/*

 * Copyright (c) 2013, 2014, 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.java.testlibrary;

import static com.oracle.java.testlibrary.Asserts.assertTrue;

import java.io.BufferedReader;

import java.io.File;

import java.io.FileReader;

import java.io.IOException;

import java.net.InetAddress;

import java.net.ServerSocket;

import java.net.UnknownHostException;

import java.util.ArrayList;

import java.util.List;

import java.util.Arrays;

import java.util.Collections;

import java.util.regex.Pattern;

import java.util.regex.Matcher;

/**

 * Common library for various test helper functions.

 */

public final class Utils {

    /**

     * 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.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);

    }

    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 opptions.

     */

    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]);

    }

    /**

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

     * options that matches regular expresions 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 opptions.

     */

    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()]);

    }

    /**

     * 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]);

    }

    /**

     * 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 Enot 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;

        }

    }

    /**

     * Returns file content as a list of strings

     *

     * @param file File to operate on

     * @return List of strings

     * @throws IOException

     */

    public static List<String> fileAsList(File file) throws IOException {

        assertTrue(file.exists() && file.isFile(),

                file.getAbsolutePath() + " does not exist or not a file");

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

        try (BufferedReader reader = new BufferedReader(new FileReader(file.getAbsolutePath()))) {

            while (reader.ready()) {

                output.add(reader.readLine().replace(NEW_LINE, ""));

            }

        }

        return output;

    }

}