package rebelsky.date;

/**
 * Whee!  A simple implementation of months.
 */
public class Month
	implements Comparable
{
	/** The month: 1 = jan, 2 = feb, ... */
	int month; 

	public Month(int _month)
	{
		this.month = _month;
	}

	/**
	 * Compare this month to another month.
	 * Precondition: other must be a month.
	 */
	public int compareTo(Object other)
	{
		Month otherMonth = (Month) other;  // If other isn't a month, this fails.
		return this.month - other.month;
	} // compareTo(Object)
	
	/**
	 * Determine if this month is the same as another object.
	 */
	public boolean equals(Object other)
	{
		// Make sure that other is a month
		if (other instanceof Month) {
		  Month otherMonth = (Month) other;
		  return this.month == otherMonth.month;
		}
		// Whoops!  other is not a Month.
		else {
			return this.toString().equals(other.toString());
		}
	} // equals(Object)
	
	/**
	 * Get the number of days in the whole year before the first day of
	 * this month.
	 */
	public int daysPreceding()
	{
		int days = 0;
		for (int i = 1; i < this.month; i++) {
			days += daysInMonth(i);
		} // for each month preceding the current month
		return days;
	} // daysPreceding

	int daysInMonth(int mon)
	{
		switch (mon) {
			case 9:
			case 4:
			case 6:
			case 11:
				return 30;
			case 2:
				return 28;
			default:
				return 31;
		} // switch
	} // daysInMonth(int)
	
	/**
	 * Represent this month as a string.
	 */
	public String toString()
	{
		return Integer.toString(month);
	} // toString()
	
	/**
	 * Get the month as an integer.
	 */
	int get()
	{
		return this.month;
	} // get()
} // class Month