/**
    * Logback: the reliable, generic, fast and flexible logging framework.
    * Copyright (C) 1999-2011, QOS.ch. All rights reserved.
    *
    * This program and the accompanying materials are dual-licensed under
    * either the terms of the Eclipse Public License v1.0 as published by
    * the Eclipse Foundation
    *
    *   or (per the licensee's choosing)
   *
   * under the terms of the GNU Lesser General Public License version 2.1
   * as published by the Free Software Foundation.
   */
  package ch.qos.logback.classic.jul;
  
  import ch.qos.logback.classic.Level;
  import ch.qos.logback.classic.Logger;
  import ch.qos.logback.classic.LoggerContext;
  import ch.qos.logback.classic.spi.LoggerContextListener;
  import ch.qos.logback.core.spi.ContextAwareBase;
  import ch.qos.logback.core.spi.LifeCycle;
  
  import java.util.Enumeration;
  import java.util.HashSet;
  import java.util.List;
  import java.util.Set;
  import java.util.logging.LogManager;
  
  
  /**
   * Propagate level changes made to a logback logger into the equivalent logger in j.u.l.
   */
  public class LevelChangePropagator extends ContextAwareBase implements LoggerContextListener, LifeCycle {
  
    private Set julLoggerSet = new HashSet();
    boolean isStarted = false;
    boolean resetJUL = false;
  
    public void setResetJUL(boolean resetJUL) {
      this.resetJUL = resetJUL;
    }
    
    public boolean isResetResistant() {
      return false;
    }
  
    public void onStart(LoggerContext context) {
    }
  
    public void onReset(LoggerContext context) {
    }
  
    public void onStop(LoggerContext context) {
    }
  
    public void onLevelChange(Logger logger, Level level) {
      propagate(logger, level);
    }
  
    private void propagate(Logger logger, Level level) {
      addInfo("Propagating " + level + " level on " + logger + " onto the JUL framework");
      java.util.logging.Logger julLogger = JULHelper.asJULLogger(logger);
      // prevent garbage collection of jul loggers whose level we set
      // see also  http://jira.qos.ch/browse/LBCLASSIC-256
      julLoggerSet.add(julLogger);
      java.util.logging.Level julLevel = JULHelper.asJULLevel(level);
      julLogger.setLevel(julLevel);
    }
  
    public void resetJULLevels() {
      LogManager lm = LogManager.getLogManager();
  
      Enumeration e = lm.getLoggerNames();
      while (e.hasMoreElements()) {
        String loggerName = (String) e.nextElement();
        java.util.logging.Logger julLogger = lm.getLogger(loggerName);
        if (JULHelper.isRegularNonRootLogger(julLogger) && julLogger.getLevel() != null) {
          addInfo("Setting level of jul logger [" + loggerName + "] to null");
          julLogger.setLevel(null);
        }
      }
    }
  
    private void propagateExistingLoggerLevels() {
      LoggerContext loggerContext = (LoggerContext) context;
      List<Logger> loggerList = loggerContext.getLoggerList();
      for (Logger l : loggerList) {
        if (l.getLevel() != null) {
          propagate(l, l.getLevel());
        }
      }
    }
  
    public void start() {
      if (resetJUL) {
        resetJULLevels();
      }
      propagateExistingLoggerLevels();
  
     isStarted = true;
   }
 
   public void stop() {
     isStarted = false;
   }
 
   public boolean isStarted() {
     return isStarted;
   }
 }