Week.java

package marubinotto.util.time;

import java.util.Calendar;

import marubinotto.util.Assert;

/**
 * marubinotto.util.time.Week
 */
public class Week extends Interval {

	public Week() {
		this(DateTime.getCurrentTime());
	}

	public Week(DateTime dateTime) {
		super(getFirstInstantOfWeek(dateTime), getEndInstantOfWeek(dateTime));
	}

	public String toString() {
		return "Week: " + getFirstDay() + " - " + getLastDay();
	}

	public DateTime getFirstDay() {
		return getStartInstant();
	}

	public DateTime getLastDay() {
		return getEndInstant();
	}

	public DateTime[] getDays() {
		DateTime[] days = new DateTime[7];
		DateTime firstDay = getFirstDay();
		days[0] = firstDay;
		for (int i = 1; i < 7; i++) {
			days[i] = firstDay.addDays(i);
		}
		return days;
	}

	public Week getLastWeek() {
		return new Week(getFirstDay().addDays(-1));
	}

	public Week getNextWeek() {
		return new Week(getLastDay().addDays(1));
	}

	// Utility methods

	public static DateTime getFirstInstantOfWeek(DateTime dateTime) {
		Assert.Arg.notNull(dateTime, "dateTime");

		Calendar calendar = DateTime.createCalendar(dateTime.getYear(),
			dateTime.getMonth(), dateTime.getDayOfMonth());
		while (true) {
			if (calendar.get(Calendar.DAY_OF_WEEK) == calendar.getFirstDayOfWeek()) {
				break;
			}
			calendar.add(Calendar.DAY_OF_MONTH, -1);
		}
		return new DateTime(calendar);
	}

	public static DateTime getEndInstantOfWeek(DateTime dateTime) {
		Assert.Arg.notNull(dateTime, "dateTime");

		DateTime firstInstant = getFirstInstantOfWeek(dateTime);
		Calendar calendar = firstInstant.toCalendar();
		calendar.add(Calendar.DAY_OF_MONTH, 7);
		calendar.add(Calendar.MILLISECOND, -1);
		return new DateTime(calendar);
	}
}