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

   1 import type { IncomingMessage, RequestListener, ServerResponse } from 'http';
   2
   3 import { StatusCodes } from 'http-status-codes';
   4
   5 import BaseError from '../../exception/BaseError';
   6 import type { UIServerConfiguration } from '../../types/ConfigurationData';
   7 import {
   8   ProcedureName,
   9   Protocol,
  10   ProtocolRequest,
  11   ProtocolResponse,
  12   ProtocolVersion,
  13   RequestPayload,
  14   ResponseStatus,
  15 } from '../../types/UIProtocol';
  16 import logger from '../../utils/Logger';
  17 import Utils from '../../utils/Utils';
  18 import { AbstractUIServer } from './AbstractUIServer';
  19 import { UIServiceUtils } from './ui-services/UIServiceUtils';
  20
  21 const moduleName = 'UIHttpServer';
  22
  23 type responseHandler = { procedureName: ProcedureName; res: ServerResponse };
  24
  25 export default class UIHttpServer extends AbstractUIServer {
  26   private readonly responseHandlers: Map<string, responseHandler>;
  27
  28   public constructor(protected readonly uiServerConfiguration: UIServerConfiguration) {
  29     super(uiServerConfiguration);
  30     this.responseHandlers = new Map<string, responseHandler>();
  31   }
  32
  33   public start(): void {
  34     this.httpServer.on('connection', (socket) => {
  35       this.sockets.add(socket);
  36       socket.on('close', () => {
  37         this.sockets.delete(socket);
  38       });
  39     });
  40     this.httpServer.on('request', this.requestListener.bind(this) as RequestListener);
  41     if (this.httpServer.listening === false) {
  42       this.httpServer.listen(this.uiServerConfiguration.options);
  43     }
  44   }
  45
  46   // eslint-disable-next-line @typescript-eslint/no-unused-vars
  47   public sendRequest(request: ProtocolRequest): void {
  48     // This is intentionally left blank
  49   }
  50
  51   public sendResponse(response: ProtocolResponse): void {
  52     const [uuid, payload] = response;
  53     if (this.responseHandlers.has(uuid) === true) {
  54       const { res } = this.responseHandlers.get(uuid);
  55       res.writeHead(this.responseStatusToStatusCode(payload.status), {
  56         'Content-Type': 'application/json',
  57       });
  58       res.end(JSON.stringify(payload));
  59       this.responseHandlers.delete(uuid);
  60     } else {
  61       logger.error(
  62         `${this.logPrefix(moduleName, 'sendResponse')} Response for unknown request id: ${uuid}`
  63       );
  64     }
  65   }
  66
  67   public logPrefix(modName?: string, methodName?: string, prefixSuffix?: string): string {
  68     const logMsgPrefix = prefixSuffix ? `UI HTTP Server ${prefixSuffix}` : 'UI HTTP Server';
  69     const logMsg =
  70       modName && methodName ? ` ${logMsgPrefix} | ${modName}.${methodName}:` : ` ${logMsgPrefix} |`;
  71     return Utils.logPrefix(logMsg);
  72   }
  73
  74   private requestListener(req: IncomingMessage, res: ServerResponse): void {
  75     if (this.authenticate(req) === false) {
  76       res.setHeader('Content-Type', 'text/plain');
  77       res.setHeader('WWW-Authenticate', 'Basic realm=users');
  78       res.writeHead(StatusCodes.UNAUTHORIZED);
  79       res.end(`${StatusCodes.UNAUTHORIZED} Unauthorized`);
  80       return;
  81     }
  82     // Expected request URL pathname: /ui/:version/:procedureName
  83     const [protocol, version, procedureName] = req.url?.split('/').slice(1) as [
  84       Protocol,
  85       ProtocolVersion,
  86       ProcedureName
  87     ];
  88     const uuid = Utils.generateUUID();
  89     this.responseHandlers.set(uuid, { procedureName, res });
  90     try {
  91       if (UIServiceUtils.isProtocolAndVersionSupported(protocol, version) === false) {
  92         throw new BaseError(`Unsupported UI protocol version: '/${protocol}/${version}'`);
  93       }
  94       this.registerProtocolVersionUIService(version);
  95       req.on('error', (error) => {
  96         logger.error(
  97           `${this.logPrefix(moduleName, 'requestListener.req.onerror')} Error on HTTP request:`,
  98           error
  99         );
 100       });
 101       if (req.method === 'POST') {
 102         const bodyBuffer = [];
 103         req
 104           .on('data', (chunk) => {
 105             bodyBuffer.push(chunk);
 106           })
 107           .on('end', () => {
 108             const body = JSON.parse(Buffer.concat(bodyBuffer).toString()) as RequestPayload;
 109             this.uiServices
 110               .get(version)
 111               .requestHandler(this.buildProtocolRequest(uuid, procedureName, body ?? {}))
 112               .catch(() => {
 113                 this.sendResponse(
 114                   this.buildProtocolResponse(uuid, { status: ResponseStatus.FAILURE })
 115                 );
 116               });
 117           });
 118       } else {
 119         throw new BaseError(`Unsupported HTTP method: '${req.method}'`);
 120       }
 121     } catch (error) {
 122       logger.error(
 123         `${this.logPrefix(moduleName, 'requestListener')} Handle HTTP request error:`,
 124         error
 125       );
 126       this.sendResponse(this.buildProtocolResponse(uuid, { status: ResponseStatus.FAILURE }));
 127     }
 128   }
 129
 130   private authenticate(req: IncomingMessage): boolean {
 131     if (this.isBasicAuthEnabled() === true) {
 132       if (this.isValidBasicAuth(req) === true) {
 133         return true;
 134       }
 135       return false;
 136     }
 137     return true;
 138   }
 139
 140   private responseStatusToStatusCode(status: ResponseStatus): StatusCodes {
 141     switch (status) {
 142       case ResponseStatus.SUCCESS:
 143         return StatusCodes.OK;
 144       case ResponseStatus.FAILURE:
 145         return StatusCodes.BAD_REQUEST;
 146       default:
 147         return StatusCodes.INTERNAL_SERVER_ERROR;
 148     }
 149   }
 150 }