WifiP2PPing.js

Mobile.Class(function WifiP2PPing(_id, _parent) {
    var _this = this;
    var _results = [];
    var _messages = {};

    //*** Constructor
    (function () {
        setTimeout(send, 500);
    })();

    function send() {
        var message = {};
        message.ping = true;
        message._id = Utils.timestamp();
        message.outTime = Date.now();
        message.receiver = _id;

        _messages[message._id] = message;
        _parent.sendMessage(message);
    }

    function calculate() {
        _results.sort(function(a, b) {
            return a - b;
        });

        _this.offset = _results[5];
    }

    //*** Event handlers

    //*** Public methods
    this.receive = function(incoming) {
        var outgoing = _messages[incoming._id];

        if (!outgoing) {
            incoming.inTime = Date.now();
            incoming.receiver = _id;
            _parent.sendMessage(incoming);
        } else {
            var currentTime = Date.now();
            var latency = Math.round((currentTime - outgoing.outTime) * 0.5);
            var pairTime = incoming.inTime;
            currentTime -= latency;

            var difference = currentTime - pairTime;

            console.log(latency, difference);

            _results.push(difference);
            _this.offset = difference;

            if (_results.length < 11) setTimeout(send, 500);
            else calculate();
        }
    }
});