/*
    * 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.appender.rewrite;
  
  import java.util.HashMap;
  import java.util.Locale;
  import java.util.Map;
  
  import org.apache.logging.log4j.Level;
  import org.apache.logging.log4j.core.LogEvent;
  import org.apache.logging.log4j.core.config.plugins.Plugin;
  import org.apache.logging.log4j.core.config.plugins.PluginAttribute;
  import org.apache.logging.log4j.core.config.plugins.PluginElement;
  import org.apache.logging.log4j.core.config.plugins.PluginFactory;
  import org.apache.logging.log4j.core.impl.Log4jLogEvent;
  import org.apache.logging.log4j.core.util.KeyValuePair;
  
  /**
   * Rewrites log event levels for a given logger name.
   * 
   * @since 2.4
   */
  @Plugin(name = "LoggerNameLevelRewritePolicy", category = "Core", elementType = "rewritePolicy", printObject = true)
  public class LoggerNameLevelRewritePolicy implements RewritePolicy {
  
      /**
       * Creates a policy to rewrite levels for a given logger name.
       * 
       * @param loggerNamePrefix
       *        The logger name prefix for events to rewrite; all event logger names that start with this string will be
       *        rewritten.
       * @param levelPairs
       *        The levels to rewrite, the key is the source level, the value the target level.
       * @return a new LoggerNameLevelRewritePolicy
       */
      @PluginFactory
      public static LoggerNameLevelRewritePolicy createPolicy(
              // @formatter:off
              @PluginAttribute("logger") final String loggerNamePrefix,
              @PluginElement("KeyValuePair") final KeyValuePair[] levelPairs) {
              // @formatter:on
          final Map<Level, Level> newMap = new HashMap<>(levelPairs.length);
          for (final KeyValuePair keyValuePair : levelPairs) {
              newMap.put(getLevel(keyValuePair.getKey()), getLevel(keyValuePair.getValue()));
          }
          return new LoggerNameLevelRewritePolicy(loggerNamePrefix, newMap);
      }
  
      private static Level getLevel(final String name) {
          return Level.getLevel(name.toUpperCase(Locale.ROOT));
      }
  
      private final String loggerName;
  
      private final Map<Level, Level> map;
  
      private LoggerNameLevelRewritePolicy(final String loggerName, final Map<Level, Level> map) {
          super();
          this.loggerName = loggerName;
          this.map = map;
      }
  
      @Override
      public LogEvent rewrite(final LogEvent event) {
          if (!event.getLoggerName().startsWith(loggerName)) {
              return event;
          }
          final Level sourceLevel = event.getLevel();
          final Level newLevel = map.get(sourceLevel);
          if (newLevel == null || newLevel == sourceLevel) {
              return event;
          }
          final LogEvent result = new Log4jLogEvent.Builder(event).setLevel(newLevel).build();
          return result;
      }
  
  }