/* MarcGrabanski.com v2.4 */
/* Pop-Up Calendar Built from Scratch by Marc Grabanski */
/* Enhanced by Keith Wood (kbwood@iprimus.com.au). */
/* Under the Creative Commons Licence http://creativecommons.org/licenses/by/3.0/
    Share or Remix it but please Attribute the authors. */
var popUpCal = {
    selectedDay: 0,
    selectedMonth: 0, // 0-11
    selectedYear: 0, // 4-digit year
    clearText: 'Clear', // Display text for clear link
    closeText: 'Close', // Display text for close link
    prevText: '<Prev', // Display text for previous month link
    nextText: 'Next>', // Display text for next month link
    currentText: 'Today', // Display text for current month link
    appendText: '', // Display text following the input box, e.g. showing the format
    buttonText: '...', // Text for trigger button
    buttonImage: '', // URL for trigger button image
    buttonImageOnly: false, // True if the image appears alone, false if it appears on a button
    dayNames: ['Su','Mo','Tu','We','Th','Fr','Sa'], // Names of days starting at Sunday
    monthNames: ['January','February','March','April','May','June','July','August','September','October','November','December'], // Names of months
    dateFormat: 'DMY/', // First three are day, month, year in the required order, fourth is the separator, e.g. US would be 'MDY/'
    yearRange: '-80:+20', // Range of years to display in drop-down, either relative to current year (-nn:+nn) or absolute (nnnn:nnnn)
    changeMonth: true, // True if month can be selected directly, false if only prev/next
    changeYear: true, // True if year can be selected directly, false if only prev/next
    firstDay: 0, // The first day of the week, Sun = 0, Mon = 1, ...
    changeFirstDay: true, // True to click on day name to change, false to remain as set
    showOtherMonths: false, // True to show dates in other months, false to leave blank
    minDate: null, // The earliest selectable date, or null for no limit
    maxDate: null, // The latest selectable date, or null for no limit
    speed: 'medium', // Speed of display/closure
    autoPopUp: 'focus', // 'focus' for popup on focus, 'button' for trigger button, or 'both' for either
    closeAtTop: true, // True to have the clear/close at the top, false to have them at the bottom
    hideIfNoPrevNext: true, // True to hide next/previous month links if not applicable, false to just disable them
    customDate: null, // Function that takes a date and returns an array with [0] = true if selectable, false if not,
        // [1] = custom CSS class name(s) or '', e.g. popUpCal.noWeekends
    fieldSettings: null, // Function that takes an input field and returns a set of custom settings for the calendar
    inline: false, // this sets the calendar to always display, use this with customEvent
    customEvent: false, // define an action for the inline calendar

    /* Initialisation. */
    init: function() {
        this.popUpShowing = false;
        this.selectingMonthYear = false;
        this.standalone = false;
        this.lastInput = null;
        this.disabledInputs = [];
        this.calendarDiv = $('<div id="calendar_div"></div>');
        $('body').append(this.calendarDiv);
        $(document).mousedown(popUpCal.checkExternalClick);
    },

    /* Pop-up the calendar in a "dialog" box. */
    showStandalone: function(dateText, prompt, callback, pos) {
        if (!this.standaloneInput) { // internal input field
            this.standaloneInput = $('<input type="text" style="position: absolute; top: -100px;"/>');
            this.standaloneInput.keydown(this.doKeyDown);
            $('body').append(this.standaloneInput);
        }
        this.standaloneInput.val(dateText);
        var windowWidth, windowHeight;
        if (self.innerHeight) { // all except Explorer
            windowWidth = self.innerWidth;
            windowHeight = self.innerHeight;
        } else if (document.documentElement && document.documentElement.clientHeight) { // Explorer 6 Strict Mode
            windowWidth = document.documentElement.clientWidth;
            windowHeight = document.documentElement.clientHeight;
        } else if (document.body) { // other Explorers
            windowWidth = document.body.clientWidth;
            windowHeight = document.body.clientHeight;
        } 
        this.pos = pos || ($.blockUI ? [0, 0] : [(windowWidth - 200) / 2,
            (windowHeight - 200) / 2]); // should use actual width/height
        this.prompt = prompt;
        this.customEvent = callback;
        this.standalone = true;
        this.calendarDiv.addClass('calendar_dialog');
        this.showFor(this.standaloneInput[0]);
        if ($.blockUI) $.blockUI(this.calendarDiv, { width: '200px' });
    },

    /* Pop-up the calendar for a given input field. */
    showFor: function(target) {
        var input = (target.nodeName && target.nodeName.toLowerCase() == 'input' ? target : this);
        if (input.nodeName.toLowerCase() != 'input') { // find from button/image trigger
            input = $('../input', input)[0];
        }
        if (popUpCal.lastInput == input) { // already here
            return;
        }
        for (var i = 0; i < popUpCal.disabledInputs.length; i++) {  // check not disabled
            if (popUpCal.disabledInputs[i] == input) {
                return;
            }
        }
        popUpCal.input = $(input);
        popUpCal.hideCalendar('');
        popUpCal.lastInput = input;
        popUpCal.setDateFromField();
        if (!popUpCal.pos) { // position below input
            popUpCal.pos = popUpCal.findPos(input);
            popUpCal.pos[1] += input.offsetHeight;
        }
        popUpCal.calendarDiv.css('position', (popUpCal.standalone && $.blockUI ? 'static' : 'absolute')).
            css('left', popUpCal.pos[0] + 'px').css('top', popUpCal.pos[1] + 'px');
        popUpCal.pos = null;
        $.extend(popUpCal, (popUpCal.fieldSettings ? popUpCal.fieldSettings(input) : {}));
        popUpCal.showCalendar();
    },

    /* Handle keystrokes. */
    doKeyDown: function(e) {
        if (popUpCal.popUpShowing) {
            switch (e.keyCode) {
                case 9:  popUpCal.hideCalendar(''); break; // hide on tab out
                case 13: popUpCal.selectDate(); break; // select the value on enter
                case 27: popUpCal.hideCalendar(popUpCal.speed); break; // hide on escape
                case 33: popUpCal.adjustDate(-1, (e.ctrlKey ? 'Y' : 'M')); break; // previous month/year on page up/+ ctrl
                case 34: popUpCal.adjustDate(+1, (e.ctrlKey ? 'Y' : 'M')); break; // next month/year on page down/+ ctrl
                case 35: if (e.ctrlKey) popUpCal.clearDate(); break; // clear on ctrl+end
                case 36: if (e.ctrlKey) popUpCal.gotoToday(); break; // current on ctrl+home
                case 37: if (e.ctrlKey) popUpCal.adjustDate(-1, 'D'); break; // -1 day on ctrl+left
                case 38: if (e.ctrlKey) popUpCal.adjustDate(-7, 'D'); break; // -1 week on ctrl+up
                case 39: if (e.ctrlKey) popUpCal.adjustDate(+1, 'D'); break; // +1 day on ctrl+right
                case 40: if (e.ctrlKey) popUpCal.adjustDate(+7, 'D'); break; // +1 week on ctrl+down
            }
        }
        else if (e.keyCode == 36 && e.ctrlKey) { // display the calendar on ctrl+home
            popUpCal.showFor(this);
        }
    },

    /* Filter entered characters. */
    doKeyPress: function(e) {
        var chr = String.fromCharCode(e.charCode == undefined ? e.keyCode : e.charCode);
        return (chr < ' ' || chr == popUpCal.dateFormat.charAt(3) || (chr >= '0' && chr <= '9')); // only allow numbers and separator
    },

    /* Attach the calendar to an input field. */
    connectCalendar: function(target) {
        var $input = $(target);
        $input.after('<span class="calendar_append">' + this.appendText + '</span>');
        if (this.autoPopUp == 'focus' || this.autoPopUp == 'both') { // pop-up calendar when in the marked fields
            $input.focus(this.showFor);
        }
        if (this.autoPopUp == 'button' || this.autoPopUp == 'both') { // pop-up calendar when button clicked
            $input.wrap('<span class="calendar_wrap"></span>').
                after(this.buttonImageOnly ? '<img class="calendar_trigger" src="' +
                this.buttonImage + '" alt="' + this.buttonText + '" title="' + this.buttonText + '"/>' :
                '<button type="button" class="calendar_trigger">' + (this.buttonImage != '' ?
                '<img src="' + this.buttonImage + '" alt="' + this.buttonText + '" title="' + this.buttonText + '"/>' :
                this.buttonText) + '</button>');
            $((this.buttonImageOnly ? 'img' : 'button') + '.calendar_trigger', $input.parent('span')).click(this.showFor);
        }
        $input.keydown(this.doKeyDown).keypress(this.doKeyPress);
    },

    /* Attach an inline calendar to a div. */
    displayInline: function(target) {
        $(target).append('<div id="calendar_inline_div"></div><div style="clear:both"></div>');
        popUpCal.selectedDay = new Date().getDate();
        popUpCal.selectedMonth = new Date().getMonth();
        popUpCal.selectedYear = new Date().getFullYear();
        popUpCal.adjustDate(); 
        popUpCal.showCalendar(); 
    },
    
    /* Enable the input field(s) for entry. */
    enableFor: function(inputs) {
        inputs = (inputs.jquery ? inputs : $(inputs));
        inputs.each(function() {
            this.disabled = false;
            $('../button.calendar_trigger', this).each(function() { this.disabled = false; });
            $('../img.calendar_trigger', this).css('opacity', '1.0');
            var $this = this;
            popUpCal.disabledInputs = $.map(popUpCal.disabledInputs,
                function(value) { return (value == $this ? null : value); }); // delete entry
        });
        return false;
    },

    /* Disable the input field(s) from entry. */
    disableFor: function(inputs) {
        inputs = (inputs.jquery ? inputs : $(inputs));
        inputs.each(function() {
            this.disabled = true;
            $('../button.calendar_trigger', this).each(function() { this.disabled = true; });
            $('../img.calendar_trigger', this).css('opacity', '0.5');
            var $this = this;
            popUpCal.disabledInputs = $.map(popUpCal.disabledInputs,
                function(value) { return (value == $this ? null : value); }); // delete entry
            popUpCal.disabledInputs[popUpCal.disabledInputs.length] = this;
        });
        return false;
    },

    /* Construct and display the calendar. */
    showCalendar: function() {
        this.popUpShowing = true;
        var today = new Date();
        today = new Date(today.getFullYear(), today.getMonth(), today.getDate()); // clear time
        // build the calendar HTML
        var controls = '<div id="calendar_control">' +
            '<a id="calendar_clear" onclick="popUpCal.clearDate();">' + this.clearText + '</a>' +
            '<a id="calendar_close" onclick="popUpCal.hideCalendar(popUpCal.speed);">' +
            this.closeText + '</a></div>';
        var html = (this.prompt ? '<div id="calendar_prompt">' + this.prompt + '</div>' : '') +
            (this.closeAtTop && !this.inline ? controls : '') + '<div id="calendar_links">' +
            (this.canAdjustMonth(-1) ? '<a id="calendar_prev" ' +
            'onclick="popUpCal.adjustDate(-1, \'M\');">' + this.prevText + '</a>' :
            (this.hideIfNoPrevNext ? '' : '<label id="calendar_prev">' + this.prevText + '</label>')) +
            (this.isInRange(today) ? '<a id="calendar_current" ' +
            'onclick="popUpCal.gotoToday();">' + this.currentText + '</a>' : '') +
            (this.canAdjustMonth(+1) ? '<a id="calendar_next" ' +
            'onclick="popUpCal.adjustDate(+1, \'M\');">' + this.nextText + '</a>' :
            (this.hideIfNoPrevNext ? '' : '<label id="calendar_next">' + this.nextText + '</label>')) +
            '</div><div id="calendar_header">';
        if (!this.changeMonth) {
            html += this.monthNames[this.selectedMonth] + '&nbsp;';
        }
        else {
            var inMinYear = (this.minDate && this.minDate.getFullYear() == this.selectedYear);
            var inMaxYear = (this.maxDate && this.maxDate.getFullYear() == this.selectedYear);
            html += '<select id="calendar_newMonth" onchange="popUpCal.selectMonthYear(this, \'M\');" ' +
                'onclick="popUpCal.clickMonthYear();">';
            for (var month = 0; month < 12; month++) {
                if ((!inMinYear || month >= this.minDate.getMonth()) &&
                        (!inMaxYear || month <= this.maxDate.getMonth())) {
                    html += '<option value="' + month + '"' +
                        (month == this.selectedMonth ? ' selected="selected"' : '') +
                        '>' + this.monthNames[month] + '</option>';
                }
            }
            html += '</select>';
        }
        if (!this.changeYear) {
            html += this.selectedYear;
        }
        else {
            // determine range of years to display
            var years = this.yearRange.split(':');
            var year = 0;
            var endYear = 0;
            if (years.length != 2) {
                year = this.selectedYear - 10;
                endYear = this.selectedYear + 10;
            }
            else if (years[0].charAt(0) == '+' || years[0].charAt(0) == '-') {
                year = this.selectedYear + parseInt(years[0]);
                endYear = this.selectedYear + parseInt(years[1]);
            }
            else {
                year = parseInt(years[0]);
                endYear = parseInt(years[1]);
            }
            year = (this.minDate ? Math.max(year, this.minDate.getFullYear()) : year);
            endYear = (this.maxDate ? Math.min(endYear, this.maxDate.getFullYear()) : endYear);
            html += '<select id="calendar_newYear" onchange="popUpCal.selectMonthYear(this, \'Y\');" ' +
                'onclick="popUpCal.clickMonthYear();">';
            for (; year <= endYear; year++) {
                html += '<option value="' + year + '"' +
                    (year == this.selectedYear ? ' selected="selected"' : '') +
                    '>' + year + '</option>';
            }
            html += '</select>';
        }
        html += '</div><table id="calendar" cellpadding="0" cellspacing="0"><thead>' +
            '<tr class="calendar_titleRow">';
        for (var dow = 0; dow < 7; dow++) {
            html += '<td>' + (this.changeFirstDay ? '<a onclick="popUpCal.changeWeekDay(this);">' : '') +
                this.dayNames[(dow + this.firstDay) % 7] + (this.changeFirstDay ? '</a>' : '') + '</td>';
        }
        html += '</tr></thead><tbody>';
        var daysInMonth = this.getDaysInMonth(this.selectedYear, this.selectedMonth);
        this.selectedDay = Math.min(this.selectedDay, daysInMonth);
        var leadDays = (this.getFirstDayOfMonth(this.selectedYear, this.selectedMonth) - this.firstDay + 7) % 7;
        var currentDate = new Date(this.currentYear, this.currentMonth, this.currentDay);
        var selectedDate = new Date(this.selectedYear, this.selectedMonth, this.selectedDay);
        var printDate = new Date(this.selectedYear, this.selectedMonth, 1 - leadDays);
        var numRows = Math.ceil((leadDays + daysInMonth) / 7); // calculate the number of rows to generate
        for (var row = 0; row < numRows; row++) { // create calendar rows
            html += '<tr class="calendar_daysRow">';
            for (var dow = 0; dow < 7; dow++) { // create calendar days
                var customSettings = (this.customDate ? this.customDate(printDate) : [true, '']);
                var otherMonth = (printDate.getMonth() != this.selectedMonth);
                var unselectable = otherMonth || !customSettings[0] ||
                    (this.minDate && printDate < this.minDate) ||
                    (this.maxDate && printDate > this.maxDate);
                html += '<td class="calendar_daysCell' +
                    ((dow + this.firstDay + 6) % 7 >= 5 ? ' calendar_weekEndCell' : '') + // highlight weekends
                    (otherMonth ? ' calendar_otherMonth' : '') + // highlight days from other months
                    (printDate.getTime() == selectedDate.getTime() ? ' calendar_daysCellOver' : '') + // highlight selected day
                    (unselectable ? ' calendar_unselectable' : '') +  // highlight unselectable days
                    (!otherMonth || this.showOtherMonths ? ' ' + customSettings[1] : '') + '"' + // highlight custom dates
                    (printDate.getTime() == currentDate.getTime() ? ' id="calendar_currentDay"' : // highlight current day
                    (printDate.getTime() == today.getTime() ? ' id="calendar_today"' : '')) + // highlight today (if different)
                    (unselectable ? '' : ' onmouseover="$(this).addClass(\'calendar_daysCellOver\');"' +
                    ' onmouseout="$(this).removeClass(\'calendar_daysCellOver\');"' +
                    ' onclick="popUpCal.selectDay(this);")') + '>' + // actions
                    (otherMonth ? (this.showOtherMonths ? printDate.getDate() : '&nbsp;') : // display for other months
                    (unselectable ? printDate.getDate() : '<a>' + printDate.getDate() + '</a>')) + '</td>'; // display for this month
                printDate.setDate(printDate.getDate() + 1);
            }
            html += '</tr>';
        }
        html += '</tbody></table>' + (this.closeAtTop || this.inline ? '' : controls) +
            '<!--[if lte IE 6.5]><iframe src="javascript:false;" id="calendar_cover"></iframe><![endif]-->';
        // add calendar to element to calendar div
        if (!this.inline) {
            this.calendarDiv.empty().append(html).show(this.speed, this.coverSelects);
            if (this.speed == '') this.coverSelects();
            this.input[0].focus();
        }
        else {
            $('#calendar_inline_div').empty().append(html);
        }
    }, // end showCalendar

    /* Fix IE < 7 select problems. */
    coverSelects: function() {
        if ($.browser.msie) {
            $('#calendar_cover').css({width: popUpCal.calendarDiv[0].offsetWidth + 4,
                height: popUpCal.calendarDiv[0].offsetHeight + 4});
        }
    },
    
    /* Hide the calendar from view. */
    hideCalendar: function(speed) {
        if (this.popUpShowing) {
            this.calendarDiv.hide(speed, this.tidyStandalone);
            if (speed == '') this.tidyStandalone();
            this.popUpShowing = false;
            this.lastInput = null;
            this.prompt = null;
            if (this.standalone && $.blockUI) $.unblockUI();
            this.standalone = false;
        }
    },

    /* Tidy up after a dialog display. */
    tidyStandalone: function() {
        popUpCal.calendarDiv.removeClass('calendar_dialog');
        $('calendar_prompt').remove();
    },

    /* Action for current link. */
    gotoToday: function() {
        var date = new Date();
        popUpCal.selectedDay = date.getDate();
        popUpCal.selectedMonth = date.getMonth();
        popUpCal.selectedYear = date.getFullYear();
        popUpCal.adjustDate();
    },

    /* Action for selecting a new month/year. */
    selectMonthYear: function(select, period) {
        popUpCal.selectingMonthYear = false;
        popUpCal[period == 'M' ? 'selectedMonth' : 'selectedYear'] =
            select.options[select.selectedIndex].value - 0;
        popUpCal.adjustDate();
    },

    /* Restore input focus after not changing month/year. */
    clickMonthYear: function() {
        if (popUpCal.selectingMonthYear && !$.browser.msie) {
            popUpCal.input[0].focus();
        }
        popUpCal.selectingMonthYear = !popUpCal.selectingMonthYear;
    },

    /* Action for changing the first week day. */
    changeWeekDay: function(a) {
        for (var i = 0; i < 7; i++) {
            if (popUpCal.dayNames[i] == a.firstChild.nodeValue) {
                popUpCal.firstDay = i;
                break;
            }
        }
        popUpCal.showCalendar();
    },

    /* Action for selecting a day. */
    selectDay: function(td) {
        popUpCal.selectedDay = $("a", td).html();
        popUpCal.selectDate();
    },

    /* Update the input field with the selected date. */
    selectDate: function(value) {
        this.currentDay = this.selectedDay;
        this.currentMonth = this.selectedMonth;
        this.currentYear = this.selectedYear;
        this.date = (value != null ? value : this.formatDate(this.selectedDay, this.selectedMonth, this.selectedYear));
        if (this.customEvent) {
            this.customEvent();  // trigger it
        } 
        else {
            // set the input field with the date and fire the change event
            this.input.val(this.date);
            this.input.trigger('change');
        }
        if (!this.inline) {
            this.hideCalendar(this.speed);
        }
    },

    /* Erase the input field and hide the calendar. */
    clearDate: function() {
        this.selectDate('');
    },

    /* Close calendar if clicked elsewhere. */
    checkExternalClick: function(event) {
        if (popUpCal.popUpShowing && !(popUpCal.standalone && $.blockUI)) {
            var node = event.target;
            var cal = popUpCal.calendarDiv[0];
            while (node && node != cal && node.className != 'calendar_trigger') {
                node = node.parentNode;
            }
            if (!node) {
                popUpCal.hideCalendar('');
            }
        }
    },

    /* Set as customDate function to prevent selection of weekends. */
    noWeekends: function(date) {
        var day = date.getDay();
        return [(day > 0 && day < 6), ''];
    },

    /* Format and display the given date. */
    formatDate: function(day, month, year) {
        month++; // adjust javascript month
        var dateString = '';
        for (var i = 0; i < 3; i++) {
            dateString += this.dateFormat.charAt(3) +
                (this.dateFormat.charAt(i) == 'D' ? (day < 10 ? '0' : '') + day :
                (this.dateFormat.charAt(i) == 'M' ? (month < 10 ? '0' : '') + month :
                (this.dateFormat.charAt(i) == 'Y' ? year : '?')));
        }
        return dateString.substring(this.dateFormat.charAt(3) ? 1 : 0);
    },

    /* Parse existing date and initialise calendar. */
    setDateFromField: function() {
        var currentDate = this.input.val().split(this.dateFormat.charAt(3));
        if (currentDate.length == 3) {
            this.currentDay = parseInt(this.trimNumber(currentDate[this.dateFormat.indexOf('D')]));
            this.currentMonth = parseInt(this.trimNumber(currentDate[this.dateFormat.indexOf('M')])) - 1;
            this.currentYear = parseInt(this.trimNumber(currentDate[this.dateFormat.indexOf('Y')]));
        }
        else {
            this.currentDay = new Date().getDate();
            this.currentMonth = new Date().getMonth();
            this.currentYear = new Date().getFullYear();
        }
        this.selectedDay = this.currentDay;
        this.selectedMonth = this.currentMonth;
        this.selectedYear = this.currentYear;
        this.adjustDate(0, 'D', true);
    },

    /* Ensure numbers are not treated as octal. */
    trimNumber: function(value) {
        if (value == '')
            return '';
        while (value.charAt(0) == '0') {
            value = value.substring(1);
        }
        return value;
    },


    /* Adjust one of the date sub-fields. */
    adjustDate: function(offset, period, dontShow) {
        var date = new Date(this.selectedYear + (period == 'Y' ? offset : 0),
            this.selectedMonth + (period == 'M' ? offset : 0),
            this.selectedDay + (period == 'D' ? offset : 0));
        // ensure it is within the bounds set
        date = (this.minDate && date < this.minDate ? this.minDate : date);
        date = (this.maxDate && date > this.maxDate ? this.maxDate : date);
        this.selectedDay = date.getDate();
        this.selectedMonth = date.getMonth();
        this.selectedYear = date.getFullYear();
        if (!dontShow) {
            this.showCalendar();
        }
    },

    /* Find the number of days in a given month. */
    getDaysInMonth: function(year, month) {
        return 32 - new Date(year, month, 32).getDate();
    },

    /* Find the day of the week of the first of a month. */
    getFirstDayOfMonth: function(year, month) {
        return new Date(year, month, 1).getDay();
    },

    /* Determines if we should allow a "next/prev" month display change. */
    canAdjustMonth: function(offset) {
        var date = new Date(this.selectedYear, this.selectedMonth + offset, 1);
        if (offset < 0) {
            date.setDate(this.getDaysInMonth(date.getFullYear(), date.getMonth()));
        }
        return this.isInRange(date);
    },

    /* Is the given date in the accepted range? */
    isInRange: function(date) {
        return ((!this.minDate || date >= this.minDate) && (!this.maxDate || date <= this.maxDate));
    },

    /* Find an object's position on the screen. */
    findPos: function(obj) {
        var curleft = curtop = 0;
        if (obj.offsetParent) {
            curleft = obj.offsetLeft;
            curtop = obj.offsetTop;
            while (obj = obj.offsetParent) {
                var origcurleft = curleft;
                curleft += obj.offsetLeft;
                if (curleft < 0) {
                    curleft = origcurleft;
                }
                curtop += obj.offsetTop;
            }
        }
        return [curleft,curtop];
    }
};

/* Attach the calendar to a jQuery selection. */
$.fn.calendar = function(settings) {
    // customise the calendar object
    $.extend(popUpCal, settings || {});
    // attach the calendar to each nominated input element
    return this.each(function() {
        if (this.nodeName.toLowerCase() == 'input') {
            popUpCal.connectCalendar(this);
        } 
        else if (this.nodeName.toLowerCase() == 'div') {
            popUpCal.displayInline(this);
        }
    });
};

/* Initialise the calendar. */
$(document).ready(function() {
   popUpCal.init();
});