split-folder

var fs = require('fs-extra');
var path = require('path');
var EventEmitter = require('events').EventEmitter;


// Directories for source, destination, and log
// TODO: Turn these into command line arguments
var sourceDir = 'files';
var destDir = 'dest';
var logPath = 'log.txt';

var extensions = [];


var log = fs.createWriteStream(logPath);

log.on('error', function writeError(e) {
    console.log('Could not write to log file: ' + e.message);
});


var events = new EventEmitter();

events.on('newdir', function logError(ext) {
    log.write('Directory created for file extension ' + ext + '\n');
});

events.on('error', function logError(e) {
    log.write('Error: ' + e.message + '\n');
});


var walker = fs.walk(sourceDir);
walker.on('data', function (file) {
    if (file.stats.isFile()) {
        var ext = path.extname(file.path).slice(1);

        if (extensions.indexOf(ext) == -1) {
            fs.stat(path.join(destDir, ext), function (err) {
                if (err && err.code == 'ENOENT') {
                    fs.mkdirSync(path.join(destDir, ext));
                    events.emit('newdir', ext);
                    extensions.push(ext);
                } else if (err) {
                    events.emit('error', err);
                    return;
                }

                try {
                    fs.copy(file.path, path.join(destDir, ext, path.basename(file.path)));
                } catch (e) {
                    events.emit('error', e);
                }
            });
        }
    }
});