// The DatePicker constructor
// oDate : Date Optional argument representing the date to select
function DatePicker( oDate ) {
	// check arguments
	if ( arguments.length == 0 ) {
		this._selectedDate = new Date;
		this._none = false;
	}
	else {
		this._selectedDate = oDate || new Date();
		this._none = oDate == null;
	}

	this._matrix = [[],[],[],[],[],[],[]];
	this._showNone = true;
	this._showToday = true;
	this._firstWeekDay = 0;	// start week with monday according to standards
	this._redWeekDay = 6;	// sunday is the default red day.

	this._dontChangeNone = false;
}

// two static fields describing the name of the months abd days
DatePicker.months = [
	"년 1월", "년 2월 ", "년 3월 ", "년 4월 ",
	"년 5월 ", "년 6월 ", "년 7월 ", "년 8월 ",
	"년 9월 ", "년 10월 ", "년 11월", "년 12월"];
DatePicker.days = ["월", "화", "수", "목", "금", "토", "일"];

DatePicker.prototype.onchange = function () {};

// create the nodes inside the date picker
DatePicker.prototype.create = function ( doc ) {
	if ( doc == null ) doc = document;

	this._document = doc;
	// create elements
	this._el = doc.createElement( "div" );
	this._el.className = "datePicker";

	// header
	var div = doc.createElement( "div" );
	div.className = "header";
	this._el.appendChild( div );
	var headerTable = doc.createElement( "table" );
	headerTable.className = "headerTable";
	headerTable.cellSpacing = 0;
	div.appendChild( headerTable );

	var tBody = doc.createElement( "tbody" );
	headerTable.appendChild( tBody );

	var tr = doc.createElement( "tr" );
	tBody.appendChild( tr );

	var td = doc.createElement( "td" );
	this._previousMonth = doc.createElement( "button" );
	this._previousMonth.className = "previousButton";
	td.appendChild( this._previousMonth );
	tr.appendChild( td );

	td = doc.createElement( "td" );
	td.className = "labelContainer";
	tr.appendChild( td );

	this._topLabel = doc.createElement( "a" );
	this._topLabel.className = "topLabel";
	this._topLabel.href = "#";
	this._topLabel.appendChild( doc.createTextNode( String.fromCharCode( 160 ) ) );
	td.appendChild( this._topLabel );

	this._labelPopup = doc.createElement( "div" );
	this._labelPopup.className = "labelPopup";
	// no insertion

	td = doc.createElement( "td" );
	this._nextMonth = doc.createElement( "button" );
	this._nextMonth.className = "nextButton";
	td.appendChild( this._nextMonth );
	tr.appendChild( td );

	// grid
	div = doc.createElement( "div" );
	div.className = "grid";
	this._el.appendChild( div );
	this._table = div;

	// footer
	div = doc.createElement( "div" );
	div.className = "footer";
	this._el.appendChild( div );

	var footerTable = doc.createElement( "table" );
	footerTable.className = "footerTable";
	footerTable.cellSpacing = 0;
	div.appendChild( footerTable );

	tBody = doc.createElement( "tbody" );
	footerTable.appendChild( tBody );

	tr = doc.createElement( "tr" );
	tBody.appendChild( tr );

	td = doc.createElement( "td" );
	this._todayButton = doc.createElement( "button" );
	this._todayButton.className = "todayButton";
	this._todayButton.appendChild( doc.createTextNode( "금일" ) );
	td.appendChild( this._todayButton );
	tr.appendChild( td );

	td = doc.createElement( "td" );
	td.className = "filler";
	td.appendChild( doc.createTextNode( String.fromCharCode( 160 ) ) );
	tr.appendChild( td );

	td = doc.createElement( "td" );
	this._noneButton = doc.createElement( "button" );
	this._noneButton.className = "noneButton";
	this._noneButton.appendChild( doc.createTextNode( "닫기" ) );
	td.appendChild( this._noneButton );
	tr.appendChild( td );


	this._createTable( doc );

	this._updateTable();
	this._setTopLabel();

	if ( !this._showNone )
		this._noneButton.style.visibility = "hidden";
	if ( !this._showToday )
		this._todayButton.style.visibility = "hidden";

	// IE55+ extension
	this._previousMonth.hideFocus = true;
	this._nextMonth.hideFocus = true;
	this._todayButton.hideFocus = true;
	this._noneButton.hideFocus = true;
	// end IE55+ extension

	// hook up events
	var dp = this;
	// buttons
	this._previousMonth.onclick = function () {
		dp._dontChangeNone = true;
		dp.goToPreviousMonth();
		dp._dontChangeNone = false;
	};
	this._nextMonth.onclick = function () {
		dp._dontChangeNone = true;
		dp.goToNextMonth();
		dp._dontChangeNone = false;
	};
	this._todayButton.onclick = function () {
		dp.goToToday();
	};
	this._noneButton.onclick = function () {
		HideDP();
	};

	this._el.onselectstart = function () {
		return false;
	};

	this._table.onclick = function ( e ) {
		// find event
		if ( e == null ) e = doc.parentWindow.event;

		// find td
		var el = e.target != null ? e.target : e.srcElement;
		while ( el.nodeType != 1 )
			el = el.parentNode;
		while ( el != null && el.tagName && el.tagName.toLowerCase() != "td" )
			el = el.parentNode;

		// if no td found, return
		if ( el == null || el.tagName == null || el.tagName.toLowerCase() != "td" )
			return;

		var d = new Date( dp._selectedDate );
		var n = Number( el.firstChild.data );
		if ( isNaN( n ) || n <= 0 || n == null )
			return;

		d.setDate( n );
		dp.setDate( d );
		HideDP();
	};

	// show popup
	this._topLabel.onclick = function ( e ) {
		dp._showLabelPopup();
		return false;
	};

	this._el.onkeydown = function ( e ) {
		if ( e == null ) e = doc.parentWindow.event;
		var kc = e.keyCode != null ? e.keyCode : e.charCode;

		if ( kc < 37 || kc > 40 ) return true;

		var d = new Date( dp._selectedDate ).valueOf();
		if ( kc == 37 ) // left
			d -= 24 * 60 * 60 * 1000;
		else if ( kc == 39 ) // right
			d += 24 * 60 * 60 * 1000;
		else if ( kc == 38 ) // up
			d -= 7 * 24 * 60 * 60 * 1000;
		else if ( kc == 40 ) // down
			d += 7 * 24 * 60 * 60 * 1000;

		dp.setDate( new Date( d ) );
		return false;
	}

	// ie6 extension
	this._el.onmousewheel = function ( e ) {
		if ( e == null ) e = doc.parentWindow.event;
		var n = - e.wheelDelta / 120;
		var d = new Date( dp._selectedDate );
		var m = d.getMonth() + n;
		d.setMonth( m );


		dp._dontChangeNone = true;
		dp.setDate( d );
		dp._dontChangeNone = false;

		return false;
	}
	return this._el;
};

DatePicker.prototype.setDate = function ( oDate ) {

	this._hideLabelPopup();

	// if null then set None
	if ( oDate == null ) {
		if ( !this._none ) {
			this._none = true;
			this._setTopLabel();
			this._updateTable();

			if ( typeof this.onchange == "function" )
				this.onchange();
		}
		return;
	}

	// if string or number create a Date object
	if ( typeof oDate == "string" || typeof oDate == "number" ) {
		oDate = new Date( oDate );
	}

	// do not update if not really changed
	if ( this._selectedDate.getDate() != oDate.getDate() ||
		this._selectedDate.getMonth() != oDate.getMonth() ||
		this._selectedDate.getFullYear() != oDate.getFullYear() ||
		this._none ) {

		if ( !this._dontChangeNone )
			this._none = false;

		this._selectedDate = new Date( oDate );

		this._setTopLabel();
		this._updateTable();
	}

	if ( typeof this.onchange == "function" )
		this.onchange();

	if ( !this._dontChangeNone )
		this._none = false;
}


DatePicker.prototype.getDate = function () {
	if ( this._none ) return null;
	return new Date( this._selectedDate );	// create a new instance
}

// creates the table elements and inserts them into the date picker
DatePicker.prototype._createTable = function ( doc ) {
	var str, i;
	var rows = 6;
	var cols = 7;
	var currentWeek = 0;

	var table = doc.createElement( "table" );
	table.className = "gridTable";
	table.cellSpacing = 0;

	var tBody = doc.createElement( "tbody" );
	table.appendChild( tBody );

	// days row
	var tr = doc.createElement( "tr" );
	tr.className = "daysRow";

	var td, tn;
	var nbsp = String.fromCharCode( 160 );
	for ( i = 0; i < cols; i++ ) {
		td = doc.createElement( "td" );
		td.appendChild( doc.createTextNode( nbsp ) );
		tr.appendChild( td );
	}
	tBody.appendChild( tr );

	// upper line
	tr = doc.createElement( "tr" );
	td = doc.createElement( "td" );
	td.className = "upperLine";
	td.colSpan = 7;
	tr.appendChild( td );
	tBody.appendChild( tr );

	// rest
	for ( i = 0; i < rows; i++ ) {
		tr = doc.createElement( "tr" );
		for ( var j = 0; j < cols; j++ ) {
			td = doc.createElement( "td" );
			td.appendChild( doc.createTextNode( nbsp ) );
			tr.appendChild( td );
		}
		tBody.appendChild( tr );
	}
	str += "</table>";

	if ( this._table != null )
		this._table.appendChild( table )
};
// this method updates all the text nodes inside the table as well
// as all the classNames on the tds
DatePicker.prototype._updateTable = function () {
	// if no element no need to continue
	if ( this._table == null ) return;

	var i;
	var str = "";
	var rows = 6;
	var cols = 7;
	var currentWeek = 0;

	var cells = new Array( rows );
	this._matrix = new Array( rows )
	for ( i = 0; i < rows; i++ ) {
		cells[i] = new Array( cols );
		this._matrix[i] = new Array( cols );
	}

	// Set the tmpDate to this month
	var tmpDate = new Date( this._selectedDate.getFullYear(),
							this._selectedDate.getMonth(), 1 );
	var today = new Date();
	// go thorugh all days this month and store the text
	// and the class name in the cells matrix
	for ( i = 1; i < 32; i++ ) {
		tmpDate.setDate( i );
		// convert to ISO, Monday is 0 and 6 is Sunday
		var weekDay = ( tmpDate.getDay() + 6 ) % 7;
		var colIndex = ( weekDay - this._firstWeekDay + 7 ) % 7;
		if ( tmpDate.getMonth() == this._selectedDate.getMonth() ) {

			var isToday = tmpDate.getDate() == today.getDate() &&
						tmpDate.getMonth() == today.getMonth() &&
						tmpDate.getFullYear() == today.getFullYear();

			cells[currentWeek][colIndex] = { text: "", className: "" };

			if ( this._selectedDate.getDate() == tmpDate.getDate() && !this._none )
				cells[currentWeek][colIndex].className += "selected ";
			if ( isToday )
				cells[currentWeek][colIndex].className += "today ";
			if ( ( tmpDate.getDay() + 6 ) % 7 == this._redWeekDay ) // ISO
				cells[currentWeek][colIndex].className += "red";

			cells[currentWeek][colIndex].text =
				this._matrix[currentWeek][colIndex] = tmpDate.getDate();

			if ( colIndex == 6 )
				currentWeek++;
		}
	}

	// fix day letter order if not standard
	var weekDays = DatePicker.days;
	if (this._firstWeekDay != 0) {
		weekDays = new Array(7);
		for ( i = 0; i < 7; i++)
			weekDays[i] = DatePicker.days[ (i + this._firstWeekDay) % 7];
	}

	// update text in days row
	var tds = this._table.firstChild.tBodies[0].rows[0].cells;
	for ( i = 0; i < cols; i++ )
		tds[i].firstChild.data = weekDays[i];

	// update the text nodes and class names
	var trs = this._table.firstChild.tBodies[0].rows;
	var tmpCell;
	var nbsp = String.fromCharCode( 160 );
	for ( var y = 0; y < rows; y++ ) {
		for (var x = 0; x < cols; x++) {
			tmpCell = trs[y + 2].cells[x];
			if ( typeof cells[y][x] != "undefined" ) {
				tmpCell.className = cells[y][x].className;
				tmpCell.firstChild.data = cells[y][x].text;
			}
			else {
				tmpCell.className = "";
				tmpCell.firstChild.data = nbsp;
			}
		}
	}
}

// sets the label showing the year and selected month
DatePicker.prototype._setTopLabel = function () {
	var str = this._selectedDate.getFullYear() + DatePicker.months[ this._selectedDate.getMonth() ];
	if ( this._topLabel != null )
		this._topLabel.lastChild.data = str;
}

DatePicker.prototype.goToNextMonth = function () {
	var d = new Date( this._selectedDate );
	d.setMonth( d.getMonth() + 1 );
	this.setDate( d );
}

DatePicker.prototype.goToPreviousMonth = function () {
	var d = new Date( this._selectedDate );
	d.setMonth( d.getMonth() - 1 );
	this.setDate( d );
}

DatePicker.prototype.goToToday = function () {
	if ( this._none )
		// change the selectedDate to force update if none was true
		this._selectedDate = new Date( this._selectedDate + 10000000000 );
	this._none = false;
	this.setDate( new Date() );
}

DatePicker.prototype.setShowToday = function ( bShowToday ) {
	if ( typeof bShowToday == "string" )
		bShowToday = !/false|0|no/i.test( bShowToday );

	if ( this._todayButton != null )
		this._todayButton.style.visibility = bShowToday ? "visible" : "hidden";
	this._showToday = bShowToday;
}

DatePicker.prototype.getShowToday = function () {
	return this._showToday;
}

DatePicker.prototype.setShowNone = function ( bShowNone ) {
	if ( typeof bShowNone == "string" )
		bShowNone = !/false|0|no/i.test( bShowNone );

	if ( this._noneButton != null )
		this._noneButton.style.visibility = bShowNone ? "visible" : "hidden";
	this._showNone = bShowNone;
}

DatePicker.prototype.getShowNone = function () {
	return this._showNone;
}

// 0 is monday and 6 is sunday as in the ISO standard
DatePicker.prototype.setFirstWeekDay = function ( nFirstWeekDay ) {
	if ( this._firstWeekDay != nFirstWeekDay ) {
		this._firstWeekDay = nFirstWeekDay;
		this._updateTable();
	}
}

DatePicker.prototype.getFirstWeekDay = function () {
	return this._firstWeekDay;
}

// 0 is monday and 6 is sunday as in the ISO standard
DatePicker.prototype.setRedWeekDay = function ( nRedWeekDay ) {
	if ( this._redWeekDay != nRedWeekDay ) {
		this._redWeekDay = nRedWeekDay;
		this._updateTable();
	}
}

DatePicker.prototype.getRedWeekDay = function () {
	return this._redWeekDay;
}


DatePicker.prototype._showLabelPopup = function () {

	/*
	this._labelPopup document.createElement( "DIV" );
	div.className = "month-popup";
	div.noWrap = true;
	el.unselectable = div.unselectable = "on";
	el.onselectstart = div.onselectstart = function () { return false; };
	*/

	var dateContext = function ( dp, d ) {
		return function ( e ) {
			dp._dontChangeNone = true;
			dp._hideLabelPopup();
			dp.setDate( d );
			dp._dontChangeNone = false;
			return false;
		};
	};

	var dp = this;

	// clear all old elements in the popup
	while ( this._labelPopup.hasChildNodes() )
		this._labelPopup.removeChild( this._labelPopup.firstChild );

	var a, tmp;
	for ( var i = -3; i < 4; i++ ) {
		tmp = new Date( this._selectedDate );
		tmp.setDate(1);	// set day to 1 to prevent overflow with shorter months
		tmp.setMonth( tmp.getMonth() + i );

		a = this._document.createElement( "a" );
		a.href = "javascript:void 0;";
		a.onclick = dateContext( dp, tmp );
		a.appendChild( this._document.createTextNode( tmp.getFullYear() +
									DatePicker.months[ tmp.getMonth() ] ) );
		if ( i == 0 )
			a.className = "selected";
		this._labelPopup.appendChild( a );
	}

	this._topLabel.parentNode.insertBefore( this._labelPopup, this._topLabel.parentNode.firstChild );
};

DatePicker.prototype._hideLabelPopup = function () {
	if ( this._labelPopup.parentNode )
		this._labelPopup.parentNode.removeChild( this._labelPopup );
};

function day2(d) {																// 2자리 숫자료 변경
	var str = new String();

	if (parseInt(d) < 10) {
		str = "0" + parseInt(d);
	} else {
		str = "" + parseInt(d);
	}
	return str;
}

function ShowDP(obj, format_str) {
	g_targetText = obj;
	g_format_str = 	format_str;

	if (obj.value.length == 8)
	{
		var setDay = new Date(obj.value.substring(0,4), obj.value.substring(4,6)-1, obj.value.substring(6,8));
	} else if (obj.value.length == 10)
	{
		var setDay = new Date(obj.value.substring(0,4), obj.value.substring(5,7)-1, obj.value.substring(8,10));
	} else {
		var setDay = new Date();
	}

	var objdiv = document.all.dpdiv;
	objdiv.appendChild(el);
	dp1.setDate(setDay);

	x = getClientLeft(obj);
	y = getClientTop(obj);
	x = document.body.scrollLeft + x;											// 스크롤 영역 보정
	y = document.body.scrollTop + y;

	objdiv.style.pixelTop	= y-100;
	objdiv.style.pixelLeft	= x-1;

	showSelects(false);
	objdiv.style.display = '';
	dp1.onchange = function () {
		var selDate = dp1.getDate();
		g_targetText.value = selDate.getFullYear().toString() + g_format_str + day2(selDate.getMonth()+1) + g_format_str + day2(selDate.getDate());
	};
}

function getClientLeft(el) {
	var r = el.getBoundingClientRect();
	return r.left;
}

function getClientTop(el) {
	var r = el.getBoundingClientRect();
	return r.top;
}

function HideDP() {
	var objdiv = document.all.dpdiv;
	objdiv.style.display = 'none';
	showSelects(true);
}

function showSelects(bVisible) {
	// only IE actually do something in here
	var selects = [];
	if (document.all)
		selects = document.all.tags("SELECT");
	var l = selects.length;
	for	(var i = 0; i < l; i++)
		selects[i].runtimeStyle.visibility = bVisible ? "" : "hidden";
}

function Calendar(obj, format_str) {
   // format_str = "/";
   ShowDP(obj, format_str);
}

var g_format_str;
var g_targetText;
var dp1 = new DatePicker();
var el = dp1.create();
dp1.setFirstWeekDay(6);
document.write("<div id=dpdiv style=\"background:buttonface;display:none;position: absolute;\"></div>");