/*
    * 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 java.io.IOException;
  import java.io.ObjectInputStream;
  import java.io.ObjectOutputStream;
  import java.util.Arrays;
  
  /**
   * Handles messages that contain an Object[].
   * <p>
   * Created for use with the CSV layout. For example:
   * </p>
   * <p>
   * {@code logger.debug(new ObjectArrayMessage(1, 2, "Bob"));}
   * </p>
   * 
   * @since 2.4
   */
  public final class ObjectArrayMessage implements Message {
  
      private static final Object[] EMPTY_OBJECT_ARRAY = new Object[0];
  
      private static final long serialVersionUID = -5903272448334166185L;
  
      private transient Object[] array;
      private transient String arrayString;
  
      /**
       * Creates the ObjectMessage.
       * 
       * @param obj
       *            The Object to format.
       */
      public ObjectArrayMessage(final Object... obj) {
          this.array = obj == null ? EMPTY_OBJECT_ARRAY : obj;
      }
  
      private boolean equalObjectsOrStrings(final Object[] left, final Object[] right) {
          return left.equals(right) || String.valueOf(left).equals(String.valueOf(right));
      }
  
      @Override
      public boolean equals(final Object o) {
          if (this == o) {
              return true;
          }
          if (o == null || getClass() != o.getClass()) {
              return false;
          }
  
          final ObjectArrayMessage that = (ObjectArrayMessage) o;
          return array == null ? that.array == null : equalObjectsOrStrings(array, that.array);
      }
  
      /**
       * Returns the object formatted using its toString method.
       * 
       * @return the String representation of the object.
       */
      @Override
      public String getFormat() {
          return getFormattedMessage();
      }
  
      /**
       * Returns the formatted object message.
       * 
       * @return the formatted object message.
       */
      @Override
      public String getFormattedMessage() {
          // LOG4J2-763: cache formatted string in case obj changes later
          if (arrayString == null) {
              arrayString = Arrays.toString(array);
          }
          return arrayString;
      }
  
      /**
       * Returns the object as if it were a parameter.
       * 
       * @return The object.
       */
     @Override
     public Object[] getParameters() {
         return array;
     }
 
     /**
      * Returns null.
      *
      * @return null.
      */
     @Override
     public Throwable getThrowable() {
         return null;
     }
 
     @Override
     public int hashCode() {
         return array.hashCode();
     }
 
     private void readObject(final ObjectInputStream in) throws IOException, ClassNotFoundException {
         in.defaultReadObject();
         array = (Object[]) in.readObject();
     }
 
     @Override
     public String toString() {
         return "ObjectArrayMessage[obj=" + getFormattedMessage() + ']';
     }
 
     private void writeObject(final ObjectOutputStream out) throws IOException {
         out.defaultWriteObject();
         out.writeObject(array);
     }
 }