/*

 * Copyright (c) 2013, 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

 * questions.

 */

package org.graalvm.compiler.test;

import static org.graalvm.compiler.debug.DebugContext.DEFAULT_LOG_STREAM;

import static org.graalvm.compiler.debug.DebugContext.NO_DESCRIPTION;

import java.io.IOException;

import java.io.PrintStream;

import java.io.PrintWriter;

import java.lang.reflect.Field;

import java.lang.reflect.Method;

import java.nio.file.FileVisitResult;

import java.nio.file.Files;

import java.nio.file.Path;

import java.nio.file.Paths;

import java.nio.file.SimpleFileVisitor;

import java.nio.file.attribute.BasicFileAttributes;

import java.nio.file.attribute.FileAttribute;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.Collection;

import java.util.Collections;

import java.util.List;

import java.util.concurrent.TimeUnit;

import org.graalvm.compiler.debug.DebugContext;

import org.graalvm.compiler.debug.DebugDumpHandler;

import org.graalvm.compiler.debug.DebugHandlersFactory;

import org.graalvm.compiler.debug.GlobalMetrics;

import org.graalvm.compiler.options.OptionValues;

import org.graalvm.compiler.serviceprovider.GraalServices;

import org.junit.After;

import org.junit.Assert;

import org.junit.AssumptionViolatedException;

import org.junit.internal.ComparisonCriteria;

import org.junit.internal.ExactComparisonCriteria;

import org.junit.rules.DisableOnDebug;

import org.junit.rules.TestRule;

import org.junit.rules.Timeout;

import jdk.vm.ci.meta.ResolvedJavaMethod;

import sun.misc.Unsafe;

/**

 * Base class that contains common utility methods and classes useful in unit tests.

 */

public class GraalTest {

    public static final Unsafe UNSAFE;

    static {

        try {

            Field theUnsafe = Unsafe.class.getDeclaredField("theUnsafe");

            theUnsafe.setAccessible(true);

            UNSAFE = (Unsafe) theUnsafe.get(Unsafe.class);

        } catch (Exception e) {

            throw new RuntimeException("exception while trying to get Unsafe", e);

        }

    }

    protected Method getMethod(String methodName) {

        return getMethod(getClass(), methodName);

    }

    protected Method getMethod(Class<?> clazz, String methodName) {

        Method found = null;

        for (Method m : clazz.getMethods()) {

            if (m.getName().equals(methodName)) {

                Assert.assertNull(found);

                found = m;

            }

        }

        if (found == null) {

            /* Now look for non-public methods (but this does not look in superclasses). */

            for (Method m : clazz.getDeclaredMethods()) {

                if (m.getName().equals(methodName)) {

                    Assert.assertNull(found);

                    found = m;

                }

            }

        }

        if (found != null) {

            return found;

        } else {

            throw new RuntimeException("method not found: " + methodName);

        }

    }

    protected Method getMethod(Class<?> clazz, String methodName, Class<?>... parameterTypes) {

        try {

            return clazz.getMethod(methodName, parameterTypes);

        } catch (NoSuchMethodException | SecurityException e) {

            throw new RuntimeException("method not found: " + methodName + "" + Arrays.toString(parameterTypes));

        }

    }

    /**

     * Compares two given objects for {@linkplain Assert#assertEquals(Object, Object) equality}.

     * Does a deep copy equality comparison if {@code expected} is an array.

     */

    protected void assertDeepEquals(Object expected, Object actual) {

        assertDeepEquals(null, expected, actual);

    }

    /**

     * Compares two given objects for {@linkplain Assert#assertEquals(Object, Object) equality}.

     * Does a deep copy equality comparison if {@code expected} is an array.

     *

     * @param message the identifying message for the {@link AssertionError}

     */

    protected void assertDeepEquals(String message, Object expected, Object actual) {

        if (ulpsDelta() > 0) {

            assertDeepEquals(message, expected, actual, ulpsDelta());

        } else {

            assertDeepEquals(message, expected, actual, equalFloatsOrDoublesDelta());

        }

    }

    /**

     * Compares two given values for equality, doing a recursive test if both values are arrays of

     * the same type.

     *

     * @param message the identifying message for the {@link AssertionError}

     * @param delta the maximum delta between two doubles or floats for which both numbers are still

     *            considered equal.

     */

    protected void assertDeepEquals(String message, Object expected, Object actual, double delta) {

        if (expected != null && actual != null) {

            Class<?> expectedClass = expected.getClass();

            Class<?> actualClass = actual.getClass();

            if (expectedClass.isArray()) {

                Assert.assertEquals(message, expectedClass, actual.getClass());

                if (expected instanceof int[]) {

                    Assert.assertArrayEquals(message, (int[]) expected, (int[]) actual);

                } else if (expected instanceof byte[]) {

                    Assert.assertArrayEquals(message, (byte[]) expected, (byte[]) actual);

                } else if (expected instanceof char[]) {

                    Assert.assertArrayEquals(message, (char[]) expected, (char[]) actual);

                } else if (expected instanceof short[]) {

                    Assert.assertArrayEquals(message, (short[]) expected, (short[]) actual);

                } else if (expected instanceof float[]) {

                    Assert.assertArrayEquals(message, (float[]) expected, (float[]) actual, (float) delta);

                } else if (expected instanceof long[]) {

                    Assert.assertArrayEquals(message, (long[]) expected, (long[]) actual);

                } else if (expected instanceof double[]) {

                    Assert.assertArrayEquals(message, (double[]) expected, (double[]) actual, delta);

                } else if (expected instanceof boolean[]) {

                    new ExactComparisonCriteria().arrayEquals(message, expected, actual);

                } else if (expected instanceof Object[]) {

                    new ComparisonCriteria() {

                        @Override

                        protected void assertElementsEqual(Object e, Object a) {

                            assertDeepEquals(message, e, a, delta);

                        }

                    }.arrayEquals(message, expected, actual);

                } else {

                    Assert.fail((message == null ? "" : message) + "non-array value encountered: " + expected);

                }

            } else if (expectedClass.equals(double.class) && actualClass.equals(double.class)) {

                Assert.assertEquals((double) expected, (double) actual, delta);

            } else if (expectedClass.equals(float.class) && actualClass.equals(float.class)) {

                Assert.assertEquals((float) expected, (float) actual, delta);

            } else {

                Assert.assertEquals(message, expected, actual);

            }

        } else {

            Assert.assertEquals(message, expected, actual);

        }

    }

    /**

     * Compares two given values for equality, doing a recursive test if both values are arrays of

     * the same type. Uses {@linkplain StrictMath#ulp(float) ULP}s for comparison of floats.

     *

     * @param message the identifying message for the {@link AssertionError}

     * @param ulpsDelta the maximum allowed ulps difference between two doubles or floats for which

     *            both numbers are still considered equal.

     */

    protected void assertDeepEquals(String message, Object expected, Object actual, int ulpsDelta) {

        ComparisonCriteria doubleUlpsDeltaCriteria = new ComparisonCriteria() {

            @Override

            protected void assertElementsEqual(Object e, Object a) {

                assertTrue(message, e instanceof Double && a instanceof Double);

                // determine acceptable error based on whether it is a normal number or a NaN/Inf

                double de = (Double) e;

                double epsilon = (!Double.isNaN(de) && Double.isFinite(de) ? ulpsDelta * Math.ulp(de) : 0);

                Assert.assertEquals(message, (Double) e, (Double) a, epsilon);

            }

        };

        ComparisonCriteria floatUlpsDeltaCriteria = new ComparisonCriteria() {

            @Override

            protected void assertElementsEqual(Object e, Object a) {

                assertTrue(message, e instanceof Float && a instanceof Float);

                // determine acceptable error based on whether it is a normal number or a NaN/Inf

                float fe = (Float) e;

                float epsilon = (!Float.isNaN(fe) && Float.isFinite(fe) ? ulpsDelta * Math.ulp(fe) : 0);

                Assert.assertEquals(message, (Float) e, (Float) a, epsilon);

            }

        };

        if (expected != null && actual != null) {

            Class<?> expectedClass = expected.getClass();

            Class<?> actualClass = actual.getClass();

            if (expectedClass.isArray()) {

                Assert.assertEquals(message, expectedClass, actualClass);

                if (expected instanceof double[] || expected instanceof Object[]) {

                    doubleUlpsDeltaCriteria.arrayEquals(message, expected, actual);

                    return;

                } else if (expected instanceof float[] || expected instanceof Object[]) {

                    floatUlpsDeltaCriteria.arrayEquals(message, expected, actual);

                    return;

                }

            } else if (expectedClass.equals(double.class) && actualClass.equals(double.class)) {

                doubleUlpsDeltaCriteria.arrayEquals(message, expected, actual);

                return;

            } else if (expectedClass.equals(float.class) && actualClass.equals(float.class)) {

                floatUlpsDeltaCriteria.arrayEquals(message, expected, actual);

                return;

            }

        }

        // anything else just use the non-ulps version

        assertDeepEquals(message, expected, actual, equalFloatsOrDoublesDelta());

    }

    /**

     * @see "https://bugs.openjdk.java.net/browse/JDK-8076557"

     */

    public static void assumeManagementLibraryIsLoadable() {

        try {

            /* Trigger loading of the management library using the bootstrap class loader. */

            GraalServices.getCurrentThreadAllocatedBytes();

        } catch (UnsatisfiedLinkError | NoClassDefFoundError | UnsupportedOperationException e) {

            throw new AssumptionViolatedException("Management interface is unavailable: " + e);

        }

    }

    /**

     * Gets the value used by {@link #assertDeepEquals(Object, Object)} and

     * {@link #assertDeepEquals(String, Object, Object)} for the maximum delta between two doubles

     * or floats for which both numbers are still considered equal.

     */

    protected double equalFloatsOrDoublesDelta() {

        return 0.0D;

    }

    // unless overridden ulpsDelta is not used

    protected int ulpsDelta() {

        return 0;

    }

    @SuppressWarnings("serial")

    public static class MultiCauseAssertionError extends AssertionError {

        private Throwable[] causes;

        public MultiCauseAssertionError(String message, Throwable... causes) {

            super(message);

            this.causes = causes;

        }

        @Override

        public void printStackTrace(PrintStream out) {

            super.printStackTrace(out);

            int num = 0;

            for (Throwable cause : causes) {

                if (cause != null) {

                    out.print("cause " + (num++));

                    cause.printStackTrace(out);

                }

            }

        }

        @Override

        public void printStackTrace(PrintWriter out) {

            super.printStackTrace(out);

            int num = 0;

            for (Throwable cause : causes) {

                if (cause != null) {

                    out.print("cause " + (num++) + ": ");

                    cause.printStackTrace(out);

                }

            }

        }

    }

    /*

     * Overrides to the normal JUnit {@link Assert} routines that provide varargs style formatting

     * and produce an exception stack trace with the assertion frames trimmed out.

     */

    /**

     * Fails a test with the given message.

     *

     * @param message the identifying message for the {@link AssertionError} (<code>null</code>

     *            okay)

     * @see AssertionError

     */

    public static void fail(String message, Object... objects) {

        AssertionError e;

        if (message == null) {

            e = new AssertionError();

        } else {

            e = new AssertionError(String.format(message, objects));

        }

        // Trim the assert frames from the stack trace

        StackTraceElement[] trace = e.getStackTrace();

        int start = 1; // Skip this frame

        String thisClassName = GraalTest.class.getName();

        while (start < trace.length && trace[start].getClassName().equals(thisClassName) && (trace[start].getMethodName().equals("assertTrue") || trace[start].getMethodName().equals("assertFalse"))) {

            start++;

        }

        e.setStackTrace(Arrays.copyOfRange(trace, start, trace.length));

        throw e;

    }

    /**

     * Asserts that a condition is true. If it isn't it throws an {@link AssertionError} with the

     * given message.

     *

     * @param message the identifying message for the {@link AssertionError} (<code>null</code>

     *            okay)

     * @param condition condition to be checked

     */

    public static void assertTrue(String message, boolean condition) {

        assertTrue(condition, message);

    }

    /**

     * Asserts that a condition is true. If it isn't it throws an {@link AssertionError} without a

     * message.

     *

     * @param condition condition to be checked

     */

    public static void assertTrue(boolean condition) {

        assertTrue(condition, null);

    }

    /**

     * Asserts that a condition is false. If it isn't it throws an {@link AssertionError} with the

     * given message.

     *

     * @param message the identifying message for the {@link AssertionError} (<code>null</code>

     *            okay)

     * @param condition condition to be checked

     */

    public static void assertFalse(String message, boolean condition) {

        assertTrue(!condition, message);

    }

    /**

     * Asserts that a condition is false. If it isn't it throws an {@link AssertionError} without a

     * message.

     *

     * @param condition condition to be checked

     */

    public static void assertFalse(boolean condition) {

        assertTrue(!condition, null);

    }

    /**

     * Asserts that a condition is true. If it isn't it throws an {@link AssertionError} with the

     * given message.

     *

     * @param condition condition to be checked

     * @param message the identifying message for the {@link AssertionError}

     * @param objects arguments to the format string

     */

    public static void assertTrue(boolean condition, String message, Object... objects) {

        if (!condition) {

            fail(message, objects);

        }

    }

    /**

     * Asserts that a condition is false. If it isn't it throws an {@link AssertionError} with the

     * given message produced by {@link String#format}.

     *

     * @param condition condition to be checked

     * @param message the identifying message for the {@link AssertionError}

     * @param objects arguments to the format string

     */

    public static void assertFalse(boolean condition, String message, Object... objects) {

        assertTrue(!condition, message, objects);

    }

    /**

     * Gets the {@link DebugHandlersFactory}s available for a {@link DebugContext}.

     */

    protected Collection<DebugHandlersFactory> getDebugHandlersFactories() {

        return Collections.emptyList();

    }

    /**

     * Gets a {@link DebugContext} object corresponding to {@code options}, creating a new one if

     * none currently exists. Debug contexts created by this method will have their

     * {@link DebugDumpHandler}s closed in {@link #afterTest()}.

     */

    protected DebugContext getDebugContext(OptionValues options) {

        return getDebugContext(options, null, null);

    }

    /**

     * Gets a {@link DebugContext} object corresponding to {@code options}, creating a new one if

     * none currently exists. Debug contexts created by this method will have their

     * {@link DebugDumpHandler}s closed in {@link #afterTest()}.

     *

     * @param options currently active options

     * @param id identification of the compilation or {@code null}

     * @param method method to use for a proper description of the context or {@code null}

     * @return configured context for compilation

     */

    protected DebugContext getDebugContext(OptionValues options, String id, ResolvedJavaMethod method) {

        List<DebugContext> cached = cachedDebugs.get();

        if (cached == null) {

            cached = new ArrayList<>();

            cachedDebugs.set(cached);

        }

        for (DebugContext debug : cached) {

            if (debug.getOptions() == options) {

                return debug;

            }

        }

        final DebugContext.Description descr;

        if (method == null) {

            descr = NO_DESCRIPTION;

        } else {

            descr = new DebugContext.Description(method, id == null ? method.getName() : id);

        }

        DebugContext debug = DebugContext.create(options, descr, globalMetrics, DEFAULT_LOG_STREAM, getDebugHandlersFactories());

        cached.add(debug);

        return debug;

    }

    private static final GlobalMetrics globalMetrics = new GlobalMetrics();

    static {

        Runtime.getRuntime().addShutdownHook(new Thread("GlobalMetricsPrinter") {

            @Override

            public void run() {

                // globalMetrics.print(new OptionValues(OptionValues.newOptionMap()));

            }

        });

    }

    private final ThreadLocal<List<DebugContext>> cachedDebugs = new ThreadLocal<>();

    @After

    public void afterTest() {

        List<DebugContext> cached = cachedDebugs.get();

        if (cached != null) {

            for (DebugContext debug : cached) {

                debug.close();

                debug.closeDumpHandlers(true);

            }

        }

    }

    private static final double TIMEOUT_SCALING_FACTOR = Double.parseDouble(System.getProperty("graaltest.timeout.factor", "1.0"));

    /**

     * Creates a {@link TestRule} that applies a given timeout.

     *

     * A test harness can scale {@code length} with a factor specified by the

     * {@code graaltest.timeout.factor} system property.

     */

    public static TestRule createTimeout(long length, TimeUnit timeUnit) {

        Timeout timeout = new Timeout((long) (length * TIMEOUT_SCALING_FACTOR), timeUnit);

        try {

            return new DisableOnDebug(timeout);

        } catch (LinkageError ex) {

            return timeout;

        }

    }

    /**

     * @see #createTimeout

     */

    public static TestRule createTimeoutSeconds(int seconds) {

        return createTimeout(seconds, TimeUnit.SECONDS);

    }

    /**

     * @see #createTimeout

     */

    public static TestRule createTimeoutMillis(long milliseconds) {

        return createTimeout(milliseconds, TimeUnit.MILLISECONDS);

    }

    public static class TemporaryDirectory implements AutoCloseable {

        public final Path path;

        private IOException closeException;