/*
    * 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;
  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 {@link java.util.Formatter}.
   * 
   * <h4>Note to implementors</h4>
   * <p>
   * This class implements the unrolled args API even though StringFormattedMessage does not. This leaves the room for
   * StringFormattedMessage to unroll itself later.
   * </p>
   */
  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;
      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 arguments The objects to format
      * @since 2.6
      */
      public StringFormattedMessage(final Locale locale, final String messagePattern, final Object... arguments) {
          this.locale = locale;
          this.messagePattern = messagePattern;
          this.argArray = arguments;
          if (arguments != null && arguments.length > 0 && arguments[arguments.length - 1] instanceof Throwable) {
              this.throwable = (Throwable) arguments[arguments.length - 1];
          }
      }
  
      /**
       * Constructs a message.
       * 
       * @param messagePattern the pattern for this message format
       * @param arguments The objects to format
       * @since 2.6
       */
      public StringFormattedMessage(final String messagePattern, final Object... arguments) {
          this(Locale.getDefault(Locale.Category.FORMAT), messagePattern, arguments);
      }
  
      /**
       * Returns the formatted message.
       * @return the formatted message.
       */
      @Override
      public String getFormattedMessage() {
          if (formattedMessage == null) {
              formattedMessage = formatMessage(messagePattern, argArray);
          }
          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 (argArray != null) {
             return argArray;
         }
         return stringArgs;
     }
 
     protected String formatMessage(final String msgPattern, final Object... args) {
         try {
             return String.format(locale, 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;
         }
 
         return Arrays.equals(stringArgs, that.stringArgs);
     }
 
     @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 getFormattedMessage();
     }
 
     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) {
             final String string = String.valueOf(obj);
             stringArgs[i] = string;
             out.writeUTF(string);
             ++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();
         }
     }
 
     /**
      * Return the throwable passed to the Message.
      *
      * @return the Throwable.
      */
     @Override
     public Throwable getThrowable() {
         return throwable;
     }
 }