/*
 * Date prototype extensions. Doesn't depend on any
 * other code. Doens't overwrite existing methods.
 *
 * Adds dayNames, abbrDayNames, monthNames and abbrMonthNames static properties and isLeapYear,
 * isWeekend, isWeekDay, getDaysInMonth, getDayName, getMonthName, getDayOfYear, getWeekOfYear,
 * setDayOfYear, addYears, addMonths, addDays, addHours, addMinutes, addSeconds methods
 *
 * Copyright (c) 2006 Jörn Zaefferer and Brandon Aaron (brandon.aaron@gmail.com || http://brandonaaron.net)
 *
 * Additional methods and properties added by Kelvin Luck: firstDayOfWeek, dateFormat, zeroTime, asString, fromString -
 * I've added my name to these methods so you know who to blame if they are broken!
 * 
 * Dual licensed under the MIT and GPL licenses:
 *   http://www.opensource.org/licenses/mit-license.php
 *   http://www.gnu.org/licenses/gpl.html
 *
 */

/**
 * An Array of day names starting with Sunday.
 * 
 * @example dayNames[0]
 * @result 'Sunday'
 *
 * @name dayNames
 * @type Array
 * @cat Plugins/Methods/Date
 */
Date.dayNames = ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'];

/**
 * An Array of abbreviated day names starting with Sun.
 * 
 * @example abbrDayNames[0]
 * @result 'Sun'
 *
 * @name abbrDayNames
 * @type Array
 * @cat Plugins/Methods/Date
 */
Date.abbrDayNames = ['Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat'];

/**
 * An Array of month names starting with Janurary.
 * 
 * @example monthNames[0]
 * @result 'January'
 *
 * @name monthNames
 * @type Array
 * @cat Plugins/Methods/Date
 */
Date.monthNames = ['January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December'];

/**
 * An Array of abbreviated month names starting with Jan.
 * 
 * @example abbrMonthNames[0]
 * @result 'Jan'
 *
 * @name monthNames
 * @type Array
 * @cat Plugins/Methods/Date
 */
Date.abbrMonthNames = ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'];

/**
 * The first day of the week for this locale.
 *
 * @name firstDayOfWeek
 * @type Number
 * @cat Plugins/Methods/Date
 * @author Kelvin Luck
 */
Date.firstDayOfWeek = 1;

/**
 * The format that string dates should be represented as (e.g. 'dd/mm/yyyy' for UK, 'mm/dd/yyyy' for US, 'yyyy-mm-dd' for Unicode etc).
 *
 * @name format
 * @type String
 * @cat Plugins/Methods/Date
 * @author Kelvin Luck
 */
Date.format = 'dd/mm/yyyy';
//Date.format = 'mm/dd/yyyy';
//Date.format = 'yyyy-mm-dd';
//Date.format = 'dd mmm yy';

(function() {

	/**
	 * Adds a given method under the given name 
	 * to the Date prototype if it doesn't
	 * currently exist.
	 *
	 * @private
	 */
	function add(name, method) {
		if( !Date.prototype[name] ) {
			Date.prototype[name] = method;
		}
	};
	
	/**
	 * Checks if the year is a leap year.
	 *
	 * @example var dtm = new Date("01/12/2008");
	 * dtm.isLeapYear();
	 * @result true
	 *
	 * @name isLeapYear
	 * @type Boolean
	 * @cat Plugins/Methods/Date
	 */
	add("isLeapYear", function() {
		var y = this.getFullYear();
		return (y%4==0 && y%100!=0) || y%400==0;
	});
	
	/**
	 * Checks if the day is a weekend day (Sat or Sun).
	 *
	 * @example var dtm = new Date("01/12/2008");
	 * dtm.isWeekend();
	 * @result false
	 *
	 * @name isWeekend
	 * @type Boolean
	 * @cat Plugins/Methods/Date
	 */
	add("isWeekend", function() {
		return this.getDay()==0 || this.getDay()==6;
	});
	
	/**
	 * Check if the day is a day of the week (Mon-Fri)
	 * 
	 * @example var dtm = new Date("01/12/2008");
	 * dtm.isWeekDay();
	 * @result false
	 * 
	 * @name isWeekDay
	 * @type Boolean
	 * @cat Plugins/Methods/Date
	 */
	add("isWeekDay", function() {
		return !this.isWeekend();
	});
	
	/**
	 * Gets the number of days in the month.
	 * 
	 * @example var dtm = new Date("01/12/2008");
	 * dtm.getDaysInMonth();
	 * @result 31
	 * 
	 * @name getDaysInMonth
	 * @type Number
	 * @cat Plugins/Methods/Date
	 */
	add("getDaysInMonth", function() {
		return [31,(this.isLeapYear() ? 29:28),31,30,31,30,31,31,30,31,30,31][this.getMonth()];
	});
	
	/**
	 * Gets the name of the day.
	 * 
	 * @example var dtm = new Date("01/12/2008");
	 * dtm.getDayName();
	 * @result 'Saturday'
	 * 
	 * @example var dtm = new Date("01/12/2008");
	 * dtm.getDayName(true);
	 * @result 'Sat'
	 * 
	 * @param abbreviated Boolean When set to true the name will be abbreviated.
	 * @name getDayName
	 * @type String
	 * @cat Plugins/Methods/Date
	 */
	add("getDayName", function(abbreviated) {
		return abbreviated ? Date.abbrDayNames[this.getDay()] : Date.dayNames[this.getDay()];
	});

	/**
	 * Gets the name of the month.
	 * 
	 * @example var dtm = new Date("01/12/2008");
	 * dtm.getMonthName();
	 * @result 'Janurary'
	 *
	 * @example var dtm = new Date("01/12/2008");
	 * dtm.getMonthName(true);
	 * @result 'Jan'
	 * 
	 * @param abbreviated Boolean When set to true the name will be abbreviated.
	 * @name getDayName
	 * @type String
	 * @cat Plugins/Methods/Date
	 */
	add("getMonthName", function(abbreviated) {
		return abbreviated ? Date.abbrMonthNames[this.getMonth()] : Date.monthNames[this.getMonth()];
	});

	/**
	 * Get the number of the day of the year.
	 * 
	 * @example var dtm = new Date("01/12/2008");
	 * dtm.getDayOfYear();
	 * @result 11
	 * 
	 * @name getDayOfYear
	 * @type Number
	 * @cat Plugins/Methods/Date
	 */
	add("getDayOfYear", function() {
		var tmpdtm = new Date("1/1/" + this.getFullYear());
		return Math.floor((this.getTime() - tmpdtm.getTime()) / 86400000);
	});
	
	/**
	 * Get the number of the week of the year.
	 * 
	 * @example var dtm = new Date("01/12/2008");
	 * dtm.getWeekOfYear();
	 * @result 2
	 * 
	 * @name getWeekOfYear
	 * @type Number
	 * @cat Plugins/Methods/Date
	 */
	add("getWeekOfYear", function() {
		return Math.ceil(this.getDayOfYear() / 7);
	});

	/**
	 * Set the day of the year.
	 * 
	 * @example var dtm = new Date("01/12/2008");
	 * dtm.setDayOfYear(1);
	 * dtm.toString();
	 * @result 'Tue Jan 01 2008 00:00:00'
	 * 
	 * @name setDayOfYear
	 * @type Date
	 * @cat Plugins/Methods/Date
	 */
	add("setDayOfYear", function(day) {
		this.setMonth(0);
		this.setDate(day);
		return this;
	});
	
	/**
	 * Add a number of years to the date object.
	 * 
	 * @example var dtm = new Date("01/12/2008");
	 * dtm.addYears(1);
	 * dtm.toString();
	 * @result 'Mon Jan 12 2009 00:00:00'
	 * 
	 * @name addYears
	 * @type Date
	 * @cat Plugins/Methods/Date
	 */
	add("addYears", function(num) {
		this.setFullYear(this.getFullYear() + num);
		return this;
	});
	
	/**
	 * Add a number of months to the date object.
	 * 
	 * @example var dtm = new Date("01/12/2008");
	 * dtm.addMonths(1);
	 * dtm.toString();
	 * @result 'Tue Feb 12 2008 00:00:00'
	 * 
	 * @name addMonths
	 * @type Date
	 * @cat Plugins/Methods/Date
	 */
	add("addMonths", function(num) {
		var tmpdtm = this.getDate();
		
		this.setMonth(this.getMonth() + num);
		
		if (tmpdtm > this.getDate())
			this.addDays(-this.getDate());
		
		return this;
	});
	
	/**
	 * Add a number of days to the date object.
	 * 
	 * @example var dtm = new Date("01/12/2008");
	 * dtm.addDays(1);
	 * dtm.toString();
	 * @result 'Sun Jan 13 2008 00:00:00'
	 * 
	 * @name addDays
	 * @type Date
	 * @cat Plugins/Methods/Date
	 */
	add("addDays", function(num) {
		this.setDate(this.getDate() + num);
		return this;
	});
	
	/**
	 * Add a number of hours to the date object.
	 * 
	 * @example var dtm = new Date("01/12/2008");
	 * dtm.addHours(24);
	 * dtm.toString();
	 * @result 'Sun Jan 13 2008 00:00:00'
	 * 
	 * @name addHours
	 * @type Date
	 * @cat Plugins/Methods/Date
	 */
	add("addHours", function(num) {
		this.setHours(this.getHours() + num);
		return this;
	});

	/**
	 * Add a number of minutes to the date object.
	 * 
	 * @example var dtm = new Date("01/12/2008");
	 * dtm.addMinutes(60);
	 * dtm.toString();
	 * @result 'Sat Jan 12 2008 01:00:00'
	 * 
	 * @name addMinutes
	 * @type Date
	 * @cat Plugins/Methods/Date
	 */
	add("addMinutes", function(num) {
		this.setMinutes(this.getMinutes() + num);
		return this;
	});
	
	/**
	 * Add a number of seconds to the date object.
	 * 
	 * @example var dtm = new Date("01/12/2008");
	 * dtm.addSeconds(60);
	 * dtm.toString();
	 * @result 'Sat Jan 12 2008 00:01:00'
	 * 
	 * @name addSeconds
	 * @type Date
	 * @cat Plugins/Methods/Date
	 */
	add("addSeconds", function(num) {
		this.setSeconds(this.getSeconds() + num);
		return this;
	});
	
	/**
	 * Sets the time component of this Date to zero for cleaner, easier comparison of dates where time is not relevant.
	 * 
	 * @example var dtm = new Date();
	 * dtm.zeroTime();
	 * dtm.toString();
	 * @result 'Sat Jan 12 2008 00:01:00'
	 * 
	 * @name zeroTime
	 * @type Date
	 * @cat Plugins/Methods/Date
	 * @author Kelvin Luck
	 */
	add("zeroTime", function() {
		this.setMilliseconds(0);
		this.setSeconds(0);
		this.setMinutes(0);
		this.setHours(0);
		return this;
	});
	
	/**
	 * Returns a string representation of the date object according to Date.format.
	 * (Date.toString may be used in other places so I purposefully didn't overwrite it)
	 * 
	 * @example var dtm = new Date("01/12/2008");
	 * dtm.asString();
	 * @result '12/01/2008' // (where Date.format == 'dd/mm/yyyy'
	 * 
	 * @name asString
	 * @type Date
	 * @cat Plugins/Methods/Date
	 * @author Kelvin Luck
	 */
	add("asString", function() {
		var r = Date.format;
		return r
			.split('yyyy').join(this.getFullYear())
			.split('yy').join(this.getYear())
			.split('mmm').join(this.getMonthName(true))
			.split('mm').join(_zeroPad(this.getMonth()+1))
			.split('dd').join(_zeroPad(this.getDate()));
	});
	
	/**
	 * Returns a new date object created from the passed String according to Date.format or false if the attempt to do this results in an invalid date object
	 * (We can't simple use Date.parse as it's not aware of locale and I chose not to overwrite it incase it's functionality is being relied on elsewhere)
	 *
	 * @example var dtm = Date.fromString("12/01/2008");
	 * dtm.toString();
	 * @result 'Sat Jan 12 2008 00:00:00' // (where Date.format == 'dd/mm/yyyy'
	 * 
	 * @name fromString
	 * @type Date
	 * @cat Plugins/Methods/Date
	 * @author Kelvin Luck
	 */
	Date.fromString = function(s)
	{
		var f = Date.format;
		var d = new Date('01/01/1977');
		var iY = f.indexOf('yyyy');
		if (iY > -1) {
			d.setFullYear(Number(s.substr(iY, 4)));
		} else {
			// TODO - this doesn't work very well - are there any rules for what is meant by a two digit year?
			d.setYear(Number(s.substr(f.indexOf('yy'), 2)));
		}
		var iM = f.indexOf('mmm');
		if (iM > -1) {
			var mStr = s.substr(iM, 3);
			for (var i=0; i<Date.abbrMonthNames.length; i++) {
				if (Date.abbrMonthNames[i] == mStr) break;
			}
			d.setMonth(i);
		} else {
			d.setMonth(Number(s.substr(f.indexOf('mm'), 2)) - 1);
		}
		d.setDate(Number(s.substr(f.indexOf('dd'), 2)));
		if (isNaN(d.getTime())) {
			return false;
		}
		return d;
	};
	
	// utility method
	var _zeroPad = function(num) {
		var s = '0'+num;
		return s.substring(s.length-2)
		//return ('0'+num).substring(-2); // doesn't work on IE :(
	};
	
})();

/** Adds the number of days array to the Date object. */
Date._MD = new Array(31,28,31,30,31,30,31,31,30,31,30,31);

/** Constants used for time computations */
Date.SECOND = 1000 /* milliseconds */;
Date.MINUTE = 60 * Date.SECOND;
Date.HOUR   = 60 * Date.MINUTE;
Date.DAY    = 24 * Date.HOUR;
Date.WEEK   =  7 * Date.DAY;

Date.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;
};

/** Returns the number of days in the current month */
Date.prototype.getMonthDays = function(month) {
	var year = this.getFullYear();
	if (typeof month == "undefined") {
		month = this.getMonth();
	}
	if (((0 == (year%4)) && ( (0 != (year%100)) || (0 == (year%400)))) && month == 1) {
		return 29;
	} else {
		return Date._MD[month];
	}
};

/** Returns the number of day in the year. */
Date.prototype.getDayOfYear = function() {
	var now = new Date(this.getFullYear(), this.getMonth(), this.getDate(), 0, 0, 0);
	var then = new Date(this.getFullYear(), 0, 0, 0, 0, 0);
	var time = now - then;
	return Math.floor(time / Date.DAY);
};

/** Returns the number of the week in year, as defined in ISO 8601. */
Date.prototype.getWeekNumber = function() {
	var d = new Date(this.getFullYear(), this.getMonth(), this.getDate(), 0, 0, 0);
	var DoW = d.getDay();
	d.setDate(d.getDate() - (DoW + 6) % 7 + 3); // Nearest Thu
	var ms = d.valueOf(); // GMT
	d.setMonth(0);
	d.setDate(4); // Thu in Week 1
	return Math.round((ms - d.valueOf()) / (7 * 864e5)) + 1;
};

/** Checks date and time equality */
Date.prototype.equalsTo = function(date) {
	return ((this.getFullYear() == date.getFullYear()) &&
		(this.getMonth() == date.getMonth()) &&
		(this.getDate() == date.getDate()) &&
		(this.getHours() == date.getHours()) &&
		(this.getMinutes() == date.getMinutes()));
};

/** Set only the year, month, date parts (keep existing time) */
Date.prototype.setDateOnly = function(date) {
	var tmp = new Date(date);
	this.setDate(1);
	this.setFullYear(tmp.getFullYear());
	this.setMonth(tmp.getMonth());
	this.setDate(tmp.getDate());
};

/** Prints the date in a string according to the given format. */
Date.prototype.print = function (str) {
	var m = this.getMonth();
	var d = this.getDate();
	var y = this.getFullYear();
	var wn = this.getWeekNumber();
	var w = this.getDay();
	var s = {};
	var hr = this.getHours();
	var pm = (hr >= 12);
	var ir = (pm) ? (hr - 12) : hr;
	var dy = this.getDayOfYear();
	if (ir == 0)
		ir = 12;
	var min = this.getMinutes();
	var sec = this.getSeconds();
	s["%a"] = Calendar._SDN[w]; // abbreviated weekday name [FIXME: I18N]
	s["%A"] = Calendar._DN[w]; // full weekday name
	s["%b"] = Calendar._SMN[m]; // abbreviated month name [FIXME: I18N]
	s["%B"] = Calendar._MN[m]; // full month name
	// FIXME: %c : preferred date and time representation for the current locale
	s["%C"] = 1 + Math.floor(y / 100); // the century number
	s["%d"] = (d < 10) ? ("0" + d) : d; // the day of the month (range 01 to 31)
	s["%e"] = d; // the day of the month (range 1 to 31)
	// FIXME: %D : american date style: %m/%d/%y
	// FIXME: %E, %F, %G, %g, %h (man strftime)
	s["%H"] = (hr < 10) ? ("0" + hr) : hr; // hour, range 00 to 23 (24h format)
	s["%I"] = (ir < 10) ? ("0" + ir) : ir; // hour, range 01 to 12 (12h format)
	s["%j"] = (dy < 100) ? ((dy < 10) ? ("00" + dy) : ("0" + dy)) : dy; // day of the year (range 001 to 366)
	s["%k"] = hr;		// hour, range 0 to 23 (24h format)
	s["%l"] = ir;		// hour, range 1 to 12 (12h format)
	s["%m"] = (m < 9) ? ("0" + (1+m)) : (1+m); // month, range 01 to 12
	s["%M"] = (min < 10) ? ("0" + min) : min; // minute, range 00 to 59
	s["%n"] = "\n";		// a newline character
	s["%p"] = pm ? "PM" : "AM";
	s["%P"] = pm ? "pm" : "am";
	// FIXME: %r : the time in am/pm notation %I:%M:%S %p
	// FIXME: %R : the time in 24-hour notation %H:%M
	s["%s"] = Math.floor(this.getTime() / 1000);
	s["%S"] = (sec < 10) ? ("0" + sec) : sec; // seconds, range 00 to 59
	s["%t"] = "\t";		// a tab character
	// FIXME: %T : the time in 24-hour notation (%H:%M:%S)
	s["%U"] = s["%W"] = s["%V"] = (wn < 10) ? ("0" + wn) : wn;
	s["%u"] = w + 1;	// the day of the week (range 1 to 7, 1 = MON)
	s["%w"] = w;		// the day of the week (range 0 to 6, 0 = SUN)
	// FIXME: %x : preferred date representation for the current locale without the time
	// FIXME: %X : preferred time representation for the current locale without the date
	s["%y"] = ('' + y).substr(2, 2); // year without the century (range 00 to 99)
	s["%Y"] = y;		// year with the century
	s["%%"] = "%";		// a literal '%' character

	var re = /%./g;
	if (!Calendar.is_ie5 && !Calendar.is_khtml)
		return str.replace(re, function (par) { return s[par] || par; });

	var a = str.match(re);
	for (var i = 0; i < a.length; i++) {
		var tmp = s[a[i]];
		if (tmp) {
			re = new RegExp(a[i], 'g');
			str = str.replace(re, tmp);
		}
	}

	return str;
};

Date.prototype.__msh_oldSetFullYear = Date.prototype.setFullYear;
Date.prototype.setFullYear = function(y) {
	var d = new Date(this);
	d.__msh_oldSetFullYear(y);
	if (d.getMonth() != this.getMonth())
		this.setDate(28);
	this.__msh_oldSetFullYear(y);
};

// END: DATE OBJECT PATCHES