/*
    * This file is part of Waarp Project (named also Waarp or GG).
    *
    *  Copyright (c) 2019, Waarp SAS, and individual contributors by the @author
    *  tags. See the COPYRIGHT.txt in the distribution for a full listing of
    * individual contributors.
    *
    *  All Waarp Project is free software: you can redistribute it and/or
    * modify it under the terms of the GNU General Public License as published by
   * the Free Software Foundation, either version 3 of the License, or (at your
   * option) any later version.
   *
   * Waarp 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 for more details.
   *
   *  You should have received a copy of the GNU General Public License along with
   * Waarp . If not, see <http://www.gnu.org/licenses/>.
   */
  package org.waarp.common.utility;
  
  import org.waarp.common.exception.InvalidArgumentException;
  import org.waarp.common.logging.SysErrLogger;
  
  import java.io.PrintStream;
  import java.lang.reflect.Field;
  import java.nio.charset.Charset;
  import java.util.Properties;
  
  import static org.waarp.common.digest.WaarpBC.*;
  
  /**
   * A collection of utility methods to retrieve and parse the values of the Java
   * system properties.
   */
  public final class SystemPropertyUtil {
    // Since logger could be not available yet, one must not declare there a Logger
  
    private static final String USING_THE_DEFAULT_VALUE2 =
        "using the default value: ";
    private static final String FIND_0_9 = "-?[0-9]+";
    private static final String USING_THE_DEFAULT_VALUE =
        USING_THE_DEFAULT_VALUE2;
    public static final String FILE_ENCODING = "file.encoding";
    /**
     * Maximum Connections to the Database. Waarp will manage by default up
     * to 10 connections, except if this is set. The minimum value is 2.
     */
    public static final String WAARP_DATABASE_CONNECTION_MAX =
        "waarp.database.connection.max";
    private static final String IO_NETTY_ALLOCATOR_TYPE =
        "io.netty.allocator.type";
    private static final String IO_POOLED = "pooled";
    private static final String IO_NETTY_NOPREFERDIRECT =
        "io.netty.noPreferDirect";
    /**
     * Recommended value is 0. Giving too small valud (>0) coud cause issues.
     * Value of -1 is default behavior of Netty.
     * Value of 0 allows Netty to allocate more memory but still
     * stable.
     * If <0, means Netty use twice Direct memory from JDK and don't use cleaner.
     * If 0, means Netty use the max JDK Direct ram and use Cleaner (recommended).
     * If >0, means Netty use this max Direct, not related to max of JDK, and
     * don't use cleaner.
     */
    private static final String IO_NETTY_MAXDIRECTMEMORY =
        "io.netty.maxDirectMemory";
  
    private static final Properties PROPS = new Properties();
    private static final String INVALID_PROPERTY = "Invalid property ";
    public static final String JAVAX_XML_TRANSFORM_TRANSFORMER_FACTORY =
        "javax.xml.transform.TransformerFactory";
    public static final String NET_SF_SAXON_TRANSFORMER_FACTORY_IMPL =
        "net.sf.saxon.TransformerFactoryImpl";
    private static Platform mOs;
  
    // Retrieve all system properties at once so that there's no need to deal with
    // security exceptions from next time. Otherwise, we might end up with logging every
    // security exceptions on every system property access or introducing more complexity
    // just because of less verbose logging.
    static {
      refresh();
      initializedTlsContext();
    }
  
    /**
     * Re-retrieves all system properties so that any post-launch properties
     * updates are retrieved.
     */
    public static void refresh() {
      Properties newProps;
      try {
        newProps = System.getProperties();
      } catch (final SecurityException e) {
        SysErrLogger.FAKE_LOGGER.ignoreLog(e);
        SysErrLogger.FAKE_LOGGER.syserr(
            "Unable to retrieve the system properties; default values will be used: " +
            e.getMessage());
        newProps = new Properties();
     }
 
     synchronized (PROPS) {
       PROPS.clear();
       PROPS.putAll(newProps);
     }
     // Ensure Pooled allocator except if something different set
     if (!contains(IO_NETTY_ALLOCATOR_TYPE) ||
         ParametersChecker.isEmpty(get(IO_NETTY_ALLOCATOR_TYPE))) {
       try {
         System.setProperty(IO_NETTY_ALLOCATOR_TYPE, IO_POOLED);
         synchronized (PROPS) {
           PROPS.clear();
           PROPS.putAll(newProps);
         }
         SysErrLogger.FAKE_LOGGER.sysout(IO_NETTY_ALLOCATOR_TYPE + ":" +
                                         io.netty.util.internal.SystemPropertyUtil.get(
                                             IO_NETTY_ALLOCATOR_TYPE));
       } catch (final Throwable ignored) {//NOSONAR
         SysErrLogger.FAKE_LOGGER.ignoreLog(ignored);
       }
     }
     // Ensure minimize DIRECT except if something different set
     if (!contains(IO_NETTY_NOPREFERDIRECT) ||
         ParametersChecker.isEmpty(get(IO_NETTY_NOPREFERDIRECT))) {
       try {
         System.setProperty(IO_NETTY_NOPREFERDIRECT, "true");
         synchronized (PROPS) {
           PROPS.clear();
           PROPS.putAll(newProps);
         }
         SysErrLogger.FAKE_LOGGER.sysout(IO_NETTY_NOPREFERDIRECT + ":" +
                                         io.netty.util.internal.SystemPropertyUtil.get(
                                             IO_NETTY_NOPREFERDIRECT));
       } catch (final Throwable ignored) {//NOSONAR
         SysErrLogger.FAKE_LOGGER.ignoreLog(ignored);
       }
     }
     // Ensure minimize Direct except if something different set
     if (!contains(IO_NETTY_MAXDIRECTMEMORY) ||
         ParametersChecker.isEmpty(get(IO_NETTY_MAXDIRECTMEMORY))) {
       try {
         System.setProperty(IO_NETTY_MAXDIRECTMEMORY, "0");
         synchronized (PROPS) {
           PROPS.clear();
           PROPS.putAll(newProps);
         }
         SysErrLogger.FAKE_LOGGER.sysout(IO_NETTY_MAXDIRECTMEMORY + ":" +
                                         io.netty.util.internal.SystemPropertyUtil.get(
                                             IO_NETTY_MAXDIRECTMEMORY));
       } catch (final Throwable ignored) {//NOSONAR
         SysErrLogger.FAKE_LOGGER.ignoreLog(ignored);
       }
     }
     if (!contains(JAVAX_XML_TRANSFORM_TRANSFORMER_FACTORY) ||
         ParametersChecker.isEmpty(
             get(JAVAX_XML_TRANSFORM_TRANSFORMER_FACTORY))) {
       try {
         System.setProperty(JAVAX_XML_TRANSFORM_TRANSFORMER_FACTORY,
                            NET_SF_SAXON_TRANSFORMER_FACTORY_IMPL);
         synchronized (PROPS) {
           PROPS.clear();
           PROPS.putAll(newProps);
         }
       } catch (final Throwable ignored) {//NOSONAR
         SysErrLogger.FAKE_LOGGER.ignoreLog(ignored);
       }
     }
     if (!contains(FILE_ENCODING) ||
         !WaarpStringUtils.UTF_8.equalsIgnoreCase(get(FILE_ENCODING))) {
       try {
         System.setProperty(FILE_ENCODING, WaarpStringUtils.UTF_8);
         try {
           final Field charset =
               Charset.class.getDeclaredField("defaultCharset");
           charset.setAccessible(true); //NOSONAR
           charset.set(null, null); //NOSONAR
         } catch (final Throwable e) {//NOSONAR
           SysErrLogger.FAKE_LOGGER.ignoreLog(e);
         }
         synchronized (PROPS) {
           PROPS.clear();
           PROPS.putAll(newProps);
         }
       } catch (final Throwable e1) {//NOSONAR
         // ignore since it is a security issue and -Dfile.encoding=UTF-8 should be used
         SysErrLogger.FAKE_LOGGER.ignoreLog(e1);
         SysErrLogger.FAKE_LOGGER.syserr(
             "Issue while trying to set UTF-8 as default file encoding: use -Dfile.encoding=UTF-8 as java command argument: " +
             e1.getMessage());
         SysErrLogger.FAKE_LOGGER.syserr(
             "Currently file.encoding is: " + get(FILE_ENCODING));
       }
     }
   }
 
   /**
    * @return True if Encoding is Correct
    */
   public static boolean isFileEncodingCorrect() {
     return contains(FILE_ENCODING) &&
            WaarpStringUtils.UTF_8.equalsIgnoreCase(get(FILE_ENCODING));
   }
 
   /**
    * Returns {@code true} if and only if the system property with the
    * specified
    * {@code key} exists.
    */
   public static boolean contains(final String key) {
     ParametersChecker.checkParameter("Key", key);
     return PROPS.containsKey(key);
   }
 
   /**
    * Returns the value of the Java system property with the specified {@code
    * key}, while falling back to
    * {@code null} if the property access fails.
    *
    * @return the property value or {@code null}
    */
   public static String get(final String key) {
     return get(key, null);
   }
 
   /**
    * Returns the value of the Java system property with the specified {@code
    * key}, while falling back to the specified
    * default value if the property access fails.
    *
    * @param key of system property
    * @param def the default value
    *
    * @return the property value. {@code def} if there's no such property or if
    *     an access to the specified property is
    *     not allowed.
    *
    * @throws IllegalArgumentException key null
    */
   public static String get(final String key, final String def) {
     ParametersChecker.checkParameter("Key", key);
     String value = PROPS.getProperty(key);
     if (value == null) {
       return def;
     }
 
     try {
       value = ParametersChecker.checkSanityString(value);
     } catch (final InvalidArgumentException e) {
       SysErrLogger.FAKE_LOGGER.syserr(INVALID_PROPERTY + key, e);
       return def;
     }
 
     return value;
   }
 
   /**
    * Returns the value of the Java system property with the specified {@code
    * key}, while falling back to the specified
    * default value if the property access fails.
    *
    * @param key of system property
    * @param def the default value
    *
    * @return the property value. {@code def} if there's no such property or if
    *     an access to the specified property is
    *     not allowed.
    *
    * @throws IllegalArgumentException key null
    */
   public static boolean get(final String key, final boolean def) {
     ParametersChecker.checkParameter("Key", key);
     String value = PROPS.getProperty(key);
     if (value == null) {
       return def;
     }
 
     value = value.trim().toLowerCase();
     if (value.isEmpty()) {
       return true;
     }
 
     if ("true".equals(value) || "yes".equals(value) || "1".equals(value)) {
       return true;
     }
 
     if ("false".equals(value) || "no".equals(value) || "0".equals(value)) {
       return false;
     }
     try {
       ParametersChecker.checkSanityString(value);
     } catch (final InvalidArgumentException e) {
       SysErrLogger.FAKE_LOGGER.syserr(INVALID_PROPERTY + key, e);
       return def;
     }
     SysErrLogger.FAKE_LOGGER.syserr(
         "Unable to parse the boolean system property '" + key + "':" + value +
         " - " + USING_THE_DEFAULT_VALUE + def);
 
     return def;
   }
 
   /**
    * Returns the value of the Java system property with the specified {@code
    * key}, while falling back to the specified
    * default value if the property access fails.
    *
    * @param key the system property
    * @param def the default value
    *
    * @return the property value. {@code def} if there's no such property or if
    *     an access to the specified property is
    *     not allowed.
    *
    * @throws IllegalArgumentException key null
    */
   public static int get(final String key, final int def) {
     ParametersChecker.checkParameter("Key", key);
     String value = PROPS.getProperty(key);
     if (value == null) {
       return def;
     }
 
     value = value.trim().toLowerCase();
     if (value.matches(FIND_0_9)) {
       try {
         return Integer.parseInt(value);
       } catch (final Exception ignored) {
         // Since logger could be not available yet
         // Ignore
         SysErrLogger.FAKE_LOGGER.ignoreLog(ignored);
       }
     }
     try {
       ParametersChecker.checkSanityString(value);
     } catch (final InvalidArgumentException e) {
       SysErrLogger.FAKE_LOGGER.syserr(INVALID_PROPERTY + key, e);
       return def;
     }
     SysErrLogger.FAKE_LOGGER.syserr(
         "Unable to parse the integer system property '" + key + "':" + value +
         " - " + USING_THE_DEFAULT_VALUE + def);
 
     return def;
   }
 
   /**
    * Returns the value of the Java system property with the specified {@code
    * key}, while falling back to the specified
    * default value if the property access fails.
    *
    * @param key of system property
    * @param def the default value
    *
    * @return the property value. {@code def} if there's no such property or if
    *     an access to the specified property is
    *     not allowed.
    *
    * @throws IllegalArgumentException key null
    */
   public static long get(final String key, final long def) {
     ParametersChecker.checkParameter("Key", key);
     String value = PROPS.getProperty(key);
     if (value == null) {
       return def;
     }
 
     value = value.trim().toLowerCase();
     if (value.matches(FIND_0_9)) {
       try {
         return Long.parseLong(value);
       } catch (final Exception ignored) {
         // Since logger could be not available yet
         // Ignore
         SysErrLogger.FAKE_LOGGER.ignoreLog(ignored);
       }
     }
     try {
       ParametersChecker.checkSanityString(value);
     } catch (final InvalidArgumentException e) {
       SysErrLogger.FAKE_LOGGER.syserr(INVALID_PROPERTY + key, e);
       return def;
     }
 
     SysErrLogger.FAKE_LOGGER.syserr(
         "Unable to parse the long integer system property '" + key + "':" +
         value + " - " + USING_THE_DEFAULT_VALUE + def);
 
     return def;
   }
 
   /**
    * Returns the value of the Java system property with the specified {@code
    * key}, while falling back to the
    * specified default value if the property access fails.
    *
    * @return the property value. {@code def} if there's no such property or if
    *     an access to the specified
    *     property is not allowed.
    */
   public static boolean getBoolean(final String key, final boolean def) {
     ParametersChecker.checkParameter("Key", key);
 
     String value = PROPS.getProperty(key);
     if (value == null) {
       return def;
     }
 
     value = value.trim().toLowerCase();
     if (value.isEmpty()) {
       return true;
     }
 
     if ("true".equals(value) || "yes".equals(value) || "1".equals(value)) {
       return true;
     }
 
     if ("false".equals(value) || "no".equals(value) || "0".equals(value)) {
       return false;
     }
 
     SysErrLogger.FAKE_LOGGER.syserr(
         "Unable to parse the boolean system property '" + key + "':" + value +
         " - " + USING_THE_DEFAULT_VALUE2 + def);
 
     return def;
   }
 
   /**
    * Returns the value of the Java system property with the specified {@code
    * key}, while falling back to the
    * specified default value if the property access fails.
    *
    * @return the property value. {@code def} if there's no such property or if
    *     an access to the specified
    *     property is not allowed.
    */
   public static int getInt(final String key, final int def) {
     ParametersChecker.checkParameter("Key", key);
 
     String value = PROPS.getProperty(key);
     if (value == null) {
       return def;
     }
 
     value = value.trim().toLowerCase();
     if (value.matches(FIND_0_9)) {
       try {
         return Integer.parseInt(value);
       } catch (final Exception e) {
         // Ignore
       }
     }
 
     SysErrLogger.FAKE_LOGGER.syserr(
         "Unable to parse the integer system property '" + key + "':" + value +
         " - " + USING_THE_DEFAULT_VALUE2 + def);
 
     return def;
   }
 
   /**
    * Returns the value of the Java system property with the specified {@code
    * key}, while falling back to the
    * specified default value if the property access fails.
    *
    * @return the property value. {@code def} if there's no such property or if
    *     an access to the specified
    *     property is not allowed.
    */
   public static long getLong(final String key, final long def) {
     ParametersChecker.checkParameter("Key", key);
 
     String value = PROPS.getProperty(key);
     if (value == null) {
       return def;
     }
 
     value = value.trim().toLowerCase();
     if (value.matches(FIND_0_9)) {
       try {
         return Long.parseLong(value);
       } catch (final Exception e) {
         // Ignore
       }
     }
 
     SysErrLogger.FAKE_LOGGER.syserr(
         "Unable to parse the long integer system property '" + key + "':" +
         value + " - " + USING_THE_DEFAULT_VALUE2 + def);
 
     return def;
   }
 
   /**
    * Returns the value of the Java system property with the specified {@code
    * key}, while falling back to the specified
    * default value if the property access fails.
    *
    * @param key of system property
    * @param def the default value
    *
    * @return the property value. {@code def} if there's no such property or if
    *     an access to the specified property is
    *     not allowed.
    *
    * @throws IllegalArgumentException key or def null
    */
   public static String getAndSet(final String key, final String def) {
     ParametersChecker.checkParameter("Key", key);
     if (def == null) {
       throw new IllegalArgumentException("Def cannot be null");
     }
     if (!PROPS.containsKey(key)) {
       System.setProperty(key, def);
       refresh();
       return def;
     }
     return PROPS.getProperty(key);
   }
 
   /**
    * Returns the value of the Java system property with the specified {@code
    * key}, while falling back to the specified
    * default value if the property access fails.
    *
    * @param key of system property
    * @param def the default value
    *
    * @return the property value. {@code def} if there's no such property or if
    *     an access to the specified property is
    *     not allowed.
    *
    * @throws IllegalArgumentException key null
    */
   public static boolean getAndSet(final String key, final boolean def) {
     ParametersChecker.checkParameter("Key", key);
     if (!PROPS.containsKey(key)) {
       System.setProperty(key, Boolean.toString(def));
       refresh();
       return def;
     }
     return get(key, def);
   }
 
   /**
    * Returns the value of the Java system property with the specified {@code
    * key}, while falling back to the specified
    * default value if the property access fails.
    *
    * @param key of system property
    * @param def the default value
    *
    * @return the property value. {@code def} if there's no such property or if
    *     an access to the specified property is
    *     not allowed.
    *
    * @throws IllegalArgumentException key null
    */
   public static int getAndSet(final String key, final int def) {
     ParametersChecker.checkParameter("Key", key);
     if (!PROPS.containsKey(key)) {
       System.setProperty(key, Integer.toString(def));
       refresh();
       return def;
     }
     return get(key, def);
   }
 
   /**
    * Returns the value of the Java system property with the specified {@code
    * key}, while falling back to the specified
    * default value if the property access fails.
    *
    * @param key of system property
    * @param def the default value
    *
    * @return the property value. {@code def} if there's no such property or if
    *     an access to the specified property is
    *     not allowed.
    *
    * @throws IllegalArgumentException key null
    */
   public static long getAndSet(final String key, final long def) {
     ParametersChecker.checkParameter("Key", key);
     if (!PROPS.containsKey(key)) {
       System.setProperty(key, Long.toString(def));
       refresh();
       return def;
     }
     return get(key, def);
   }
 
   /**
    * Set the value of the Java system property with the specified {@code key}
    * to the specified default value.
    *
    * @param key of system property
    * @param def the default value
    *
    * @return the ancient value.
    *
    * @throws IllegalArgumentException key or def null
    */
   public static String set(final String key, final String def) {
     ParametersChecker.checkParameter("Key", key);
     if (def == null) {
       throw new IllegalArgumentException("Def cannot be null");
     }
     String old = null;
     if (PROPS.containsKey(key)) {
       old = PROPS.getProperty(key);
     }
     System.setProperty(key, def);
     refresh();
     return old;
   }
 
   /**
    * Set the value of the Java system property with the specified {@code key}
    * to the specified default value.
    *
    * @param key of system property
    * @param def the default value
    *
    * @return the ancient value.
    *
    * @throws IllegalArgumentException key null
    */
   public static boolean set(final String key, final boolean def) {
     ParametersChecker.checkParameter("Key", key);
     boolean old = false;
     if (PROPS.containsKey(key)) {
       old = get(key, def);
     }
     System.setProperty(key, Boolean.toString(def));
     refresh();
     return old;
   }
 
   /**
    * Set the value of the Java system property with the specified {@code key}
    * to the specified default value.
    *
    * @param key of system property
    * @param def the default value
    *
    * @return the ancient value.
    *
    * @throws IllegalArgumentException key null
    */
   public static int set(final String key, final int def) {
     ParametersChecker.checkParameter("Key", key);
     int old = 0;
     if (PROPS.containsKey(key)) {
       old = get(key, def);
     }
     System.setProperty(key, Integer.toString(def));
     refresh();
     return old;
   }
 
   /**
    * Set the value of the Java system property with the specified {@code key}
    * to the specified default value.
    *
    * @param key of system property
    * @param def the default value
    *
    * @return the ancient value.
    *
    * @throws IllegalArgumentException key null
    */
   public static long set(final String key, final long def) {
     ParametersChecker.checkParameter("Key", key);
     long old = 0;
     if (PROPS.containsKey(key)) {
       old = get(key, def);
     }
     System.setProperty(key, Long.toString(def));
     refresh();
     return old;
   }
 
   /**
    * Remove the key of the Java system property with the specified {@code
    * key}.
    *
    * @param key of system property
    *
    * @throws IllegalArgumentException key null
    */
   public static void clear(final String key) {
     ParametersChecker.checkParameter("Key", key);
     PROPS.remove(key);
     System.clearProperty(key);
     refresh();
   }
 
   /**
    * Print to System.out the content of the properties
    *
    * @param out the output stream to be used
    *
    * @throws IllegalArgumentException out null
    */
   public static void debug(final PrintStream out) {
     ParametersChecker.checkParameter("Out", out);
     PROPS.list(out);
   }
 
   /**
    * Inspired from http://commons.apache.org/lang/api-2.4/org/apache/commons/lang/
    * SystemUtils.html
    */
   public enum Platform {
     /**
      * Windows
      */
     WINDOWS,
     /**
      * Mac
      */
     MAC,
     /**
      * Unix
      */
     UNIX,
     /**
      * Solaris
      */
     SOLARIS,
     /**
      * Unsupported
      */
     UNSUPPORTED
   }
 
   /**
    * @return the Platform
    */
   public static Platform getOS() {
     if (mOs == null) {
       mOs = Platform.UNSUPPORTED;
       String os = "";
       try {
         os = System.getProperty("os.name").toLowerCase();
       } catch (final Exception ignored) {
         // ignore
         SysErrLogger.FAKE_LOGGER.ignoreLog(ignored);
       }
       if (os.contains("win")) {
         mOs = Platform.WINDOWS;
         // Windows
       }
       if (os.contains("mac")) {
         mOs = Platform.MAC;
         // Mac
       }
       if (os.contains("nux")) {
         mOs = Platform.UNIX;
         // Linux
       }
       if (os.contains("nix")) {
         mOs = Platform.UNIX;
         // Unix
       }
       if (os.contains("sunos")) {
         mOs = Platform.SOLARIS;
         // Solaris
       }
     }
     return mOs;
   }
 
   /**
    * @return True if Windows
    */
   public static boolean isWindows() {
     return getOS() == Platform.WINDOWS;
   }
 
   /**
    * @return True if Mac
    */
   public static boolean isMac() {
     return getOS() == Platform.MAC;
   }
 
   /**
    * @return True if Unix
    */
   public static boolean isUnix() {
     return getOS() == Platform.UNIX;
   }
 
   /**
    * @return True if Solaris
    */
   public static boolean isSolaris() {
     return getOS() == Platform.SOLARIS;
   }
 
   public static void debug() {
     PROPS.list(System.out);//NOSONAR
   }
 
   private SystemPropertyUtil() {
     // Unused
   }
 }