import java.time.LocalDate;
import java.time.DayOfWeek;
public class Meetup {
private final LocalDate startOfMonth;
public Meetup(int monthOfYear, int year) {
startOfMonth = LocalDate.of(year, monthOfYear, 1);
}
LocalDate day(DayOfWeek dayOfWeek, MeetupSchedule schedule) {
LocalDate current = cycleToNext(dayOfWeek, startOfMonth);
switch (schedule) {
case FIRST:
break;
case SECOND:
current = current.plusWeeks(1);
break;
case THIRD:
current = current.plusWeeks(2);
break;
case FOURTH:
current = current.plusWeeks(3);
break;
case TEENTH:
while (current.getDayOfMonth() < 13) {
current = current.plusWeeks(1);
}
break;
case LAST:
current = cycleToPrev(dayOfWeek, startOfMonth.plusMonths(1).minusDays(1));
break;
default:
return null;
}
return current;
}
private LocalDate cycleToPrev(DayOfWeek dayOfWeek, LocalDate current) {
while (current.getDayOfWeek() != dayOfWeek) {
current = current.minusDays(1);
}
return current;
}
private LocalDate cycleToNext(DayOfWeek dayOfWeek, LocalDate current) {
while (current.getDayOfWeek() != dayOfWeek) {
current = current.plusDays(1);
}
return current;
}
}