/*

 * Copyright (c) 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 requires;

import java.io.IOException;

import java.lang.management.ManagementFactory;

import java.lang.management.RuntimeMXBean;

import java.nio.file.Files;

import java.nio.file.Paths;

import java.util.ArrayList;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

import java.util.concurrent.Callable;

import java.util.regex.Matcher;

import java.util.regex.Pattern;

import sun.hotspot.gc.GC;

/**

 * The Class to be invoked by jtreg prior Test Suite execution to

 * collect information about VM.

 * Properties set by this Class will be available in the @requires expressions.

 */

public class VMProps implements Callable<Map<String, String>> {

    /**

     * Collects information about VM properties.

     * This method will be invoked by jtreg.

     *

     * @return Map of property-value pairs.

     */

    @Override

    public Map<String, String> call() {

        Map<String, String> map = new HashMap<>();

        map.put("vm.flavor", vmFlavor());

        map.put("vm.compMode", vmCompMode());

        map.put("vm.bits", vmBits());

        map.put("vm.flightRecorder", vmFlightRecorder());

        map.put("vm.simpleArch", vmArch());

        vmGC(map); // vm.gc.X = true/false

        dump(map);

        return map;

    }

    /**

     * @return vm.simpleArch value of "os.simpleArch" property of tested JDK.

     */

    protected String vmArch() {

        String arch = System.getProperty("os.arch");

        if (arch.equals("x86_64") || arch.equals("amd64")) {

            return "x64";

        }

        else if (arch.contains("86")) {

            return "x86";

        } else {

            return arch;

        }

    }

    /**

     * @return VM type value extracted from the "java.vm.name" property.

     */

    protected String vmFlavor() {

        // E.g. "Java HotSpot(TM) 64-Bit Server VM"

        String vmName = System.getProperty("java.vm.name");

        if (vmName == null) {

            return null;

        }

        Pattern startP = Pattern.compile(".* (\\S+) VM");

        Matcher m = startP.matcher(vmName);

        if (m.matches()) {

            return m.group(1).toLowerCase();

        }

        return null;

    }

    /**

     * @return VM compilation mode extracted from the "java.vm.info" property.

     */

    protected String vmCompMode() {

        // E.g. "mixed mode"

        String vmInfo = System.getProperty("java.vm.info");

        if (vmInfo == null) {

            return null;

        }

        int k = vmInfo.toLowerCase().indexOf(" mode");

        if (k < 0) {

            return null;

        }

        vmInfo = vmInfo.substring(0, k);

        switch (vmInfo) {

            case "mixed" : return "Xmixed";

            case "compiled" : return "Xcomp";

            case "interpreted" : return "Xint";

            default: return null;

        }

    }

    /**

     * @return VM bitness, the value of the "sun.arch.data.model" property.

     */

    protected String vmBits() {

        return System.getProperty("sun.arch.data.model");

    }

    /**

     * @return "true" if Flight Recorder is enabled, "false" if is disabled.

     */

    protected String vmFlightRecorder() {

        RuntimeMXBean runtimeMxBean = ManagementFactory.getRuntimeMXBean();

        List<String> arguments = runtimeMxBean.getInputArguments();

        if (arguments.contains("-XX:+UnlockCommercialFeatures")) {

            if (arguments.contains("-XX:+FlightRecorder")) {

                return "true";

            }

            if (arguments.contains("-XX:-FlightRecorder")) {

                return "false";

            }

            if (arguments.stream()

                    .anyMatch(option -> option.startsWith("-XX:StartFlightRecording"))) {

                return "true";

            }

        }

        return "false";

    }

    /**

     * For all existing GC sets vm.gc.X property.

     * Example vm.gc.G1=true means:

     *    VM supports G1

     *    User either set G1 explicitely (-XX:+UseG1GC) or did not set any GC

     * @param map - property-value pairs

     */

    protected void vmGC(Map<String, String> map){

        GC currentGC = GC.current();

        boolean isByErgo = GC.currentSetByErgo();

        List<GC> supportedGC = GC.allSupported();

        for (GC gc: GC.values()) {

            boolean isSupported = supportedGC.contains(gc);

            boolean isAcceptable = isSupported && (gc == currentGC || isByErgo);

            map.put("vm.gc." + gc.name(), "" + isAcceptable);

        }

    }

    /**

     * Dumps the map to the file if the file name is given as the property.

     * This functionality could be helpful to know context in the real

     * execution.

     *

     * @param map

     */

    protected void dump(Map<String, String> map) {

        String dumpFileName = System.getProperty("vmprops.dump");

        if (dumpFileName == null) {

            return;

        }

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

        map.forEach((k, v) -> lines.add(k + ":" + v));

        try {

            Files.write(Paths.get(dumpFileName), lines);

        } catch (IOException e) {

            throw new RuntimeException("Failed to dump properties into '"

                    + dumpFileName + "'", e);

        }

    }

    /**

     * This method is for the testing purpose only.

     * @param args

     */

    public static void main(String args[]) {

        Map<String, String> map = new VMProps().call();

        map.forEach((k, v) -> System.out.println(k + ": '" + v + "'"));

    }

}