package interval;

import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
import java.util.Iterator;
import java.util.TimeZone;

public abstract class Interval implements Iterator<Date> {
	public static final String TIMEZONE = "Europe/Amsterdam";

	protected Date endDate;
	protected TimeZone timeZone;
	protected Calendar calendar;

	public Interval() {}

	public Interval(Date startDate, Date endDate, String timeZoneID) {
		setTimeZone(timeZoneID);
		setDate(startDate, endDate);
	}

	public void setTimeZone(String timeZoneID) {
		timeZone = TimeZone.getTimeZone(timeZoneID);
		calendar = new GregorianCalendar(TimeZone.getTimeZone(TIMEZONE));		
	}

	public Interval(Date startDate, Date endDate) {
		this(startDate, endDate, TIMEZONE);
	}
	
	public void setDate(Date startDate, Date endDate) {
		if (timeZone == null) {
			setTimeZone(TIMEZONE);
		}
		calendar.setTime(startDate);
		adjust();
		this.endDate = endDate;
	}

	public void remove() {}

	public Date get() {
		return calendar.getTime();
	}

	public abstract Date next();

	public boolean hasNext() {
		return next().compareTo(endDate) < 0;
	}

	protected abstract void adjust();
}