socket.js

const { camelToKebab } = require('./case-convert');

class SocketEmitter {
	constructor (API, path) {
		this._events = {};
		this._connection = null;
		this._settings = API.settings;
		this.socket = null;
		this.path = path;
	}

	connect (attempts = 0) {
		this._socket = new WebSocket(`${this._settings.secure ? 'wss' : 'ws'}://${this._settings.base}/${this.path}`);
		this._connection = new Promise(resolve => {
			this._socket.onopen = () => {
				this._socket.send('["session",' + localStorage.getItem('session') + ']');
				this._connection = null;
				resolve();
				this._dispatch('open', [attempts > 0]);
				attempts = 0;
			};
		});

		this._socket.onmessage = e => {
			var args = JSON.parse(e.data);
			if (args[0] == 'session') localStorage.setItem('session', JSON.stringify(args[1]));
			this._dispatch(args[0], args.slice(1));
		};

		this._socket.onclose = e => {
			if (this._socket._disableReconnect || this._settings.reconnectAttempts != -1 && attempts == this._settings.reconnectAttempts) {
				this._dispatch('close', [e.code, e.reason]);
				this._socket = null;
			} else {
				this._dispatch('reconnect', [attempts + 1]);
				setTimeout(() => this.connect(++attempts), this._settings.reconnectTimeout * 1000);
			}
		};
	}

	_dispatch (event, args) {
		const listeners = this._events[event];
		if (listeners) {
			for (let i = 0; i < listeners.length; i++) {
				listeners[i].apply(null, args);
				if (listeners[i].once) listeners.splice(i, 1);
			}
		}
	}

	on (event, listener) {
		if (this._events[event]) this._events[event].push(listener);
		else this._events[event] = [listener];
	}

	once (event, listener) {
		listener.once = true;
		this.on(event, listener);
	}

	off (event, listener) {
		const listeners = this._events[event];
		if (listeners) {
			var i = listeners.findIndex(l => l === listener);
			if (~i) listeners.splice(i, 1);
		}
	}

	emit () {
		let args = [];
		for (let i = 0; i < arguments.length; i++) args[i] = arguments[i];

		const send = () => this._socket.send(JSON.stringify(args));
		if (this._connection) this._connection.then(send);
		else send();
	}

	close () {
		this._socket._disableReconnect = true;
		this._socket.close();
		this._dispatch('close', [0, 'ManualClose']);
		this._events = {};
	}
}

exports.initSockets = API => API._sockets = {};
exports.registerSocket = (API, name) => API._sockets[name] = new SocketEmitter(API, camelToKebab(name));
exports.getSocket = (API, name) => {
	const emitter = API._sockets[name];
	if (!emitter._connection) emitter.connect();
}