/*

 * Copyright (c) 2013, 2016, 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 jdk.test.lib;

import java.io.File;

import java.io.IOException;

import java.lang.reflect.Field;

import java.net.InetAddress;

import java.net.MalformedURLException;

import java.net.ServerSocket;

import java.net.URL;

import java.net.URLClassLoader;

import java.net.UnknownHostException;

import java.nio.file.Files;

import java.nio.file.Path;

import java.nio.file.Paths;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.Collection;

import java.util.Collections;

import java.util.Iterator;

import java.util.Map;

import java.util.HashMap;

import java.util.List;

import java.util.Objects;

import java.util.Random;

import java.util.function.BooleanSupplier;

import java.util.concurrent.TimeUnit;

import java.util.function.Consumer;

import java.util.function.Function;

import java.util.regex.Matcher;

import java.util.regex.Pattern;

import jdk.internal.misc.Unsafe;

import static jdk.test.lib.Asserts.assertTrue;

import jdk.test.lib.process.ProcessTools;

import jdk.test.lib.process.OutputAnalyzer;

/**

 * Common library for various test helper functions.

 */

public final class Utils {

    /**

     * Returns the value of 'test.class.path' system property.

     */

    public static final String TEST_CLASS_PATH = System.getProperty("test.class.path", ".");

    /**

     * Returns the sequence used by operating system to separate lines.

     */

    public static final String NEW_LINE = System.getProperty("line.separator");

    /**

     * Returns the value of 'test.vm.opts' system property.

     */

    public static final String VM_OPTIONS = System.getProperty("test.vm.opts", "").trim();

    /**

     * Returns the value of 'test.java.opts' system property.

     */

    public static final String JAVA_OPTIONS = System.getProperty("test.java.opts", "").trim();

    /**

     * Returns the value of 'test.src' system property.

     */

    public static final String TEST_SRC = System.getProperty("test.src", "").trim();

    private static Unsafe unsafe = null;

    /**

     * Defines property name for seed value.

     */

    public static final String SEED_PROPERTY_NAME = "jdk.test.lib.random.seed";

    /* (non-javadoc)

     * Random generator with (or without) predefined seed. Depends on

     * "jdk.test.lib.random.seed" property value.

     */

    private static volatile Random RANDOM_GENERATOR;

    /**

     * Contains the seed value used for {@link java.util.Random} creation.

     */

    public static final long SEED = Long.getLong(SEED_PROPERTY_NAME, new Random().nextLong());

    /**

    * Returns the value of 'test.timeout.factor' system property

    * converted to {@code double}.

    */

    public static final double TIMEOUT_FACTOR;

    static {

        String toFactor = System.getProperty("test.timeout.factor", "1.0");

        TIMEOUT_FACTOR = Double.parseDouble(toFactor);

    }

    /**

    * Returns the value of JTREG default test timeout in milliseconds

    * converted to {@code long}.

    */

    public static final long DEFAULT_TEST_TIMEOUT = TimeUnit.SECONDS.toMillis(120);

    private Utils() {

        // Private constructor to prevent class instantiation

    }

    /**

     * Returns the list of VM options.

     *

     * @return List of VM options

     */

    public static List<String> getVmOptions() {

        return Arrays.asList(safeSplitString(VM_OPTIONS));

    }

    /**

     * Returns the list of VM options with -J prefix.

     *

     * @return The list of VM options with -J prefix

     */

    public static List<String> getForwardVmOptions() {

        String[] opts = safeSplitString(VM_OPTIONS);

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

            opts[i] = "-J" + opts[i];

        }

        return Arrays.asList(opts);

    }

    /**

     * Returns the default JTReg arguments for a jvm running a test.

     * This is the combination of JTReg arguments test.vm.opts and test.java.opts.

     * @return An array of options, or an empty array if no options.

     */

    public static String[] getTestJavaOpts() {

        List<String> opts = new ArrayList<String>();

        Collections.addAll(opts, safeSplitString(VM_OPTIONS));

        Collections.addAll(opts, safeSplitString(JAVA_OPTIONS));

        return opts.toArray(new String[0]);

    }

    /**

     * Combines given arguments with default JTReg arguments for a jvm running a test.

     * This is the combination of JTReg arguments test.vm.opts and test.java.opts

     * @return The combination of JTReg test java options and user args.

     */

    public static String[] addTestJavaOpts(String... userArgs) {

        List<String> opts = new ArrayList<String>();

        Collections.addAll(opts, getTestJavaOpts());

        Collections.addAll(opts, userArgs);

        return opts.toArray(new String[0]);

    }

    /**

     * Removes any options specifying which GC to use, for example "-XX:+UseG1GC".

     * Removes any options matching: -XX:(+/-)Use*GC

     * Used when a test need to set its own GC version. Then any

     * GC specified by the framework must first be removed.

     * @return A copy of given opts with all GC options removed.

     */

    private static final Pattern useGcPattern = Pattern.compile(

            "(?:\\-XX\\:[\\+\\-]Use.+GC)"

            + "|(?:\\-Xconcgc)");

    public static List<String> removeGcOpts(List<String> opts) {

        List<String> optsWithoutGC = new ArrayList<String>();

        for (String opt : opts) {

            if (useGcPattern.matcher(opt).matches()) {

                System.out.println("removeGcOpts: removed " + opt);

            } else {

                optsWithoutGC.add(opt);

            }

        }

        return optsWithoutGC;

    }

    /**

     * Returns the default JTReg arguments for a jvm running a test without

     * options that matches regular expressions in {@code filters}.

     * This is the combination of JTReg arguments test.vm.opts and test.java.opts.

     * @param filters Regular expressions used to filter out options.

     * @return An array of options, or an empty array if no options.

     */

    public static String[] getFilteredTestJavaOpts(String... filters) {

        String options[] = getTestJavaOpts();

        if (filters.length == 0) {

            return options;

        }

        List<String> filteredOptions = new ArrayList<String>(options.length);

        Pattern patterns[] = new Pattern[filters.length];

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

            patterns[i] = Pattern.compile(filters[i]);

        }

        for (String option : options) {

            boolean matched = false;

            for (int i = 0; i < patterns.length && !matched; i++) {

                Matcher matcher = patterns[i].matcher(option);

                matched = matcher.find();

            }

            if (!matched) {

                filteredOptions.add(option);

            }

        }

        return filteredOptions.toArray(new String[filteredOptions.size()]);

    }

    /**

     * Splits a string by white space.

     * Works like String.split(), but returns an empty array

     * if the string is null or empty.

     */

    private static String[] safeSplitString(String s) {

        if (s == null || s.trim().isEmpty()) {

            return new String[] {};

        }

        return s.trim().split("\\s+");

    }

    /**

     * @return The full command line for the ProcessBuilder.

     */

    public static String getCommandLine(ProcessBuilder pb) {

        StringBuilder cmd = new StringBuilder();

        for (String s : pb.command()) {

            cmd.append(s).append(" ");

        }

        return cmd.toString();

    }

    /**

     * Returns the free port on the local host.

     * The function will spin until a valid port number is found.

     *

     * @return The port number

     * @throws InterruptedException if any thread has interrupted the current thread

     * @throws IOException if an I/O error occurs when opening the socket

     */

    public static int getFreePort() throws InterruptedException, IOException {

        int port = -1;

        while (port <= 0) {

            Thread.sleep(100);

            ServerSocket serverSocket = null;

            try {

                serverSocket = new ServerSocket(0);

                port = serverSocket.getLocalPort();

            } finally {

                serverSocket.close();

            }

        }

        return port;

    }

    /**

     * Returns the name of the local host.

     *

     * @return The host name

     * @throws UnknownHostException if IP address of a host could not be determined

     */

    public static String getHostname() throws UnknownHostException {

        InetAddress inetAddress = InetAddress.getLocalHost();

        String hostName = inetAddress.getHostName();

        assertTrue((hostName != null && !hostName.isEmpty()),

                "Cannot get hostname");

        return hostName;

    }

    /**

     * Uses "jcmd -l" to search for a jvm pid. This function will wait

     * forever (until jtreg timeout) for the pid to be found.

     * @param key Regular expression to search for

     * @return The found pid.

     */

    public static int waitForJvmPid(String key) throws Throwable {

        final long iterationSleepMillis = 250;

        System.out.println("waitForJvmPid: Waiting for key '" + key + "'");

        System.out.flush();

        while (true) {

            int pid = tryFindJvmPid(key);

            if (pid >= 0) {

                return pid;

            }

            Thread.sleep(iterationSleepMillis);

        }

    }

    /**

     * Searches for a jvm pid in the output from "jcmd -l".

     *

     * Example output from jcmd is:

     * 12498 sun.tools.jcmd.JCmd -l

     * 12254 /tmp/jdk8/tl/jdk/JTwork/classes/com/sun/tools/attach/Application.jar

     *

     * @param key A regular expression to search for.

     * @return The found pid, or -1 if not found.

     * @throws Exception If multiple matching jvms are found.

     */

    public static int tryFindJvmPid(String key) throws Throwable {

        OutputAnalyzer output = null;

        try {

            JDKToolLauncher jcmdLauncher = JDKToolLauncher.create("jcmd");

            jcmdLauncher.addToolArg("-l");

            output = ProcessTools.executeProcess(jcmdLauncher.getCommand());

            output.shouldHaveExitValue(0);

            // Search for a line starting with numbers (pid), follwed by the key.

            Pattern pattern = Pattern.compile("([0-9]+)\\s.*(" + key + ").*\\r?\\n");

            Matcher matcher = pattern.matcher(output.getStdout());

            int pid = -1;

            if (matcher.find()) {

                pid = Integer.parseInt(matcher.group(1));

                System.out.println("findJvmPid.pid: " + pid);

                if (matcher.find()) {

                    throw new Exception("Found multiple JVM pids for key: " + key);

                }

            }

            return pid;

        } catch (Throwable t) {

            System.out.println(String.format("Utils.findJvmPid(%s) failed: %s", key, t));

            throw t;

        }

    }

    /**

     * Adjusts the provided timeout value for the TIMEOUT_FACTOR

     * @param tOut the timeout value to be adjusted

     * @return The timeout value adjusted for the value of "test.timeout.factor"

     *         system property

     */

    public static long adjustTimeout(long tOut) {

        return Math.round(tOut * Utils.TIMEOUT_FACTOR);

    }

    /**

     * Return the contents of the named file as a single String,

     * or null if not found.

     * @param filename name of the file to read

     * @return String contents of file, or null if file not found.

     * @throws  IOException

     *          if an I/O error occurs reading from the file or a malformed or

     *          unmappable byte sequence is read

     */

    public static String fileAsString(String filename) throws IOException {

        Path filePath = Paths.get(filename);

        if (!Files.exists(filePath)) return null;

        return new String(Files.readAllBytes(filePath));

    }

    /**

     * @return Unsafe instance.

     */

    public static synchronized Unsafe getUnsafe() {

        if (unsafe == null) {

            try {

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

                f.setAccessible(true);

                unsafe = (Unsafe) f.get(null);

            } catch (NoSuchFieldException | IllegalAccessException e) {

                throw new RuntimeException("Unable to get Unsafe instance.", e);

            }

        }

        return unsafe;

    }

    private static final char[] hexArray = new char[]{'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'};

    /**

     * Returns hex view of byte array

     *

     * @param bytes byte array to process

     * @return Space separated hexadecimal string representation of bytes

     */

    public static String toHexString(byte[] bytes) {

        char[] hexView = new char[bytes.length * 3];

        int i = 0;

        for (byte b : bytes) {

            hexView[i++] = hexArray[(b >> 4) & 0x0F];

            hexView[i++] = hexArray[b & 0x0F];

            hexView[i++] = ' ';

        }

        return new String(hexView);

    }

    /**

     * Returns {@link java.util.Random} generator initialized with particular seed.

     * The seed could be provided via system property {@link Utils#SEED_PROPERTY_NAME}

     * In case no seed is provided, the method uses a random number.

     * The used seed printed to stdout.

     * @return {@link java.util.Random} generator with particular seed.

     */

    public static Random getRandomInstance() {

        if (RANDOM_GENERATOR == null) {

            synchronized (Utils.class) {

                if (RANDOM_GENERATOR == null) {

                    RANDOM_GENERATOR = new Random(SEED);

                    System.out.printf("For random generator using seed: %d%n", SEED);

                    System.out.printf("To re-run test with same seed value please add \"-D%s=%d\" to command line.%n", SEED_PROPERTY_NAME, SEED);

                }

            }

        }

        return RANDOM_GENERATOR;

    }

    /**

     * Returns random element of non empty collection

     *

     * @param <T> a type of collection element

     * @param collection collection of elements

     * @return random element of collection

     * @throws IllegalArgumentException if collection is empty

     */

    public static <T> T getRandomElement(Collection<T> collection)

            throws IllegalArgumentException {

        if (collection.isEmpty()) {

            throw new IllegalArgumentException("Empty collection");

        }

        Random random = getRandomInstance();

        int elementIndex = 1 + random.nextInt(collection.size() - 1);

        Iterator<T> iterator = collection.iterator();

        while (--elementIndex != 0) {

            iterator.next();

        }

        return iterator.next();

    }

    /**

     * Returns random element of non empty array

     *

     * @param <T> a type of array element

     * @param array array of elements

     * @return random element of array

     * @throws IllegalArgumentException if array is empty

     */

    public static <T> T getRandomElement(T[] array)

            throws IllegalArgumentException {

        if (array == null || array.length == 0) {

            throw new IllegalArgumentException("Empty or null array");

        }

        Random random = getRandomInstance();

        return array[random.nextInt(array.length)];

    }

    /**

     * Wait for condition to be true

     *

     * @param condition, a condition to wait for

     */

    public static final void waitForCondition(BooleanSupplier condition) {

        waitForCondition(condition, -1L, 100L);

    }

    /**

     * Wait until timeout for condition to be true

     *

     * @param condition, a condition to wait for

     * @param timeout a time in milliseconds to wait for condition to be true

     * specifying -1 will wait forever

     * @return condition value, to determine if wait was successful

     */

    public static final boolean waitForCondition(BooleanSupplier condition,

            long timeout) {

        return waitForCondition(condition, timeout, 100L);

    }

    /**

     * Wait until timeout for condition to be true for specified time

     *

     * @param condition, a condition to wait for

     * @param timeout a time in milliseconds to wait for condition to be true,

     * specifying -1 will wait forever

     * @param sleepTime a time to sleep value in milliseconds

     * @return condition value, to determine if wait was successful

     */

    public static final boolean waitForCondition(BooleanSupplier condition,

            long timeout, long sleepTime) {

        long startTime = System.currentTimeMillis();

        while (!(condition.getAsBoolean() || (timeout != -1L

                && ((System.currentTimeMillis() - startTime) > timeout)))) {

            try {

                Thread.sleep(sleepTime);

            } catch (InterruptedException e) {

                Thread.currentThread().interrupt();

                throw new Error(e);

            }

        }

        return condition.getAsBoolean();

    }