/*
 * Copyright (c) 1999, 2017, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
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 */

package java.lang;

import java.io.PrintStream;
import java.util.Arrays;
import java.util.List;
import java.util.Optional;

class VersionProps {

 private static final String launcher_name =
 "java";

 private static final String java_version =
 "11.0.2";

 private static final String java_version_date =
 "2019-01-15";

 private static final String java_runtime_name =
 "Java(TM) SE Runtime Environment";

 private static final String java_runtime_version =
 "11.0.2+9-LTS";

 private static final String VERSION_NUMBER =
 "11.0.2";

 private static final String VERSION_BUILD =
 "9";

 private static final String VERSION_PRE =
 "";

 private static final String VERSION_OPT =
 "LTS";

 private static final boolean isLTS =
 "LTS".startsWith("LTS");

 private static final String VENDOR_VERSION_STRING =
 "18.9";

 private static final String vendor_version =
 (VENDOR_VERSION_STRING.length() > 0
 ? " " + VENDOR_VERSION_STRING : "");

 static {
 init();
 }

 public static void init() {
 System.setProperty("java.version", java_version);
 System.setProperty("java.version.date", java_version_date);
 System.setProperty("java.runtime.version", java_runtime_version);
 System.setProperty("java.runtime.name", java_runtime_name);
 if (VENDOR_VERSION_STRING.length() > 0)
 System.setProperty("java.vendor.version", VENDOR_VERSION_STRING);
 }

 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) {
 // Let's find the size of an array required to hold $VNUM components
 int size = 0;
 int prevIndex = 0;
 do {
 prevIndex = version.indexOf('.', prevIndex) + 1;
 size++;
 } while (prevIndex > 0);
 Integer[] verNumbers = new Integer[size];

 // Fill in the array with $VNUM components
 int n = 0;
 prevIndex = 0;
 int index = version.indexOf('.');
 while (index > -1) {
 verNumbers[n] = parseVersionNumber(version, prevIndex, index);
 prevIndex = index + 1; // Skip the period
 index = version.indexOf('.', prevIndex);
 n++;
 }
 verNumbers[n] = parseVersionNumber(version, prevIndex, version.length());

 if (verNumbers[0] == 0 || verNumbers[n] == 0)
 throw new IllegalArgumentException("Leading/trailing zeros not allowed (" +
 Arrays.toString(verNumbers) + ")");

 return List.of(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.
 */
 public static void print(boolean err) {
 print(err, false);
 }

 /**
 * 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(boolean err) {
 print(err, true);
 }

 /**
 * Print version info.
 */
 private static void print(boolean err, boolean newln) {
 PrintStream ps = err ? System.err : System.out;

 /* First line: platform version. */
 if (err) {
 ps.println(launcher_name + " version \"" + java_version + "\""
 + " " + java_version_date
 + (isLTS ? " LTS" : ""));
 } else {
 /* Use a format more in line with GNU conventions */
 ps.println(launcher_name + " " + java_version
 + " " + java_version_date
 + (isLTS ? " LTS" : ""));
 }

 /* Second line: runtime version (ie, libraries). */
 String jdk_debug_level = System.getProperty("jdk.debug", "release");
 if ("release".equals(jdk_debug_level)) {
 /* Do not show debug level "release" builds */
 jdk_debug_level = "";
 } else {
 jdk_debug_level = jdk_debug_level + " ";
 }

 ps.println(java_runtime_name + vendor_version
 + " (" + jdk_debug_level + "build " + java_runtime_version + ")");

 /* 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 + vendor_version
 + " (" + jdk_debug_level + "build " + java_vm_version + ", "
 + java_vm_info + ")");

 }

}