/*

 * Copyright (c) 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.

 */

import static jdk.testlibrary.Asserts.assertGreaterThan;

import static jdk.testlibrary.Asserts.assertTrue;

import java.io.BufferedWriter;

import java.io.File;

import java.io.FileWriter;

import java.io.IOException;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.List;

import jdk.testlibrary.Asserts;

import jdk.testlibrary.JDKToolLauncher;

import jdk.testlibrary.OutputAnalyzer;

import jdk.testlibrary.Utils;

/**

 * The helper class for running jps utility and verifying output from it

 */

public final class JpsHelper {

    /**

     * Helper class for handling jps arguments

     */

    public enum JpsArg {

        q,

        l,

        m,

        v,

        V;

        /**

         * Generate all possible combinations of {@link JpsArg}

         * (31 argument combinations and no arguments case)

         */

        public static List<List<JpsArg>> generateCombinations() {

            final int argCount = JpsArg.values().length;

            // If there are more than 30 args this algorithm will overflow.

            Asserts.assertLessThan(argCount, 31, "Too many args");

            List<List<JpsArg>> combinations = new ArrayList<>();

            int combinationCount = (int) Math.pow(2, argCount);

            for (int currCombo = 0; currCombo < combinationCount; ++currCombo) {

                List<JpsArg> combination = new ArrayList<>();

                for (int position = 0; position < argCount; ++position) {

                    int bit = 1 << position;

                    if ((bit & currCombo) != 0) {

                        combination.add(JpsArg.values()[position]);

                    }

                }

                combinations.add(combination);

            }

            return combinations;

        }

        /**

         *  Return combination of {@link JpsArg} as a String array

         */

        public static String[] asCmdArray(List<JpsArg> jpsArgs) {

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

            for (JpsArg jpsArg : jpsArgs) {

                list.add("-" + jpsArg.toString());

            }

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

        }

    }

    /**

     * VM arguments to start test application with

     */

    public static final String[] VM_ARGS = {"-Xmx512m", "-XX:+UseParallelGC"};

    /**

     * VM flag to start test application with

     */

    public static final String VM_FLAG = "+DisableExplicitGC";

    private static File vmFlagsFile = null;

    private static List<String> testVmArgs = null;

    private static File manifestFile = null;

    /**

     * Create a file containing VM_FLAG in the working directory

     */

    public static File getVmFlagsFile() throws IOException {

        if (vmFlagsFile == null) {

            vmFlagsFile = new File("vmflags");

            try (BufferedWriter output = new BufferedWriter(new FileWriter(vmFlagsFile))) {

                output.write(VM_FLAG);

            }

            vmFlagsFile.deleteOnExit();

        }

        return vmFlagsFile;

    }

    /**

     * Return a list of VM arguments

     */

    public static List<String> getVmArgs() throws IOException {

        if (testVmArgs == null) {

            testVmArgs = new ArrayList<>();

            testVmArgs.addAll(Arrays.asList(VM_ARGS));

            testVmArgs.add("-XX:Flags=" + getVmFlagsFile().getAbsolutePath());

        }

        return testVmArgs;

    }

    /**

     * Start jps utility without any arguments

     */

    public static OutputAnalyzer jps() throws Exception {

        return jps(null, null);

    }

    /**

     * Start jps utility with tool arguments

     */

    public static OutputAnalyzer jps(String... toolArgs) throws Exception {

        return jps(null, Arrays.asList(toolArgs));

    }

    /**

     * Start jps utility with VM args and tool arguments

     */

    public static OutputAnalyzer jps(List<String> vmArgs, List<String> toolArgs) throws Exception {

        JDKToolLauncher launcher = JDKToolLauncher.createUsingTestJDK("jps");

        if (vmArgs != null) {

            for (String vmArg : vmArgs) {

                launcher.addVMArg(vmArg);

            }

        }

        if (toolArgs != null) {

            for (String toolArg : toolArgs) {

                launcher.addToolArg(toolArg);

            }

        }

        ProcessBuilder processBuilder = new ProcessBuilder(launcher.getCommand());

        System.out.println(Arrays.toString(processBuilder.command().toArray()).replace(",", ""));

        OutputAnalyzer output = new OutputAnalyzer(processBuilder.start());

        System.out.println(output.getOutput());

        return output;

    }

    /**

     * Verify jps output contains pids and programs' name information.

     * The function will discard any lines that come before the first line with pid.

     * This can happen if the JVM outputs a warning message for some reason

     * before running jps.

     *

     * The output can look like:

     * 35536 Jps

     * 35417 Main

     * 31103 org.eclipse.equinox.launcher_1.3.0.v20120522-1813.jar

     */

    public static void verifyJpsOutput(OutputAnalyzer output, String regex) throws Exception {

        output.shouldHaveExitValue(0);

        int matchedCount = output.shouldMatchByLineFrom(regex, regex);

        assertGreaterThan(matchedCount , 0, "Found no lines matching pattern: " + regex);

    }

    /**

     * Compare jps output with a content in a file line by line

     */

    public static void verifyOutputAgainstFile(OutputAnalyzer output) throws IOException {

        String testSrc = System.getProperty("test.src", "?");

        File file = new File(testSrc, "usage.out");

        List<String> fileOutput = Utils.fileAsList(file);

        List<String> outputAsLines = output.asLines();

        assertTrue(outputAsLines.containsAll(fileOutput),

                "The ouput should contain all content of " + file.getAbsolutePath());

    }

    private static File getManifest(String className) throws IOException {

        if (manifestFile == null) {

            manifestFile = new File(className + ".mf");

            try (BufferedWriter output = new BufferedWriter(new FileWriter(manifestFile))) {

                output.write("Main-Class: " + className + Utils.NEW_LINE);

            }

        }

        return manifestFile;

    }

    /**

     * Build a jar of test classes in runtime

     */

    public static File buildJar(String className) throws Exception {

        File jar = new File(className + ".jar");

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

        jarArgs.add("-cfm");

        jarArgs.add(jar.getAbsolutePath());

        File manifestFile = getManifest(className);

        jarArgs.add(manifestFile.getAbsolutePath());

        String testClassPath = System.getProperty("test.class.path", "?");

        for (String path : testClassPath.split(File.pathSeparator)) {

            jarArgs.add("-C");

            jarArgs.add(path);

            jarArgs.add(".");

        }

        System.out.println("Running jar " + jarArgs.toString());

        sun.tools.jar.Main jarTool = new sun.tools.jar.Main(System.out, System.err, "jar");

        if (!jarTool.run(jarArgs.toArray(new String[jarArgs.size()]))) {

            throw new Exception("jar failed: args=" + jarArgs.toString());

        }

        manifestFile.delete();

        jar.deleteOnExit();

        return jar;

    }

}