src/charging-station/ui-server/UIWebSocketServer.ts

   1 import type { IncomingMessage } from 'http';
   2 import type internal from 'stream';
   3
   4 import { StatusCodes } from 'http-status-codes';
   5 import WebSocket, { type RawData, WebSocketServer } from 'ws';
   6
   7 import {
   8   type ProtocolRequest,
   9   type ProtocolResponse,
  10   type UIServerConfiguration,
  11   WebSocketCloseEventStatusCode,
  12 } from '../../types';
  13 import { logger } from '../../utils/Logger';
  14 import { Utils } from '../../utils/Utils';
  15 import { AbstractUIServer, UIServerUtils } from '../internal';
  16
  17 const moduleName = 'UIWebSocketServer';
  18
  19 export class UIWebSocketServer extends AbstractUIServer {
  20   private readonly webSocketServer: WebSocketServer;
  21
  22   public constructor(protected readonly uiServerConfiguration: UIServerConfiguration) {
  23     super(uiServerConfiguration);
  24     this.webSocketServer = new WebSocketServer({
  25       handleProtocols: UIServerUtils.handleProtocols,
  26       noServer: true,
  27     });
  28   }
  29
  30   public start(): void {
  31     // eslint-disable-next-line @typescript-eslint/no-unused-vars
  32     this.webSocketServer.on('connection', (ws: WebSocket, req: IncomingMessage): void => {
  33       if (UIServerUtils.isProtocolAndVersionSupported(ws.protocol) === false) {
  34         logger.error(
  35           `${this.logPrefix(
  36             moduleName,
  37             'start.server.onconnection'
  38           )} Unsupported UI protocol version: '${ws.protocol}'`
  39         );
  40         ws.close(WebSocketCloseEventStatusCode.CLOSE_PROTOCOL_ERROR);
  41       }
  42       const [, version] = UIServerUtils.getProtocolAndVersion(ws.protocol);
  43       this.registerProtocolVersionUIService(version);
  44       ws.on('message', (rawData) => {
  45         const request = this.validateRawDataRequest(rawData);
  46         if (request === false) {
  47           ws.close(WebSocketCloseEventStatusCode.CLOSE_INVALID_PAYLOAD);
  48           return;
  49         }
  50         const [requestId] = request as ProtocolRequest;
  51         this.responseHandlers.set(requestId, ws);
  52         this.uiServices
  53           .get(version)
  54           ?.requestHandler(request)
  55           .catch(() => {
  56             /* Error caught by AbstractUIService */
  57           });
  58       });
  59       ws.on('error', (error) => {
  60         logger.error(`${this.logPrefix(moduleName, 'start.ws.onerror')} WebSocket error:`, error);
  61       });
  62       ws.on('close', (code, reason) => {
  63         logger.debug(
  64           `${this.logPrefix(
  65             moduleName,
  66             'start.ws.onclose'
  67           )} WebSocket closed: '${Utils.getWebSocketCloseEventStatusString(
  68             code
  69           )}' - '${reason.toString()}'`
  70         );
  71       });
  72     });
  73     // eslint-disable-next-line @typescript-eslint/no-unused-vars
  74     this.httpServer.on('connect', (req: IncomingMessage, socket: internal.Duplex, head: Buffer) => {
  75       if (req.headers?.connection !== 'Upgrade' || req.headers?.upgrade !== 'websocket') {
  76         socket.write(`HTTP/1.1 ${StatusCodes.BAD_REQUEST} Bad Request\r\n\r\n`);
  77         socket.destroy();
  78       }
  79     });
  80     this.httpServer.on(
  81       'upgrade',
  82       (req: IncomingMessage, socket: internal.Duplex, head: Buffer): void => {
  83         this.authenticate(req, (err) => {
  84           if (err) {
  85             socket.write(`HTTP/1.1 ${StatusCodes.UNAUTHORIZED} Unauthorized\r\n\r\n`);
  86             socket.destroy();
  87             return;
  88           }
  89           try {
  90             this.webSocketServer.handleUpgrade(req, socket, head, (ws: WebSocket) => {
  91               this.webSocketServer.emit('connection', ws, req);
  92             });
  93           } catch (error) {
  94             logger.error(
  95               `${this.logPrefix(
  96                 moduleName,
  97                 'start.httpServer.on.upgrade'
  98               )} Error at handling connection upgrade:`,
  99               error
 100             );
 101           }
 102         });
 103       }
 104     );
 105     this.startHttpServer();
 106   }
 107
 108   public sendRequest(request: ProtocolRequest): void {
 109     this.broadcastToClients(JSON.stringify(request));
 110   }
 111
 112   public sendResponse(response: ProtocolResponse): void {
 113     const responseId = response[0];
 114     try {
 115       if (this.responseHandlers.has(responseId)) {
 116         const ws = this.responseHandlers.get(responseId) as WebSocket;
 117         if (ws?.readyState === WebSocket.OPEN) {
 118           ws.send(JSON.stringify(response));
 119         } else {
 120           logger.error(
 121             `${this.logPrefix(
 122               moduleName,
 123               'sendResponse'
 124             )} Error at sending response id '${responseId}', WebSocket is not open: ${
 125               ws?.readyState
 126             }`
 127           );
 128         }
 129       } else {
 130         logger.error(
 131           `${this.logPrefix(
 132             moduleName,
 133             'sendResponse'
 134           )} Response for unknown request id: ${responseId}`
 135         );
 136       }
 137     } catch (error) {
 138       logger.error(
 139         `${this.logPrefix(
 140           moduleName,
 141           'sendResponse'
 142         )} Error at sending response id '${responseId}':`,
 143         error
 144       );
 145     } finally {
 146       this.responseHandlers.delete(responseId);
 147     }
 148   }
 149
 150   public logPrefix = (modName?: string, methodName?: string, prefixSuffix?: string): string => {
 151     const logMsgPrefix = prefixSuffix
 152       ? `UI WebSocket Server ${prefixSuffix}`
 153       : 'UI WebSocket Server';
 154     const logMsg =
 155       Utils.isNotEmptyString(modName) && Utils.isNotEmptyString(methodName)
 156         ? ` ${logMsgPrefix} | ${modName}.${methodName}:`
 157         : ` ${logMsgPrefix} |`;
 158     return Utils.logPrefix(logMsg);
 159   };
 160
 161   private broadcastToClients(message: string): void {
 162     for (const client of this.webSocketServer.clients) {
 163       if (client?.readyState === WebSocket.OPEN) {
 164         client.send(message);
 165       }
 166     }
 167   }
 168
 169   private validateRawDataRequest(rawData: RawData): ProtocolRequest | false {
 170     // logger.debug(
 171     //   `${this.logPrefix(
 172     //     moduleName,
 173     //     'validateRawDataRequest'
 174     //   )} Raw data received in string format: ${rawData.toString()}`
 175     // );
 176
 177     const request = JSON.parse(rawData.toString()) as ProtocolRequest;
 178
 179     if (Array.isArray(request) === false) {
 180       logger.error(
 181         `${this.logPrefix(
 182           moduleName,
 183           'validateRawDataRequest'
 184         )} UI protocol request is not an array:`,
 185         request
 186       );
 187       return false;
 188     }
 189
 190     if (request.length !== 3) {
 191       logger.error(
 192         `${this.logPrefix(moduleName, 'validateRawDataRequest')} UI protocol request is malformed:`,
 193         request
 194       );
 195       return false;
 196     }
 197
 198     if (Utils.validateUUID(request[0]) === false) {
 199       logger.error(
 200         `${this.logPrefix(
 201           moduleName,
 202           'validateRawDataRequest'
 203         )} UI protocol request UUID field is invalid:`,
 204         request
 205       );
 206       return false;
 207     }
 208
 209     return request;
 210   }
 211 }