var _cronLibLoaded = false;
    function convert(input) {
        var expr = (input || '').trim();
        if (!expr) return '';
        if (!_cronLibLoaded) {
            loadScriptPromise('https://cdnjs.cloudflare.com/ajax/libs/cronstrue/2.50.0/cronstrue.min.js').then(function() {
                _cronLibLoaded = true;
                $('#box1').trigger('keyup');
            }).catch(function() {
                _cronLibLoaded = 'failed';
                $('#box1').trigger('keyup');
            });
            return 'Loading...';
        }
        if (_cronLibLoaded === 'failed' || typeof cronstrue === 'undefined') {
            return 'Reader failed to load. Please check your connection.';
        }
        try {
            var english = cronstrue.toString(expr, { use24HourTimeFormat: true });
            var next = _ctCronNext(expr, 5);
            var out = english;
            if (next.length) {
                out += '\n\nNext 5 runs:\n' + next.map(function(d){ return '  • ' + d.toString(); }).join('\n');
            }
            return out;
        } catch (e) {
            return 'Could not parse: ' + e.message;
        }
    }

    function _ctCronNext(expr, count) {
        try {
            var parts = expr.split(/\s+/);
            if (parts.length < 5) return [];
            var minute = _ctCronField(parts[0], 0, 59);
            var hour = _ctCronField(parts[1], 0, 23);
            var day = _ctCronField(parts[2], 1, 31);
            var month = _ctCronField(parts[3], 1, 12);
            var dow = _ctCronField(parts[4], 0, 6);
            var results = [];
            var d = new Date();
            d.setSeconds(0, 0); d.setMinutes(d.getMinutes() + 1);
            var maxIter = 60 * 24 * 366 * 4;
            while (results.length < count && maxIter-- > 0) {
                if (month.indexOf(d.getMonth() + 1) >= 0
                    && day.indexOf(d.getDate()) >= 0
                    && dow.indexOf(d.getDay()) >= 0
                    && hour.indexOf(d.getHours()) >= 0
                    && minute.indexOf(d.getMinutes()) >= 0) {
                    results.push(new Date(d.getTime()));
                }
                d.setMinutes(d.getMinutes() + 1);
            }
            return results;
        } catch (e) { return []; }
    }

    function _ctCronField(spec, min, max) {
        if (spec === '*' || spec === '?') {
            var all = []; for (var i = min; i <= max; i++) all.push(i); return all;
        }
        var out = [];
        spec.split(',').forEach(function(part) {
            var step = 1;
            var stepParts = part.split('/');
            if (stepParts.length === 2) step = parseInt(stepParts[1], 10) || 1;
            var base = stepParts[0];
            var lo = min, hi = max;
            if (base === '*') { lo = min; hi = max; }
            else if (base.indexOf('-') >= 0) {
                var rangeParts = base.split('-');
                lo = parseInt(rangeParts[0], 10); hi = parseInt(rangeParts[1], 10);
            } else {
                lo = hi = parseInt(base, 10);
            }
            for (var v = lo; v <= hi; v += step) out.push(v);
        });
        return out;
    }







var _loadedScripts = {};
function loadScriptPromise(url) {
    if (_loadedScripts[url]) return _loadedScripts[url];
    _loadedScripts[url] = new Promise(function (resolve, reject) {
        var s = document.createElement('script');
        s.src = url;
        s.onload = resolve;
        s.onerror = reject;
        document.head.appendChild(s);
    });
    return _loadedScripts[url];
}

function replaceAll(find, replace, str) {
    return str.replace(new RegExp(find, 'g'), replace);
}

function beautify(str) {


    var result = '';

    var length = str.length;

    var i = 0;

    var braceCountLeft = 0;
    var braceCountRight = 0;

    var withinQuotes = false;

    while (i < length) {

        var c = str[i];

        if (c == '"' && (i == 0 || c[i - 1] != '\\')) {
            // non-escaped quotes
            withinQuotes = !withinQuotes;
        }

        if (!withinQuotes && (c == '}' || c == '{' || c == ',')) {

            console.log('Start####' + result);

            // look back and remove carriage returns and whitespace that are already there

            var resultIndex = result.length - 1;
            while (resultIndex >= 0 && (result[resultIndex] == ' ' || result[resultIndex] == '\r' || result[resultIndex] == '\n' || result[resultIndex] == '\t')) {

                resultIndex = resultIndex - 1;
                result = result.substr(0, resultIndex + 1);

                console.log('char ' + result[resultIndex] + '-----' + result + 'zzz ' + result.length + ' ' + resultIndex);

            }


            if (c == '{') {
                braceCountLeft++;
                result += c + '\r' + GetTabs(braceCountLeft - braceCountRight);
            } else if (c == '}') {
                braceCountRight++;
                // precede with carriage return
                result += '\r' + GetTabs(braceCountLeft - braceCountRight) + c;
            } else if (c == ',') {
                result += c + '\r' + GetTabs(braceCountLeft - braceCountRight);
            }

            var nextChar = '';

            // advance through whitespace and remove carriage returns that are already there
            while (i < length && (str[i + 1] == ' ' || str[i + 1] == '\r' || str[i + 1] == '\n' || str[i + 1] == '\t')) {
                i++;
            }

        } else {

            result += str[i];

        }


        i++;

    }

    return result;

}

function GetTabs(count) {

    var result = '';

    for (var i = 0; i < count; i++) {
        result += '    ';
    }

    return result;

}