) {
            TTY.print(" " + input.toString(Verbosity.Id));
        }
        TTY.println(")");
        if (node instanceof AbstractMergeNode) {
            for (PhiNode phi : ((AbstractMergeNode) node).phis()) {
                outputNode(phi);
            }
        }
    }

    private <T extends Node> void testHelper(String snippet, Class<T> clazz) {
        StructuredGraph graph = parseEager(snippet, AllowAssumptions.NO);
        new CanonicalizerPhase().apply(graph, new PhaseContext(getProviders()));
        new CanonicalizerPhase().apply(graph, new PhaseContext(getProviders()));
        DebugContext debug = graph.getDebug();
        debug.dump(DebugContext.BASIC_LEVEL, graph, "Graph " + snippet);
        Assert.assertFalse("shouldn't have nodes of type " + clazz, graph.getNodes().filter(clazz).iterator().hasNext());
    }
}
