/*
    * 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.message;
  
  import org.apache.logging.log4j.util.PerformanceSensitive;
  
  /**
   * Mutable Message wrapper around a String message.
   * @since 2.6
   */
  @PerformanceSensitive("allocation")
  public class ReusableSimpleMessage implements ReusableMessage, CharSequence, ParameterVisitable, Clearable {
      private static final long serialVersionUID = -9199974506498249809L;
      private static Object[] EMPTY_PARAMS = new Object[0];
      private CharSequence charSequence;
  
      public void set(final String message) {
          this.charSequence = message;
      }
  
      public void set(final CharSequence charSequence) {
          this.charSequence = charSequence;
      }
  
      @Override
      public String getFormattedMessage() {
          return String.valueOf(charSequence);
      }
  
      @Override
      public String getFormat() {
          return charSequence instanceof String ? (String) charSequence : null;
      }
  
      @Override
      public Object[] getParameters() {
          return EMPTY_PARAMS;
      }
  
      @Override
      public Throwable getThrowable() {
          return null;
      }
  
      @Override
      public void formatTo(final StringBuilder buffer) {
          buffer.append(charSequence);
      }
  
      /**
       * This message does not have any parameters, so this method returns the specified array.
       * @param emptyReplacement the parameter array to return
       * @return the specified array
       */
      @Override
      public Object[] swapParameters(final Object[] emptyReplacement) {
          return emptyReplacement;
      }
  
      /**
       * This message does not have any parameters so this method always returns zero.
       * @return 0 (zero)
       */
      @Override
      public short getParameterCount() {
          return 0;
      }
  
      @Override
      public <S> void forEachParameter(final ParameterConsumer<S> action, final S state) {
      }
  
      @Override
      public Message memento() {
          return new SimpleMessage(charSequence);
      }
  
      // CharSequence impl
  
      @Override
      public int length() {
          return charSequence == null ? 0 : charSequence.length();
      }
  
      @Override
     public char charAt(final int index) {
         return charSequence.charAt(index);
     }
 
     @Override
     public CharSequence subSequence(final int start, final int end) {
         return charSequence.subSequence(start, end);
     }
 
     @Override
     public void clear() {
         charSequence = null;
     }
 }