/*
    * 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.text.MessageFormat;
  import java.util.Arrays;
  import java.util.IllegalFormatException;
  import java.util.Locale;
  
  import org.apache.logging.log4j.Logger;
  import org.apache.logging.log4j.status.StatusLogger;
  
  /**
   * Handles messages that consist of a format string conforming to java.text.MessageFormat.
   *
   * @serial In version 2.1, due to a bug in the serialization format, the serialization format was changed along with
   * its {@code serialVersionUID} value.
   */
  public class MessageFormatMessage implements Message {
  
      private static final Logger LOGGER = StatusLogger.getLogger();
  
      private static final long serialVersionUID = 1L;
  
      private static final int HASHVAL = 31;
  
      private String messagePattern;
      private transient Object[] parameters;
      private String[] serializedParameters;
      private transient String formattedMessage;
      private transient Throwable throwable;
      private final Locale locale;
  
      /**
       * Constructs a message.
       * 
       * @param locale the locale for this message format
       * @param messagePattern the pattern for this message format
       * @param parameters The objects to format
       * @since 2.6
       */
      public MessageFormatMessage(final Locale locale, final String messagePattern, final Object... parameters) {
          this.locale = locale;
          this.messagePattern = messagePattern;
          this.parameters = parameters;
          final int length = parameters == null ? 0 : parameters.length;
          if (length > 0 && parameters[length - 1] instanceof Throwable) {
              this.throwable = (Throwable) parameters[length - 1];
          }
      }
  
      /**
       * Constructs a message.
       * 
       * @param messagePattern the pattern for this message format
       * @param parameters The objects to format
       */
      public MessageFormatMessage(final String messagePattern, final Object... parameters) {
          this(Locale.getDefault(Locale.Category.FORMAT), messagePattern, parameters);
      }
  
      /**
       * Returns the formatted message.
       * @return the formatted message.
       */
      @Override
      public String getFormattedMessage() {
          if (formattedMessage == null) {
              formattedMessage = formatMessage(messagePattern, parameters);
          }
          return formattedMessage;
      }
  
      /**
       * Returns the message pattern.
       * @return the message pattern.
       */
      @Override
      public String getFormat() {
          return messagePattern;
      }
 
     /**
      * Returns the message parameters.
      * @return the message parameters.
      */
     @Override
     public Object[] getParameters() {
         if (parameters != null) {
             return parameters;
         }
         return serializedParameters;
     }
 
     protected String formatMessage(final String msgPattern, final Object... args) {
         try {
             final MessageFormat temp = new MessageFormat(msgPattern, locale);
             return temp.format(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 MessageFormatMessage that = (MessageFormatMessage) o;
 
         if (messagePattern != null ? !messagePattern.equals(that.messagePattern) : that.messagePattern != null) {
             return false;
         }
         return Arrays.equals(serializedParameters, that.serializedParameters);
     }
 
     @Override
     public int hashCode() {
         int result = messagePattern != null ? messagePattern.hashCode() : 0;
         result = HASHVAL * result + (serializedParameters != null ? Arrays.hashCode(serializedParameters) : 0);
         return result;
     }
 
 
     @Override
     public String toString() {
         return getFormattedMessage();
     }
 
     private void writeObject(final ObjectOutputStream out) throws IOException {
         getFormattedMessage();
         out.writeUTF(formattedMessage);
         out.writeUTF(messagePattern);
         final int length = parameters == null ? 0 : parameters.length;
         out.writeInt(length);
         serializedParameters = new String[length];
         if (length > 0) {
             for (int i = 0; i < length; i++) {
                 serializedParameters[i] = String.valueOf(parameters[i]);
                 out.writeUTF(serializedParameters[i]);
             }
         }
     }
 
     private void readObject(final ObjectInputStream in) throws IOException {
         parameters = null;
         throwable = null;
         formattedMessage = in.readUTF();
         messagePattern = in.readUTF();
         final int length = in.readInt();
         serializedParameters = new String[length];
         for (int i = 0; i < length; ++i) {
             serializedParameters[i] = in.readUTF();
         }
     }
 
     /**
      * Return the throwable passed to the Message.
      *
      * @return the Throwable.
      */
     @Override
     public Throwable getThrowable() {
         return throwable;
     }
 }