swaf/src/components/WebSocketServerComponent.ts

import config from "config";
import {Express, Router} from "express";
import {WebSocketServer} from "ws";

import Application from "../Application.js";
import ApplicationComponent from "../ApplicationComponent.js";
import {logger} from "../Logger.js";
import WebSocketListener from "../WebSocketListener.js";
import ExpressAppComponent from "./ExpressAppComponent.js";
import RedisComponent from "./RedisComponent.js";

export default class WebSocketServerComponent extends ApplicationComponent {
    private wss?: WebSocketServer;

    public async init(): Promise<void> {
        const app = this.getApp();

        app.require(ExpressAppComponent);
        app.require(RedisComponent);
    }

    public async initRoutes(router: Router): Promise<void> {
        router.use((req, res, next) => {
            res.locals.websocketUrl = config.get('app.public_websocket_url');
            next();
        });
    }

    public async start(_app: Express): Promise<void> {
        const app = this.getApp();

        const listeners: { [p: string]: WebSocketListener<Application> } = app.getWebSocketListeners();
        this.wss = new WebSocketServer({
            server: app.as(ExpressAppComponent).getServer(),
        }, () => {
            logger.info(`Websocket server started over webserver.`);
        }).on('error', (err) => {
            logger.error(err, 'An error occurred in the websocket server.');
        }).on('connection', (socket, request) => {
            const listener = request.url ? listeners[request.url] : null;

            if (!listener) {
                socket.close(1002, `Path not found ${request.url}`);
                return;
            }

            logger.debug(`Websocket on ${request.url}`);
            listener.handle(socket, request).catch(err => {
                logger.error(err, 'Error in websocket listener.');
            });
        });
    }

    public async stop(): Promise<void> {
        const wss = this.wss;
        if (wss) {
            await this.close('WebSocket server', callback => wss.close(callback));
        }
    }
}