var CALENDAR = function() {
    var wrap, label,
        months = ["JAN", "FEB", "MAR", "APR", "May", "Jun", "Jul", "AUG", "SEP", "OCT", "NOV", "DEC"];

    function init(newWrap) {
        wrap = jQuery(newWrap || "#cal");
        label = wrap.find("#label");
        switchMonth(null, new Date().getMonth(), new Date().getFullYear());
        wrap.find(".cal-pre").bind("click.calender", function() {
            switchMonth(false);
        });
        wrap.find(".cal-nxt").bind("click.calender", function() {
            switchMonth(true);
        });
    }

    function switchMonth(next, month, year) {

        var curr = label.text().trim().split(" "),
            calendar, tempYear = parseInt(curr[1], 10);
        tempYear = parseInt(jQuery('#year').text(), 10);
        month = month || ((next) ? ((curr[0] === "DEC") ? 0 : months.indexOf(curr[0]) + 1) : ((curr[0] === "Jan") ? 0 : months.indexOf(curr[0]) - 1));
        year = year || ((next && month === 0) ? tempYear + 1 : (!next && month === 11) ? tempYear - 1 : tempYear);

        console.profile("createCal");
        calendar = createCal(year, month);
        console.profileEnd("createCal");

        jQuery("#cal-frame", wrap)
            .find(".curr")
            .removeClass("curr")
            .addClass("temp")
            .end()
            .prepend(calendar.calendar())
            .find(".temp")
            .fadeOut("slow", function() {
                jQuery(this).remove();
            });

        var yeear = calendar.label.trim().split(" ");
        label.find('#month').text(yeear[0]);
        label.find('#year').text(yeear[1]);
    }

    function createCal(year, month) {

        var day = 1,
            i, j, haveDays = true,
            startDay = new Date(year, month, day).getDay(),
            daysInMonth = [31, (((year % 4 === 0) && (year % 100 !== 0)) || (year % 400 === 0)) ? 29 : 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31],
            calendar = [];
        if (createCal.cache[year]) {
            if (createCal.cache[year][month]) {
                return createCal.cache[year][month];
            }
        } else {
            createCal.cache[year] = {};
        }
        i = 0;
        while (haveDays) {
            calendar[i] = [];
            for (j = 0; j < 7; j++) {
                if (i === 0) {
                    if (j === startDay) {
                        calendar[i][j] = day++;
                        startDay++;
                    }
                } else if (day <= daysInMonth[month]) {
                    calendar[i][j] = day++;
                } else {
                    calendar[i][j] = "";
                    haveDays = false;
                }
                if (day > daysInMonth[month]) {
                    haveDays = false;
                }
            }
            i++;
        }

        if (calendar[5]) {
            for (i = 0; i < calendar[5].length; i++) {
                if (calendar[5][i] !== "") {
                    calendar[4][i] = "<span>" + calendar[4][i] + "</span><span>" + calendar[5][i] + "</span>";
                }
            }
            calendar = calendar.slice(0, 5);
        }

        for (i = 0; i < calendar.length; i++) {
            calendar[i] = "<tr><td>" + calendar[i].join("</td><td>") + "</td></tr>";
        }

        calendar = jQuery("<table>" + calendar.join("") + "</table").addClass("curr");

        jQuery("td:empty", calendar).addClass("nil");
        if (month === new Date().getMonth()) {
            jQuery('td', calendar).filter(function() {
                return jQuery(this).text() === new Date().getDate().toString();
            }).addClass("today");
        }

        createCal.cache[year][month] = {
            calendar: function() {
                return calendar.clone();
            },
            label: months[month] + " " + year
        };

        return createCal.cache[year][month];
    }
    createCal.cache = {};

    return {
        init: init,
        switchMonth: switchMonth,
        createCal: createCal
    };

};