/*
var selectDate = new Date();
selectDate.setFullYear(2007); // 2007年
selectDate.setMonth(11 - 1); //  11月
selectDate.setDate(19); // 19日
*/

function myDateSelecter() {
	this.fromYear = 2007;
	this.toYear = 2012;
	this.months = ["一月", "二月", "三月", "四月", "五月", "六月", "七月", "八月", "九月", "十月", "十一月", "十二月"];
	this.weeks = ["日", "一", "二", "三", "四", "五", "六"];
	this.selectDate = new Date();

	this.write_css();
	this.write_html();
	this.write_calendar();

	this.layout = document.getElementById('dateSelecter');

	var obj = this;

	this.month_sel = document.getElementById('month_sel');
	this.month_sel.onchange = function() {
		obj.on_month_change(this.value);
	}

	this.year_sel = document.getElementById('year_sel');
	this.year_sel.onchange = function() {
		obj.on_year_change(this.value);
	}

	this.clear_but = document.getElementById('clear');
	this.clear_but.onclick= function() {
		if( obj.formatObj )
			obj.formatObj.value = '';
	}

	this.close_but = document.getElementById('close');
	this.close_but.onclick= function() {
		obj.hide();
	}

}

myDateSelecter.prototype.write = function(str) {
	document.write(str);
}

myDateSelecter.prototype.write_css = function() {
	this.write("<style type='text/css'>");
	this.write(".div_input { border: 1px #cccccc solid; width: 36px; height: 18px; text-align: center; cursor: hand; }");
	this.write(".div_table { border: 0px; background: #cccccc; width: 160px; }");
	this.write(".div_table TR { background: #ffffff; height: 18px; text-align: center; }");
	this.write(".div_table TD { padding: 2px; font-size: 12px; height: 18px; text-align: center; }");
	this.write(".td_day { cursor: hand; }");
	this.write(".td_selected { background: #cccccc; }");
	this.write(".div_table SELECT { height: 25px; width: 100%; }");
	this.write(".div_left { float: left; width: 70px; }");
	this.write(".div_right { float: right; width: 70px; }");
	this.write("</style>");
}

myDateSelecter.prototype.write_html = function() {
	this.write("    <div id='dateSelecter' style='display: none; width: 160px; position:absolute; z-index:9; left: 0px; top: 0px;' >");
	this.write("		<table class='div_table' cellspacing='1' cellpadding='0'>");
	this.write("			<tr>");
	this.write("				<td colspan='7'>");
	this.write("					<div class='div_left'>");
	this.write("						<select id='month_sel' size='1'>");
									for( var c=0; c<this.months.length; c++ ) {
										this.write("<option value='" + (c + 1) + "' " + (this.selectDate.getMonth()==c ? "selected='selected'" : "") + ">" + this.months[c] + "</option>");
									}
	this.write("						</select>");
	this.write("					</div>");
	this.write("					<div class='div_right'>");
	this.write("						<select id='year_sel' size='1'");
									for( var c=this.fromYear; c<=this.toYear; c++ ) {
										this.write("<option value='" + c + "' " + (this.selectDate.getFullYear()==c ? "selected='selected'" : "") + ">" + c + "</option>");
									}
	this.write("						</select>");
	this.write("					</div>");
	this.write("				</td>");
	this.write("			</tr>");
	this.write("			<tr>");
						for( var c=0; c<this.weeks.length; c++ ) {
							this.write("<td>" + this.weeks[c] + "</td>");
						}
	this.write("			</tr>");
					for( var r=0; r<6; r++ ) {
						this.write("<tr>");
						for( var c=0; c<7; c++ ) {
							this.write("<td id='td_" + r + "_" + c + "'> </td>");
						}
						this.write("</tr>");
					}
	this.write("		<tr><td colspan='7'><input class='div_input' type='button' id='clear' value='清除' /> <input class='div_input' type='button' id='close' value='關閉' /></td></tr>");
	this.write("		</table>");
	this.write("		</div>");
	this.write("	</div>");
}
		
myDateSelecter.prototype.td_on_click = function(td) {
			var tds = document.getElementsByTagName("TD");
			for( var c=0; c<tds.length; c++ ) {
				if(tds[c].className == 'td_day td_selected')
				   tds[c].className = 'td_day';
			}
			td.className = 'td_day td_selected';
}

myDateSelecter.prototype.td_on_dblclick = function(td) {
			this.td_on_click(td);
			this.selectDate.setDate( parseInt(td.innerHTML) );
			//this.dateSelecter.style.display = 'none';
			if( this.formatObj ) {
				//this.formatObj.value = this.selectDate;
				// DateUtil.js
				this.formatObj.value = DateUtil.formatDate(this.selectDate, this.formatType);
				this.formatObj.click();
			}
			this.hide();
}

myDateSelecter.prototype.on_month_change = function(m) {
			 this.selectDate.setMonth( parseInt(m) - 1 );
			 this.write_calendar();
}

myDateSelecter.prototype.on_year_change = function(y) {
			 this.selectDate.setFullYear( parseInt(y) );
			 this.write_calendar();
}

myDateSelecter.prototype.write_calendar = function() {
			var obj = this;
			var d = this.selectDate;
			var month_day_count = get_month_day_count(d);
			var row = get_row(d);
			var col = get_col(d);
			var month_first_day_col = get_month_first_day_col(d);

			var cell_count = 0;
			var cur_notempty_cell = 0;
			for( var r=1; r<=6; r++ ) {
				for( var c=1; c<=7; c++ ) {
					cell_count ++;
					var td = document.getElementById( "td_" + (r-1) + "_" + (c-1) );
					if(cell_count >= month_first_day_col && cur_notempty_cell < month_day_count) {
						cur_notempty_cell ++;
						if(r == row && c == col) {
							td.className = 'td_day td_selected';
						}
						else
							td.className = 'td_day';
						td.onclick = function() { obj.td_on_click(this); };
						td.ondblclick = function() { obj.td_on_dblclick(this); };
						td.innerHTML = "" + cur_notempty_cell;
					}
					else {
						try {
							td.innerHTML = "";
							td.className = '';
							td.onclick = function() {};
							td.ondblclick = function() {};
						} catch(e) {}
					}
				}
			}
}

// 修改這個函數，可以返回不同格式的日期,懶得再寫了
myDateSelecter.prototype.show = function(input, format) {
	this.formatObj = document.getElementById(input);
	this.formatType = format;
//	this.formatObj.focus();

	if( this.formatObj.value != '' ) {
		// DateUtil.js
		//alert(1);
		var d = DateUtil.parseDate(this.formatObj.value, this.formatType);
		//alert(d);
		this.selectDate = d;
		this.month_sel.selectedIndex = this.selectDate.getMonth();
		//this.year_sel.selectedIndex = this.selectDate.getMonth();
		var ops = this.year_sel.options;
		for( var c=0; c<ops.length; c++ ) {
			if( ops[c].value == (this.selectDate.getFullYear() + '') ) {
				this.year_sel.selectedIndex = c;
				break ;
			}
		}
		this.write_calendar();
	}

	this.layout.style.left = window.event.clientX+20;
	this.layout.style.top = window.event.clientY+310;
	this.layout.style.display = "block";
}

myDateSelecter.prototype.hide = function() {
	this.layout.style.display = "none";
}

function get_row(d) { // 當前天的所在行,從1開始
	return Math.ceil( (d.getDate() + get_month_first_day_col(d) - 1) / 7 );
}

function get_col(d) { // 當前天的所在列,從1~7
	return d.getDay() + 1;
}

function get_month_day_count(d) { // 當前月的天數
	var md = d.getMonth() + 1;
	if( md == 1 || md == 3 || md == 5 || md == 7 || md == 8 || md == 10 || md == 12)
		return 31;
	else if( d.getFullYear() % 4 > 0 && md == 2)
		return 28;
	else if( d.getFullYear() % 4 == 0 && md == 2)
		return 29;
	else
		return 30;
}

function get_month_first_day_col(d) { // 當前月第一天的所在列,肯定是第一行
	var t = d.getDate();
	d.setDate(1);
	var r = get_col(d);
	d.setDate(t);
	return r;
}

function get_total_row(d) {
	return Math.ceil( (get_month_first_day_col(d) + get_month_day_count(d)) / 7 );
}


// DateUtil 是來自別人的代碼

function DateUtil() {}

DateUtil.parseDate = function(str, fmt) {
var today = new Date();
var y = 0;
var m = -1;
var d = 0;
var a = str.split(/\W+/);
var b = fmt.match(/%./g);
var i = 0, j = 0;
var hr = 0;
var min = 0;
for (i = 0; i < a.length; ++i) {
	if (!a[i])
		continue;
	switch (b[i]) {
		case "%d":
		case "%e":
		d = parseInt(a[i], 10);
		break;

		case "%m":
		m = parseInt(a[i], 10) - 1;
		break;

		case "%Y":
		case "%y":
		y = parseInt(a[i], 10);
		(y < 100) && (y += (y > 29) ? 1900 : 2000);
		break;

		case "%b":
		case "%B":
		for (j = 0; j < 12; ++j) {
			if (Calendar._MN[j].substr(0, a[i].length).toLowerCase() == a[i].toLowerCase()) { m = j; break; }
		}
		break;

		case "%H":
		case "%I":
		case "%k":
		case "%l":
		hr = parseInt(a[i], 10);
		break;

		case "%P":
		case "%p":
		if (/pm/i.test(a[i]) && hr < 12)
			hr += 12;
		else if (/am/i.test(a[i]) && hr >= 12)
			hr -= 12;
		break;

		case "%M":
		min = parseInt(a[i], 10);
		break;
	}
}
if (isNaN(y)) y = today.getFullYear();
if (isNaN(m)) m = today.getMonth();
if (isNaN(d)) d = today.getDate();
if (isNaN(hr)) hr = today.getHours();
if (isNaN(min)) min = today.getMinutes();
if (y != 0 && m != -1 && d != 0)
	return new Date(y, m, d, hr, min, 0);
y = 0; m = -1; d = 0;
for (i = 0; i < a.length; ++i) {
	if (a[i].search(/[a-zA-Z]+/) != -1) {
		var t = -1;
		for (j = 0; j < 12; ++j) {
			if (Calendar._MN[j].substr(0, a[i].length).toLowerCase() == a[i].toLowerCase()) { t = j; break; }
		}
		if (t != -1) {
			if (m != -1) {
				d = m+1;
			}
			m = t;
		}
	} else if (parseInt(a[i], 10) <= 12 && m == -1) {
		m = a[i]-1;
	} else if (parseInt(a[i], 10) > 31 && y == 0) {
		y = parseInt(a[i], 10);
		(y < 100) && (y += (y > 29) ? 1900 : 2000);
	} else if (d == 0) {
		d = a[i];
	}
}
if (y == 0)
	y = today.getFullYear();
if (m != -1 && d != 0)
	return new Date(y, m, d, hr, min, 0);
return today;
}

DateUtil.formatDate = function(date, fmt) {
var today = date;
var y = 0;
var m = -1;
var d = 0;
//var a = str.split(/\W+/);
var b = fmt.match(/%./g);
var i = 0, j = 0;
var hr = 0;
var min = 0;
var sec = 0;
for (i = 0; i < b.length; ++i) {
	switch (b[i]) {
		case "%d":
		case "%e":
		//d = parseInt(a[i], 10);
		d = today.getDate();
		break;

		case "%m":
		//m = parseInt(a[i], 10) - 1;
		m = today.getMonth() + 1;
		break;

		case "%Y":
		case "%y":
		//y = parseInt(a[i], 10);
		//(y < 100) && (y += (y > 29) ? 1900 : 2000);
		y = today.getFullYear();
		break;

		case "%b":
		case "%B":
		for (j = 0; j < 12; ++j) {
			if (Calendar._MN[j].substr(0, a[i].length).toLowerCase() == a[i].toLowerCase()) { m = j; break; }
		}
		break;

		case "%H":
		case "%I":
		case "%k":
		case "%l":
		//hr = parseInt(a[i], 10);
		hr = today.getHours() + 1;
		break;

		case "%P":
		case "%p":
		if (/pm/i.test(a[i]) && hr < 12)
			hr += 12;
		else if (/am/i.test(a[i]) && hr >= 12)
			hr -= 12;
		break;

		case "%M":
		//min = parseInt(a[i], 10);
		min = today.getMinutes() + 1;
		break;

		case "%s":
		case "%S":
			sec = today.getSeconds() + 1;
			break;
	}
}
if (isNaN(y)) y = today.getFullYear();
if (isNaN(m)) m = today.getMonth();
if (isNaN(d)) d = today.getDate();
if (isNaN(hr)) hr = today.getHours();
if (isNaN(min)) min = today.getMinutes();


return fmt.replace(/%(y|Y)/, y + '').replace(/%m/, m + '').replace(/%(d|D)/, d + '');
}

var mydser = new myDateSelecter();