content: /*******************************************************************************
   * Software Name : RCS IMS Stack
   *
   * Copyright (C) 2010-2016 Orange.
   *
   * Licensed 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 com.gsma.rcs.utils;
  
  import java.text.ParseException;
  import java.text.SimpleDateFormat;
  import java.util.Date;
  import java.util.TimeZone;
  
  import android.text.format.Time;
  
  /**
   * Date utility functions
   * 
   * @author jexa7410
   * @author Deutsche Telekom
   */
  public class DateUtils {
      /**
       * UTC time zone
       */
      private static TimeZone UTC = TimeZone.getTimeZone("UTC");
  
      /**
       * ISO 8601 date formats
       */
      private static SimpleDateFormat ISO8601DATEFORMAT[] = {
              new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssZ"),
              new SimpleDateFormat("yyyy-MM-dd'T'HH:mmZ")
      };
  
      /**
       * Encode a long date to string value in Z format (see RFC 3339)
       * 
       * @param date Date in milliseconds
       * @return String
       */
      public static String encodeDate(long date) {
          Time t = new Time(UTC.getID());
          t.set(date);
          return t.format3339(false);
      }
  
      /**
       * Decode a string date to long value (see ISO8601 and RFC 3339)
       * 
       * @param date Date as string
       * @return Milliseconds
       */
      public static long decodeDate(String date) {
          long millis = -1;
  
          // Try to use ISO8601
          String normalizedDate = date.replaceAll("Z$", "+0000");
          for (int i = 0; millis == -1 && i < ISO8601DATEFORMAT.length; i++) {
              try {
                  Date iso8601 = ISO8601DATEFORMAT[i].parse(normalizedDate);
                  millis = iso8601.getTime();
              } catch (ParseException ex) {
                  // Try next format
              }
          }
  
          // If still not valid format is found let's try RFC3339
          if (millis == -1) {
              Time t = new Time(UTC.getID());
              t.parse3339(date);
              millis = t.toMillis(false);
          }
  
          return millis;
      }
  }
  