/*
    * Copyright 2012-2021 CodeLibs Project and the Others.
    *
    * Licensed under the Apache License, Version 2.0 (the "License");
    * you may not use this file except in compliance with the License.
    * You may obtain a copy of the License at
    *
    *     http://www.apache.org/licenses/LICENSE-2.0
    *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
   * either express or implied. See the License for the specific language
   * governing permissions and limitations under the License.
   */
  package org.codelibs.fess.util;
  
  import java.util.Arrays;
  import java.util.regex.Matcher;
  import java.util.regex.Pattern;
  
  public final class JvmUtil {
      private static final Pattern VERSION_PREFIX_PATTERN = Pattern.compile("([0-9]+)(\\-?):(.*)");
  
      private JvmUtil() {
          // nothing
      }
  
      public static String[] filterJvmOptions(final String[] values) {
          final int version = getJavaVersion();
          return Arrays.stream(values).map(s -> {
              final Matcher matcher = VERSION_PREFIX_PATTERN.matcher(s);
              if (!matcher.matches()) {
                  return s;
              }
              final int v = Integer.parseInt(matcher.group(1));
              if ("-".equals(matcher.group(2))) {
                  if (version >= v) {
                      return matcher.group(3);
                  }
              } else if (v == version) {
                  return matcher.group(3);
              }
              return null;
          }).filter(s -> s != null).toArray(n -> new String[n]);
      }
  
      public static int getJavaVersion() {
          final String javaVersion = System.getProperty("java.version");
          int version = 8;
          if (javaVersion != null) {
              final String[] split = javaVersion.split("[\\._]");
              if (split.length > 0) {
                  version = Integer.parseInt(split[0]);
                  if (version == 1 && split.length > 1) {
                      version = Integer.parseInt(split[1]);
                  }
              }
          }
          return version;
      }
  }