lib/src/service/WebsocketServer.ts

import {Unit, UnitStatus} from '../lifecycle/Unit'
import {Inject, Singleton} from '../di'
import * as WebSocket from 'ws'
import {HTTPServer} from './HTTPServer'
import {Logging} from './Logging'
import {ErrorWithContext} from '../util'
import {Request} from '../http/lifecycle/Request'

@Singleton()
export class WebsocketServer extends Unit {
    @Inject()
    protected readonly http!: HTTPServer

    @Inject()
    protected readonly logging!: Logging

    protected server?: WebSocket.Server

    public async up(): Promise<void> {
        // Make sure the HTTP server is started. Otherwise, this is going to fail anyway
        if ( this.http.status !== UnitStatus.Started ) {
            throw new ErrorWithContext('Cannot start WebsocketServer without HTTPServer.', {
                suggestion: 'Make sure the HTTPServer is registered in your Units.extollo.ts file, and it is listed before the WebsocketServer.',
            })
        }

        // Start the websocket server
        this.logging.info('Starting WebSocket server...')
        this.server = new WebSocket.Server<WebSocket.WebSocket>({
            server: this.http.getServer(),
        })

        // Register the websocket handler
        this.server.on('connection', (ws, request) => {
            this.logging.info('Got WebSocket connection! ' + request.method)
            const extolloReq = new Request(request)
            this.logging.debug(ws)
            this.logging.debug(request)
        })
    }

    public down(): Promise<void> {
        return new Promise(res => {
            // Stop the websocket server, if it exists
            if ( this.server ) {
                this.server.close(() => res())
            }
        })
    }
}