/* functions taken from phpjs.org */

function checkdate( month, day, year ) {
    // Returns true(1) if it is a valid date in gregorian calendar  
    // 
    // version: 906.2303
    // discuss at: http://phpjs.org/functions/checkdate
    // +   original by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
    // +   improved by: Pyerre
    // *     example 1: checkdate(12, 31, 2000);
    // *     returns 1: true
    // *     example 2: checkdate(2, 29, 2001);
    // *     returns 2: false
    // *     example 3: checkdate(03, 31, 2008);
    // *     returns 3: true
    // *     example 4: checkdate(1, 390, 2000);
    // *     returns 4: false
    var myDate = new Date();
    myDate.setFullYear( year, (month - 1), day );

    return month >= 1 && month <= 12 && year >= 1 && year <= 32767 && ((myDate.getMonth()+1) == month && day<32);
}

function date (format, timestamp) {
    // http://kevin.vanzonneveld.net
    // +   original by: Carlos R. L. Rodrigues (http://www.jsfromhell.com)
    // +      parts by: Peter-Paul Koch (http://www.quirksmode.org/js/beat.html)
    // +   improved by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
    // +   improved by: MeEtc (http://yass.meetcweb.com)
    // +   improved by: Brad Touesnard
    // +   improved by: Tim Wiel
    // +   improved by: Bryan Elliott
    //
    // +   improved by: Brett Zamir (http://brett-zamir.me)
    // +   improved by: David Randall
    // +      input by: Brett Zamir (http://brett-zamir.me)
    // +   bugfixed by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
    // +   improved by: Brett Zamir (http://brett-zamir.me)
    // +   improved by: Brett Zamir (http://brett-zamir.me)
    // +   improved by: Theriault
    // +  derived from: gettimeofday
    // +      input by: majak
    // +   bugfixed by: majak
    // +   bugfixed by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
    // +      input by: Alex
    // +   bugfixed by: Brett Zamir (http://brett-zamir.me)
    // +   improved by: Theriault
    // +   improved by: Brett Zamir (http://brett-zamir.me)
    // +   improved by: Theriault
    // +   improved by: Thomas Beaucourt (http://www.webapp.fr)
    // +   improved by: JT
    // +   improved by: Theriault
    // +   improved by: Rafal Kukawski (http://blog.kukawski.pl)
    // +   bugfixed by: omid (http://phpjs.org/functions/380:380#comment_137122)
    // +      input by: Martin
    // +      input by: Alex Wilson
    // %        note 1: Uses global: php_js to store the default timezone
    // %        note 2: Although the function potentially allows timezone info (see notes), it currently does not set
    // %        note 2: per a timezone specified by date_default_timezone_set(). Implementers might use
    // %        note 2: this.php_js.currentTimezoneOffset and this.php_js.currentTimezoneDST set by that function
    // %        note 2: in order to adjust the dates in this function (or our other date functions!) accordingly
    // *     example 1: date('H:m:s \\m \\i\\s \\m\\o\\n\\t\\h', 1062402400);
    // *     returns 1: '09:09:40 m is month'
    // *     example 2: date('F j, Y, g:i a', 1062462400);
    // *     returns 2: 'September 2, 2003, 2:26 am'
    // *     example 3: date('Y W o', 1062462400);
    // *     returns 3: '2003 36 2003'
    // *     example 4: x = date('Y m d', (new Date()).getTime()/1000); 
    // *     example 4: (x+'').length == 10 // 2009 01 09
    // *     returns 4: true
    // *     example 5: date('W', 1104534000);
    // *     returns 5: '53'
    // *     example 6: date('B t', 1104534000);
    // *     returns 6: '999 31'
    // *     example 7: date('W U', 1293750000.82); // 2010-12-31
    // *     returns 7: '52 1293750000'
    // *     example 8: date('W', 1293836400); // 2011-01-01
    // *     returns 8: '52'
    // *     example 9: date('W Y-m-d', 1293974054); // 2011-01-02
    // *     returns 9: '52 2011-01-02'
    var that = this,
        jsdate, f, formatChr = /\\?([a-z])/gi,
        formatChrCb,
        // Keep this here (works, but for code commented-out
        // below for file size reasons)
        //, tal= [],
        _pad = function (n, c) {
            if ((n = n + '').length < c) {
                return new Array((++c) - n.length).join('0') + n;
            }
            return n;
        },
        txt_words = ["Sun", "Mon", "Tues", "Wednes", "Thurs", "Fri", "Satur", "January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"];
    formatChrCb = function (t, s) {
        return f[t] ? f[t]() : s;
    };
    f = {
        // Day
        d: function () { // Day of month w/leading 0; 01..31
            return _pad(f.j(), 2);
        },
        D: function () { // Shorthand day name; Mon...Sun
            return f.l().slice(0, 3);
        },
        j: function () { // Day of month; 1..31
            return jsdate.getDate();
        },
        l: function () { // Full day name; Monday...Sunday
            return txt_words[f.w()] + 'day';
        },
        N: function () { // ISO-8601 day of week; 1[Mon]..7[Sun]
            return f.w() || 7;
        },
        S: function () { // Ordinal suffix for day of month; st, nd, rd, th
            var j = f.j();
            return j < 4 | j > 20 && ['st', 'nd', 'rd'][j%10 - 1] || 'th'; 
        },
        w: function () { // Day of week; 0[Sun]..6[Sat]
            return jsdate.getDay();
        },
        z: function () { // Day of year; 0..365
            var a = new Date(f.Y(), f.n() - 1, f.j()),
                b = new Date(f.Y(), 0, 1);
            return Math.round((a - b) / 864e5) + 1;
        },

        // Week
        W: function () { // ISO-8601 week number
            var a = new Date(f.Y(), f.n() - 1, f.j() - f.N() + 3),
                b = new Date(a.getFullYear(), 0, 4);
            return _pad(1 + Math.round((a - b) / 864e5 / 7), 2);
        },

        // Month
        F: function () { // Full month name; January...December
            return txt_words[6 + f.n()];
        },
        m: function () { // Month w/leading 0; 01...12
            return _pad(f.n(), 2);
        },
        M: function () { // Shorthand month name; Jan...Dec
            return f.F().slice(0, 3);
        },
        n: function () { // Month; 1...12
            return jsdate.getMonth() + 1;
        },
        t: function () { // Days in month; 28...31
            return (new Date(f.Y(), f.n(), 0)).getDate();
        },

        // Year
        L: function () { // Is leap year?; 0 or 1
            var j = f.Y();
            return j%4==0 & j%100!=0 | j%400==0;
        },
        o: function () { // ISO-8601 year
            var n = f.n(),
                W = f.W(),
                Y = f.Y();
            return Y + (n === 12 && W < 9 ? -1 : n === 1 && W > 9);
        },
        Y: function () { // Full year; e.g. 1980...2010
            return jsdate.getFullYear();
        },
        y: function () { // Last two digits of year; 00...99
            return (f.Y() + "").slice(-2);
        },

        // Time
        a: function () { // am or pm
            return jsdate.getHours() > 11 ? "pm" : "am";
        },
        A: function () { // AM or PM
            return f.a().toUpperCase();
        },
        B: function () { // Swatch Internet time; 000..999
            var H = jsdate.getUTCHours() * 36e2,
                // Hours
                i = jsdate.getUTCMinutes() * 60,
                // Minutes
                s = jsdate.getUTCSeconds(); // Seconds
            return _pad(Math.floor((H + i + s + 36e2) / 86.4) % 1e3, 3);
        },
        g: function () { // 12-Hours; 1..12
            return f.G() % 12 || 12;
        },
        G: function () { // 24-Hours; 0..23
            return jsdate.getHours();
        },
        h: function () { // 12-Hours w/leading 0; 01..12
            return _pad(f.g(), 2);
        },
        H: function () { // 24-Hours w/leading 0; 00..23
            return _pad(f.G(), 2);
        },
        i: function () { // Minutes w/leading 0; 00..59
            return _pad(jsdate.getMinutes(), 2);
        },
        s: function () { // Seconds w/leading 0; 00..59
            return _pad(jsdate.getSeconds(), 2);
        },
        u: function () { // Microseconds; 000000-999000
            return _pad(jsdate.getMilliseconds() * 1000, 6);
        },

        // Timezone
        e: function () { // Timezone identifier; e.g. Atlantic/Azores, ...
            // The following works, but requires inclusion of the very large
            // timezone_abbreviations_list() function.
/*              return this.date_default_timezone_get();
*/
            throw 'Not supported (see source code of date() for timezone on how to add support)';
        },
        I: function () { // DST observed?; 0 or 1
            // Compares Jan 1 minus Jan 1 UTC to Jul 1 minus Jul 1 UTC.
            // If they are not equal, then DST is observed.
            var a = new Date(f.Y(), 0),
                // Jan 1
                c = Date.UTC(f.Y(), 0),
                // Jan 1 UTC
                b = new Date(f.Y(), 6),
                // Jul 1
                d = Date.UTC(f.Y(), 6); // Jul 1 UTC
            return 0 + ((a - c) !== (b - d));
        },
        O: function () { // Difference to GMT in hour format; e.g. +0200
            var tzo = jsdate.getTimezoneOffset(),
                a = Math.abs(tzo);
            return (tzo > 0 ? "-" : "+") + _pad(Math.floor(a / 60) * 100 + a % 60, 4);
        },
        P: function () { // Difference to GMT w/colon; e.g. +02:00
            var O = f.O();
            return (O.substr(0, 3) + ":" + O.substr(3, 2));
        },
        T: function () { // Timezone abbreviation; e.g. EST, MDT, ...
            // The following works, but requires inclusion of the very
            // large timezone_abbreviations_list() function.
/*              var abbr = '', i = 0, os = 0, default = 0;
            if (!tal.length) {
                tal = that.timezone_abbreviations_list();
            }
            if (that.php_js && that.php_js.default_timezone) {
                default = that.php_js.default_timezone;
                for (abbr in tal) {
                    for (i=0; i < tal[abbr].length; i++) {
                        if (tal[abbr][i].timezone_id === default) {
                            return abbr.toUpperCase();
                        }
                    }
                }
            }
            for (abbr in tal) {
                for (i = 0; i < tal[abbr].length; i++) {
                    os = -jsdate.getTimezoneOffset() * 60;
                    if (tal[abbr][i].offset === os) {
                        return abbr.toUpperCase();
                    }
                }
            }
*/
            return 'UTC';
        },
        Z: function () { // Timezone offset in seconds (-43200...50400)
            return -jsdate.getTimezoneOffset() * 60;
        },

        // Full Date/Time
        c: function () { // ISO-8601 date.
            return 'Y-m-d\\Th:i:sP'.replace(formatChr, formatChrCb);
        },
        r: function () { // RFC 2822
            return 'D, d M Y H:i:s O'.replace(formatChr, formatChrCb);
        },
        U: function () { // Seconds since UNIX epoch
            return jsdate / 1000 | 0;
        }
    };
    this.date = function (format, timestamp) {
        that = this;
        jsdate = (timestamp == null ? new Date() : // Not provided
        (timestamp instanceof Date) ? new Date(timestamp) : // JS Date()
        new Date(timestamp * 1000) // UNIX timestamp (auto-convert to int)
        );
        return format.replace(formatChr, formatChrCb);
    };
    return this.date(format, timestamp);
}

function strtotime (str, now) {
    // http://kevin.vanzonneveld.net
    // +   original by: Caio Ariede (http://caioariede.com)
    // +   improved by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
    // +      input by: David
    // +   improved by: Caio Ariede (http://caioariede.com)
    // +   improved by: Brett Zamir (http://brett-zamir.me)
    // +   bugfixed by: Wagner B. Soares
    // +   bugfixed by: Artur Tchernychev
    // %        note 1: Examples all have a fixed timestamp to prevent tests to fail because of variable time(zones)
    // *     example 1: strtotime('+1 day', 1129633200);
    // *     returns 1: 1129719600
    // *     example 2: strtotime('+1 week 2 days 4 hours 2 seconds', 1129633200);
    // *     returns 2: 1130425202
    // *     example 3: strtotime('last month', 1129633200);
    // *     returns 3: 1127041200
    // *     example 4: strtotime('2009-05-04 08:30:00');
    // *     returns 4: 1241418600
    var i, l, match, s, parse = '';

    str = str.replace(/\s{2,}|^\s|\s$/g, ' '); // unecessary spaces
    str = str.replace(/[\t\r\n]/g, ''); // unecessary chars
    if (str === 'now') {
        return now === null || isNaN(now) ? new Date().getTime() / 1000 | 0 : now | 0;
    } else if (!isNaN(parse = Date.parse(str))) {
        return parse / 1000 | 0;
    } else if (now) {
        now = new Date(now * 1000); // Accept PHP-style seconds
    } else {
        now = new Date();
    }

    str = str.toLowerCase();

    var __is = {
        day: {
            'sun': 0,
            'mon': 1,
            'tue': 2,
            'wed': 3,
            'thu': 4,
            'fri': 5,
            'sat': 6
        },
        mon: [
            'jan',
            'feb',
            'mar',
            'apr',
            'may',
            'jun',
            'jul',
            'aug',
            'sep',
            'oct',
            'nov',
            'dec'
        ]
    };

    var process = function (m) {
        var ago = (m[2] && m[2] === 'ago');
        var num = (num = m[0] === 'last' ? -1 : 1) * (ago ? -1 : 1);

        switch (m[0]) {
        case 'last':
        case 'next':
            switch (m[1].substring(0, 3)) {
            case 'yea':
                now.setFullYear(now.getFullYear() + num);
                break;
            case 'mon':
                now.setMonth(now.getMonth() + num);
                break;
            case 'wee':
                now.setDate(now.getDate() + (num * 7));
                break;
            case 'day':
                now.setDate(now.getDate() + num);
                break;
            case 'hou':
                now.setHours(now.getHours() + num);
                break;
            case 'min':
                now.setMinutes(now.getMinutes() + num);
                break;
            case 'sec':
                now.setSeconds(now.getSeconds() + num);
                break;
            default:
                var day = __is.day[m[1].substring(0, 3)];
                if (typeof day !== 'undefined') {
                    var diff = day - now.getDay();
                    if (diff === 0) {
                        diff = 7 * num;
                    } else if (diff > 0) {
                        if (m[0] === 'last') {
                            diff -= 7;
                        }
                    } else {
                        if (m[0] === 'next') {
                            diff += 7;
                        }
                    }
                    now.setDate(now.getDate() + diff);
                }
            }
            break;

        default:
            if (/\d+/.test(m[0])) {
                num *= parseInt(m[0], 10);

                switch (m[1].substring(0, 3)) {
                case 'yea':
                    now.setFullYear(now.getFullYear() + num);
                    break;
                case 'mon':
                    now.setMonth(now.getMonth() + num);
                    break;
                case 'wee':
                    now.setDate(now.getDate() + (num * 7));
                    break;
                case 'day':
                    now.setDate(now.getDate() + num);
                    break;
                case 'hou':
                    now.setHours(now.getHours() + num);
                    break;
                case 'min':
                    now.setMinutes(now.getMinutes() + num);
                    break;
                case 'sec':
                    now.setSeconds(now.getSeconds() + num);
                    break;
                }
            } else {
                return false;
            }
            break;
        }
        return true;
    };

    match = str.match(/^(\d{2,4}-\d{2}-\d{2})(?:\s(\d{1,2}:\d{2}(:\d{2})?)?(?:\.(\d+))?)?$/);
    if (match !== null) {
        if (!match[2]) {
            match[2] = '00:00:00';
        } else if (!match[3]) {
            match[2] += ':00';
        }

        s = match[1].split(/-/g);

        s[1] = __is.mon[s[1] - 1] || s[1];
        s[0] = +s[0];

        s[0] = (s[0] >= 0 && s[0] <= 69) ? '20' + (s[0] < 10 ? '0' + s[0] : s[0] + '') : (s[0] >= 70 && s[0] <= 99) ? '19' + s[0] : s[0] + '';
        return parseInt(this.strtotime(s[2] + ' ' + s[1] + ' ' + s[0] + ' ' + match[2]) + (match[4] ? match[4] / 1000 : ''), 10);
    }

    var regex = '([+-]?\\d+\\s' + '(years?|months?|weeks?|days?|hours?|min|minutes?|sec|seconds?' + '|sun\\.?|sunday|mon\\.?|monday|tue\\.?|tuesday|wed\\.?|wednesday' + '|thu\\.?|thursday|fri\\.?|friday|sat\\.?|saturday)' + '|(last|next)\\s' + '(years?|months?|weeks?|days?|hours?|min|minutes?|sec|seconds?' + '|sun\\.?|sunday|mon\\.?|monday|tue\\.?|tuesday|wed\\.?|wednesday' + '|thu\\.?|thursday|fri\\.?|friday|sat\\.?|saturday))' + '(\\sago)?';

    match = str.match(new RegExp(regex, 'gi')); // Brett: seems should be case insensitive per docs, so added 'i'
    if (match === null) {
        return false;
    }

    for (i = 0, l = match.length; i < l; i++) {
        if (!process(match[i].split(' '))) {
            return false;
        }
    }

    return now.getTime() / 1000 | 0;
}
