/**
    * Logback: the reliable, generic, fast and flexible logging framework.
    * Copyright (C) 1999-2015, 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<java.util.logging.Logger> julLoggerSet = new HashSet<java.util.logging.Logger>();
      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//LOGBACK-404
          julLoggerSet.add(julLogger);
          java.util.logging.Level julLevel = JULHelper.asJULLevel(level);
          julLogger.setLevel(julLevel);
      }
  
      public void resetJULLevels() {
          LogManager lm = LogManager.getLogManager();
  
          Enumeration<String> e = lm.getLoggerNames();
          while (e.hasMoreElements()) {
              String loggerName = 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;
     }
 }