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

   1 import type { IncomingMessage } from 'node:http';
   2 import type { Duplex } from 'node:stream';
   3
   4 import { StatusCodes } from 'http-status-codes';
   5 import { type RawData, WebSocket, WebSocketServer } from 'ws';
   6
   7 import { AbstractUIServer } from './AbstractUIServer';
   8 import { UIServerUtils } from './UIServerUtils';
   9 import {
  10   type ProtocolRequest,
  11   type ProtocolResponse,
  12   type UIServerConfiguration,
  13   WebSocketCloseEventStatusCode,
  14 } from '../../types';
  15 import {
  16   Constants,
  17   getWebSocketCloseEventStatusString,
  18   isNotEmptyString,
  19   isNullOrUndefined,
  20   logPrefix,
  21   logger,
  22   validateUUID,
  23 } from '../../utils';
  24
  25 const moduleName = 'UIWebSocketServer';
  26
  27 export class UIWebSocketServer extends AbstractUIServer {
  28   private readonly webSocketServer: WebSocketServer;
  29
  30   public constructor(protected readonly uiServerConfiguration: UIServerConfiguration) {
  31     super(uiServerConfiguration);
  32     this.webSocketServer = new WebSocketServer({
  33       handleProtocols: UIServerUtils.handleProtocols,
  34       noServer: true,
  35     });
  36   }
  37
  38   public start(): void {
  39     // eslint-disable-next-line @typescript-eslint/no-unused-vars
  40     this.webSocketServer.on('connection', (ws: WebSocket, req: IncomingMessage): void => {
  41       if (UIServerUtils.isProtocolAndVersionSupported(ws.protocol) === false) {
  42         logger.error(
  43           `${this.logPrefix(
  44             moduleName,
  45             'start.server.onconnection'
  46           )} Unsupported UI protocol version: '${ws.protocol}'`
  47         );
  48         ws.close(WebSocketCloseEventStatusCode.CLOSE_PROTOCOL_ERROR);
  49       }
  50       const [, version] = UIServerUtils.getProtocolAndVersion(ws.protocol);
  51       this.registerProtocolVersionUIService(version);
  52       ws.on('message', (rawData) => {
  53         const request = this.validateRawDataRequest(rawData);
  54         if (request === false) {
  55           ws.close(WebSocketCloseEventStatusCode.CLOSE_INVALID_PAYLOAD);
  56           return;
  57         }
  58         const [requestId] = request as ProtocolRequest;
  59         this.responseHandlers.set(requestId, ws);
  60         this.uiServices
  61           .get(version)
  62           ?.requestHandler(request)
  63           .then((protocolResponse: ProtocolResponse) => {
  64             if (!isNullOrUndefined(protocolResponse)) {
  65               this.sendResponse(protocolResponse);
  66             }
  67           })
  68           .catch(Constants.EMPTY_FUNCTION);
  69       });
  70       ws.on('error', (error) => {
  71         logger.error(`${this.logPrefix(moduleName, 'start.ws.onerror')} WebSocket error:`, error);
  72       });
  73       ws.on('close', (code, reason) => {
  74         logger.debug(
  75           `${this.logPrefix(
  76             moduleName,
  77             'start.ws.onclose'
  78           )} WebSocket closed: '${getWebSocketCloseEventStatusString(
  79             code
  80           )}' - '${reason.toString()}'`
  81         );
  82       });
  83     });
  84     // eslint-disable-next-line @typescript-eslint/no-unused-vars
  85     this.httpServer.on('connect', (req: IncomingMessage, socket: Duplex, head: Buffer) => {
  86       if (req.headers?.connection !== 'Upgrade' || req.headers?.upgrade !== 'websocket') {
  87         socket.write(`HTTP/1.1 ${StatusCodes.BAD_REQUEST} Bad Request\r\n\r\n`);
  88         socket.destroy();
  89       }
  90     });
  91     this.httpServer.on('upgrade', (req: IncomingMessage, socket: Duplex, head: Buffer): void => {
  92       this.authenticate(req, (err) => {
  93         if (err) {
  94           socket.write(`HTTP/1.1 ${StatusCodes.UNAUTHORIZED} Unauthorized\r\n\r\n`);
  95           socket.destroy();
  96           return;
  97         }
  98         try {
  99           this.webSocketServer.handleUpgrade(req, socket, head, (ws: WebSocket) => {
 100             this.webSocketServer.emit('connection', ws, req);
 101           });
 102         } catch (error) {
 103           logger.error(
 104             `${this.logPrefix(
 105               moduleName,
 106               'start.httpServer.on.upgrade'
 107             )} Error at handling connection upgrade:`,
 108             error
 109           );
 110         }
 111       });
 112     });
 113     this.startHttpServer();
 114   }
 115
 116   public sendRequest(request: ProtocolRequest): void {
 117     this.broadcastToClients(JSON.stringify(request));
 118   }
 119
 120   public sendResponse(response: ProtocolResponse): void {
 121     const responseId = response[0];
 122     try {
 123       if (this.hasResponseHandler(responseId)) {
 124         const ws = this.responseHandlers.get(responseId) as WebSocket;
 125         if (ws?.readyState === WebSocket.OPEN) {
 126           ws.send(JSON.stringify(response));
 127         } else {
 128           logger.error(
 129             `${this.logPrefix(
 130               moduleName,
 131               'sendResponse'
 132             )} Error at sending response id '${responseId}', WebSocket is not open: ${
 133               ws?.readyState
 134             }`
 135           );
 136         }
 137       } else {
 138         logger.error(
 139           `${this.logPrefix(
 140             moduleName,
 141             'sendResponse'
 142           )} Response for unknown request id: ${responseId}`
 143         );
 144       }
 145     } catch (error) {
 146       logger.error(
 147         `${this.logPrefix(
 148           moduleName,
 149           'sendResponse'
 150         )} Error at sending response id '${responseId}':`,
 151         error
 152       );
 153     } finally {
 154       this.responseHandlers.delete(responseId);
 155     }
 156   }
 157
 158   public logPrefix = (modName?: string, methodName?: string, prefixSuffix?: string): string => {
 159     const logMsgPrefix = prefixSuffix
 160       ? `UI WebSocket Server ${prefixSuffix}`
 161       : 'UI WebSocket Server';
 162     const logMsg =
 163       isNotEmptyString(modName) && isNotEmptyString(methodName)
 164         ? ` ${logMsgPrefix} | ${modName}.${methodName}:`
 165         : ` ${logMsgPrefix} |`;
 166     return logPrefix(logMsg);
 167   };
 168
 169   private broadcastToClients(message: string): void {
 170     for (const client of this.webSocketServer.clients) {
 171       if (client?.readyState === WebSocket.OPEN) {
 172         client.send(message);
 173       }
 174     }
 175   }
 176
 177   private validateRawDataRequest(rawData: RawData): ProtocolRequest | false {
 178     // logger.debug(
 179     //   `${this.logPrefix(
 180     //     moduleName,
 181     //     'validateRawDataRequest'
 182     //   )} Raw data received in string format: ${rawData.toString()}`
 183     // );
 184
 185     const request = JSON.parse(rawData.toString()) as ProtocolRequest;
 186
 187     if (Array.isArray(request) === false) {
 188       logger.error(
 189         `${this.logPrefix(
 190           moduleName,
 191           'validateRawDataRequest'
 192         )} UI protocol request is not an array:`,
 193         request
 194       );
 195       return false;
 196     }
 197
 198     if (request.length !== 3) {
 199       logger.error(
 200         `${this.logPrefix(moduleName, 'validateRawDataRequest')} UI protocol request is malformed:`,
 201         request
 202       );
 203       return false;
 204     }
 205
 206     if (validateUUID(request[0]) === false) {
 207       logger.error(
 208         `${this.logPrefix(
 209           moduleName,
 210           'validateRawDataRequest'
 211         )} UI protocol request UUID field is invalid:`,
 212         request
 213       );
 214       return false;
 215     }
 216
 217     return request;
 218   }
 219 }