Server.js

import { Server as WebSocketServer } from "uws";
import winston from "winston";
import Client from "./Client";

import { AsyncEventEmitter } from "../../common/utility";


const defaultOptions = {
  wssOptions: {
    port: 8080
  }
};


export const State = Object.freeze({
  READY:    "READY",
  STARTING: "STARTING",
  RUNNING:  "RUNNING",
  STOPPING: "STOPPING",
  STOPPED:  "STOPPED"
});

export const Events = Object.freeze({
  STARTING: "server:starting",
  STARTED:  "server:started",
  STOPPING: "server:stopping",
  STOPPED:  "server:stopped"
});


export default class Server extends AsyncEventEmitter {
  
  constructor(options = { }) {
    super(Object.assign({ }, defaultOptions, options));
    this.state   = State.READY;
    this.wss     = null;
    this.clients = new Set();
  }
  
  async start() {
    if ((this.state != State.READY) && (this.state != State.STOPPED))
      throw new Error(`Can't start server while state is ${ this.state }`);
    
    this.logger.info("Starting up METATON ...");
    await this.emit(Events.STARTING);
    
    this.logger.info("Starting WebSocket Server ...");
    this.wss = new WebSocketServer(this.options.wssOptions);
    this.wss.on("connection", (ws) => clientConnected.call(this, ws));
    
    this.logger.info("Finalizing METATON startup ...");
    await this.emit(Events.STARTED);
    
    this.logger.info("METATON ready to rock!");
  }
  
  async stop() {
    if (this.state != State.RUNNING)
      throw new Error(`Can't stop server while state is ${ this.state }`);
    
    this.logger.info("Stopping METATON gracefully ...");
    await this.emit(Events.STOPPING);
    
    this.wss.close();
    this.wss = null;
    
    this.logger.info("Finalizing METATON shutdown ...");
    await this.emit(Events.STOPPED);
    
    this.logger.info("METATON ready to chill.");
  }
  
}


function clientConnected(ws) {
  const client = new Client(this, ws);
  this.clients.add(client);
  
  client.on(Client.Events.DISCONNECTED,
    () => this.clients.delete(client));
  
  for (const event of Object.values(Client.Events))
    client.on(event, (...args) => this.emit(client, ...args));
  
  this.emit(Client.Events.CONNECTED, client);
}