var crypto = require("crypto");

function Listener() {
	var self = {}

	var key = crypto.randomBytes(16).toString("hex");
	self.key = key;

	var events = [];
	var waiter = null;

	function respond() {
		waiter.end(JSON.stringify(events));
		waiter = null;
		events = [];
	}

	self.emit = function(name, args) {
		events.push({ name: name, args: args });

		if (waiter != null) {
			respond();
		}
	}

	self.handle = function(res) {
		waiter = res;

		if (events.length > 0) {
			respond();
		}
	}

	return self;
}

function WebEvents() {
	var self = {}

	var listeners = {};

	self.emit = function(name, args) {
		for (var i in listeners) {
			listeners[i].emit(name, args);
		}
	}

	self.handle = function(req, res) {
		var parts = req.url.substring(1).split("/");

		if (parts[0] !== "webevents")
			return;

		res.writeHead(200, { "content-type": "application/json" });

		if (parts[1] === "register") {
			var listener = Listener();
			listeners[listener.key] = listener;
			res.end(JSON.stringify({ key: listener.key }));

		} else if (parts[1] === "await") {
			var listener = listeners[parts[2]];
			if (!listener) {
				res.end(JSON.stringify({
					error: "ENOTREGISTERED"
				}));
				return;
			}

			listener.handle(res);
		}
	}

	return self
}

module.exports = WebEvents;