// Calendar: a Javascript class for Mootools that adds accessible and unobtrusive date pickers to your form elements <http://electricprism.com/aeron/calendar>
// Calendar RC4, Copyright (c) 2007 Aeron Glemann <http://electricprism.com/aeron>, MIT Style License.

var Calendar = new Class({

 options: {
 blocked: [], // blocked dates
 classes:['calendar','prev','next','month','year','invalid','valid','inactive','active','hover'], // ['calendar', 'prev', 'next', 'month', 'year', 'today', 'invalid', 'valid', 'inactive', 'active', 'hover', 'hilite']
 days:['Pazar','Pazartesi','Salı','Çarşamba','Perşembe','Cuma','Cumartesi'], // days of the week starting at sunday
 direction: 0, // -1 past, 0 past + future, 1 future
 draggable: true,
 months:['Ocak','Şubat','Mart','Nisan','Mayıs','Haziran','Temmuz','Ağustos','Eylül','Ekim','Kasım','Aralık'],
 navigation: 1, // 0 = no nav; 1 = single nav for month; 2 = dual nav for month and year
 offset: 0, // first day of the week: 0 = sunday, 1 = monday, etc..
 
 onHideStart: Class.empty,
 onHideComplete: Class.empty,
 onShowStart: Class.empty,
 onShowComplete: Class.empty,
 pad: 1, // padding between multiple calendars
 tweak: {x: 0, y: 0} // tweak calendar positioning
 },

 // initialize: calendar constructor
 // @param obj (obj) a js object containing the form elements and format strings { id: 'format', id: 'format' etc }
 // @param props (obj) optional properties

 initialize: function(obj, options) {
 // basic error checking
 if (!obj) { return false; }

 this.setOptions(options);

 // create our classes array
 var keys = ['calendar', 'prev', 'next', 'month', 'year', 'today', 'invalid', 'valid', 'inactive', 'active', 'hover', 'hilite'];

 var values = keys.map(function(key, i) {
 if (this.options.classes[i]) {
 if (this.options.classes[i].length) { key = this.options.classes[i]; }
 }
 return key;
 }, this);

 this.classes = values.associate(keys);

 // create cal element with css styles required for proper cal functioning
 this.calendar = new Element('div', {
 'styles': { left: '-1000px', opacity: 0, position: 'absolute', top: '-1000px', zIndex: 1000 }
 }).addClass(this.classes.calendar).injectInside(document.body);

 this.calendar.coord = this.calendar.getCoordinates();

 // iex 6 needs a transparent iframe underneath the calendar in order to not allow select elements to render through
 if (window.ie6) {
 this.iframe = new Element('iframe', {
 'styles': { height: this.calendar.coord.height + 'px', left: '-1000px', position: 'absolute', top: '-1000px', width: this.calendar.coord.width + 'px', zIndex: 999 }
 }).injectInside(document.body);
 this.iframe.style.filter = 'progid:DXImageTransform.Microsoft.Alpha(style=0,opacity=0)';
 }

 // initialize fade method
 this.fx = this.calendar.effect('opacity', {
 onStart: function() {
 if (this.calendar.getStyle('opacity') == 0) { // show
 if (window.ie6) { this.iframe.setStyle('display', 'block'); }
 this.calendar.setStyle('display', 'block');
 this.fireEvent('onShowStart', this.element);
 }
 else { // hide
 this.fireEvent('onHideStart', this.element);
 }
 }.bind(this),
 onComplete: function() {
 if (this.calendar.getStyle('opacity') == 0) { // hidden
 this.calendar.setStyle('display', 'none');
 if (window.ie6) { this.iframe.setStyle('display', 'none'); }
 this.fireEvent('onHideComplete', this.element);
 }
 else { // shown
 this.fireEvent('onShowComplete', this.element);
 }
 }.bind(this)
 });

 // initialize drag method
 if (window.Drag && this.options.draggable) {
 this.drag = new Drag.Move(this.calendar, {
 onDrag: function() {
 if (window.ie6) { this.iframe.setStyles({ left: this.calendar.style.left, top: this.calendar.style.top }); }
 }.bind(this)
 });
 }

 // create calendars array
 this.calendars = [];

 var id = 0;
 var d = new Date(); // today

 d.setDate(d.getDate() + this.options.direction.toInt()); // correct today for directional offset

 for (var i in obj) {
 var cal = {
 button: new Element('button', { 'type': 'button' }),
 el: $(i),
 els: [],
 id: id++,
 month: d.getMonth(),
 visible: false,
 year: d.getFullYear()
 };

 // fix for bad element (naughty, naughty element!)
 if (!this.element(i, obj[i], cal)) { continue; }

 cal.el.addClass(this.classes.calendar);

 // create cal button
 cal.button.addClass(this.classes.calendar).addEvent('click', function(cal) { this.toggle(cal); }.pass(cal, this)).injectAfter(cal.el);

 // read in default value
 cal.val = this.read(cal);

 $extend(cal, this.bounds(cal)); // abs bounds of calendar

 $extend(cal, this.values(cal)); // valid days, months, years

 this.rebuild(cal);

 this.calendars.push(cal); // add to cals array
 }
 },


 // blocked: returns an array of blocked days for the month / year
 // @param cal (obj)
 // @returns blocked days (array)

 blocked: function(cal) {
 var blocked = [];
 var offset = new Date(cal.year, cal.month, 1).getDay(); // day of the week (offset)
 var last = new Date(cal.year, cal.month + 1, 0).getDate(); // last day of this month

 this.options.blocked.each(function(date) {
 var values = date.split(' ');

 for (var i = 0; i < 3; i++) {
 if (!values[i]) { values[i] = '*'; } // make sure blocked date contains values for at least d, m and y
 values[i] = values[i].contains(',') ? values[i].split(',') : new Array(values[i]); // split multiple values
 }

 if (values[2].contains(cal.year + '') || values[2].contains('*')) {
 if (values[1].contains(cal.month + 1 + '') || values[1].contains('*')) {
 values[0].each(function(val) { // if blocked value indicates this month / year
 if (val > 0) { blocked.push(val.toInt()); } // add date to blocked array
 });

 if (values[3]) { // optional value for day of week
 values[3] = values[3].contains(',') ? values[3].split(',') : new Array(values[3]);

 for (var i = 0; i < last; i++) {
 var day = (i + offset) % 7;

 if (values[3].contains(day + '')) {
 blocked.push(i + 1); // add every date that corresponds to the blocked day of the week to the blocked array
 }
 }
 }
 }
 }
 }, this);

 return blocked;
 },


 // bounds: returns the start / end bounds of the calendar
 // @param cal (obj)
 // @returns obj

 bounds: function(cal) {
 // 1. first we assume the calendar has no bounds (or a thousand years in either direction)

 // by default the calendar will accept a millennium in either direction
 var start = new Date(1000, 0, 1); // jan 1, 1000
 var end = new Date(2999, 11, 31); // dec 31, 2999

 // 2. but if the cal is one directional we adjust accordingly
 var date = new Date().getDate() + this.options.direction.toInt();

 if (this.options.direction > 0) {
 start = new Date();
 start.setDate(date + this.options.pad * cal.id);
 }

 if (this.options.direction < 0) {
 end = new Date();
 end.setDate(date - this.options.pad * (this.calendars.length - cal.id - 1));
 }

 // 3. then we can further filter the limits by using the pre-existing values in the selects
 cal.els.each(function(el) {
 if (el.getTag() == 'select') {
 if (el.format.test('(y|Y)')) { // search for a year select
 var years = [];

 el.getChildren().each(function(option) { // get options
 var values = this.unformat(option.value, el.format);

 if (!years.contains(values[0])) { years.push(values[0]); } // add to years array
 }, this);

 years.sort(this.sort);

 if (years[0] > start.getFullYear()) {
 d = new Date(years[0], start.getMonth() + 1, 0); // last day of new month

 if (start.getDate() > d.getDate()) { start.setDate(d.getDate()); }

 start.setYear(years[0]);
 }

 if (years.getLast() < end.getFullYear()) {
 d = new Date(years.getLast(), end.getMonth() + 1, 0); // last day of new month

 if (end.getDate() > d.getDate()) { end.setDate(d.getDate()); }

 end.setYear(years.getLast());
 }
 }

 if (el.format.test('(F|m|M|n)')) { // search for a month select
 var months_start = [];
 var months_end = [];

 el.getChildren().each(function(option) { // get options
 var values = this.unformat(option.value, el.format);

 if ($type(values[0]) != 'number' || values[0] == years[0]) { // if it's a year / month combo for curr year, or simply a month select
 if (!months_start.contains(values[1])) { months_start.push(values[1]); } // add to months array
 }

 if ($type(values[0]) != 'number' || values[0] == years.getLast()) { // if it's a year / month combo for curr year, or simply a month select
 if (!months_end.contains(values[1])) { months_end.push(values[1]); } // add to months array
 }
 }, this);

 months_start.sort(this.sort);
 months_end.sort(this.sort);

 if (months_start[0] > start.getMonth()) {
 d = new Date(start.getFullYear(), months_start[0] + 1, 0); // last day of new month

 if (start.getDate() > d.getDate()) { start.setDate(d.getDate()); }

 start.setMonth(months_start[0]);
 }

 if (months_end.getLast() < end.getMonth()) {
 d = new Date(start.getFullYear(), months_end.getLast() + 1, 0); // last day of new month

 if (end.getDate() > d.getDate()) { end.setDate(d.getDate()); }

 end.setMonth(months_end.getLast());
 }
 }
 }
 }, this);

 return { 'start': start, 'end': end };
 },


 // caption: returns the caption element with header and navigation
 // @param cal (obj)
 // @returns caption (element)

 caption: function(cal) {
 // start by assuming navigation is allowed
 var navigation = {
 prev: { 'month': true, 'year': true },
 next: { 'month': true, 'year': true }
 };

 // if we're in an out of bounds year
 if (cal.year == cal.start.getFullYear()) {
 navigation.prev.year = false;
 if (cal.month == cal.start.getMonth() && this.options.navigation == 1) {
 navigation.prev.month = false;
 }
 }
 if (cal.year == cal.end.getFullYear()) {
 navigation.next.year = false;
 if (cal.month == cal.end.getMonth() && this.options.navigation == 1) {
 navigation.next.month = false;
 }
 }

 // special case of improved navigation but months array with only 1 month we can disable all month navigation
 if ($type(cal.months) == 'array') {
 if (cal.months.length == 1 && this.options.navigation == 2) {
 navigation.prev.month = navigation.next.month = false;
 }
 }

 var caption = new Element('caption');

 var prev = new Element('a').addClass(this.classes.prev).appendText('\x3c'); // <
 var next = new Element('a').addClass(this.classes.next).appendText('\x3e'); // >

 if (this.options.navigation == 2) {
 var month = new Element('span').addClass(this.classes.month).injectInside(caption);

 if (navigation.prev.month) { prev.clone().addEvent('click', function(cal) { this.navigate(cal, 'm', -1); }.pass(cal, this)).injectInside(month); }

 month.adopt(new Element('span').appendText(this.options.months[cal.month]));

 if (navigation.next.month) { next.clone().addEvent('click', function(cal) { this.navigate(cal, 'm', 1); }.pass(cal, this)).injectInside(month); }

 var year = new Element('span').addClass(this.classes.year).injectInside(caption);

 if (navigation.prev.year) { prev.clone().addEvent('click', function(cal) { this.navigate(cal, 'y', -1); }.pass(cal, this)).injectInside(year); }

 year.adopt(new Element('span').appendText(cal.year));

 if (navigation.next.year) { next.clone().addEvent('click', function(cal) { this.navigate(cal, 'y', 1); }.pass(cal, this)).injectInside(year); }
 }
 else { // 1 or 0
 if (navigation.prev.month && this.options.navigation) { prev.clone().addEvent('click', function(cal) { this.navigate(cal, 'm', -1); }.pass(cal, this)).injectInside(caption); }

 caption.adopt(new Element('span').addClass(this.classes.month).appendText(this.options.months[cal.month]));

 caption.adopt(new Element('span').addClass(this.classes.year).appendText(cal.year));

 if (navigation.next.month && this.options.navigation) { next.clone().addEvent('click', function(cal) { this.navigate(cal, 'm', 1); }.pass(cal, this)).injectInside(caption); }

 }

 return caption;
 },


 // changed: run when a select value is changed
 // @param cal (obj)

 changed: function(cal) {
 cal.val = this.read(cal); // update calendar val from inputs

 $extend(cal, this.values(cal)); // update bounds - based on curr month

 this.rebuild(cal); // rebuild days select

 if (!cal.val) { return; } // in case the same date was clicked the cal has no set date we should exit

 if (cal.val.getDate() < cal.days[0]) { cal.val.setDate(cal.days[0]); }
 if (cal.val.getDate() > cal.days.getLast()) { cal.val.setDate(cal.days.getLast()); }

 cal.els.each(function(el) { // then we can set the value to the field
 el.value = this.format(cal.val, el.format);
 }, this);

 this.check(cal); // checks other cals

 this.calendars.each(function(kal) { // update cal graphic if visible
 if (kal.visible) { this.display(kal); }
 }, this);
 },


 // check: checks other calendars to make sure no overlapping values
 // @param cal (obj)

 check: function(cal) {
 this.calendars.each(function(kal, i) {
 if (kal.val) { // if calendar has value set
 var change = false;

 if (i < cal.id) { // preceding calendar
 var bound = new Date(Date.parse(cal.val));

 bound.setDate(bound.getDate() - (this.options.pad * (cal.id - i)));

 if (bound < kal.val) { change = true; }
 }
 if (i > cal.id) { // following calendar
 var bound = new Date(Date.parse(cal.val));

 bound.setDate(bound.getDate() + (this.options.pad * (i - cal.id)));

 if (bound > kal.val) { change = true; }
 }

 if (change) {
 if (kal.start > bound) { bound = kal.start; }
 if (kal.end < bound) { bound = kal.end; }

 kal.month = bound.getMonth();
 kal.year = bound.getFullYear();

 $extend(kal, this.values(kal));

 // TODO - IN THE CASE OF SELECT MOVE TO NEAREST VALID VALUE
 // IN THE CASE OF INPUT DISABLE

 // if new date is not valid better unset cal value
 // otherwise it would mean incrementally checking to find the nearest valid date which could be months / years away
 kal.val = kal.days.contains(bound.getDate()) ? bound : null;

 this.write(kal);

 if (kal.visible) { this.display(kal); } // update cal graphic if visible
 }
 }
 }, this);
 },


 // clicked: run when a valid day is clicked in the calendar
 // @param cal (obj)

 clicked: function(td, day, cal) {
 cal.val = (this.value(cal) == day) ? null : new Date(cal.year, cal.month, day); // set new value - if same then disable

 this.write(cal);

 // ok - in the special case that it's all selects and there's always a date no matter what (at least as far as the form is concerned)
 // we can't let the calendar undo a date selection - it's just not possible!!
 if (!cal.val) { cal.val = this.read(cal); }

 if (cal.val) {
 this.check(cal); // checks other cals
 this.toggle(cal); // hide cal
 }
 else { // remove active class and replace with valid
 td.addClass(this.classes.valid);
 td.removeClass(this.classes.active);
 }
 },


 // display: create calendar element
 // @param cal (obj)

 display: function(cal) {
 // 1. header and navigation
 this.calendar.empty(); // init div

 this.calendar.className = this.classes.calendar + ' ' + this.options.months[cal.month].toLowerCase();

 var div = new Element('div').injectInside(this.calendar); // a wrapper div to help correct browser css problems with the caption element

 var table = new Element('table').injectInside(div).adopt(this.caption(cal));

 // 2. day names
 var thead = new Element('thead').injectInside(table);

 var tr = new Element('tr').injectInside(thead);

 for (var i = 0; i <= 6; i++) {
 var th = this.options.days[(i + this.options.offset) % 7];

 tr.adopt(new Element('th', { 'title': th }).appendText(th.substr(0, 1)));
 }

 // 3. day numbers
 var tbody = new Element('tbody').injectInside(table);
 var tr = new Element('tr').injectInside(tbody);

 var d = new Date(cal.year, cal.month, 1);
 var offset = ((d.getDay() - this.options.offset) + 7) % 7; // day of the week (offset)
 var last = new Date(cal.year, cal.month + 1, 0).getDate(); // last day of this month
 var prev = new Date(cal.year, cal.month, 0).getDate(); // last day of previous month
 var active = this.value(cal); // active date (if set and within curr month)
 var valid = cal.days; // valid days for curr month
 var inactive = []; // active dates set by other calendars
 var hilited = [];
 this.calendars.each(function(kal, i) {
 if (kal != cal && kal.val) {
 if (cal.year == kal.val.getFullYear() && cal.month == kal.val.getMonth()) { inactive.push(kal.val.getDate()); }

 if (cal.val) {
 for (var day = 1; day <= last; day++) {
 d.setDate(day);

 if ((i < cal.id && d > kal.val && d < cal.val) || (i > cal.id && d > cal.val && d < kal.val)) {
 if (!hilited.contains(day)) { hilited.push(day); }
 }
 }
 }
 }
 }, this);
 var d = new Date();
 var today = new Date(d.getFullYear(), d.getMonth(), d.getDate()).getTime(); // today obv

 for (var i = 1; i < 43; i++) { // 1 to 42 (6 x 7 or 6 weeks)
 if ((i - 1) % 7 == 0) { tr = new Element('tr').injectInside(tbody); } // each week is it's own table row

 var td = new Element('td').injectInside(tr);

 var day = i - offset;
 var date = new Date(cal.year, cal.month, day);

 var cls = '';

 if (day === active) { cls = this.classes.active; } // active
 else if (inactive.contains(day)) { cls = this.classes.inactive; } // inactive
 else if (valid.contains(day)) { cls = this.classes.valid; } // valid
 else if (day >= 1 && day <= last) { cls = this.classes.invalid; } // invalid

 if (date.getTime() == today) { cls = cls + ' ' + this.classes.today; } // adds class for today

 if (hilited.contains(day)) { cls = cls + ' ' + this.classes.hilite; } // adds class if hilited

 td.addClass(cls);

 if (valid.contains(day)) { // if it's a valid - clickable - day we add interaction
 td.setProperty('title', this.format(date, 'D M jS Y'));

 td.addEvents({
 'click': function(td, day, cal) {
 this.clicked(td, day, cal);
 }.pass([td, day, cal], this),
 'mouseover': function(td, cls) {
 td.addClass(cls);
 }.pass([td, this.classes.hover]),
 'mouseout': function(td, cls) {
 td.removeClass(cls);
 }.pass([td, this.classes.hover])
 });
 }

 // pad calendar with last days of prev month and first days of next month
 if (day < 1) { day = prev + day; }
 else if (day > last) { day = day - last; }

 td.appendText(day);
 }
 },


 // element: helper function
 // @param el (string) element id
 // @param f (string) format string
 // @param cal (obj)

 element: function(el, f, cal) {
 if ($type(f) == 'object') { // in the case of multiple inputs per calendar
 for (var i in f) {
 if (!this.element(i, f[i], cal)) { return false; }
 }

 return true;
 }

 el = $(el);

 if (!el) { return false; }

 el.format = f;

 if (el.getTag() == 'select') { // select elements allow the user to manually set the date via select option
 el.addEvent('change', function(cal) { this.changed(cal); }.pass(cal, this));
 }
 else { // input (type text) elements restrict the user to only setting the date via the calendar
 el.readOnly = true;
 el.addEvent('focus', function(cal) { this.toggle(cal); }.pass(cal, this));
 }

 cal.els.push(el);

 return true;
 },


 // format: formats a date object according to passed in instructions
 // @param date (obj)
 // @param f (string) any combination of punctuation / separators and d, j, D, l, S, m, n, F, M, y, Y
 // @returns string

 format: function(date, f) {
 var g = '';

 if (date) {
 var d = date.getDate(); // 1 - 31
 var day = this.options.days[date.getDay()]; // Sunday - Saturday
 var m = date.getMonth() + 1; // 1 - 12
 var month = this.options.months[date.getMonth()]; // January - December
 var y = date.getFullYear() + ''; // 19xx - 20xx

 for (var i = 0; i < f.length; i++) {
 var c = f.charAt(i); // format char

 switch(c) {
 // year cases
 case 'y': // xx - xx
 y = y.substr(2);
 case 'Y': // 19xx - 20xx
 g += y;
 break;

 // month cases
 case 'm': // 01 - 12
 if (m < 10) { m = '0' + m; }
 case 'n': // 1 - 12
 g += m;
 break;

 case 'M': // Jan - Dec
 month = month.substr(0, 3);
 case 'F': // January - December
 g += month;
 break;

 // day cases
 case 'd': // 01 - 31
 if (d < 10) { d = '0' + d; }
 case 'j': // 1 - 31
 g += d;
 break;

 case 'D': // Sun - Sat
 day = day.substr(0, 3);
 case 'l': // Sunday - Saturday
 g += day;
 break;

 case 'S': // st, nd, rd or th (works well with j)
 if (d % 10 == 1 && d != '11') { g += 'st'; }
 else if (d % 10 == 2 && d != '12') { g += 'nd'; }
 else if (d % 10 == 3 && d != '13') { g += 'rd'; }
 else { g += 'th'; }
 break;

 default:
 g += c;
 }
 }
 }

 return g; // return format with values replaced
 },


 // navigate: calendar navigation
 // @param cal (obj)
 // @param type (str) m or y for month or year
 // @param n (int) + or - for next or prev

 navigate: function(cal, type, n) {
 switch (type) {
 case 'm': // month
 if ($type(cal.months) == 'array') {
 var i = cal.months.indexOf(cal.month) + n; // index of current month

 if (i < 0 || i == cal.months.length) { // out of range
 if (this.options.navigation == 1) { // if type 1 nav we'll need to increment the year
 this.navigate(cal, 'y', n);
 }

 i = (i < 0) ? cal.months.length - 1 : 0;
 }

 cal.month = cal.months[i];
 }
 else {
 var i = cal.month + n;

 if (i < 0 || i == 12) {
 if (this.options.navigation == 1) {
 this.navigate(cal, 'y', n);
 }

 i = (i < 0) ? 11 : 0;
 }

 cal.month = i;
 }
 break;

 case 'y': // year
 if ($type(cal.years) == 'array') {
 var i = cal.years.indexOf(cal.year) + n;

 cal.year = cal.years[i];
 }
 else {
 cal.year += n;
 }
 break;
 }

 $extend(cal, this.values(cal));

 if ($type(cal.months) == 'array') { // if the calendar has a months select
 var i = cal.months.indexOf(cal.month); // and make sure the curr months exists for the new year

 if (i < 0) { cal.month = cal.months[0]; } // otherwise we'll reset the month
 }


 this.display(cal);
 },


 // read: compiles cal value based on array of inputs passed in
 // @param cal (obj)
 // @returns date (obj) or (null)

 read: function(cal) {
 var arr = [null, null, null];

 cal.els.each(function(el) {
 // returns an array which may contain empty values
 var values = this.unformat(el.value, el.format);

 values.each(function(val, i) {
 if ($type(val) == 'number') { arr[i] = val; }
 });
 }, this);

 // we can update the cals month and year values
 if ($type(arr[0]) == 'number') { cal.year = arr[0]; }
 if ($type(arr[1]) == 'number') { cal.month = arr[1]; }

 var val = null;

 if (arr.every(function(i) { return $type(i) == 'number'; })) { // if valid date
 var last = new Date(arr[0], arr[1] + 1, 0).getDate(); // last day of month

 if (arr[2] > last) { arr[2] = last; } // make sure we stay within the month (ex in case default day of select is 31 and month is feb)

 val = new Date(arr[0], arr[1], arr[2]);
 }

 return (cal.val == val) ? null : val; // if new date matches old return null (same date clicked twice = disable)
 },


 // rebuild: rebuilds days + months selects
 // @param cal (obj)

 rebuild: function(cal) {
 cal.els.each(function(el) {
 /*
 if (el.getTag() == 'select' && el.format.test('^(F|m|M|n)$')) { // special case for months-only select
 if (!cal.options) { cal.options = el.clone(); } // clone a copy of months select

 var val = (cal.val) ? cal.val.getMonth() : el.value.toInt();

 el.empty(); // initialize select

 cal.months.each(function(month) {
 // create an option element
 var option = new Element('option', {
 'selected': (val == month),
 'value': this.format(new Date(1, month, 1), el.format);
 }).appendText(day).injectInside(el);
 }, this);
 }
 */

 if (el.getTag() == 'select' && el.format.test('^(d|j)$')) { // special case for days-only select
 var d = this.value(cal);

 if (!d) { d = el.value.toInt(); } // if the calendar doesn't have a set value, try to use value from select

 el.empty(); // initialize select

 cal.days.each(function(day) {
 // create an option element
 var option = new Element('option', {
 'selected': (d == day),
 'value': ((el.format == 'd' && day < 10) ? '0' + day : day)
 }).appendText(day).injectInside(el);
 }, this);
 }
 }, this);
 },


 // sort: helper function for numerical sorting

 sort: function(a, b) {
 return a - b;
 },


 // toggle: show / hide calendar
 // @param cal (obj)

 toggle: function(cal) {
 document.removeEvent('mousedown', this.fn); // always remove the current mousedown script first

 if (cal.visible) { // simply hide curr cal
 cal.visible = false;
 cal.button.removeClass(this.classes.active); // active

 this.fx.start(1, 0);
 }
 else { // otherwise show (may have to hide others)
 // hide cal on out-of-bounds click
 this.fn = function(e, cal) {
 var e = new Event(e);

 var el = e.target;

 var stop = false;

 while (el != document.body && el.nodeType == 1) {
 if (el == this.calendar) { stop = true; }
 this.calendars.each(function(kal) {
 if (kal.button == el || kal.els.contains(el)) { stop = true; }
 });

 if (stop) {
 e.stop();
 return false;
 }
 else { el = el.parentNode; }
 }

 this.toggle(cal);
 }.create({ 'arguments': cal, 'bind': this, 'event': true });

 document.addEvent('mousedown', this.fn);

 this.calendars.each(function(kal) {
 if (kal == cal) {
 kal.visible = true;
 kal.button.addClass(this.classes.active); // css c-icon-active
 }
 else {
 kal.visible = false;
 kal.button.removeClass(this.classes.active); // css c-icon-active
 }
 }, this);

 var size = window.getSize().scrollSize;

 var coord = cal.button.getCoordinates();

 var x = coord.right + this.options.tweak.x;
 var y = coord.top + this.options.tweak.y;

 // make sure the calendar doesn't open off screen (does't work in safari!?)
 if (x + this.calendar.coord.width > size.x) { x -= (x + this.calendar.coord.width - size.x); }
 if (y + this.calendar.coord.height > size.y) { y -= (y + this.calendar.coord.height - size.y); }

 this.calendar.setStyles({ left: x + 'px', top: y + 'px' });

 if (window.ie6) { this.iframe.setStyles({ left: x + 'px', top: y + 'px' }); }

 this.display(cal);

 this.fx.start(0, 1);
 }
 },


 // unformat: takes a value from an input and parses the d, m and y elements
 // @param val (string)
 // @param f (string) any combination of punctuation / separators and d, j, D, l, S, m, n, F, M, y, Y
 // @returns array

 unformat: function(val, f) {
 f = f.escapeRegExp();

 var re = {
 d: '([0-9]{2})',
 j: '([0-9]{1,2})',
 D: '(' + this.options.days.map(function(day) { return day.substr(0, 3); }).join('|') + ')',
 l: '(' + this.options.days.join('|') + ')',
 S: '(st|nd|rd|th)',
 F: '(' + this.options.months.join('|') + ')',
 m: '([0-9]{2})',
 M: '(' + this.options.months.map(function(month) { return month.substr(0, 3); }).join('|') + ')',
 n: '([0-9]{1,2})',
 Y: '([0-9]{4})',
 y: '([0-9]{2})'
 }

 var arr = []; // array of indexes

 var g = '';

 // convert our format string to regexp
 for (var i = 0; i < f.length; i++) {
 var c = f.charAt(i);

 if (re[c]) {
 arr.push(c);

 g += re[c];
 }
 else {
 g += c;
 }
 }

 // match against date
 var matches = val.match('^' + g + '$');

 var dates = new Array(3);

 if (matches) {
 matches = matches.slice(1); // remove first match which is the date

 arr.each(function(c, i) {
 i = matches[i];

 switch(c) {
 // year cases
 case 'y':
 i = '19' + i; // 2 digit year assumes 19th century (same as JS)
 case 'Y':
 dates[0] = i.toInt();
 break;

 // month cases
 case 'F':
 i = i.substr(0, 3);
 case 'M':
 i = this.options.months.map(function(month) { return month.substr(0, 3); }).indexOf(i) + 1;
 case 'm':
 case 'n':
 dates[1] = i.toInt() - 1;
 break;

 // day cases
 case 'd':
 case 'j':
 dates[2] = i.toInt();
 break;
 }
 }, this);
 }

 return dates;
 },


 // value: returns day value of calendar if set
 // @param cal (obj)
 // @returns day (int) or null

 value: function(cal) {
 var day = null;

 if (cal.val) {
 if (cal.year == cal.val.getFullYear() && cal.month == cal.val.getMonth()) { day = cal.val.getDate(); }
 }

 return day;
 },


 // values: returns the years, months (for curr year) and days (for curr month and year) for the calendar
 // @param cal (obj)
 // @returns obj

 values: function(cal) {
 var years, months, days;

 cal.els.each(function(el) {
 if (el.getTag() == 'select') {
 if (el.format.test('(y|Y)')) { // search for a year select
 years = [];

 el.getChildren().each(function(option) { // get options
 var values = this.unformat(option.value, el.format);

 if (!years.contains(values[0])) { years.push(values[0]); } // add to years array
 }, this);

 years.sort(this.sort);
 }

 if (el.format.test('(F|m|M|n)')) { // search for a month select
 months = []; // 0 - 11 should be

 el.getChildren().each(function(option) { // get options
 var values = this.unformat(option.value, el.format);

 if ($type(values[0]) != 'number' || values[0] == cal.year) { // if it's a year / month combo for curr year, or simply a month select
 if (!months.contains(values[1])) { months.push(values[1]); } // add to months array
 }
 }, this);

 months.sort(this.sort);
 }

 if (el.format.test('(d|j)') && !el.format.test('^(d|j)$')) { // search for a day select, but NOT a days only select
 days = []; // 1 - 31

 el.getChildren().each(function(option) { // get options
 var values = this.unformat(option.value, el.format);

 // in the special case of days we dont want the value if its a days only select
 // otherwise that will screw up the options rebuilding
 // we will take the values if they are exact dates though
 if (values[0] == cal.year && values[1] == cal.month) {
 if (!days.contains(values[2])) { days.push(values[2]); } // add to days array
 }
 }, this);
 }
 }
 }, this);

 // we start with what would be the first and last days were there no restrictions
 var first = 1;
 var last = new Date(cal.year, cal.month + 1, 0).getDate(); // last day of the month

 // if we're in an out of bounds year
 if (cal.year == cal.start.getFullYear()) {
 // in the special case of improved navigation but no months array, we'll need to construct one
 if (months == null && this.options.navigation == 2) {
 months = [];

 for (var i = 0; i < 12; i ++) {
 if (i >= cal.start.getMonth()) { months.push(i); }
 }
 }

 // if we're in an out of bounds month
 if (cal.month == cal.start.getMonth()) {
 first = cal.start.getDate(); // first day equals day of bound
 }
 }
 if (cal.year == cal.end.getFullYear()) {
 // in the special case of improved navigation but no months array, we'll need to construct one
 if (months == null && this.options.navigation == 2) {
 months = [];

 for (var i = 0; i < 12; i ++) {
 if (i <= cal.end.getMonth()) { months.push(i); }
 }
 }

 if (cal.month == cal.end.getMonth()) {
 last = cal.end.getDate(); // last day equals day of bound
 }
 }

 // let's get our invalid days
 var blocked = this.blocked(cal);

 // finally we can prepare all the valid days in a neat little array
 if ($type(days) == 'array') { // somewhere there was a days select
 days = days.filter(function(day) {
 if (day >= first && day <= last && !blocked.contains(day)) { return day; }
 });
 }
 else { // no days select we'll need to construct a valid days array
 days = [];

 for (var i = first; i <= last; i++) {
 if (!blocked.contains(i)) { days.push(i); }
 }
 }

 days.sort(this.sort); // sorting our days will give us first and last of month

 return { 'days': days, 'months': months, 'years': years };
 },


 // write: sets calendars value to form elements
 // @param cal (obj)

 write: function(cal) {
 this.rebuild(cal); // in the case of options, we'll need to make sure we have the correct number of days available

 cal.els.each(function(el) { // then we can set the value to the field
 el.value = this.format(cal.val, el.format);
 }, this);
 }
});

Calendar.implement(new Events, new Options);