/*
    * 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.Arrays;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  
  import org.apache.logging.log4j.Logger;
  import org.apache.logging.log4j.core.Core;
  import org.apache.logging.log4j.core.LogEvent;
  import org.apache.logging.log4j.core.config.Configuration;
  import org.apache.logging.log4j.core.config.Property;
  import org.apache.logging.log4j.core.config.plugins.Plugin;
  import org.apache.logging.log4j.core.config.plugins.PluginConfiguration;
  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.ContextDataFactory;
  import org.apache.logging.log4j.core.impl.Log4jLogEvent;
  import org.apache.logging.log4j.status.StatusLogger;
  import org.apache.logging.log4j.util.StringMap;
  
  /**
   * This policy modifies events by replacing or possibly adding keys and values to the MapMessage.
   */
  @Plugin(name = "PropertiesRewritePolicy", category = Core.CATEGORY_NAME, elementType = "rewritePolicy", printObject = true)
  public final class PropertiesRewritePolicy implements RewritePolicy {
  
      /**
       * Allows subclasses access to the status logger without creating another instance.
       */
      protected static final Logger LOGGER = StatusLogger.getLogger();
  
      private final Map<Property, Boolean> properties;
  
      private final Configuration config;
  
      private PropertiesRewritePolicy(final Configuration config, final List<Property> props) {
          this.config = config;
          this.properties = new HashMap<>(props.size());
          for (final Property property : props) {
              final Boolean interpolate = Boolean.valueOf(property.getValue().contains("${"));
              properties.put(property, interpolate);
          }
      }
  
      /**
       * Rewrites the event.
       * @param source a logging event that may be returned or
       * used to create a new logging event.
       * @return The LogEvent after rewriting.
       */
      @Override
      public LogEvent rewrite(final LogEvent source) {
          final StringMap newContextData = ContextDataFactory.createContextData(source.getContextData());
          for (final Map.Entry<Property, Boolean> entry : properties.entrySet()) {
              final Property prop = entry.getKey();
              newContextData.putValue(prop.getName(), entry.getValue().booleanValue() ?
                  config.getStrSubstitutor().replace(prop.getValue()) : prop.getValue());
          }
  
          return new Log4jLogEvent.Builder(source).setContextData(newContextData).build();
      }
  
      @Override
      public String toString() {
          final StringBuilder sb = new StringBuilder();
          sb.append(" {");
          boolean first = true;
          for (final Map.Entry<Property, Boolean> entry : properties.entrySet()) {
              if (!first) {
                  sb.append(", ");
              }
              final Property prop = entry.getKey();
              sb.append(prop.getName()).append('=').append(prop.getValue());
              first = false;
          }
          sb.append('}');
          return sb.toString();
      }
  
      /**
       * Creates a PropertiesRewritePolicy.
       * @param config The Configuration.
      * @param props key/value pairs for the new keys and values.
      * @return The PropertiesRewritePolicy.
      */
     @PluginFactory
     public static PropertiesRewritePolicy createPolicy(@PluginConfiguration final Configuration config,
                                                 @PluginElement("Properties") final Property[] props) {
         if (props == null || props.length == 0) {
             LOGGER.error("Properties must be specified for the PropertiesRewritePolicy");
             return null;
         }
         final List<Property> properties = Arrays.asList(props);
         return new PropertiesRewritePolicy(config, properties);
     }
 }