/*
    * 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 java.util.ArrayList;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  import java.util.Objects;
  
  import org.apache.logging.log4j.Level;
  import org.apache.logging.log4j.Marker;
  import org.apache.logging.log4j.core.Filter;
  import org.apache.logging.log4j.core.LogEvent;
  import org.apache.logging.log4j.core.Logger;
  import org.apache.logging.log4j.core.config.Node;
  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.util.KeyValuePair;
  import org.apache.logging.log4j.message.MapMessage;
  import org.apache.logging.log4j.message.Message;
  
  /**
   * A Filter that operates on a Map.
   */
  @Plugin(name = "MapFilter", category = Node.CATEGORY, elementType = Filter.ELEMENT_TYPE, printObject = true)
  public class MapFilter extends AbstractFilter {
  
      private final Map<String, List<String>> map;
  
      private final boolean isAnd;
  
      protected MapFilter(final Map<String, List<String>> map, final boolean oper, final Result onMatch,
                          final Result onMismatch) {
          super(onMatch, onMismatch);
          Objects.requireNonNull(map, "map cannot be null");
          this.isAnd = oper;
          this.map = map;
      }
  
      @Override
      public Result filter(final Logger logger, final Level level, final Marker marker, final Message msg,
                           final Throwable t) {
          if (msg instanceof MapMessage) {
              return filter(((MapMessage) msg).getData()) ? onMatch : onMismatch;
          }
          return Result.NEUTRAL;
      }
  
      @Override
      public Result filter(final LogEvent event) {
          final Message msg = event.getMessage();
          if (msg instanceof MapMessage) {
              return filter(((MapMessage) msg).getData()) ? onMatch : onMismatch;
          }
          return Result.NEUTRAL;
      }
  
      protected boolean filter(final Map<String, String> data) {
          boolean match = false;
          for (final Map.Entry<String, List<String>> entry : map.entrySet()) {
              final String toMatch = data.get(entry.getKey());
              if (toMatch != null) {
                  match = entry.getValue().contains(toMatch);
              } else {
                  match = false;
              }
              if ((!isAnd && match) || (isAnd && !match)) {
                  break;
              }
          }
          return match;
      }
  
      @Override
      public String toString() {
          final StringBuilder sb = new StringBuilder();
          sb.append("isAnd=").append(isAnd);
          if (map.size() > 0) {
              sb.append(", {");
              boolean first = true;
              for (final Map.Entry<String, List<String>> entry : map.entrySet()) {
                  if (!first) {
                     sb.append(", ");
                 }
                 first = false;
                 final List<String> list = entry.getValue();
                 final String value = list.size() > 1 ? list.get(0) : list.toString();
                 sb.append(entry.getKey()).append('=').append(value);
             }
             sb.append('}');
         }
         return sb.toString();
     }
 
     protected boolean isAnd() {
         return isAnd;
     }
 
     protected Map<String, List<String>> getMap() {
         return map;
     }
 
     @PluginFactory
     public static MapFilter createFilter(
             @PluginElement("Pairs") final KeyValuePair[] pairs,
             @PluginAttribute("operator") final String oper,
             @PluginAttribute("onMatch") final Result match,
             @PluginAttribute("onMismatch") final Result mismatch) {
         if (pairs == null || pairs.length == 0) {
             LOGGER.error("keys and values must be specified for the MapFilter");
             return null;
         }
         final Map<String, List<String>> map = new HashMap<>();
         for (final KeyValuePair pair : pairs) {
             final String key = pair.getKey();
             if (key == null) {
                 LOGGER.error("A null key is not valid in MapFilter");
                 continue;
             }
             final String value = pair.getValue();
             if (value == null) {
                 LOGGER.error("A null value for key " + key + " is not allowed in MapFilter");
                 continue;
             }
             List<String> list = map.get(pair.getKey());
             if (list != null) {
                 list.add(value);
             } else {
                 list = new ArrayList<>();
                 list.add(value);
                 map.put(pair.getKey(), list);
             }
         }
         if (map.isEmpty()) {
             LOGGER.error("MapFilter is not configured with any valid key value pairs");
             return null;
         }
         final boolean isAnd = oper == null || !oper.equalsIgnoreCase("or");
         return new MapFilter(map, isAnd, match, mismatch);
     }
 }