package can.lyj.com;

public class Mycalander {

	/**
	 * 
	 * @param year
	 *            年份
	 * @return
	 */
	private static boolean isLoopYear(int year) {

		return ((year % 4 == 0 && year % 100 != 0) || (year % 400 == 0));

	}

	/**
	 * 
	 * @param year
	 *            年份
	 * @return 获得当前日期的第一天是星期几
	 */
	private static int getWeek(int year, int month) {
		long days = 0, sum = 0;
		final int MAX = 366, MIN = 365, Day_OF_WEEK = 7;

		for (int y = 1; y < year; y++) {
			days = isLoopYear(y) ? MAX : MIN;
			sum += days;
		}
		for (int mon = 1; mon < month; mon++) {
			if (mon != 2) {
				int dy = isBig(mon) ? 31 : 30;
				sum += dy;

			} else if (mon == 2) {
				sum += isLoopYear(year) ? 29 : 28;
			}
		}
		int week = (int) ((sum + 1) % Day_OF_WEEK);
		return week;

	}

	/**
	 * 
	 * @param month月份
	 *            判断是大月还是小月
	 */
	private static boolean isBig(int month) {
		switch (month) {
		case 1:case 3:case 5:case 7:case 8 : case 10 :case 12:
			return true;

		default:
			return false;
		}
	}

	private static int getHowDay(int currMonth, int year) {
		if (currMonth == 2) {
			if (isLoopYear(year)) {
				return 29;
			} else
				return 28;
		}
		return isBig(currMonth) ? 31 : 30;
	}

	/**
	 * 根据年月获得日历数组
	 * 
	 * @param years
	 * @param months
	 * @return
	 */
	public static int[][] getDateAry(int years, int months) {
		int[][] date = new int[6][7];
		int howDays = getHowDay(months, years);
		final int before=getHowDay( months==1?12:months-1,months==1?years-1:years);
		int howWeek = getWeek(years, months);
		int first=before-howWeek+1;
		int index = 0;
		int priveous=1;
		for (int i = 0; i < 6; i++) {
			for (int j = 0; j < 7 ; j++) {
				if (i == 0) {
					if (j < howWeek) {
						date[0][j]=first++;
					} else {
						date[0][j] = ++index;
					}

				} else if( index <howDays){
					date[i][j] = ++index;
				}
				else{
					date[i][j]=priveous;
					priveous++;
				}
				
			}

		}
		return date;

	}

}