/*
    * 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.log4j.pattern;
  
  import org.apache.log4j.helpers.LogLog;
  import org.apache.log4j.spi.LoggingEvent;
  
  import java.text.SimpleDateFormat;
  import java.text.DateFormat;
  import java.text.FieldPosition;
  import java.text.ParsePosition;
  import java.util.Date;
  import java.util.TimeZone;
  
  
  /**
   * Convert and format the event's date in a StringBuffer.
   *
   * @author Ceki Gülcü
   */
  public final class DatePatternConverter extends LoggingEventPatternConverter {
      /**
       * ABSOLUTE string literal.
       */
    private static final String ABSOLUTE_FORMAT = "ABSOLUTE";
      /**
       * SimpleTimePattern for ABSOLUTE.
       */
    private static final String ABSOLUTE_TIME_PATTERN = "HH:mm:ss,SSS";
  
  
      /**
       * DATE string literal.
       */
    private static final String DATE_AND_TIME_FORMAT = "DATE";
      /**
       * SimpleTimePattern for DATE.
       */
    private static final String DATE_AND_TIME_PATTERN = "dd MMM yyyy HH:mm:ss,SSS";
  
      /**
       * ISO8601 string literal.
       */
    private static final String ISO8601_FORMAT = "ISO8601";
      /**
       * SimpleTimePattern for ISO8601.
       */
    private static final String ISO8601_PATTERN = "yyyy-MM-dd HH:mm:ss,SSS";
    /**
     * Date format.
     */
    private final CachedDateFormat df;
  
      /**
       * This class wraps a DateFormat and forces the time zone to the
       *   default time zone before each format and parse request.
       */
    private static class DefaultZoneDateFormat extends DateFormat {
       /**
        * Serialization version ID.
        */
       private static final long serialVersionUID = 1;
       /**
           * Wrapped instance of DateFormat.
           */
      private final DateFormat dateFormat;
  
          /**
           * Construct new instance.
           * @param format format, may not be null.
           */
      public DefaultZoneDateFormat(final DateFormat format) {
          dateFormat = format;
      }
  
          /**
           * @{inheritDoc}
           */
      public StringBuffer format(Date date, StringBuffer toAppendTo, FieldPosition fieldPosition) {
          dateFormat.setTimeZone(TimeZone.getDefault());
          return dateFormat.format(date, toAppendTo, fieldPosition);
      }
  
          /**
          * @{inheritDoc}
          */
     public Date parse(String source, ParsePosition pos) {
         dateFormat.setTimeZone(TimeZone.getDefault());
         return dateFormat.parse(source, pos);
     }
   }
   
   /**
    * Private constructor.
    * @param options options, may be null.
    */
   private DatePatternConverter(final String[] options) {
     super("Date", "date");
 
     String patternOption;
 
     if ((options == null) || (options.length == 0)) {
       // the branch could be optimized, but here we are making explicit
       // that null values for patternOption are allowed.
       patternOption = null;
     } else {
       patternOption = options[0];
     }
 
     String pattern;
 
     if (
       (patternOption == null)
         || patternOption.equalsIgnoreCase(ISO8601_FORMAT)) {
       pattern = ISO8601_PATTERN;
     } else if (patternOption.equalsIgnoreCase(ABSOLUTE_FORMAT)) {
       pattern = ABSOLUTE_TIME_PATTERN;
     } else if (patternOption.equalsIgnoreCase(DATE_AND_TIME_FORMAT)) {
       pattern = DATE_AND_TIME_PATTERN;
     } else {
       pattern = patternOption;
     }
 
     int maximumCacheValidity = 1000;
     DateFormat simpleFormat = null;
 
     try {
       simpleFormat = new SimpleDateFormat(pattern);
       maximumCacheValidity = CachedDateFormat.getMaximumCacheValidity(pattern);
     } catch (IllegalArgumentException e) {
         LogLog.warn(
           "Could not instantiate SimpleDateFormat with pattern "
           + patternOption, e);
 
       // default to the ISO8601 format
       simpleFormat = new SimpleDateFormat(ISO8601_PATTERN);
     }
 
     // if the option list contains a TZ option, then set it.
     if ((options != null) && (options.length > 1)) {
       TimeZone tz = TimeZone.getTimeZone((String) options[1]);
       simpleFormat.setTimeZone(tz);
     } else {
       simpleFormat = new DefaultZoneDateFormat(simpleFormat);
     }
 
     df = new CachedDateFormat(simpleFormat, maximumCacheValidity);
   }
 
   /**
    * Obtains an instance of pattern converter.
    * @param options options, may be null.
    * @return instance of pattern converter.
    */
   public static DatePatternConverter newInstance(
     final String[] options) {
     return new DatePatternConverter(options);
   }
 
   /**
    * {@inheritDoc}
    */
   public void format(final LoggingEvent event, final StringBuffer output) {
     synchronized(this) {
     	df.format(event.timeStamp, output);
     }
   }
 
   /**
    * {@inheritDoc}
    */
   public void format(final Object obj, final StringBuffer output) {
     if (obj instanceof Date) {
       format((Date) obj, output);
     }
 
     super.format(obj, output);
   }
 
   /**
    * Append formatted date to string buffer.
    * @param date date
    * @param toAppendTo buffer to which formatted date is appended.
    */
   public void format(final Date date, final StringBuffer toAppendTo) {
     synchronized(this) {
     	df.format(date.getTime(), toAppendTo);
     }
   }
 }