$(function(){
	// 달력 넘기기
	$("#prev_month, #prev_year, #next_month, #next_year").click(function() {
		var param = {month : $(this).attr("month"), year : $(this).attr("year")};
		calender(param);
	});
	
	// 달력 선택
	$(document).on("click", ".calendar_event td a", function(){
		
		var year  = $(this).attr("year");
		var month = $(this).attr("month");
		var day   = $(this).attr("day");
		
		$("#lately_day").val(year + "." + (Number(month)+1) + "." + day);
	});
});

$(document).ready(function() {
	calender();	
});

// 달력 그리기
function calender(param) {
	
	var now   = new Date();
	var thismonth = now.getDay();
	var thismonth = now.getMonth();
	var thisyear  = now.getFullYear();
	
	var opts = {
		month: thismonth,
		year: thisyear
	};
	
	$.extend(opts, param);
	
	month = parseInt(opts.month);
	year  = parseInt(opts.year);
	var innerHtml = '';
	
	// 다음달
	if (month == 11) {
		$("#next_month").attr("month", "0");
		$("#next_month").attr("year", (year + 1));
	} else {
		$("#next_month").attr("month", (month + 1));
		$("#next_month").attr("year", year);
	}
		
	// 이전달
	if (month == 0) {
		$("#prev_month").attr("month", "11");
		$("#prev_month").attr("year", (year - 1));
	} else {
		$("#prev_month").attr("month", (month - 1));
		$("#prev_month").attr("year", year);
	}	
	
	// 다음해
	$("#next_year").attr("month", month);
	$("#next_year").attr("year", (year + 1));
	
	// 이전해
	$("#prev_year").attr("month", month);
	$("#prev_year").attr("year", (year - 1));
	
	// 현재
	$("#cal_date").html(year + ". " + (month + 1));

	var days 		 = getDaysInMonth(month, year);
       var firstDayDate = new Date(year, month, 1);
       var firstDay	 = firstDayDate.getDay();
	
	var prev_days 	 = getDaysInMonth(month, year);
       var firstDayDate = new Date(year, month, 1);
       var firstDay	 = firstDayDate.getDay();
	
	var prev_m 		 = (month == 0) ? 11 : month - 1;
	var prev_y 		 = (prev_m == 11) ? year - 1 : year;
	var prev_days 	 = getDaysInMonth(prev_m, prev_y);
	firstDay 		 = (firstDay == 0 && firstDayDate) ? 7 : firstDay;

	var i = 0;
    for (j = 0 ; j < 42 ; j++){
		var sun = "";
     	if (j % 7 == 0) {
       		innerHtml += '<tr>';
       		sun = "sun";
         }
     	
       	if (j < firstDay) {
       		if(month == 0) {
         		innerHtml += '<td class="disable"><div><a href="javascript:void(0);" year="' + (year - 1) + '" month="11" day="' + (prev_days - firstDay + j + 1) + '"><span class="date">' + (prev_days - firstDay + j + 1) + '</span><span class="day">today</span></a></div></td>';
       		} else {
         		innerHtml += '<td class="disable"><div><a href="javascript:void(0);" year="' + year + '" month="' + (month - 1) + '" day="' + (prev_days - firstDay + j + 1) + '"><span class="date">' + (prev_days - firstDay + j + 1) + '</span><span class="day">today</span></a></div></td>';
       		}
		} else if (j >= (firstDay + getDaysInMonth(month, year))) {
			i = i+1;
			if(month == 11) {
         		innerHtml += '<td class="disable"><div><a href="javascript:void(0);" year="' + (year + 1) + '" month="0" day="' + i + '"><span class="date">' + i + '</span><span class="day">today</span></a></div></td>';
			} else {
         		innerHtml += '<td class="disable"><div><a href="javascript:void(0);" year="' + year + '" month="' + (month + 1) + '" day="' + i + '"><span class="date">' + i + '</span><span class="day">today</span></a></div></td>';
			}
       	} else {
         	innerHtml += '<td><div><a href="javascript:void(0);" year="' + year + '" month="' + month + '" day="' + (j-firstDay+1) + '"><span class="date ' + sun + '">' + (j-firstDay+1) + '</span><span class="day">today</span></a></div></td>';
       	}
       	if (j % 7 == 6) {
     	    innerHtml += '</tr>';
       	}
    }

	$("#cal_body").html(innerHtml);
}

function getDaysInMonth(month, year) {
	var daysInMonth = [31,28,31,30,31,30,31,31,30,31,30,31];
	if ((month == 1) && (year % 4 == 0) && ((year % 100 != 0) || (year % 400 == 0))){
	  return 29;
	}else{
	  return daysInMonth[month];
	}
}