/*
 * Copyright (c) 2015, 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 optionsvalidation;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.Reader;
import java.lang.management.GarbageCollectorMXBean;
import java.lang.management.ManagementFactory;
import java.math.BigDecimal;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.StringTokenizer;
import java.util.function.Predicate;
import jdk.test.lib.process.OutputAnalyzer;
import jdk.test.lib.Platform;
import jdk.test.lib.process.ProcessTools;

public class JVMOptionsUtils {

    /* Java option which print options with ranges */
    private static final String PRINT_FLAGS_RANGES = "-XX:+PrintFlagsRanges";

    private static final String UNLOCK_FLAG1 = "-XX:+UnlockDiagnosticVMOptions";
    private static final String UNLOCK_FLAG2 = "-XX:+UnlockExperimentalVMOptions";

    /* StringBuilder to accumulate failed message */
    private static final StringBuilder finalFailedMessage = new StringBuilder();

    /* Used to start the JVM with the same type as current */
    static String VMType;

    /* Used to start the JVM with the same GC type as current */
    static String GCType;

    private static Map<String, JVMOption> optionsAsMap;

    static {
        if (Platform.isServer()) {
            VMType = "-server";
        } else if (Platform.isClient()) {
            VMType = "-client";
        } else if (Platform.isMinimal()) {
            VMType = "-minimal";
        } else if (Platform.isGraal()) {
            VMType = "-graal";
        } else {
            VMType = null;
        }

        List<GarbageCollectorMXBean> gcMxBeans = ManagementFactory.getGarbageCollectorMXBeans();

        GCType = null;

        for (GarbageCollectorMXBean gcMxBean : gcMxBeans) {
            switch (gcMxBean.getName()) {
                case "MarkSweepCompact":
                    GCType = "-XX:+UseSerialGC";
                    break;
                case "PS Scavenge":
                    GCType = "-XX:+UseParallelGC";
                    break;
                case "G1 Old Generation":
                    GCType = "-XX:+UseG1GC";
                    break;
            }
        }
    }

    public static boolean fitsRange(String optionName, BigDecimal number) throws Exception {
        JVMOption option;
        String minRangeString = null;
        String maxRangeString = null;
        boolean fits = true;

        if (optionsAsMap == null) {
            optionsAsMap = getOptionsWithRangeAsMap();
        }

        option = optionsAsMap.get(optionName);
        if (option != null) {
            minRangeString = option.getMin();
            if (minRangeString != null) {
                fits = (number.compareTo(new BigDecimal(minRangeString)) >= 0);
            }
            maxRangeString = option.getMax();
            if (maxRangeString != null) {
                fits &= (number.compareTo(new BigDecimal(maxRangeString)) <= 0);
            }
        }

        return fits;
    }

    public static boolean fitsRange(String optionName, String number) throws Exception {
        String lowerCase = number.toLowerCase();
        String multiplier = "1";
        if (lowerCase.endsWith("k")) {
            multiplier = "1024";
            lowerCase = lowerCase.substring(0, lowerCase.length()-1);
        } else if (lowerCase.endsWith("m")) {
            multiplier = "1048576"; //1024*1024
            lowerCase = lowerCase.substring(0, lowerCase.length()-1);
        } else if (lowerCase.endsWith("g")) {
            multiplier = "1073741824"; //1024*1024*1024
            lowerCase = lowerCase.substring(0, lowerCase.length()-1);
        } else if (lowerCase.endsWith("t")) {
            multiplier = "1099511627776"; //1024*1024*1024*1024
            lowerCase = lowerCase.substring(0, lowerCase.length()-1);
        }
        BigDecimal valueBig = new BigDecimal(lowerCase);
        BigDecimal multiplierBig = new BigDecimal(multiplier);
        return fitsRange(optionName, valueBig.multiply(multiplierBig));
    }

    public static String getMinOptionRange(String optionName) throws Exception {
        JVMOption option;
        String minRange = null;

        if (optionsAsMap == null) {
            optionsAsMap = getOptionsWithRangeAsMap();
        }

        option = optionsAsMap.get(optionName);
        if (option != null) {
            minRange = option.getMin();
        }

        return minRange;
    }

    public static String getMaxOptionRange(String optionName) throws Exception {
        JVMOption option;
        String maxRange = null;

        if (optionsAsMap == null) {
            optionsAsMap = getOptionsWithRangeAsMap();
        }

        option = optionsAsMap.get(optionName);
        if (option != null) {
            maxRange = option.getMax();
        }

        return maxRange;
    }

    /**
     * Add dependency for option depending on it's name. E.g. enable G1 GC for
     * G1 options or add prepend options to not hit constraints.
     *
     * @param option option
     */
    private static void addNameDependency(JVMOption option) {
        String name = option.getName();

        if (name.startsWith("G1")) {
            option.addPrepend("-XX:+UseG1GC");
        }

        if (name.startsWith("NUMA")) {
            option.addPrepend("-XX:+UseNUMA");
        }

        switch (name) {
            case "MinHeapFreeRatio":
                option.addPrepend("-XX:MaxHeapFreeRatio=100");
                break;
            case "MaxHeapFreeRatio":
                option.addPrepend("-XX:MinHeapFreeRatio=0");
                break;
            case "MinMetaspaceFreeRatio":
                option.addPrepend("-XX:MaxMetaspaceFreeRatio=100");
                break;
            case "MaxMetaspaceFreeRatio":
                option.addPrepend("-XX:MinMetaspaceFreeRatio=0");
                break;
            case "G1RefProcDrainInterval":
                option.addPrepend("-XX:+ExplicitGCInvokesConcurrent");
                break;
            case "InitialTenuringThreshold":
                option.addPrepend("-XX:MaxTenuringThreshold=" + option.getMax());
                break;
            case "NUMAInterleaveGranularity":
                option.addPrepend("-XX:+UseNUMAInterleaving");
                break;
            case "VerifyGCStartAt":
                option.addPrepend("-XX:+VerifyBeforeGC");
                option.addPrepend("-XX:+VerifyAfterGC");
                break;
            case "NewSizeThreadIncrease":
                option.addPrepend("-XX:+UseSerialGC");
                break;
            case "SharedBaseAddress":
            case "SharedSymbolTableBucketSize":
                option.addPrepend("-XX:+UnlockDiagnosticVMOptions");
                option.addPrepend("-XX:SharedArchiveFile=TestOptionsWithRanges.jsa");
                option.addPrepend("-Xshare:dump");
                break;
            case "TLABWasteIncrement":
                option.addPrepend("-XX:+UseParallelGC");
                break;
            default:
                /* Do nothing */
                break;
        }
    }

    /**
     * Parse JVM Options. Get input from "inputReader". Parse using
     * "-XX:+PrintFlagsRanges" output format.
     *
     * @param inputReader input data for parsing
     * @param withRanges true if needed options with defined ranges inside JVM
     * @param acceptOrigin predicate for option origins. Origins can be
     * "product", "diagnostic" etc. Accept option only if acceptOrigin evaluates
     * to true.
     * @return map from option name to the JVMOption object
     * @throws IOException if an error occurred while reading the data
     */
    private static Map<String, JVMOption> getJVMOptions(Reader inputReader,
            boolean withRanges, Predicate<String> acceptOrigin) throws IOException {
        BufferedReader reader = new BufferedReader(inputReader);
        String type;
        String line;
        String token;
        String name;
        StringTokenizer st;
        JVMOption option;
        Map<String, JVMOption> allOptions = new LinkedHashMap<>();

        // Skip first line
        line = reader.readLine();

        while ((line = reader.readLine()) != null) {
            /*
             * Parse option from following line:
             * <type> <name> [ <min, optional> ... <max, optional> ] {<origin>}
             */
            st = new StringTokenizer(line);

            type = st.nextToken();

            name = st.nextToken();

            option = JVMOption.createVMOption(type, name);

            /* Skip '[' */
            token = st.nextToken();

            /* Read min range or "..." if range is absent */
            token = st.nextToken();

            if (token.equals("...") == false) {
                if (!withRanges) {
                    /*
                     * Option have range, but asked for options without
                     * ranges => skip it
                     */
                    continue;
                }

                /* Mark this option as option which range is defined in VM */
                option.optionWithRange();

                option.setMin(token);

                /* Read "..." and skip it */
                token = st.nextToken();

                /* Get max value */
                token = st.nextToken();
                option.setMax(token);
            } else if (withRanges) {
                /*
                 * Option not have range, but asked for options with
                 * ranges => skip it
                 */
                continue;
            }

            /* Skip ']' */
            token = st.nextToken();

            /* Read origin of the option */
            token = st.nextToken();

            while (st.hasMoreTokens()) {
                token += st.nextToken();
            };
            token = token.substring(1, token.indexOf("}"));

            if (acceptOrigin.test(token)) {
                addNameDependency(option);

                allOptions.put(name, option);
            }
        }

        return allOptions;
    }

    static void failedMessage(String optionName, String value, boolean valid, String message) {
        String temp;

        if (valid) {
            temp = "valid";
        } else {
            temp = "invalid";
        }

        failedMessage(String.format("Error processing option %s with %s value '%s'! %s",
                optionName, temp, value, message));
    }

    static void failedMessage(String message) {
        System.err.println("TEST FAILED: " + message);
        finalFailedMessage.append(String.format("(%s)%n", message));
    }

    static void printOutputContent(OutputAnalyzer output) {
        System.err.println(String.format("stdout content[%s]", output.getStdout()));
        System.err.println(String.format("stderr content[%s]%n", output.getStderr()));
    }

    /**
     * Return string with accumulated failure messages
     *
     * @return string with accumulated failure messages
     */
    public static String getMessageWithFailures() {
        return finalFailedMessage.toString();
    }

    /**
     * Run command line tests for options passed in the list
     *
     * @param options list of options to test
     * @return number of failed tests
     * @throws Exception if java process can not be started
     */
    public static int runCommandLineTests(List<? extends JVMOption> options) throws Exception {
        int failed = 0;

        for (JVMOption option : options) {
            failed += option.testCommandLine();
        }

        return failed;
    }

    /**
     * Test passed options using DynamicVMOption isValidValue and isInvalidValue
     * methods. Only tests writeable options.
     *
     * @param options list of options to test
     * @return number of failed tests
     */
    public static int runDynamicTests(List<? extends JVMOption> options) {
        int failed = 0;

        for (JVMOption option : options) {
            failed += option.testDynamic();
        }

        return failed;
    }

    /**
     * Test passed options using Jcmd. Only tests writeable options.
     *
     * @param options list of options to test
     * @return number of failed tests
     */
    public static int runJcmdTests(List<? extends JVMOption> options) {
        int failed = 0;

        for (JVMOption option : options) {
            failed += option.testJcmd();
        }

        return failed;
    }

    /**
     * Test passed option using attach method. Only tests writeable options.
     *
     * @param options list of options to test
     * @return number of failed tests
     * @throws Exception if an error occurred while attaching to the target JVM
     */
    public static int runAttachTests(List<? extends JVMOption> options) throws Exception {
        int failed = 0;

        for (JVMOption option : options) {
            failed += option.testAttach();
        }

        return failed;
    }

    /**
     * Get JVM options as map. Can return options with defined ranges or options
     * without range depending on "withRanges" argument. "acceptOrigin"
     * predicate can be used to filter option origin.
     *
     * @param withRanges true if needed options with defined ranges inside JVM
     * @param acceptOrigin predicate for option origins. Origins can be
     * "product", "diagnostic" etc. Accept option only if acceptOrigin evaluates
     * to true.
     * @param additionalArgs additional arguments to the Java process which ran
     * with "-XX:+PrintFlagsRanges"
     * @return map from option name to the JVMOption object
     * @throws Exception if a new process can not be created or an error
     * occurred while reading the data
     */
    private static Map<String, JVMOption> getOptionsAsMap(boolean withRanges, Predicate<String> acceptOrigin,
            String... additionalArgs) throws Exception {
        Map<String, JVMOption> result;
        Process p;
        List<String> runJava = new ArrayList<>();

        if (additionalArgs.length > 0) {
            runJava.addAll(Arrays.asList(additionalArgs));
        }

        if (VMType != null) {
            runJava.add(VMType);
        }

        if (GCType != null) {
            runJava.add(GCType);
        }
        runJava.add(UNLOCK_FLAG1);
        runJava.add(UNLOCK_FLAG2);
        runJava.add(PRINT_FLAGS_RANGES);
        runJava.add("-version");

        p = ProcessTools.createJavaProcessBuilder(runJava.toArray(new String[0])).start();

        result = getJVMOptions(new InputStreamReader(p.getInputStream()), withRanges, acceptOrigin);

        p.waitFor();

        return result;
    }

    /**
     * Get JVM options as list. Can return options with defined ranges or
     * options without range depending on "withRanges" argument. "acceptOrigin"
     * predicate can be used to filter option origin.
     *
     * @param withRanges true if needed options with defined ranges inside JVM
     * @param acceptOrigin predicate for option origins. Origins can be
     * "product", "diagnostic" etc. Accept option only if acceptOrigin evaluates
     * to true.
     * @param additionalArgs additional arguments to the Java process which ran
     * with "-XX:+PrintFlagsRanges"
     * @return List of options
     * @throws Exception if a new process can not be created or an error
     * occurred while reading the data
     */
    public static List<JVMOption> getOptions(boolean withRanges, Predicate<String> acceptOrigin,
            String... additionalArgs) throws Exception {
        return new ArrayList<>(getOptionsAsMap(withRanges, acceptOrigin, additionalArgs).values());
    }

    /**
     * Get JVM options with ranges as list. "acceptOrigin" predicate can be used
     * to filter option origin.
     *
     * @param acceptOrigin predicate for option origins. Origins can be
     * "product", "diagnostic" etc. Accept option only if acceptOrigin evaluates
     * to true.
     * @param additionalArgs additional arguments to the Java process which ran
     * with "-XX:+PrintFlagsRanges"
     * @return List of options
     * @throws Exception if a new process can not be created or an error
     * occurred while reading the data
     */
    public static List<JVMOption> getOptionsWithRange(Predicate<String> acceptOrigin, String... additionalArgs) throws Exception {
        return getOptions(true, acceptOrigin, additionalArgs);
    }

    /**
     * Get JVM options with ranges as list.
     *
     * @param additionalArgs additional arguments to the Java process which ran
     * with "-XX:+PrintFlagsRanges"
     * @return list of options
     * @throws Exception if a new process can not be created or an error
     * occurred while reading the data
     */
    public static List<JVMOption> getOptionsWithRange(String... additionalArgs) throws Exception {
        return getOptionsWithRange(origin -> true, additionalArgs);
    }

    /**
     * Get JVM options with range as map. "acceptOrigin" predicate can be used
     * to filter option origin.
     *
     * @param acceptOrigin predicate for option origins. Origins can be
     * "product", "diagnostic" etc. Accept option only if acceptOrigin evaluates
     * to true.
     * @param additionalArgs additional arguments to the Java process which ran
     * with "-XX:+PrintFlagsRanges"
     * @return Map from option name to the JVMOption object
     * @throws Exception if a new process can not be created or an error
     * occurred while reading the data
     */
    public static Map<String, JVMOption> getOptionsWithRangeAsMap(Predicate<String> acceptOrigin, String... additionalArgs) throws Exception {
        return getOptionsAsMap(true, acceptOrigin, additionalArgs);
    }

    /**
     * Get JVM options with range as map
     *
     * @param additionalArgs additional arguments to the Java process which ran
     * with "-XX:+PrintFlagsRanges"
     * @return map from option name to the JVMOption object
     * @throws Exception if a new process can not be created or an error
     * occurred while reading the data
     */
    public static Map<String, JVMOption> getOptionsWithRangeAsMap(String... additionalArgs) throws Exception {
        return getOptionsWithRangeAsMap(origin -> true, additionalArgs);
    }
}