DateTimeUtils.java

/*
    Copyright (C) 2012 Prasanna Thirumalai
    
    This file is part of StackX.

    StackX is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    StackX is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with StackX.  If not, see <http://www.gnu.org/licenses/>.
 */

package com.prasanna.android.stacknetwork.utils;

import java.text.SimpleDateFormat;
import java.util.Date;

public class DateTimeUtils {
  private static final String JUST_NOW = "just now";
  private static final String AGO = "ago";

  private static final SimpleDateFormat formatter = new SimpleDateFormat("MMM dd yyyy HH:mm");

  public static final String SECOND = "s";
  public static final String MINUTE = "m";
  public static final String HOUR = "h";
  public static final String DAY = "d";
  public static final String MONTH = "M";
  public static final String YEAR = "y";

  public static final int SECONDS_IN_MIN = 60;
  public static final int SECONDS_IN_HOUR = 3600;
  public static final int SECONDS_IN_DAY = 3600 * 24;
  public static final int DAYS_IN_MONTH = 30;
  public static final int MONTHS_IN_YEAR = 12;

  public static String toDateString(long seconds) {
    return formatter.format(new Date(seconds * 1000L));
  }

  public static String getElapsedDurationSince(long seconds) {
    String unit = SECOND;
    String residueUnit = null;

    long currentTimeInSeconds = System.currentTimeMillis() / 1000;
    long elapsedTimeInSeconds = currentTimeInSeconds - seconds;

    int count = 0;
    int residue = 0;

    if (elapsedTimeInSeconds > SECONDS_IN_MIN && elapsedTimeInSeconds < SECONDS_IN_HOUR) {
      count = (int) (elapsedTimeInSeconds / SECONDS_IN_MIN);
      unit = MINUTE;
    } else if (elapsedTimeInSeconds > SECONDS_IN_HOUR && elapsedTimeInSeconds < SECONDS_IN_DAY) {
      count = (int) (elapsedTimeInSeconds / SECONDS_IN_HOUR);
      unit = HOUR;
    } else if (elapsedTimeInSeconds > SECONDS_IN_DAY) {
      count = (int) (elapsedTimeInSeconds / SECONDS_IN_DAY);
      if (count > DAYS_IN_MONTH) {

        residue = count % DAYS_IN_MONTH;
        count /= DAYS_IN_MONTH;

        if (count > MONTHS_IN_YEAR) {
          residue = count % MONTHS_IN_YEAR;
          count /= MONTHS_IN_YEAR;
          unit = YEAR;
          residueUnit = MONTH;
        } else {
          unit = MONTH;
          residueUnit = DAY;
        }
      } else {
        unit = DAY;
      }
    }

    if (count == 0)
      return JUST_NOW;

    String duration = new String(count + unit);

    if (residue > 0)
      duration += " " + residue + residueUnit;

    duration += " " + AGO;
    return duration;
  }
}