var allMonth=[31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31];
var allNameOfWeekDays=["一","二", "三", "四", "五", "六", "日"];
var allNameOfMonths=["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"];
var newDate=new Date();
var yearZero=newDate.getFullYear();
var monthZero=newDate.getMonth();
var day=newDate.getDate();
var currentDay=0, currentDayZero=0;
var month=monthZero, year=yearZero;
var yearMin=2008, yearMax=2020;
var target='';
var hoverEle=false;
function setTarget(e){
  if(e) return e.target;
  if(event) return event.srcElement;
}
function newElement(type, attrs, content, toNode) {
  var ele=document.createElement(type);
  if(attrs) {
	   for(var i=0; i<attrs.length; i++) {
			eval('ele.'+attrs[i][0]+(attrs[i][2] ? '=\u0027' :'=')+attrs[i][1]+(attrs[i][2] ? '\u0027' :''));
	   }
  }
  if(content) ele.appendChild(document.createTextNode(content));
  if(toNode) toNode.appendChild(ele);
  return ele;
}
function setMonth(ele){month=parseInt(ele.value);calender()}
function setYear(ele){year=parseInt(ele.value);calender()}

function setValue(ele) {
  if(ele.parentNode.className=='week' && ele.firstChild){
	   var dayOut=ele.firstChild.nodeValue;
	   if(dayOut < 10) dayOut='0'+dayOut;
	   var monthOut=month+1;
	   if(monthOut < 10) monthOut='0'+monthOut;
	   target.value=year+'-'+monthOut+'-'+dayOut;
	   removeCalender();
  }
}

function removeCalender() {
  var parentEle=document.getElementById("calender");
  while(parentEle.firstChild) parentEle.removeChild(parentEle.firstChild);
  document.getElementById('basis').parentNode.removeChild(document.getElementById('basis'));
}

function calender() {
  var parentEle=document.getElementById("calender");
  parentEle.onmouseover=function(e) {
	   var ele=setTarget(e);
	   if(ele.parentNode.className=='week' && ele.firstChild && ele!=hoverEle) {
			if(hoverEle) hoverEle.className=hoverEle.className.replace(/hoverEle ?/,'');
			hoverEle=ele;
			ele.className='hoverEle '+ele.className;
	   } else {
			if(hoverEle) {
				 hoverEle.className=hoverEle.className.replace(/hoverEle ?/,'');
				 hoverEle=false;
			}
	   }
  }
  while(parentEle.firstChild) parentEle.removeChild(parentEle.firstChild);
  function check(){
	   if(year%4==0&&(year%100!=0||year%400==0))allMonth[1]=29;
	   else allMonth[1]=28;
  }
  function addClass (name) { if(!currentClass){currentClass=name} else {currentClass+=' '+name} };
  if(month < 0){month+=12; year-=1}
  if(month > 11){month-=12; year+=1}
  if(year==yearMax-1) yearMax+=1;
  if(year==yearMin) yearMin-=1;
  check();
  var control=newElement('p',[['id','control',1]],false,parentEle);
  var controlPlus=newElement('a', [['href','javascript:month--;calender()',1],['className','controlPlus',1]], '<', control);
  var select=newElement('select', [['onchange',function(){setMonth(this)}]], false, control);
  for(var i=0; i<allNameOfMonths.length; i++) newElement('option', [['value',i,1]], allNameOfMonths[i], select);
  select.selectedIndex=month;
  select=newElement('select', [['onchange',function(){setYear(this)}]], false, control);
  for(var i=yearMin; i<yearMax; i++) newElement('option', [['value',i,1]], i, select);
  select.selectedIndex=year-yearMin;
  controlPlus=newElement('a', [['href','javascript:month++;calender()',1],['className','controlPlus',1]], '>', control);
  check();
  currentDay=1-new Date(year,month,1).getDay();
  if(currentDay > 0) currentDay-=7;
  currentDayZero=currentDay;
  var newMonth=newElement('table',[['cellSpacing',0,1],['onclick',function(e){setValue(setTarget(e))}]], false, parentEle);
  var newMonthBody=newElement('tbody', false, false, newMonth);
  var tr=newElement('tr', [['className','head',1]], false, newMonthBody);
  tr=newElement('tr', [['className','weekdays',1]], false, newMonthBody);
  for(i=0;i<7;i++) td=newElement('td', false, allNameOfWeekDays[i], tr);     
  tr=newElement('tr', [['className','week',1]], false, newMonthBody);
  for(i=0; i<allMonth[month]-currentDayZero; i++){
	   var currentClass=false;               
	   currentDay++;
	   if(currentDay==day && month==monthZero && year==yearZero) addClass ('today');
	   if(currentDay <= 0 ) {
			if(currentDayZero!=-7) td=newElement('td', false, false, tr);
	   }
	   else {
			if((currentDay-currentDayZero)%7==0) addClass ('holiday');
			td=newElement('td', (!currentClass ? false : [['className',currentClass,1]] ), currentDay, tr);
			if((currentDay-currentDayZero)%7==0) tr=newElement('tr', [['className','week',1]], false, newMonthBody);
	   }
	   if(i==allMonth[month]-currentDayZero-1){
			i++;
			while(i%7!=0){i++;td=newElement('td', false, false, tr)};
	   }
  }
}
function showCalender(ele) {
  if(document.getElementById('basis')) { removeCalender() }
  else {
	   target=document.getElementById(ele.id.replace(/for_/,'')); 
	   var basis=ele.parentNode.insertBefore(document.createElement('div'),ele);
	   basis.id='basis';
	   newElement('div', [['id','calender',1]], false, basis);
	   calender();
  }
}