/*
 * Date Format 1.2.3
 * (c) 2007-2009 Steven Levithan <stevenlevithan.com>
 * MIT license
 *
 * Includes enhancements by Scott Trenda <scott.trenda.net>
 * and Kris Kowal <cixar.com/~kris.kowal/>
 *
 * Accepts a date, a mask, or a date and a mask.
 * Returns a formatted version of the given date.
 * The date defaults to the current date/time.
 * The mask defaults to dateFormat.masks.default.
 */

var dateFormat = function ()
{
	var	token = /d{1,4}|m{1,4}|yy(?:yy)?|([HhMsTt])\1?|[LloSZ]|"[^"]*"|'[^']*'/g,
		timezone = /\b(?:[PMCEA][SDP]T|(?:Pacific|Mountain|Central|Eastern|Atlantic) (?:Standard|Daylight|Prevailing) Time|(?:GMT|UTC)(?:[-+]\d{4})?)\b/g,
		timezoneClip = /[^-+\dA-Z]/g,
		pad = function (val, len) {
			val = String(val);
			len = len || 2;
			while (val.length < len) val = "0" + val;
			return val;
		};

	// Regexes and supporting functions are cached through closure
	return function (date, mask, utc) {
		var dF = dateFormat;

		// You can't provide utc if you skip other args (use the "UTC:" mask prefix)
		if (arguments.length == 1 && Object.prototype.toString.call(date) == "[object String]" && !/\d/.test(date)) {
			mask = date;
			date = undefined;
		}

		// Passing date through Date applies Date.parse, if necessary
		date = date ? new Date(date) : new Date;
		if (isNaN(date)) throw SyntaxError("invalid date");

		mask = String(dF.masks[mask] || mask || dF.masks["default"]);

		// Allow setting the utc argument via the mask
		if (mask.slice(0, 4) == "UTC:") {
			mask = mask.slice(4);
			utc = true;
		}

		var	_ = utc ? "getUTC" : "get",
			d = date[_ + "Date"](),
			D = date[_ + "Day"](),
			m = date[_ + "Month"](),
			y = date[_ + "FullYear"](),
			H = date[_ + "Hours"](),
			M = date[_ + "Minutes"](),
			s = date[_ + "Seconds"](),
			L = date[_ + "Milliseconds"](),
			o = utc ? 0 : date.getTimezoneOffset(),
			flags = {
				d:    d,
				dd:   pad(d),
				ddd:  dF.i18n.dayNames[D],
				dddd: dF.i18n.dayNames[D + 7],
				m:    m + 1,
				mm:   pad(m + 1),
				mmm:  dF.i18n.monthNames[m],
				mmmm: dF.i18n.monthNames[m + 12],
				yy:   String(y).slice(2),
				yyyy: y,
				h:    H % 12 || 12,
				hh:   pad(H % 12 || 12),
				H:    H,
				HH:   pad(H),
				M:    M,
				MM:   pad(M),
				s:    s,
				ss:   pad(s),
				l:    pad(L, 3),
				L:    pad(L > 99 ? Math.round(L / 10) : L),
				t:    H < 12 ? "a"  : "p",
				tt:   H < 12 ? "am" : "pm",
				T:    H < 12 ? "A"  : "P",
				TT:   H < 12 ? "AM" : "PM",
				Z:    utc ? "UTC" : (String(date).match(timezone) || [""]).pop().replace(timezoneClip, ""),
				o:    (o > 0 ? "-" : "+") + pad(Math.floor(Math.abs(o) / 60) * 100 + Math.abs(o) % 60, 4),
				S:    ["th", "st", "nd", "rd"][d % 10 > 3 ? 0 : (d % 100 - d % 10 != 10) * d % 10]
			};

		return mask.replace(token, function ($0) {
			return $0 in flags ? flags[$0] : $0.slice(1, $0.length - 1);
		});
	};
}();

// Some common format strings
dateFormat.masks = {
	"default":      "ddd mmm dd yyyy HH:MM:ss",
	shortDate:      "m/d/yy",
	mediumDate:     "mmm d, yyyy",
	longDate:       "mmmm d, yyyy",
	fullDate:       "dddd, mmmm d, yyyy",
	shortTime:      "h:MM TT",
	mediumTime:     "h:MM:ss TT",
	longTime:       "h:MM:ss TT Z",
	isoDate:        "yyyy-mm-dd",
	isoTime:        "HH:MM:ss",
	isoDateTime:    "yyyy-mm-dd'T'HH:MM:ss",
	isoUtcDateTime: "UTC:yyyy-mm-dd'T'HH:MM:ss'Z'"
};

// Internationalization strings
dateFormat.i18n = {
	dayNames: [
		"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat",
		"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"
	],
	monthNames: [
		"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec",
		"January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"
	]
};

// For convenience...
Date.prototype.format = function (mask, utc) {
	return dateFormat(this, mask, utc);
};


// =============================================================================
function convertDateFormat(dateStr)
{
	// Irrespective of going from US-UK or UK-US we simply need to swap the first and second values round
	var datePat = /^(\d{1,2})(\/|-)(\d{1,2})\2(\d{4})$/;
	var matchArray = dateStr.match(datePat);
	
	// Check passed value at least matches format
	if (matchArray == null)
	{
		return false;
	}
	
	return matchArray[3] + "/" + matchArray[1] + "/" + matchArray[4];
}


// =============================================================================
function isValidDate(dateStr, location)
{
	// Date validation function based on work by Sandeep V. Tamhankar (stamhankar@hotmail.com)
	// Modified by Ian Hayward (ian@mantissadesigns.net)

	// Checks for the following valid date formats:
	// DD/MM/YY, DD/MM/YYYY, DD-MM-YY, DD-MM-YYYY || MM/DD/YY, MM/DD/YYYY, MM-DD-YY, MM-DD-YYYY

	var datePat = /^(\d{1,2})(\/|-)(\d{1,2})\2(\d{4})$/; // requires 4 digit year
	var matchArray = dateStr.match(datePat); 
	var errors = true;
	
	// Check passed value at least matches format
	if (matchArray == null)
	{
		if(errors) { alert(dateStr + " Date is not in a valid format."); }
		return false;
	}

	// Check on required locale
	if(location == 'US')
	{
		// Pass date parts to variables using US format for break down: MM/DD/YYYY	
		day = matchArray[3];
		month = matchArray[1];
		year = matchArray[4];
	}
	else
	{
		// Pass date parts to variables using GMT format for break down: DD/MM/YYYY	
		day = matchArray[1];
		month = matchArray[3];
		year = matchArray[4];
	}

	// Check day range
	if (day < 1 || day > 31)
	{
		if(errors) { alert("Day must be between 1 and 31."); }
		return false;
	}
	
	// Check month range
	if (month < 1 || month > 12)
	{
		if(errors) { alert("Month must be between 1 and 12."); }
		return false;
	}
	
	// Check 30 day months
	if ((month == 4 || month == 6 || month == 9 || month == 11) && day == 31)
	{
		if(errors) { alert("Month " + month + " doesn't have 31 days!") }
		return false;
	}
	
	// Check leap year
	if (month == 2)
	{
		var isleap = (year % 4 == 0 && (year % 100 != 0 || year % 400 == 0));
		if (day > 29 || (day == 29 && !isleap))
		{
			if(errors) { alert("February " + year + " doesn't have " + day + " days!"); }
			return false;
		}
	}

	// All tests were passed, return success
	return true;
}


// =============================================================================
function isValidTime(timeStr)
{
	// Time validation function based on work by Sandeep V. Tamhankar (stamhankar@hotmail.com)
	// Modified by Ian Hayward (ian@mantissadesigns.net)

	// Checks if time is in HH:MM:SS AM/PM format.
	// The seconds and AM/PM are optional.

	function d2(val)
	{
		return (val < 10) ? '0' + val : val;
	}

	var timePat = /^(\d{1,2}):(\d{2})(:(\d{2}))?(\s?(AM|am|PM|pm))?$/;
	var matchArray = timeStr.match(timePat);
	var errors = true;

	// Check passed value at least matches format
	if (matchArray == null)
	{
		if (errors) { alert("Time is not in a valid format."); }
		return false;
	}
	
	// Declare and set initial values for time parts
	var hour	= matchArray[1];
	var minute	= matchArray[2];
	var second	= 0;
	var ampm	= null;

	if(matchArray[3])
	{
		second = matchArray[3]
	}

	if(matchArray[5])
	{
		ampm = matchArray[5];
	}

	//alert( 'time: "' + hour + '" "' + minute + '" "' + second + '" "' + ampm + '"' )
	if (hour < 0 || hour > 23)
	{
		if (errors) { alert("Hour must be between 1 and 23."); }
		return false;
	}

	//if ( hour <= 12 && ( ampm == null ) ) {
	//  if ( confirm( "Please indicate which time format you are using.  OK = Standard Time, CANCEL = Military Time" ) ) {
	//alert( "You must specify AM or PM." );
	//    return false;
	//  }
	//}

	if (hour > 12 && (ampm != null))
	{
		if (errors) { alert( "You can't specify AM or PM for 24 hour clock." ); }
		return false;
	}

	//if(ampm != null){
	// if(ampm.toString().toUpperCase()=='PM')
	//       hour = hour + 12;
	//	}

	if (minute < 0 || minute > 59)
	{
		if (errors) { alert( "Minutes must be between 0 and 59." ); }
		return false;
	}

	timeVal = d2(hour) + ':' + d2(minute)

	if (second && (second < 0 || second > 59))
	{
		if (errors) { alert("Seconds must be between 0 and 59."); }
		return false;
	}
	else
	{
		timeVal += ':' + d2(second)
	}

	if (ampm != null)
	{
		timeVal += ' ' + ampm
	}
	else
	{
		if (hour < 13)
			timeVal += ' AM'
		else
			timeVal += ' PM'
	}

	return true;
}


// =============================================================================
function dateDiff(start, finish, clock1, clock2)
{
	// Declare required objects
	var date1 = new Date();
	var date2 = new Date();
	var diff = new Date();
	var errors = true;

	// Check all required data has been passed
	if (start == '' || finish == '' || clock1 == '' || clock2 == '')
	{
		if (errors) { alert("Failed 1"); }
		return 0;
	}

	// Validates first date
	if (isValidDate(start, 'UK') && isValidTime(clock1))
	{
		date1temp = new Date(convertDateFormat(start) + " " + clock1);
		date1.setTime(date1temp.getTime());
	}
	else
	{
		if (errors) { alert("Failed 2"); }
		return 0;
	}

	// Validates second date
	if (isValidDate(finish, 'UK') && isValidTime(clock2))
	{
		date2temp = new Date(convertDateFormat(finish) + " " + clock2);
		date2.setTime(date2temp.getTime());
	}
	else
	{
		if (errors) { alert("Failed 3"); }
		return 0;
	}

	// Sets difference date to difference of first date and second date
	diff.setTime(Math.abs(date1.getTime() - date2.getTime()));
	timediff = diff.getTime();

	// Break down into time chunks
	hours = Math.floor(timediff / (1000 * 60 * 60));
	mins = Math.floor(timediff / (1000 * 60));
	secs = Math.floor(timediff / 1000);

	//alert('Hours ' + hours);
	//alert('mins ' + mins);
	//alert('secs ' + secs);

	return mins2hours(mins);
}


// =============================================================================
function mins2hours(mins)
{
	return (Math.floor(mins / 60)) + ":" + (mins % 60);
}