/*
    * Licensed to the Apache Software Foundation (ASF) under one or more
    * contributor license agreements. See the NOTICE file distributed with
    * this work for additional information regarding copyright ownership.
    * The ASF licenses this file to You under the Apache license, Version 2.0
    * (the "License"); you may not use this file except in compliance with
    * the License. You may obtain a copy of the License at
    *
    *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the license for the specific language governing permissions and
   * limitations under the license.
   */
  package org.apache.logging.log4j.core.filter;
  
  import org.apache.logging.log4j.Level;
  import org.apache.logging.log4j.Marker;
  import org.apache.logging.log4j.ThreadContext;
  import org.apache.logging.log4j.core.LogEvent;
  import org.apache.logging.log4j.core.Logger;
  import org.apache.logging.log4j.core.config.plugins.Plugin;
  import org.apache.logging.log4j.core.config.plugins.PluginAttr;
  import org.apache.logging.log4j.core.config.plugins.PluginElement;
  import org.apache.logging.log4j.core.config.plugins.PluginFactory;
  import org.apache.logging.log4j.core.helpers.KeyValuePair;
  import org.apache.logging.log4j.message.Message;
  
  import java.util.HashMap;
  import java.util.Map;
  
  /**
   * Compare against a log level that is associated with an MDC value.
   */
  @Plugin(name = "DynamicThresholdFilter", category = "Core", elementType = "filter", printObject = true)
  public final class DynamicThresholdFilter extends AbstractFilter {
      private Map<String, Level> levelMap = new HashMap<String, Level>();
      private Level defaultThreshold = Level.ERROR;
      private final String key;
  
      private DynamicThresholdFilter(final String key, final Map<String, Level> pairs, final Level defaultLevel,
                                     final Result onMatch, final Result onMismatch) {
          super(onMatch, onMismatch);
          if (key == null) {
              throw new NullPointerException("key cannot be null");
          }
          this.key = key;
          this.levelMap = pairs;
          this.defaultThreshold = defaultLevel;
      }
  
      public String getKey() {
          return this.key;
      }
  
      @Override
      public Result filter(final Logger logger, final Level level, final Marker marker, final String msg,
                           final Object... params) {
          return filter(level);
      }
  
      @Override
      public Result filter(final Logger logger, final Level level, final Marker marker, final Object msg,
                           final Throwable t) {
          return filter(level);
      }
  
      @Override
      public Result filter(final Logger logger, final Level level, final Marker marker, final Message msg,
                           final Throwable t) {
          return filter(level);
      }
  
      @Override
      public Result filter(final LogEvent event) {
          return filter(event.getLevel());
      }
  
      private Result filter(final Level level) {
          final Object value = ThreadContext.get(key);
          if (value != null) {
              Level ctxLevel = levelMap.get(value);
              if (ctxLevel == null) {
                  ctxLevel = defaultThreshold;
              }
              return level.isAtLeastAsSpecificAs(ctxLevel) ? onMatch : onMismatch;
          }
          return Result.NEUTRAL;
  
      }
  
      public Map<String, Level> getLevelMap() {
          return levelMap;
      }
  
      @Override
      public String toString() {
         final StringBuilder sb = new StringBuilder();
         sb.append("key=").append(key);
         sb.append(", default=").append(defaultThreshold);
         if (levelMap.size() > 0) {
             sb.append("{");
             boolean first = true;
             for (final Map.Entry<String, Level> entry : levelMap.entrySet()) {
                 if (!first) {
                     sb.append(", ");
                     first = false;
                 }
                 sb.append(entry.getKey()).append("=").append(entry.getValue());
             }
             sb.append("}");
         }
         return sb.toString();
     }
 
     /**
      * Create the DynamicThresholdFilter.
      * @param key The name of the key to compare.
      * @param pairs An array of value and Level pairs.
      * @param levelName The default Level.
      * @param match The action to perform if a match occurs.
      * @param mismatch The action to perform if no match occurs.
      * @return The DynamicThresholdFilter.
      */
     @PluginFactory
     public static DynamicThresholdFilter createFilter(@PluginAttr("key") final String key,
                                                       @PluginElement("pairs") final KeyValuePair[] pairs,
                                                       @PluginAttr("defaultThreshold") final String levelName,
                                                       @PluginAttr("onmatch") final String match,
                                                       @PluginAttr("onmismatch") final String mismatch) {
         final Result onMatch = Result.toResult(match);
         final Result onMismatch = Result.toResult(mismatch);
         final Map<String, Level> map = new HashMap<String, Level>();
         for (final KeyValuePair pair : pairs) {
             map.put(pair.getKey(), Level.toLevel(pair.getValue()));
         }
         final Level level = Level.toLevel(levelName, Level.ERROR);
         return new DynamicThresholdFilter(key, map, level, onMatch, onMismatch);
     }
 }