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