/**
    * 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.sift;
  
  import ch.qos.logback.classic.LoggerContext;
  import ch.qos.logback.classic.selector.ContextSelector;
  import ch.qos.logback.classic.spi.ILoggingEvent;
  import ch.qos.logback.classic.util.ContextSelectorStaticBinder;
  import ch.qos.logback.core.sift.AbstractDiscriminator;
  
  /**
   * This discriminator returns the value context as determined by JNDI. If the
   * said value is null, then a default value is returned.
   * 
   * <p>
   * Both Key and the DefaultValue are user specified properties.
   * 
   * @author Ceki G&uuml;lc&uuml;
   * 
   */
  public class JNDIBasedContextDiscriminator extends AbstractDiscriminator<ILoggingEvent> {
  
      private static final String KEY = "contextName";
      private String defaultValue;
  
      /**
       * Return the name of the current context name as found in the logging event.
       */
      public String getDiscriminatingValue(ILoggingEvent event) {
          ContextSelector selector = ContextSelectorStaticBinder.getSingleton().getContextSelector();
  
          if (selector == null) {
              return defaultValue;
          }
  
          LoggerContext lc = selector.getLoggerContext();
          if (lc == null) {
              return defaultValue;
          }
  
          return lc.getName();
      }
  
      public String getKey() {
          return KEY;
      }
  
      public void setKey(String key) {
          throw new UnsupportedOperationException("Key cannot be set. Using fixed key " + KEY);
      }
  
      /**
       * @see #setDefaultValue(String)
       * @return
       */
      public String getDefaultValue() {
          return defaultValue;
      }
  
      /**
       * The default context name in case the context name is not set for the current
       * logging event.
       * 
       * @param defaultValue
       */
      public void setDefaultValue(String defaultValue) {
          this.defaultValue = defaultValue;
      }
  }