/*
    * 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.pattern;
  
  import org.apache.logging.log4j.core.LogEvent;
  import org.apache.logging.log4j.core.config.Configuration;
  import org.apache.logging.log4j.core.config.plugins.Plugin;
  import org.apache.logging.log4j.message.Message;
  import org.apache.logging.log4j.message.MultiformatMessage;
  
  /**
   * Returns the event's rendered message in a StringBuilder.
   */
  @Plugin(name = "MessagePatternConverter", category = PatternConverter.CATEGORY)
  @ConverterKeys({ "m", "msg", "message" })
  public final class MessagePatternConverter extends LogEventPatternConverter {
  
      private final String[] formats;
  
      private final Configuration config;
  
      /**
       * Private constructor.
       * @param options options, may be null.
       */
      private MessagePatternConverter(final Configuration config, final String[] options) {
          super("Message", "message");
          formats = options;
          this.config = config;
      }
  
      /**
       * Obtains an instance of pattern converter.
       *
       * @param config The Configuration.
       * @param options options, may be null.
       * @return instance of pattern converter.
       */
      public static MessagePatternConverter newInstance(final Configuration config, final String[] options) {
          return new MessagePatternConverter(config, options);
      }
  
      /**
       * {@inheritDoc}
       */
      @Override
      public void format(final LogEvent event, final StringBuilder toAppendTo) {
          final Message msg = event.getMessage();
          if (msg != null) {
              String result;
              if (msg instanceof MultiformatMessage) {
                  result = ((MultiformatMessage) msg).getFormattedMessage(formats);
              } else {
                  result = msg.getFormattedMessage();
              }
              if (result != null) {
                  toAppendTo.append(result);
              } else {
                  toAppendTo.append("null");
              }
          }
      }
  }