//  **************************************************************************************************
//  ********************************       GLOBAL VARIABLES        ***********************************
//  variables used for the datePicker functionality, which has the global access in the implementation
//  **************************************************************************************************

var datePickerDivID = "datepicker";
var iFrameDivID = "datepickeriframe";
var dayArrayShort = new Array('Su', 'Mo', 'Tu', 'We', 'Th', 'Fr', 'Sa');
var dayArrayMed = new Array('Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat');
var dayArrayLong = new Array('Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday');
var monthArrayShort = new Array('Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec');
var monthArrayMed = new Array('Jan', 'Feb', 'Mar', 'Apr', 'May', 'June', 'July', 'Aug', 'Sept', 'Oct', 'Nov', 'Dec');
var monthArrayLong = new Array('January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December');
var monthWidget, dayWidget, yearWidget; 
var maxYear, nextYear;
var minYear, prevYear;
var allowFutureDate;
var disableFutureDate = false;
var currentDate = new Date();
var exceedsCurrentDate = false;

// This is the main function you'll call from the onClick event of a button. 
function displayDatePicker(dateFieldName, displayBelowThisObject, mxYear, mnYear, futureDate)
{
    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 ;
    }
    monthWidget = document.getElementsByName(dateFieldName+".month")[0];
    dayWidget = document.getElementsByName(dateFieldName+".day")[0];
    yearWidget = document.getElementsByName(dateFieldName+".year")[0];
    maxYear="";
    minYear="";
    allowFutureDate = (futureDate === 'false') ? false : true;
    exceedsCurrentDate = false;
    if(mxYear)
        maxYear = parseInt(mxYear, 10);
    if(mnYear)
        minYear = parseInt(mnYear, 10);

    drawDatePicker(dateFieldName, x, y);
}


function drawDatePicker(dateFieldName, x, y)
{
    var dt = getFieldDate();
    // 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)) {
        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(dateFieldName, 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
    var crlf = "\r\n";
    var TABLE = "<table cols=7 class='dpTable'>" + crlf;
    var xTABLE = "</table>" + crlf;
    var TR = "<tr class='dpTR'>";
    var TR_title = "<tr class='dpTitleTR'>";
    var TR_days = "<tr class='dpDayTR'>";
    var TR_todaybutton = "<tr class='dpTodayButtonTR'>";
    var xTR = "</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_title = "<td colspan=5 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, "&lt;", 'previous-button') + xTD;
    html += TD_title + DIV_title + monthArrayLong[ thisDay.getMonth()] + " " + thisDay.getFullYear() + xDIV + xTD;
    html += TD_buttons + getButtonCode(dateFieldName, thisDay, 1, "&gt;", 'next-button') + xTD;
    html += xTR;
 
    // 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 < thisDay.getDay(); i++)
        html += TD + "&nbsp;" + xTD;
 
    // now, the days of the month
    do {
        dayNum = thisDay.getDate();
        if(!allowFutureDate)
        {
            if( (thisDay.getMonth() >= currentDate.getMonth()) && (thisDay.getFullYear() >= currentDate.getFullYear()) )
                disableFutureDate = true;
            else disableFutureDate = false;
            var this_day = new Date(thisDay.getDate() + " " + monthArrayShort[thisDay.getMonth()] + " " + thisDay.getFullYear());
            var current_date = new Date(currentDate.getDate() + " " + monthArrayShort[currentDate.getMonth()] + " " + currentDate.getFullYear());
            if(Date.parse(this_day) > Date.parse(current_date))
                exceedsCurrentDate = true;
            else exceedsCurrentDate = false;
        }
        if(exceedsCurrentDate || (maxYear < thisDay.getFullYear()))
        {
            TD_onclick = " style='text-decoration:line-through;'\">";
        }
        else
            TD_onclick = " onclick=\"updateDateField('" + getDateString(thisDay) + "');\">";
    
        if (dayNum == day)
            html += TD_selected + TD_onclick + DIV_selected + dayNum + xDIV + xTD;
        else
            html += TD + TD_onclick + dayNum + xTD;
    
        // if this is a Saturday, start a new row
        if (thisDay.getDay() == 6)
            html += xTR + TR;
    
        // increment the day
        thisDay.setDate(thisDay.getDate() + 1);
    } while (thisDay.getDate() > 1)
 
    // fill in any trailing blanks
    if (thisDay.getDay() > 0) {
        for (i = 6; i > thisDay.getDay(); i--)
            html += TD + "&nbsp;" + xTD;
    }
    html += xTR;
 
    // add a button to allow the user to easily return to today, or close the calendar
    html += TR_todaybutton + TD_todaybutton;
    if(currentDate.getFullYear() <= maxYear)
        html += "<button class='dpTodayButton' onClick='refreshDatePicker(\"" + dateFieldName + "\");'>Today</button> ";
    html += "<button class='dpTodayButton' onClick='updateDateField();'>close</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, id)
{
    var newMonth = (dateVal.getMonth () + adjust) % 12;
    var newYear = dateVal.getFullYear() + parseInt((dateVal.getMonth() + adjust) / 12);
    if (newMonth < 0) {
        newMonth += 12;
        newYear += -1;
    }
    if(id == 'next-button') nextYear = newYear;
    if(id == 'previous-button') prevYear = newYear;
    return "<button id='"+id+"' class='dpButton' onClick='refreshDatePicker(\"" + dateFieldName + "\", " + newYear + ", " + newMonth + ");'>" + label + "</button>";
}


// Convert a JavaScript Date object to a string 
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);
 
    return monthString + "/" + dayString + "/" + dateVal.getFullYear();
}


// Convert a string to a JavaScript Date object.
function getFieldDate()
{
    var dateVal;
    var day, month, year;
    var d, m, y;

    month = monthWidget.value;
    if(dayWidget)
        day = dayWidget.value;
    else
        day = 1;
    year = yearWidget.value;

    if(!month || !day || !year)
    {
        if(currentDate.getFullYear() <= maxYear)
            return new Date();
        else
        {
            var tempDate = 	new Date();
            tempDate.setFullYear(maxYear);
            return tempDate;
        }
    }
    try {
        d = parseInt(day, 10);
        m = parseInt(monthArrayShort.indexOf(month), 10);
        y = parseInt(year, 10);

        dateVal = new Date(y, m, d);
    } catch(e) {
        dateVal = new Date();
    }
 
    return dateVal;
}


// Setting values from the datePicker control to target widgets
function updateDateField(dateString)
{

    if (dateString)
    {
        var dArray = dateString.split("/");
        if(dayWidget)
            dayWidget.value = parseInt(dArray[1],10);
        monthWidget.value = monthArrayShort[dArray[0]-1];
        yearWidget.value = dArray[2];
    }
    var pickerDiv = document.getElementById(datePickerDivID);
    pickerDiv.style.visibility = "hidden";
    pickerDiv.style.display = "none";
 
    adjustiFrame();
 
}


function adjustiFrame(pickerDiv, iFrameDiv)
{
    // disabling previous/next month buttons, if the conditions meets
    if((maxYear && (nextYear > maxYear)) || exceedsCurrentDate )
        document.getElementById("next-button").disabled = true;
    if(minYear && (prevYear < minYear))
        document.getElementById("previous-button").disabled = true;
    // put a try/catch block around the whole thing, just in case
    try {
        if (!document.getElementById(iFrameDivID)) {
            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) {
    }
 
}

// creating prototype for indexOf of Array objects
// to get the index of the specific element in the Array
Array.prototype.indexOf = function(obj){
    var len = this.length;
    for(var i=0; i<len; i++){
        if(this[i]==obj){
            return i;
        }
    }
    return -1;
}