/*

 * Copyright (c) 1999, 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.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * 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 java.lang;

import java.io.PrintStream;

import java.util.ArrayList;

import java.util.List;

import java.util.Optional;

class VersionProps {

    private static final String launcher_name =

        "@@LAUNCHER_NAME@@";

    private static final String java_version =

        "@@VERSION_SHORT@@";

    private static final String java_runtime_name =

        "@@RUNTIME_NAME@@";

    private static final String java_runtime_version =

        "@@VERSION_STRING@@";

    private static final String VERSION_NUMBER =

        "@@VERSION_NUMBER@@";

    private static final String VERSION_BUILD =

        "@@VERSION_BUILD@@";

    private static final String VERSION_PRE =

        "@@VERSION_PRE@@";

    private static final String VERSION_OPT =

        "@@VERSION_OPT@@";

    static {

        init();

    }

    public static void init() {

        System.setProperty("java.version", java_version);

        System.setProperty("java.runtime.version", java_runtime_version);

        System.setProperty("java.runtime.name", java_runtime_name);

    }

    private static int parseVersionNumber(String version, int prevIndex, int index) {

        if (index - prevIndex > 1 &&

            Character.digit(version.charAt(prevIndex), 10) <= 0)

            throw new IllegalArgumentException("Leading zeros not supported (" +

                    version.substring(prevIndex, index) + ")");

        return Integer.parseInt(version, prevIndex, index, 10);

    }

    // This method is reflectively used by regression tests.

    static List<Integer> parseVersionNumbers(String version) {

        List<Integer> verNumbers = new ArrayList<>(4);

        int prevIndex = 0;

        int index = version.indexOf('.');

        while (index > 0) {

            verNumbers.add(parseVersionNumber(version, prevIndex, index));

            prevIndex = index + 1; // Skip the period

            index = version.indexOf('.', prevIndex);

        }

        verNumbers.add(parseVersionNumber(version, prevIndex, version.length()));

        if (verNumbers.get(0) == 0 || verNumbers.get(verNumbers.size() - 1) == 0)

            throw new IllegalArgumentException("Leading/trailing zeros not supported (" +

                    verNumbers + ")");

        return verNumbers;

    }

    static List<Integer> versionNumbers() {

        return parseVersionNumbers(VERSION_NUMBER);

    }

    static Optional<String> pre() {

        return optionalOf(VERSION_PRE);

    }

    static Optional<Integer> build() {

        return VERSION_BUILD.isEmpty() ?

                Optional.empty() :

                Optional.of(Integer.parseInt(VERSION_BUILD));

    }

    static Optional<String> optional() {

        return optionalOf(VERSION_OPT);

    }

    // Treat empty strings as value not being present

    private static Optional<String> optionalOf(String value) {

        if (!value.isEmpty()) {

            return Optional.of(value);

        } else {

            return Optional.empty();

        }

    }

    /**

     * In case you were wondering this method is called by java -version.

     * Sad that it prints to stderr; would be nicer if default printed on

     * stdout.

     */

    public static void print() {

        print(System.err);

    }

    /**

     * This is the same as print except that it adds an extra line-feed

     * at the end, typically used by the -showversion in the launcher

     */

    public static void println() {

        print(System.err);

        System.err.println();

    }

    /**

     * Give a stream, it will print version info on it.

     */

    public static void print(PrintStream ps) {

        boolean isHeadless = false;

        /* Report that we're running headless if the property is true */

        String headless = System.getProperty("java.awt.headless");

        if ( (headless != null) && (headless.equalsIgnoreCase("true")) ) {

            isHeadless = true;

        }

        /* First line: platform version. */

        ps.println(launcher_name + " version \"" + java_version + "\"");

        /* Second line: runtime version (ie, libraries). */

        String jdk_debug_level = System.getProperty("jdk.debug", "release");

        /* Debug level is not printed for "release" builds */

        if ("release".equals(jdk_debug_level)) {

            jdk_debug_level = "";

        } else {

            jdk_debug_level = jdk_debug_level + " ";

        }

        ps.print(java_runtime_name + " (" + jdk_debug_level + "build " + java_runtime_version);

        ps.println(')');

        /* Third line: JVM information. */

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

        String java_vm_version = System.getProperty("java.vm.version");

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

        ps.println(java_vm_name + " (" + jdk_debug_level + "build " + java_vm_version + ", " +

                   java_vm_info + ")");

    }

}