fix-pex.js

var fs = require('fs'),
    https = require('https'),
    async = require('async'),
    yaml = require('js-yaml');

var TIMESTAMP = 1422921600;
var data = fs.readFileSync('permissions.yml');
var doc = yaml.safeLoad(data);

//

function lookupName(name, callback) {
    var url = "https://api.mojang.com/users/profiles/minecraft/" + name + "?at=" + TIMESTAMP;

    https.get(url, function(res) {
        res.setEncoding('utf8');

        res.on('data', function(data) {
            callback(JSON.parse(data));
        });
    });
}

//

var newUsers = { };
var users = doc.users;
var names = [];

for (uuid in users) {
    var user = users[uuid];
    if (!user.options || !user.options.name) continue;

    names.push({ id: uuid, name: user.options.name });
}

async.each(names,
    function(item, callback) {
        var uuid = item.id;
        var name = item.name;
        
        lookupName(name, function(data) {
            var newUUID = data.id.substring(0, 8) + '-' + data.id.substring(8, 4) + '-' + data.id.substring(12, 4) + '-' + data.id.substring(16);
            newUsers[newUUID] = users[uuid];

            callback();
        });
    }, function() {
        doc.users = newUsers;
        console.log(yaml.safeDump(doc));
    }
);