next method

SolarWeek next(int weeks, bool separateMonth)

Implementation

SolarWeek next(int weeks, bool separateMonth) {
  if (0 == weeks) {
    return SolarWeek.fromYmd(_year, _month, _day, _start);
  }
  Solar solar  = Solar.fromYmd(_year, _month, _day);
  if (separateMonth) {
    int n = weeks;
    SolarWeek week = SolarWeek.fromYmd(solar.getYear(), solar.getMonth(), solar.getDay(), _start);
    int month = _month;
    bool plus = n > 0;
    while (0 != n) {
      solar = solar.next(plus ? 7 : -7);
      week = SolarWeek.fromYmd(solar.getYear(), solar.getMonth(), solar.getDay(), _start);
      int weekMonth = week.getMonth();
      if (month != weekMonth) {
        int index = week.getIndex();
        if (plus) {
          if (1 == index) {
            Solar firstDay = week.getFirstDay();
            week = SolarWeek.fromYmd(firstDay.getYear(), firstDay.getMonth(), firstDay.getDay(), _start);
            weekMonth = week.getMonth();
          } else {
            solar = Solar.fromYmd(week.getYear(), week.getMonth(), 1);
            week = SolarWeek.fromYmd(solar.getYear(), solar.getMonth(), solar.getDay(), _start);
          }
        } else {
          if (SolarUtil.getWeeksOfMonth(week.getYear(), week.getMonth(), _start) == index) {
            Solar lastDay = week.getFirstDay().next(6);
            week = SolarWeek.fromYmd(lastDay.getYear(), lastDay.getMonth(), lastDay.getDay(), _start);
            weekMonth = week.getMonth();
          } else {
            solar = Solar.fromYmd(week.getYear(), week.getMonth(), SolarUtil.getDaysOfMonth(week.getYear(), week.getMonth()));
            week = SolarWeek.fromYmd(solar.getYear(), solar.getMonth(), solar.getDay(), _start);
          }
        }
        month = weekMonth;
      }
      n -= plus ? 1 : -1;
    }
    return week;
  } else {
    solar = solar.next(weeks * 7);
    return SolarWeek.fromYmd(solar.getYear(), solar.getMonth(), solar.getDay(), _start);
  }
}