package jalview.javascript.log4j;

import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.ObjectStreamException;
import java.io.Serializable;

/**
 * Defines the minimum set of levels recognized by the system, that is
 * <code>OFF</code>, <code>FATAL</code>, <code>ERROR</code>, <code>WARN</code>,
 * <code>INFO</code>, <code>DEBUG</code> and <code>ALL</code>.
 * 
 * <p>
 * The <code>Level</code> class may be subclassed to define a larger level set.
 * </p>
 * 
 * @author Ceki G&uuml;lc&uuml;
 */
public class Level extends Priority implements Serializable
{

  private static final String ALL_NAME = "ALL";

  private static final String TRACE_NAME = "TRACE";

  private static final String DEBUG_NAME = "DEBUG";

  private static final String INFO_NAME = "INFO";

  private static final String WARN_NAME = "WARN";

  private static final String ERROR_NAME = "ERROR";

  private static final String FATAL_NAME = "FATAL";

  private static final String OFF_NAME = "OFF";

  /**
   * TRACE level integer value.
   * 
   * @since 1.2.12
   */
  public static final int TRACE_INT = 5000;

  /**
   * The <code>OFF</code> has the highest possible rank and is intended to turn
   * off logging.
   */
  final static public Level OFF = new Level(OFF_INT, OFF_NAME, 0);

  /**
   * The <code>FATAL</code> level designates very severe error events that will
   * presumably lead the application to abort.
   */
  final static public Level FATAL = new Level(FATAL_INT, FATAL_NAME, 0);

  /**
   * The <code>ERROR</code> level designates error events that might still allow
   * the application to continue running.
   */
  final static public Level ERROR = new Level(ERROR_INT, ERROR_NAME, 3);

  /**
   * The <code>WARN</code> level designates potentially harmful situations.
   */
  final static public Level WARN = new Level(WARN_INT, WARN_NAME, 4);

  /**
   * The <code>INFO</code> level designates informational messages that
   * highlight the progress of the application at coarse-grained level.
   */
  final static public Level INFO = new Level(INFO_INT, INFO_NAME, 6);

  /**
   * The <code>DEBUG</code> Level designates fine-grained informational events
   * that are most useful to debug an application.
   */
  final static public Level DEBUG = new Level(DEBUG_INT, DEBUG_NAME, 7);

  /**
   * The <code>TRACE</code> Level designates finer-grained informational events
   * than the <code>DEBUG</code level.
   * 
   * @since 1.2.12
   */
  public static final Level TRACE = new Level(TRACE_INT, TRACE_NAME, 7);

  /**
   * The <code>ALL</code> has the lowest possible rank and is intended to turn
   * on all logging.
   */
  final static public Level ALL = new Level(ALL_INT, ALL_NAME, 7);

  /**
   * Serialization version id.
   */
  static final long serialVersionUID = 3491141966387921974L;

  /**
   * Instantiate a Level object.
   */
  protected Level(int level, String levelStr, int syslogEquivalent)
  {
    super(level, levelStr, syslogEquivalent);
  }

  /**
   * Convert the string passed as argument to a level. If the conversion fails,
   * then this method returns {@link #DEBUG}.
   */
  public static Level toLevel(String sArg)
  {
    return toLevel(sArg, Level.DEBUG);
  }

  /**
   * Convert an integer passed as argument to a level. If the conversion fails,
   * then this method returns {@link #DEBUG}.
   */
  public static Level toLevel(int val)
  {
    return toLevel(val, Level.DEBUG);
  }

  /**
   * Convert an integer passed as argument to a level. If the conversion fails,
   * then this method returns the specified default.
   */
  public static Level toLevel(int val, Level defaultLevel)
  {
    switch (val)
    {
    case ALL_INT:
      return ALL;
    case DEBUG_INT:
      return Level.DEBUG;
    case INFO_INT:
      return Level.INFO;
    case WARN_INT:
      return Level.WARN;
    case ERROR_INT:
      return Level.ERROR;
    case FATAL_INT:
      return Level.FATAL;
    case OFF_INT:
      return OFF;
    case TRACE_INT:
      return Level.TRACE;
    default:
      return defaultLevel;
    }
  }

  /**
   * Convert the string passed as argument to a level. If the conversion fails,
   * then this method returns the value of <code>defaultLevel</code>.
   */
  public static Level toLevel(String sArg, Level defaultLevel)
  {
    if (sArg == null)
    {
      return defaultLevel;
    }
    String s = sArg.toUpperCase();

    if (s.equals(ALL_NAME))
    {
      return Level.ALL;
    }
    if (s.equals(DEBUG_NAME))
    {
      return Level.DEBUG;
    }
    if (s.equals(INFO_NAME))
    {
      return Level.INFO;
    }
    if (s.equals(WARN_NAME))
    {
      return Level.WARN;
    }
    if (s.equals(ERROR_NAME))
    {
      return Level.ERROR;
    }
    if (s.equals(FATAL_NAME))
    {
      return Level.FATAL;
    }
    if (s.equals(OFF_NAME))
    {
      return Level.OFF;
    }
    if (s.equals(TRACE_NAME))
    {
      return Level.TRACE;
    }
    //
    // For Turkish i problem, see bug 40937
    //
    if (s.equals("\u0130NFO"))
    {
      return Level.INFO;
    }
    return defaultLevel;
  }

  /**
   * Custom deserialization of Level.
   * 
   * @param s
   *          serialization stream.
   * @throws IOException
   *           if IO exception.
   * @throws ClassNotFoundException
   *           if class not found.
   */
  private void readObject(final ObjectInputStream s)
          throws IOException, ClassNotFoundException
  {
    s.defaultReadObject();
    level = s.readInt();
    syslogEquivalent = s.readInt();
    levelStr = s.readUTF();
    if (levelStr == null)
    {
      levelStr = "";
    }
  }

  /**
   * Serialize level.
   * 
   * @param s
   *          serialization stream.
   * @throws IOException
   *           if exception during serialization.
   */
  private void writeObject(final ObjectOutputStream s) throws IOException
  {
    s.defaultWriteObject();
    s.writeInt(level);
    s.writeInt(syslogEquivalent);
    s.writeUTF(levelStr);
  }

  /**
   * Resolved deserialized level to one of the stock instances. May be overriden
   * in classes derived from Level.
   * 
   * @return resolved object.
   * @throws ObjectStreamException
   *           if exception during resolution.
   */
  private Object readResolve() throws ObjectStreamException
  {
    //
    // if the deserizalized object is exactly an instance of Level
    //
    if (getClass() == Level.class)
    {
      return toLevel(level);
    }
    //
    // extension of Level can't substitute stock item
    //
    return this;
  }

}