/*
    * 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.Logger;
  import org.apache.logging.log4j.status.StatusLogger;
  
  import java.io.IOException;
  import java.io.ObjectInputStream;
  import java.io.ObjectOutputStream;
  import java.util.Arrays;
  import java.util.IllegalFormatException;
  
  /**
   * Handles messages that consist of a format string conforming to java.util.Formatter.
   */
  public class StringFormattedMessage implements Message {
  
      private static final Logger LOGGER = StatusLogger.getLogger();
  
      private static final long serialVersionUID = -665975803997290697L;
  
      private static final int HASHVAL = 31;
  
      private String messagePattern;
      private transient Object[] argArray;
      private String[] stringArgs;
      private transient String formattedMessage;
  
      public StringFormattedMessage(final String messagePattern, final Object... arguments) {
          this.messagePattern = messagePattern;
          this.argArray = arguments;
      }
  
      /**
       * Returns the formatted message.
       * @return the formatted message.
       */
      public String getFormattedMessage() {
          if (formattedMessage == null) {
              formattedMessage = formatMessage(messagePattern, argArray);
          }
          return formattedMessage;
      }
  
      /**
       * Returns the message pattern.
       * @return the message pattern.
       */
      public String getFormat() {
          return messagePattern;
      }
  
      /**
       * Returns the message parameters.
       * @return the message parameters.
       */
      public Object[] getParameters() {
          if (argArray != null) {
              return argArray;
          }
          return stringArgs;
      }
  
      protected String formatMessage(final String msgPattern, final Object... args) {
          try {
              return String.format(msgPattern, args);
          } catch (final IllegalFormatException ife) {
              LOGGER.error("Unable to format msg: " + msgPattern, ife);
              return msgPattern;
          }
      }
  
      @Override
      public boolean equals(final Object o) {
          if (this == o) {
              return true;
          }
          if (o == null || getClass() != o.getClass()) {
              return false;
          }
  
          final StringFormattedMessage that = (StringFormattedMessage) o;
  
          if (messagePattern != null ? !messagePattern.equals(that.messagePattern) : that.messagePattern != null) {
             return false;
         }
         if (!Arrays.equals(stringArgs, that.stringArgs)) {
             return false;
         }
 
         return true;
     }
 
     @Override
     public int hashCode() {
         int result = messagePattern != null ? messagePattern.hashCode() : 0;
         result = HASHVAL * result + (stringArgs != null ? Arrays.hashCode(stringArgs) : 0);
         return result;
     }
 
 
     @Override
     public String toString() {
         return "StringFormatMessage[messagePattern=" + messagePattern + ", args=" +
             Arrays.toString(argArray) +  "]";
     }
 
     private void writeObject(final ObjectOutputStream out) throws IOException {
         out.defaultWriteObject();
         getFormattedMessage();
         out.writeUTF(formattedMessage);
         out.writeUTF(messagePattern);
         out.writeInt(argArray.length);
         stringArgs = new String[argArray.length];
         int i = 0;
         for (final Object obj : argArray) {
             stringArgs[i] = obj.toString();
             ++i;
         }
     }
 
     private void readObject(final ObjectInputStream in) throws IOException, ClassNotFoundException {
         in.defaultReadObject();
         formattedMessage = in.readUTF();
         messagePattern = in.readUTF();
         final int length = in.readInt();
         stringArgs = new String[length];
         for (int i = 0; i < length; ++i) {
             stringArgs[i] = in.readUTF();
         }
     }
 
     /**
      * Always returns null.
      *
      * @return null
      */
     public Throwable getThrowable() {
         return null;
     }
 }