function _ctParsePageRange(spec, totalPages) {
        var value = (spec || '').trim().toLowerCase();
        if (!value || value === 'all' || value === '*') {
            var all = [];
            for (var i = 0; i < totalPages; i++) all.push(i);
            return all;
        }

        var selected = {};
        var parts = value.split(',');
        for (var p = 0; p < parts.length; p++) {
            var part = parts[p].trim();
            if (!part) continue;
            if (part.indexOf('-') > -1) {
                var range = part.split('-');
                var start = parseInt(range[0], 10);
                var end = parseInt(range[1], 10);
                if (!isFinite(start) || !isFinite(end)) continue;
                if (start > end) { var t = start; start = end; end = t; }
                start = Math.max(1, start);
                end = Math.min(totalPages, end);
                for (var i = start; i <= end; i++) selected[i - 1] = true;
            } else {
                var num = parseInt(part, 10);
                if (isFinite(num) && num >= 1 && num <= totalPages) selected[num - 1] = true;
            }
        }

        var result = Object.keys(selected).map(function(k) { return parseInt(k, 10); }).sort(function(a, b) { return a - b; });
        return result;
    }

    function processFile(blob, fileName) {
        var inputs = $('.extra-input input');
        var rawAngle = parseInt(inputs[0] && inputs[0].value ? inputs[0].value : '90', 10);
        if (!isFinite(rawAngle)) rawAngle = 90;
        var pagesSpec = inputs[1] && inputs[1].value ? inputs[1].value : 'all';

        var angle = ((rawAngle % 360) + 360) % 360;
        if (angle % 90 !== 0) {
            angle = (Math.round(angle / 90) * 90) % 360;
        }

        loadScriptPromise('https://cdn.jsdelivr.net/npm/pdf-lib@1.17.1/dist/pdf-lib.min.js').then(async function() {
            try {
                var srcBytes = await blob.arrayBuffer();
                var pdfDoc = await PDFLib.PDFDocument.load(srcBytes, { ignoreEncryption: true });
                var targets = _ctParsePageRange(pagesSpec, pdfDoc.getPageCount());
                if (!targets.length) {
                    alert('No valid pages were selected.');
                    return;
                }

                for (var i = 0; i < targets.length; i++) {
                    var page = pdfDoc.getPage(targets[i]);
                    var current = page.getRotation().angle || 0;
                    page.setRotation(PDFLib.degrees((current + angle + 360) % 360));
                }

                var outBytes = await pdfDoc.save();
                var baseName = (fileName || 'document').replace(/\.pdf$/i, '');
                add_file_output(URL.createObjectURL(new Blob([outBytes], { type: 'application/pdf' })), baseName + '-rotated.pdf');
            } catch (err) {
                alert('Could not rotate this PDF file. Encrypted PDFs are not supported.');
            }
        }).catch(function() {
            alert('Could not load PDF tools in your browser.');
        });
    }







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;

}