/*
    * The Kuali Financial System, a comprehensive financial management system for higher education.
    * 
    * Copyright 2005-2014 The Kuali Foundation
    * 
    * This program is free software: you can redistribute it and/or modify
    * it under the terms of the GNU Affero General Public License as
    * published by the Free Software Foundation, either version 3 of the
    * License, or (at your option) any later version.
   * 
   * This program 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 Affero General Public License for more details.
   * 
   * You should have received a copy of the GNU Affero General Public License
   * along with this program.  If not, see <http://www.gnu.org/licenses/>.
   */
  package org.kuali.kfs.sys.util;
  
  import java.sql.Timestamp;
  import java.util.Calendar;
  import java.util.Date;
  import java.util.GregorianCalendar;
  
  import org.kuali.kfs.sys.KFSConstants;
  import org.kuali.rice.krad.util.ObjectUtils;
  
  /**
   * Utility methods for comparing dates
   *
   *
   */
  public class KfsDateUtils {
      /**
       * Adds null-safety to commons.DateUtils isSameDay method.
       *
       * @return true if both dates are null or represent the same day
       */
      public static boolean isSameDay(Date date1, Date date2) {
          boolean same = false;
  
          if ((date1 == null) && (date2 == null)) {
              same = true;
          }
          else if ((date1 != null) && (date2 != null)) {
              return org.apache.commons.lang.time.DateUtils.isSameDay(date1, date2);
          }
          else {
              same = false;
          }
  
          return same;
      }
  
      /**
       * Adds null-safety to commons.DateUtils isSameDay method.
       *
       * @return true if both calendars are null or represent the same day
       */
      public static boolean isSameDay(Calendar cal1, Calendar cal2) {
          boolean same = false;
  
          if ((cal1 == null) && (cal2 == null)) {
              same = true;
          }
          else if ((cal1 != null) && (cal2 != null)) {
              return org.apache.commons.lang.time.DateUtils.isSameDay(cal1, cal2);
          }
          else {
              same = false;
          }
  
          return same;
      }
  
      /**
       * Converts the given java.util.Date into an equivalent java.sql.Date
       *
       * @param date
       * @return java.sql.Date constructed from the given java.util.Date
       */
      public static java.sql.Date convertToSqlDate(java.util.Date date) {
          return new java.sql.Date(date.getTime());
      }
  
  
      /**
       * Convert the given java.sql.date into a java.sql.date of which all the time fields are set to 0.
       *
       * @param date
       * @return
       */
      public static java.sql.Date clearTimeFields(java.sql.Date date) {
          Calendar timelessCal = new GregorianCalendar();
          timelessCal.setTime(date);
          timelessCal.set(Calendar.HOUR_OF_DAY, 0);
          timelessCal.set(Calendar.MINUTE, 0);
          timelessCal.set(Calendar.SECOND, 0);
         timelessCal.set(Calendar.MILLISECOND, 0);
 
         return new java.sql.Date(timelessCal.getTimeInMillis());
     }
 
 
     /**
      * Convert the given java.util.date into a java.util.date of which all the time fields are set to 0.
      *
      * @param date
      * @return
      */
     public static java.util.Date clearTimeFields(java.util.Date date) {
         Calendar timelessCal = new GregorianCalendar();
         timelessCal.setTime(date);
         timelessCal.set(Calendar.HOUR_OF_DAY, 0);
         timelessCal.set(Calendar.MINUTE, 0);
         timelessCal.set(Calendar.SECOND, 0);
         timelessCal.set(Calendar.MILLISECOND, 0);
 
         return new java.util.Date(timelessCal.getTimeInMillis());
     }
 
     /**
      * @param startDateTime
      * @param endDateTime
      * @return the difference in days between the second timestamp and first
      */
     public static double getDifferenceInDays(Timestamp startDateTime, Timestamp endDateTime) {
         int difference = 0;
 
         Calendar startCalendar = Calendar.getInstance();
         startCalendar.setTime(startDateTime);
 
         Calendar endCalendar = Calendar.getInstance();
         endCalendar.setTime(endDateTime);
 
         // First, get difference in whole days
         Calendar startCompare = Calendar.getInstance();
         startCompare.setTime(startDateTime);
         startCompare.set(Calendar.HOUR_OF_DAY, 0);
         startCompare.set(Calendar.MINUTE, 0);
         startCompare.set(Calendar.SECOND, 0);
         startCompare.set(Calendar.MILLISECOND, 0);
 
         Calendar endCompare = Calendar.getInstance();
         endCompare.setTime(endDateTime);
         endCompare.set(Calendar.HOUR_OF_DAY, 0);
         endCompare.set(Calendar.MINUTE, 0);
         endCompare.set(Calendar.SECOND, 0);
         endCompare.set(Calendar.MILLISECOND, 0);
 
         return (endCompare.getTimeInMillis() - startCompare.getTimeInMillis()) / ((double)KFSConstants.MILLSECONDS_PER_DAY);
     }
 
     /**
      * @param startDateTime
      * @param endDateTime
      * @return the difference in hours between the second timestamp and first
      */
     public static double getDifferenceInHours(Timestamp startDateTime, Timestamp endDateTime) {
         int difference = 0;
 
         Calendar startCalendar = Calendar.getInstance();
         startCalendar.setTime(startDateTime);
 
         Calendar endCalendar = Calendar.getInstance();
         endCalendar.setTime(endDateTime);
 
         // First, get difference in whole days
         Calendar startCompare = Calendar.getInstance();
         startCompare.setTime(startDateTime);
         startCompare.set(Calendar.HOUR_OF_DAY, 0);
         startCompare.set(Calendar.MINUTE, 0);
 
         Calendar endCompare = Calendar.getInstance();
         endCompare.setTime(endDateTime);
         endCompare.set(Calendar.HOUR_OF_DAY, 0);
         endCompare.set(Calendar.MINUTE, 0);
 
         return (endCalendar.getTimeInMillis() - startCalendar.getTimeInMillis()) / (60.0000 * 60.0000 * 1000.0000);
     }
 
     /**
      *
      * This method is a utility method to create a new java.sql.Date in one line.
      *
      * @param year
      * @param month
      * @param day
      *
      * @return a populated java.sql.Date with the year, month, and day specified, and no values for hour, minute, second,
      *         millisecond
      *
      */
     public static java.sql.Date newDate(Integer year, Integer month, Integer day) {
 
         // test for null arguments
         if (year == null) {
             throw new IllegalArgumentException("Argument 'year' passed in was null.");
         }
         if (month == null) {
             throw new IllegalArgumentException("Argument 'month' passed in was null.");
         }
         if (day == null) {
             throw new IllegalArgumentException("Argument 'day' passed in was null.");
         }
 
         Calendar calendar = Calendar.getInstance();
         calendar.set(Calendar.YEAR, year);
         calendar.set(Calendar.MONTH, month);
         calendar.set(Calendar.DAY_OF_MONTH, day);
         calendar.clear(Calendar.HOUR_OF_DAY);
         calendar.clear(Calendar.MINUTE);
         calendar.clear(Calendar.SECOND);
         calendar.clear(Calendar.MILLISECOND);
 
         return new java.sql.Date(calendar.getTimeInMillis());
     }
 
     /**
      *
      * This method is a utility method to create a new java.sql.Date in one line.
      *
      * @param year
      * @param month
      * @param day
      * @param hour
      * @param minute
      * @param second
      *
      * @return a populated java.sql.Date with the year, month, hour, minute, and second populated, with no value for millisecond.
      *
      */
     public static java.sql.Date newDate(Integer year, Integer month, Integer day, Integer hour, Integer minute, Integer second) {
 
         // test for null arguments
         if (year == null) {
             throw new IllegalArgumentException("Argument 'year' passed in was null.");
         }
         if (month == null) {
             throw new IllegalArgumentException("Argument 'month' passed in was null.");
         }
         if (day == null) {
             throw new IllegalArgumentException("Argument 'day' passed in was null.");
         }
         if (hour == null) {
             throw new IllegalArgumentException("Argument 'hour' passed in was null.");
         }
         if (minute == null) {
             throw new IllegalArgumentException("Argument 'minute' passed in was null.");
         }
         if (second == null) {
             throw new IllegalArgumentException("Argument 'second' passed in was null.");
         }
 
         Calendar calendar = Calendar.getInstance();
         calendar.set(Calendar.YEAR, year);
         calendar.set(Calendar.MONTH, month);
         calendar.set(Calendar.DAY_OF_MONTH, day);
         calendar.set(Calendar.HOUR_OF_DAY, hour);
         calendar.set(Calendar.MINUTE, minute);
         calendar.set(Calendar.SECOND, second);
         calendar.clear(Calendar.MILLISECOND);
 
         return new java.sql.Date(calendar.getTimeInMillis());
     }
 
     /**
      * Determines if the given date d1 is on the same day or an earlier day than the given date d2.
      * @param d1 a date
      * @param d2 another date, to compare the first date to
      * @return true if d1 is earlier or the same day as d2, false otherwise or if either value is null
      */
     public static boolean isSameDayOrEarlier(Date d1, Date d2) {
         if (ObjectUtils.isNull(d1) || ObjectUtils.isNull(d2)) {
             return false;
         }
         if (isSameDay(d1, d2)) {
             return true;
         }
         return d1.compareTo(d2) < 0;
     }
 
     /**
      * Determines if the given date d1 is on the same day or a later day than the given date d2.
      * @param d1 a date
      * @param d2 another date, to compare the first date to
      * @return true if d1 is later or the same day as d2, false otherwise or if either value is null
      */
     public static boolean isSameDayOrLater(Date d1, Date d2) {
         if (ObjectUtils.isNull(d1) || ObjectUtils.isNull(d2)) {
             return false; // we can't compare against nulls
         }
         if (isSameDay(d1, d2)) {
             return true;
         }
         return d1.compareTo(d2) > 0;
     }
 }