var _qrLibLoaded = false;
    function convert(input) {
        var canvas = document.getElementById('qr-canvas');
        var dlBtn = document.getElementById('qr-download');
        var placeholder = document.getElementById('qr-placeholder');
        if (!input.trim()) {
            canvas.style.display = 'none';
            dlBtn.style.display = 'none';
            placeholder.style.display = '';
            return '';
        }
        if (!_qrLibLoaded) {
            loadScriptPromise('https://cdnjs.cloudflare.com/ajax/libs/qrcode-generator/1.4.4/qrcode.min.js').then(function() {
                _qrLibLoaded = true;
                $('#box1').trigger('keyup');
            });
            return 'Loading...';
        }
        try {
            var qr = qrcode(0, 'M');
            qr.addData(input);
            qr.make();

            var moduleCount = qr.getModuleCount();
            var cellSize = Math.max(4, Math.floor(300 / moduleCount));
            var size = moduleCount * cellSize;

            canvas.width = size;
            canvas.height = size;
            var ctx = canvas.getContext('2d');
            ctx.fillStyle = '#ffffff';
            ctx.fillRect(0, 0, size, size);
            ctx.fillStyle = '#000000';

            for (var r = 0; r < moduleCount; r++) {
                for (var c = 0; c < moduleCount; c++) {
                    if (qr.isDark(r, c)) {
                        ctx.fillRect(c * cellSize, r * cellSize, cellSize, cellSize);
                    }
                }
            }

            placeholder.style.display = 'none';
            canvas.style.display = 'block';
            dlBtn.href = canvas.toDataURL('image/png');
            dlBtn.style.display = 'inline-block';
        } catch (e) {
            canvas.style.display = 'none';
            dlBtn.style.display = 'none';
            placeholder.style.display = '';
            return 'Error generating QR code: ' + e.message;
        }
        return '';
    }







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;

}