package org.kuali.coeus.s2sgen.impl.datetime;
   
   import org.apache.commons.lang3.StringUtils;
   import org.kuali.coeus.sys.api.model.ScaleTwoDecimal;
   import org.springframework.stereotype.Component;
   
   import java.math.BigDecimal;
   import java.math.RoundingMode;
   import java.util.Calendar;
  import java.util.TimeZone;
  
  @Component("s2SDateTimeService")
  public class S2SDateTimeServiceImpl implements S2SDateTimeService {
  
      /**
       *
       * This method computes the number of months between any 2 given {@link java.sql.Date} objects
       *
       * @param dateStart starting date.
       * @param dateEnd end date.
       *
       * @return number of months between the start date and end date.
       */
      @Override
      public ScaleTwoDecimal getNumberOfMonths(java.util.Date dateStart, java.util.Date dateEnd) {
          ScaleTwoDecimal monthCount = ScaleTwoDecimal.ZERO;
          int fullMonthCount = 0;
  
          Calendar startDate = Calendar.getInstance();
          Calendar endDate = Calendar.getInstance();
          startDate.setTime(dateStart);
          endDate.setTime(dateEnd);
  
          startDate.clear(Calendar.HOUR);
          startDate.clear(Calendar.MINUTE);
          startDate.clear(Calendar.SECOND);
          startDate.clear(Calendar.MILLISECOND);
  
          endDate.clear(Calendar.HOUR);
          endDate.clear(Calendar.MINUTE);
          endDate.clear(Calendar.SECOND);
          endDate.clear(Calendar.MILLISECOND);
  
          if (startDate.after(endDate)) {
              return ScaleTwoDecimal.ZERO;
          }
          int startMonthDays = startDate.getActualMaximum(Calendar.DATE) - startDate.get(Calendar.DATE);
          startMonthDays++;
          int startMonthMaxDays = startDate.getActualMaximum(Calendar.DATE);
          BigDecimal startMonthFraction = BigDecimal.valueOf(startMonthDays).setScale(2, RoundingMode.HALF_UP).divide(BigDecimal.valueOf(startMonthMaxDays).setScale(2, RoundingMode.HALF_UP), RoundingMode.HALF_UP);
  
          int endMonthDays = endDate.get(Calendar.DATE);
          int endMonthMaxDays = endDate.getActualMaximum(Calendar.DATE);
  
          BigDecimal endMonthFraction = BigDecimal.valueOf(endMonthDays).setScale(2, RoundingMode.HALF_UP).divide(BigDecimal.valueOf(endMonthMaxDays).setScale(2, RoundingMode.HALF_UP), RoundingMode.HALF_UP);
  
          startDate.set(Calendar.DATE, 1);
          endDate.set(Calendar.DATE, 1);
  
          while (startDate.getTimeInMillis() < endDate.getTimeInMillis()) {
              startDate.set(Calendar.MONTH, startDate.get(Calendar.MONTH) + 1);
              fullMonthCount++;
          }
          fullMonthCount = fullMonthCount - 1;
          monthCount = monthCount.add(new ScaleTwoDecimal(fullMonthCount)).add(new ScaleTwoDecimal(startMonthFraction)).add(new ScaleTwoDecimal(endMonthFraction));
          return monthCount;
      }
  
      @Override
      public String removeTimezoneFactor(String applicationXmlText) {
          Calendar cal = Calendar.getInstance();
          int dstOffsetMilli = cal.get(Calendar.DST_OFFSET);
          int zoneOffsetMilli = cal.get(Calendar.ZONE_OFFSET);
          zoneOffsetMilli = cal.getTimeZone().useDaylightTime()?zoneOffsetMilli+dstOffsetMilli:zoneOffsetMilli;
          int zoneOffset = zoneOffsetMilli/(1000*60*60);
          String timezoneId = TimeZone.getTimeZone("GMT" + zoneOffset).getID();
          String offset="+00:00";
          if(timezoneId.length()>6){
              offset = timezoneId.substring(timezoneId.length()-6);
          }
          String filteredApplicationStr = StringUtils.remove(applicationXmlText, offset);
          return filteredApplicationStr;
      }
  
      /**
       * This method returns a {@link Calendar} whose date matches the date passed as {@link String}
       *
       * @param dateStr string in "MM/dd/yyyy" format for which the Calendar value has to be returned.
       * @return Calendar calendar value corresponding to the date string.
       */
      @Override
      public Calendar convertDateStringToCalendar(String dateStr) {
          Calendar calendar = null;
          if (dateStr != null) {
              calendar = Calendar.getInstance();
              calendar.set(Integer.parseInt(dateStr.substring(6, 10)), Integer.parseInt(dateStr.substring(0, 2)) - 1,
                      Integer.parseInt(dateStr.substring(3, 5)));
          }
          return calendar;
     }
 
     /**
      * This method is used to get Calendar date for the corresponding date object.
      *
      * @param date(Date) date for which Calendar value has to be found.
      * @return calendar value corresponding to the date.
      */
     @Override
     public Calendar convertDateToCalendar(java.util.Date date) {
         Calendar calendar = null;
         if (date != null) {
             calendar = Calendar.getInstance();
             calendar.setTime(date);
         }
         return calendar;
     }
 }