var datePickerDivID = "datepicker";
var iFrameDivID = "datepickeriframe";

var dayArrayShort = new Array('Mo', 'Tu', 'We', 'Th', 'Fr', 'Sa', 'Su');
var dayArrayMed = dayArrayShort;
var dayArrayLong = dayArrayShort;
var monthArrayShort = new Array('Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec');
var monthArrayMed = monthArrayShort;
var monthArrayLong = new Array('January','February','March','April','May','June','July','August','September','October','November','December');

var defaultDateSeparator = "-";        // common values would be "/" or "."
var defaultDateFormat = "ymd"    // valid values are "mdy", "dmy", and "ymd"
var dateSeparator = defaultDateSeparator;
var dateFormat = defaultDateFormat;

function rusGetDay(d) {
	return (d.getDay()==0 ? 6 :d.getDay()-1);
}

function displayDatePicker(dateFieldName, displayBelowThisObject, dtFormat, dtSep)
{
  var targetDateField = document.getElementsByName (dateFieldName).item(0);

  if (!displayBelowThisObject)
    displayBelowThisObject = targetDateField;

  if (dtSep)
    dateSeparator = dtSep;
  else
    dateSeparator = defaultDateSeparator;

  if (dtFormat)
    dateFormat = dtFormat;
  else
    dateFormat = defaultDateFormat;

  var x = displayBelowThisObject.offsetLeft;
  var y = displayBelowThisObject.offsetTop + displayBelowThisObject.offsetHeight ;

  // deal with elements inside tables and such
  var parent = displayBelowThisObject;
  while (parent.offsetParent) {
    parent = parent.offsetParent;
    x += parent.offsetLeft;
    y += parent.offsetTop ;
  }

  drawDatePicker(targetDateField, x, y);
}
function drawDatePicker(targetDateField, x, y)
{
  var dt = getFieldDate(targetDateField.value );

  // the datepicker table will be drawn inside of a <div> with an ID defined by the
  // global datePickerDivID variable. If such a div doesn't yet exist on the HTML
  // document we're working with, add one.
  if (!document.getElementById(datePickerDivID)) {
    // don't use innerHTML to update the body, because it can cause global variables
    // that are currently pointing to objects on the page to have bad references
    //document.body.innerHTML += "<div id='" + datePickerDivID + "' class='dpDiv'></div>";
    var newNode = document.createElement("div");
    newNode.setAttribute("id", datePickerDivID);
    newNode.setAttribute("class", "dpDiv");
    newNode.setAttribute("style", "visibility: hidden;");
    document.body.appendChild(newNode);
  }

  // move the datepicker div to the proper x,y coordinate and toggle the visiblity
  var pickerDiv = document.getElementById(datePickerDivID);
  pickerDiv.style.position = "absolute";
  pickerDiv.style.left = x + "px";
  pickerDiv.style.top = y + "px";
  pickerDiv.style.visibility = (pickerDiv.style.visibility == "visible" ? "hidden" : "visible");
  pickerDiv.style.display = (pickerDiv.style.display == "block" ? "none" : "block");
  pickerDiv.style.zIndex = 10000;

  // draw the datepicker table
  refreshDatePicker(targetDateField.name, dt.getFullYear(), dt.getMonth(), dt.getDate());
}


/**
This is the function that actually draws the datepicker calendar.
*/
function refreshDatePicker(dateFieldName, year, month, day)
{
  // if no arguments are passed, use today's date; otherwise, month and year
  // are required (if a day is passed, it will be highlighted later)
  var thisDay = new Date();

  if ((month >= 0) && (year > 0)) {
    thisDay = new Date(year, month, 1);
  } else {
    day = thisDay.getDate();
    thisDay.setDate(1);
  }

  // the calendar will be drawn as a table
  // you can customize the table elements with a global CSS style sheet,
  // or by hardcoding style and formatting elements below
  var crlf = "\r\n";
  var TABLE = "<div class='dpTableCont'><table class='dpTable' cellspacing='0' cellpadding='0'>" + crlf;
  var xTABLE = "</table></div>" + crlf;
  var TR = "<tr class='dpTR'>";
  var TR_title = "<tr><td colspan='7'><table cellspacing='0' cellpadding='0' class='dpTitle'><tr>";
  var TR_days = "<tr class='dpDayTR'>";
//  var TR_todaybutton = "<tr class='dpTodayButtonTR'>";
  var xTR = "</tr>" + crlf;
  var xTR_title = "</tr></table></td></tr>" + crlf;
  var TD = "<td class='dpTD' onMouseOut='this.className=\"dpTD\";' onMouseOver=' this.className=\"dpTDHover\";' ";    // leave this tag open, because we'll be adding an onClick event
  var TD_empty = "<td class='dpTD'>";
  var TD_title = "<td class='dpTitleTD'>";
  var TD_buttons = "<td class='dpButtonTD'>";
//  var TD_todaybutton = "<td colspan=7 class='dpTodayButtonTD'>";
  var TD_days = "<td class='dpDayTD'>";
  var TD_selected = "<td class='dpDayHighlightTD' onMouseOut='this.className=\"dpDayHighlightTD\";' onMouseOver='this.className=\"dpTDHover\";' ";    // leave this tag open, because we'll be adding an onClick event
  var xTD = "</td>" + crlf;
  var DIV_title = "<div class='dpTitleText'>";
  var DIV_selected = "<div class='dpDayHighlight'>";
  var xDIV = "</div>";

  // start generating the code for the calendar table
  var html = TABLE;

  // this is the title bar, which displays the month and the buttons to
  // go back to a previous month or forward to the next month
  html += TR_title;
  html += TD_buttons + getButtonCode(dateFieldName, thisDay, -1, "src='/img/button_left.gif' width='18' height='13' alt='Предыдущий месяц'>") + xTD;
  html += TD_title + monthArrayLong[ thisDay.getMonth()] + " " + thisDay.getFullYear() + xTD;
  html += TD_buttons + getButtonCode(dateFieldName, thisDay, 1, "src='/img/button_right.gif' width='18' height='13' alt='Следующий месяц'>") + xTD;
  html += xTR_title;

  // this is the row that indicates which day of the week we're on
  html += TR_days;
  for(i = 0; i < dayArrayShort.length; i++)
    html += TD_days + dayArrayShort[i] + xTD;
  html += xTR;

  // now we'll start populating the table with days of the month
  html += TR;

  // first, the leading blanks
  for (i = 0; i < rusGetDay(thisDay); i++)
    html += TD_empty + "&nbsp;" + xTD;

  // now, the days of the month
  do {
    dayNum = thisDay.getDate();
    TD_onclick = " onclick=\"updateDateField('" + dateFieldName + "', '" + getDateString(thisDay) + "');\">";

    if (dayNum == day)
      html += TD_selected + TD_onclick + dayNum + xTD;
    else
      html += TD + TD_onclick + dayNum + xTD;

    // if this is a Saturday, start a new row
    if (rusGetDay(thisDay) == 6)
      html += xTR + TR;

    // increment the day
    thisDay.setDate(thisDay.getDate() + 1);
  } while (thisDay.getDate() > 1)

  // fill in any trailing blanks
  if (rusGetDay(thisDay) > 0) {
    for (i = 6; i >= rusGetDay(thisDay); i--)
    html += TD_empty + "&nbsp;" + xTD;
  }
  html += xTR;

  // add a button to allow the user to easily return to today, or close the calendar
//  var today = new Date();
//  var todayString = "Today is " + dayArrayMed[rusGetDay(today)] + ", " + monthArrayMed[ today.getMonth()] + " " + today.getDate();
//  html += TR_todaybutton + TD_todaybutton;
//  html += "<button class='dpTodayButton' onClick='updateDateField(\"" + dateFieldName + "\");'>закрыть</button>";
//  html += xTD + xTR;

  // and finally, close the table
  html += xTABLE;

  document.getElementById(datePickerDivID).innerHTML = html;
  // add an "iFrame shim" to allow the datepicker to display above selection lists
  adjustiFrame();
}


/**
Convenience function for writing the code for the buttons that bring us back or forward
a month.
*/
function getButtonCode(dateFieldName, dateVal, adjust, label)
{
  var newMonth = (dateVal.getMonth () + adjust) % 12;
  var newYear = dateVal.getFullYear() + parseInt((dateVal.getMonth() + adjust)/12);
  if (newMonth < 0) {
    newMonth += 12;
    newYear += -1;
  }

  return "<img class='dpButton' onClick='refreshDatePicker(\"" + dateFieldName + "\", " + newYear + ", " + newMonth + ");'" + label;
}


/**
Convert a JavaScript Date object to a string, based on the dateFormat and dateSeparator
variables at the beginning of this script library.
*/
function getDateString(dateVal)
{
  var dayString = "00" + dateVal.getDate();
  var monthString = "00" + (dateVal.getMonth()+1);
  dayString = dayString.substring(dayString.length - 2);
  monthString = monthString.substring(monthString.length - 2);

  switch (dateFormat) {
    case "dmy" :
      return dayString + dateSeparator + monthString + dateSeparator + dateVal.getFullYear();
    case "ymd" :
      return dateVal.getFullYear() + dateSeparator + monthString + dateSeparator + dayString;
    case "mdy" :
    default :
      return monthString + dateSeparator + dayString + dateSeparator + dateVal.getFullYear();
  }
}


/**
Convert a string to a JavaScript Date object.
*/
function getFieldDate(dateString)
{
  var dateVal;
  var dArray;
  var d, m, y;

  try {
    dArray = splitDateString(dateString);
    if (dArray) {
      switch (dateFormat) {
        case "dmy" :
          d = parseInt(dArray[0], 10);
          m = parseInt(dArray[1], 10) - 1;
          y = parseInt(dArray[2], 10);
          break;
        case "ymd" :
          d = parseInt(dArray[2], 10);
          m = parseInt(dArray[1], 10) - 1;
          y = parseInt(dArray[0], 10);
          break;
        case "mdy" :
        default :
          d = parseInt(dArray[1], 10);
          m = parseInt(dArray[0], 10) - 1;
          y = parseInt(dArray[2], 10);
          break;
      }
      dateVal = new Date(y, m, d);
    } else if (dateString) {
      dateVal = new Date(dateString);
    } else {
      dateVal = new Date();
    }
  } catch(e) {
    dateVal = new Date();
  }

  return dateVal;
}


/**
Try to split a date string into an array of elements, using common date separators.
If the date is split, an array is returned; otherwise, we just return false.
*/
function splitDateString(dateString)
{
  var dArray;
  if (dateString.indexOf("/") >= 0)
    dArray = dateString.split("/");
  else if (dateString.indexOf(".") >= 0)
    dArray = dateString.split(".");
  else if (dateString.indexOf("-") >= 0)
    dArray = dateString.split("-");
  else if (dateString.indexOf("\\") >= 0)
    dArray = dateString.split("\\");
  else
    dArray = false;

  return dArray;
}

function updateDateField(dateFieldName, dateString)
{
  var targetDateField = document.getElementsByName (dateFieldName).item(0);
  if (dateString)
    targetDateField.value = dateString;

  var pickerDiv = document.getElementById(datePickerDivID);
  pickerDiv.style.visibility = "hidden";
  pickerDiv.style.display = "none";

  adjustiFrame();
if(targetDateField.visible) {
  targetDateField.focus();
}

  // after the datepicker has closed, optionally run a user-defined function called
  // datePickerClosed, passing the field that was just updated as a parameter
  // (note that this will only run if the user actually selected a date from the datepicker)
  if ((dateString) && (typeof(datePickerClosed) == "function"))
    datePickerClosed(targetDateField);
}

function datePickerClosed(targetDateField) {
	var n=targetDateField.name.substr(targetDateField.name.length-1,1);
	var a = targetDateField.value.split('-');
	if(targetDateField.form.elements['d'+n]) {
		var o = targetDateField.form.elements['d'+n].options;
		for(var i=0;i<o.length;i++) {
			if(o.item(i).value==a[2]) {
				o.item(i).selected = true;
			}
		}
	}
	if(targetDateField.form.elements['m'+n]) {
		var o = targetDateField.form.elements['m'+n].options;
		for(var i=0;i<o.length;i++) {
			if(o.item(i).value==(a[0]+a[1])) {
				o.item(i).selected = true;
			}
		}
	}
}

function adjustiFrame(pickerDiv, iFrameDiv)
{
  // we know that Opera doesn't like something about this, so if we
  // think we're using Opera, don't even try
  var is_opera = (navigator.userAgent.toLowerCase().indexOf("opera") != -1);
  if (is_opera)
    return;

  // put a try/catch block around the whole thing, just in case
  try {
    if (!document.getElementById(iFrameDivID)) {
      // don't use innerHTML to update the body, because it can cause global variables
      // that are currently pointing to objects on the page to have bad references
      //document.body.innerHTML += "<iframe id='" + iFrameDivID + "' src='javascript:false;' scrolling='no' frameborder='0'>";
      var newNode = document.createElement("iFrame");
      newNode.setAttribute("id", iFrameDivID);
      newNode.setAttribute("src", "javascript:false;");
      newNode.setAttribute("scrolling", "no");
      newNode.setAttribute ("frameborder", "0");
      document.body.appendChild(newNode);
    }

    if (!pickerDiv)
      pickerDiv = document.getElementById(datePickerDivID);
    if (!iFrameDiv)
      iFrameDiv = document.getElementById(iFrameDivID);

    try {
      iFrameDiv.style.position = "absolute";
      iFrameDiv.style.width = pickerDiv.offsetWidth;
      iFrameDiv.style.height = pickerDiv.offsetHeight ;
      iFrameDiv.style.top = pickerDiv.style.top;
      iFrameDiv.style.left = pickerDiv.style.left;
      iFrameDiv.style.zIndex = pickerDiv.style.zIndex - 1;
      iFrameDiv.style.visibility = pickerDiv.style.visibility ;
      iFrameDiv.style.display = pickerDiv.style.display;
    } catch(e) {
    }

  } catch (ee) {
  }

}
