var _ctFfmpegV2A = null;
    var _ctV2AFormats = {
        mp3:  { codec: ['-c:a', 'libmp3lame'], lossy: true, mime: 'audio/mpeg' },
        m4a:  { codec: ['-c:a', 'aac'], lossy: true, mime: 'audio/mp4' },
        ogg:  { codec: ['-c:a', 'libvorbis'], lossy: true, mime: 'audio/ogg' },
        wav:  { codec: ['-c:a', 'pcm_s16le'], lossy: false, mime: 'audio/wav' },
        flac: { codec: ['-c:a', 'flac'], lossy: false, mime: 'audio/flac' }
    };

    function _ctEnsureFfmpegV2A() {
        if (_ctFfmpegV2A) return Promise.resolve(_ctFfmpegV2A);
        return loadScriptPromise('https://unpkg.com/@ffmpeg/ffmpeg@0.11.6/dist/ffmpeg.min.js').then(function() {
            var ns = window.FFmpeg || {};
            if (!ns.createFFmpeg) throw new Error('FFmpeg library failed to load');
            var ffmpeg = ns.createFFmpeg({
                log: false,
                corePath: 'https://unpkg.com/@ffmpeg/core@0.11.0/dist/ffmpeg-core.js'
            });
            _ctFfmpegV2A = { ffmpeg: ffmpeg, fetchFile: ns.fetchFile };
            return ffmpeg.load().then(function(){ return _ctFfmpegV2A; });
        });
    }

    function _ctV2AStatus(msg) {
        var el = document.getElementById('v2a-status');
        if (el) el.textContent = msg || '';
    }

    function _ctV2AToggleBitrate() {
        var fmt = _ctV2AFormats[$('#v2a-format').val()] || _ctV2AFormats.mp3;
        $('#v2a-bitrate-wrap').toggle(fmt.lossy);
    }
    $(function() {
        $('#v2a-format').on('change', _ctV2AToggleBitrate);
        _ctV2AToggleBitrate();
    });

    function processFile(blob, fileName) {
        var key = $('#v2a-format').val();
        var fmt = _ctV2AFormats[key] || _ctV2AFormats.mp3;
        if (!_ctV2AFormats[key]) key = 'mp3';
        var bitrate = parseInt($('#v2a-bitrate').val(), 10) || 192;

        var ext = ((fileName || '').toLowerCase().split('.').pop() || 'mp4');
        var inName = 'in.' + ext;
        var outName = 'out.' + key;
        var args = ['-i', inName, '-vn', '-map', '0:a:0'].concat(fmt.codec);
        if (fmt.lossy) args = args.concat(['-b:a', bitrate + 'k']);
        args.push(outName);

        _ctV2AStatus('Loading converter...');
        _ctEnsureFfmpegV2A().then(function(ctx) {
            var ffmpeg = ctx.ffmpeg, fetchFile = ctx.fetchFile;
            _ctV2AStatus('Extracting audio...');
            return fetchFile(blob).then(function(buf) {
                try { ffmpeg.FS('unlink', inName); } catch (e) {}
                try { ffmpeg.FS('unlink', outName); } catch (e) {}
                ffmpeg.FS('writeFile', inName, buf);
                return ffmpeg.run.apply(ffmpeg, args).then(function() {
                    var data;
                    try { data = ffmpeg.FS('readFile', outName); } catch (e) {}
                    if (!data || !data.length) {
                        _ctV2AStatus('');
                        alert('This video does not seem to have an audio track.');
                        return;
                    }
                    var outBlob = new Blob([data.buffer], { type: fmt.mime });
                    var base = (fileName || 'audio').replace(/\.[^.]+$/, '');
                    add_file_output(URL.createObjectURL(outBlob), base + '.' + key);
                    _ctV2AStatus('');
                    try { ffmpeg.FS('unlink', inName); } catch (e) {}
                    try { ffmpeg.FS('unlink', outName); } catch (e) {}
                });
            });
        }).catch(function(err) {
            _ctV2AStatus('');
            alert('Could not extract audio from this video: ' + (err && err.message || err) + '. The first run downloads ~30 MB of conversion code - please check your connection and try again.');
        });
    }






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;

}