/*
---

script: Date.js

name: Date

description: Extends the Date native object to include methods useful in managing dates.

license: MIT-style license

authors:
  - Aaron Newton
  - Nicholas Barthelemy - https://svn.nbarthelemy.com/date-js/
  - Harald Kirshner - mail [at] digitarald.de; http://digitarald.de
  - Scott Kyle - scott [at] appden.com; http://appden.com

requires:
  - Core/Array
  - Core/String
  - Core/Number
  - /Lang
  - /Date.English.US
  - /MooTools.More

provides: [Date]

...
*/

(function(){

var Date = this.Date;

if (!Date.now) Date.now = $time;

Date.Methods = {
	ms: 'Milliseconds',
	year: 'FullYear',
	min: 'Minutes',
	mo: 'Month',
	sec: 'Seconds',
	hr: 'Hours'
};

['Date', 'Day', 'FullYear', 'Hours', 'Milliseconds', 'Minutes', 'Month', 'Seconds', 'Time', 'TimezoneOffset',
	'Week', 'Timezone', 'GMTOffset', 'DayOfYear', 'LastMonth', 'LastDayOfMonth', 'UTCDate', 'UTCDay', 'UTCFullYear',
	'AMPM', 'Ordinal', 'UTCHours', 'UTCMilliseconds', 'UTCMinutes', 'UTCMonth', 'UTCSeconds', 'UTCMilliseconds'].each(function(method){
	Date.Methods[method.toLowerCase()] = method;
});

var pad = function(what, length){
	return new Array(length - String(what).length + 1).join('0') + what;
};

Date.implement({

	set: function(prop, value){
		switch ($type(prop)){
			case 'object':
				for (var p in prop) this.set(p, prop[p]);
				break;
			case 'string':
				prop = prop.toLowerCase();
				var m = Date.Methods;
				if (m[prop]) this['set' + m[prop]](value);
		}
		return this;
	},

	get: function(prop){
		prop = prop.toLowerCase();
		var m = Date.Methods;
		if (m[prop]) return this['get' + m[prop]]();
		return null;
	},

	clone: function(){
		return new Date(this.get('time'));
	},

	increment: function(interval, times){
		interval = interval || 'day';
		times = $pick(times, 1);

		switch (interval){
			case 'year':
				return this.increment('month', times * 12);
			case 'month':
				var d = this.get('date');
				this.set('date', 1).set('mo', this.get('mo') + times);
				return this.set('date', d.min(this.get('lastdayofmonth')));
			case 'week':
				return this.increment('day', times * 7);
			case 'day':
				return this.set('date', this.get('date') + times);
		}

		if (!Date.units[interval]) throw new Error(interval + ' is not a supported interval');

		return this.set('time', this.get('time') + times * Date.units[interval]());
	},

	decrement: function(interval, times){
		return this.increment(interval, -1 * $pick(times, 1));
	},

	isLeapYear: function(){
		return Date.isLeapYear(this.get('year'));
	},

	clearTime: function(){
		return this.set({hr: 0, min: 0, sec: 0, ms: 0});
	},

	diff: function(date, resolution){
		if ($type(date) == 'string') date = Date.parse(date);
		
		return ((date - this) / Date.units[resolution || 'day'](3, 3)).round(); // non-leap year, 30-day month
	},

	getLastDayOfMonth: function(){
		return Date.daysInMonth(this.get('mo'), this.get('year'));
	},

	getDayOfYear: function(){
		return (Date.UTC(this.get('year'), this.get('mo'), this.get('date') + 1) 
			- Date.UTC(this.get('year'), 0, 1)) / Date.units.day();
	},

	getWeek: function(){
		return (this.get('dayofyear') / 7).ceil();
	},
	
	getOrdinal: function(day){
		return Date.getMsg('ordinal', day || this.get('date'));
	},

	getTimezone: function(){
		return this.toString()
			.replace(/^.*? ([A-Z]{3}).[0-9]{4}.*$/, '$1')
			.replace(/^.*?\(([A-Z])[a-z]+ ([A-Z])[a-z]+ ([A-Z])[a-z]+\)$/, '$1$2$3');
	},

	getGMTOffset: function(){
		var off = this.get('timezoneOffset');
		return ((off > 0) ? '-' : '+') + pad((off.abs() / 60).floor(), 2) + pad(off % 60, 2);
	},

	setAMPM: function(ampm){
		ampm = ampm.toUpperCase();
		var hr = this.get('hr');
		if (hr > 11 && ampm == 'AM') return this.decrement('hour', 12);
		else if (hr < 12 && ampm == 'PM') return this.increment('hour', 12);
		return this;
	},

	getAMPM: function(){
		return (this.get('hr') < 12) ? 'AM' : 'PM';
	},

	parse: function(str){
		this.set('time', Date.parse(str));
		return this;
	},

	isValid: function(date) {
		return !isNaN((date || this).valueOf());
	},

	format: function(f){
		if (!this.isValid()) return 'invalid date';
		f = f || '%x %X';
		f = formats[f.toLowerCase()] || f; // replace short-hand with actual format
		var d = this;
		return f.replace(/%([a-z%])/gi,
			function($0, $1){
				switch ($1){
					case 'a': return Date.getMsg('days')[d.get('day')].substr(0, 3);
					case 'A': return Date.getMsg('days')[d.get('day')];
					case 'b': return Date.getMsg('months')[d.get('month')].substr(0, 3);
					case 'B': return Date.getMsg('months')[d.get('month')];
					case 'c': return d.toString();
					case 'd': return pad(d.get('date'), 2);
					case 'D': return d.get('date');
					case 'e': return d.get('date');
					case 'H': return pad(d.get('hr'), 2);
					case 'I': return ((d.get('hr') % 12) || 12);
					case 'j': return pad(d.get('dayofyear'), 3);
					case 'm': return pad((d.get('mo') + 1), 2);
					case 'M': return pad(d.get('min'), 2);
					case 'o': return d.get('ordinal');
					case 'p': return Date.getMsg(d.get('ampm'));
					case 's': return Math.round(d / 1000);
					case 'S': return pad(d.get('seconds'), 2);
					case 'U': return pad(d.get('week'), 2);
					case 'w': return d.get('day');
					case 'x': return d.format(Date.getMsg('shortDate'));
					case 'X': return d.format(Date.getMsg('shortTime'));
					case 'y': return d.get('year').toString().substr(2);
					case 'Y': return d.get('year');
					case 'T': return d.get('GMTOffset');
					case 'Z': return d.get('Timezone');
					case 'z': return pad(d.get('ms'), 3);
				}
				return $1;
			}
		);
	},

	toISOString: function(){
		return this.format('iso8601');
	}

});

Date.alias('toISOString', 'toJSON');
Date.alias('diff', 'compare');
Date.alias('format', 'strftime');

var formats = {
	db: '%Y-%m-%d %H:%M:%S',
	compact: '%Y%m%dT%H%M%S',
	iso8601: '%Y-%m-%dT%H:%M:%S%T',
	rfc822: '%a, %d %b %Y %H:%M:%S %Z',
	'short': '%d %b %H:%M',
	'long': '%B %d, %Y %H:%M'
};

var parsePatterns = [];
var nativeParse = Date.parse;

var parseWord = function(type, word, num){
	var ret = -1;
	var translated = Date.getMsg(type + 's');
	switch ($type(word)){
		case 'object':
			ret = translated[word.get(type)];
			break;
		case 'number':
			ret = translated[word];
			if (!ret) throw new Error('Invalid ' + type + ' index: ' + word);
			break;
		case 'string':
			var match = translated.filter(function(name){
				return this.test(name);
			}, new RegExp('^' + word, 'i'));
			if (!match.length)    throw new Error('Invalid ' + type + ' string');
			if (match.length > 1) throw new Error('Ambiguous ' + type);
			ret = match[0];
	}

	return (num) ? translated.indexOf(ret) : ret;
};

Date.extend({

	getMsg: function(key, args) {
		return MooTools.lang.get('Date', key, args);
	},

	units: {
		ms: $lambda(1),
		second: $lambda(1000),
		minute: $lambda(60000),
		hour: $lambda(3600000),
		day: $lambda(86400000),
		week: $lambda(608400000),
		month: function(month, year){
			var d = new Date;
			return Date.daysInMonth($pick(month, d.get('mo')), $pick(year, d.get('year'))) * 86400000;
		},
		year: function(year){
			year = year || new Date().get('year');
			return Date.isLeapYear(year) ? 31622400000 : 31536000000;
		}
	},

	daysInMonth: function(month, year){
		return [31, Date.isLeapYear(year) ? 29 : 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31][month];
	},

	isLeapYear: function(year){
		return ((year % 4 === 0) && (year % 100 !== 0)) || (year % 400 === 0);
	},

	parse: function(from){
		var t = $type(from);
		if (t == 'number') return new Date(from);
		if (t != 'string') return from;
		from = from.clean();
		if (!from.length) return null;

		var parsed;
		parsePatterns.some(function(pattern){
			var bits = pattern.re.exec(from);
			return (bits) ? (parsed = pattern.handler(bits)) : false;
		});

		return parsed || new Date(nativeParse(from));
	},

	parseDay: function(day, num){
		return parseWord('day', day, num);
	},

	parseMonth: function(month, num){
		return parseWord('month', month, num);
	},

	parseUTC: function(value){
		var localDate = new Date(value);
		var utcSeconds = Date.UTC(
			localDate.get('year'),
			localDate.get('mo'),
			localDate.get('date'),
			localDate.get('hr'),
			localDate.get('min'),
			localDate.get('sec'),
			localDate.get('ms')
		);
		return new Date(utcSeconds);
	},

	orderIndex: function(unit){
		return Date.getMsg('dateOrder').indexOf(unit) + 1;
	},

	defineFormat: function(name, format){
		formats[name] = format;
	},

	defineFormats: function(formats){
		for (var name in formats) Date.defineFormat(name, formats[name]);
	},

	parsePatterns: parsePatterns, // this is deprecated
	
	defineParser: function(pattern){
		parsePatterns.push((pattern.re && pattern.handler) ? pattern : build(pattern));
	},
	
	defineParsers: function(){
		Array.flatten(arguments).each(Date.defineParser);
	},
	
	define2DigitYearStart: function(year){
		startYear = year % 100;
		startCentury = year - startYear;
	}

});

var startCentury = 1900;
var startYear = 70;

var regexOf = function(type){
	return new RegExp('(?:' + Date.getMsg(type).map(function(name){
		return name.substr(0, 3);
	}).join('|') + ')[a-z]*');
};

var replacers = function(key){
	switch(key){
		case 'x': // iso8601 covers yyyy-mm-dd, so just check if month is first
			return ((Date.orderIndex('month') == 1) ? '%m[-./]%d' : '%d[-./]%m') + '([-./]%y)?';
		case 'X':
			return '%H([.:]%M)?([.:]%S([.:]%s)?)? ?%p? ?%T?';
	}
	return null;
};

var keys = {
	d: /[0-2]?[0-9]|3[01]/,
	H: /[01]?[0-9]|2[0-3]/,
	I: /0?[1-9]|1[0-2]/,
	M: /[0-5]?\d/,
	s: /\d+/,
	o: /[a-z]*/,
	p: /[ap]\.?m\.?/,
	y: /\d{2}|\d{4}/,
	Y: /\d{4}/,
	T: /Z|[+-]\d{2}(?::?\d{2})?/
};

keys.m = keys.I;
keys.S = keys.M;

var currentLanguage;

var recompile = function(language){
	currentLanguage = language;
	
	keys.a = keys.A = regexOf('days');
	keys.b = keys.B = regexOf('months');
	
	parsePatterns.each(function(pattern, i){
		if (pattern.format) parsePatterns[i] = build(pattern.format);
	});
};

var build = function(format){
	if (!currentLanguage) return {format: format};
	
	var parsed = [];
	var re = (format.source || format) // allow format to be regex
	 .replace(/%([a-z])/gi,
		function($0, $1){
			return replacers($1) || $0;
		}
	).replace(/\((?!\?)/g, '(?:') // make all groups non-capturing
	 .replace(/ (?!\?|\*)/g, ',? ') // be forgiving with spaces and commas
	 .replace(/%([a-z%])/gi,
		function($0, $1){
			var p = keys[$1];
			if (!p) return $1;
			parsed.push($1);
			return '(' + p.source + ')';
		}
	).replace(/\[a-z\]/gi, '[a-z\\u00c0-\\uffff]'); // handle unicode words

	return {
		format: format,
		re: new RegExp('^' + re + '$', 'i'),
		handler: function(bits){
			bits = bits.slice(1).associate(parsed);
			var date = new Date().clearTime(),
				year = bits.y || bits.Y;
			
			if (year != null) handle.call(date, 'y', year); // need to start in the right year
			if ('d' in bits) handle.call(date, 'd', 1);
			if ('m' in bits || 'b' in bits || 'B' in bits) handle.call(date, 'm', 1);
			
			for (var key in bits) handle.call(date, key, bits[key]);
			return date;
		}
	};
};

var handle = function(key, value){
	if (!value) return this;

	switch(key){
		case 'a': case 'A': return this.set('day', Date.parseDay(value, true));
		case 'b': case 'B': return this.set('mo', Date.parseMonth(value, true));
		case 'd': return this.set('date', value);
		case 'H': case 'I': return this.set('hr', value);
		case 'm': return this.set('mo', value - 1);
		case 'M': return this.set('min', value);
		case 'p': return this.set('ampm', value.replace(/\./g, ''));
		case 'S': return this.set('sec', value);
		case 's': return this.set('ms', ('0.' + value) * 1000);
		case 'w': return this.set('day', value);
		case 'Y': return this.set('year', value);
		case 'y':
			value = +value;
			if (value < 100) value += startCentury + (value < startYear ? 100 : 0);
			return this.set('year', value);
		case 'T':
			if (value == 'Z') value = '+00';
			var offset = value.match(/([+-])(\d{2}):?(\d{2})?/);
			offset = (offset[1] + '1') * (offset[2] * 60 + (+offset[3] || 0)) + this.getTimezoneOffset();
			return this.set('time', this - offset * 60000);
	}

	return this;
};

Date.defineParsers(
	'%Y([-./]%m([-./]%d((T| )%X)?)?)?', // "1999-12-31", "1999-12-31 11:59pm", "1999-12-31 23:59:59", ISO8601
	'%Y%m%d(T%H(%M%S?)?)?', // "19991231", "19991231T1159", compact
	'%x( %X)?', // "12/31", "12.31.99", "12-31-1999", "12/31/2008 11:59 PM"
	'%d%o( %b( %Y)?)?( %X)?', // "31st", "31st December", "31 Dec 1999", "31 Dec 1999 11:59pm"
	'%b( %d%o)?( %Y)?( %X)?', // Same as above with month and day switched
	'%Y %b( %d%o( %X)?)?', // Same as above with year coming first
	'%o %b %d %X %T %Y' // "Thu Oct 22 08:11:23 +0000 2009"
);

MooTools.lang.addEvent('langChange', function(language){
	if (MooTools.lang.get('Date')) recompile(language);
}).fireEvent('langChange', MooTools.lang.getCurrentLanguage());

})();
