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

   1 import { IncomingMessage, RequestListener, Server, 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 UIServiceFactory from './ui-services/UIServiceFactory';
  20 import { UIServiceUtils } from './ui-services/UIServiceUtils';
  21
  22 const moduleName = 'UIHttpServer';
  23
  24 type responseHandler = { procedureName: ProcedureName; res: ServerResponse };
  25
  26 export default class UIHttpServer extends AbstractUIServer {
  27   private readonly responseHandlers: Map<string, responseHandler>;
  28
  29   public constructor(protected readonly uiServerConfiguration: UIServerConfiguration) {
  30     super(uiServerConfiguration);
  31     this.httpServer = new Server(this.requestListener.bind(this) as RequestListener);
  32     this.responseHandlers = new Map<string, responseHandler>();
  33   }
  34
  35   public start(): void {
  36     if (this.httpServer.listening === false) {
  37       this.httpServer.listen(this.uiServerConfiguration.options);
  38     }
  39   }
  40
  41   public stop(): void {
  42     this.chargingStations.clear();
  43   }
  44
  45   // eslint-disable-next-line @typescript-eslint/no-unused-vars
  46   public sendRequest(request: ProtocolRequest): void {
  47     // This is intentionally left blank
  48   }
  49
  50   public sendResponse(response: ProtocolResponse): void {
  51     const [uuid, payload] = response;
  52     const statusCode = this.responseStatusToStatusCode(payload.status);
  53     if (this.responseHandlers.has(uuid) === true) {
  54       const { res } = this.responseHandlers.get(uuid);
  55       res.writeHead(statusCode, { 'Content-Type': 'application/json' });
  56       res.write(JSON.stringify(payload));
  57       res.end();
  58       this.responseHandlers.delete(uuid);
  59     } else {
  60       logger.error(
  61         `${this.logPrefix(moduleName, 'sendResponse')} Response for unknown request id: ${uuid}`
  62       );
  63     }
  64   }
  65
  66   public logPrefix(modName?: string, methodName?: string, prefixSuffix?: string): string {
  67     const logMsgPrefix = prefixSuffix ? `UI HTTP Server ${prefixSuffix}` : 'UI HTTP Server';
  68     const logMsg =
  69       modName && methodName ? ` ${logMsgPrefix} | ${modName}.${methodName}:` : ` ${logMsgPrefix} |`;
  70     return Utils.logPrefix(logMsg);
  71   }
  72
  73   private requestListener(req: IncomingMessage, res: ServerResponse): void {
  74     if (this.authenticate(req) === false) {
  75       res.setHeader('Content-Type', 'text/plain');
  76       res.setHeader('WWW-Authenticate', 'Basic realm=users');
  77       res.writeHead(StatusCodes.UNAUTHORIZED);
  78       res.end(`${StatusCodes.UNAUTHORIZED} Unauthorized`);
  79       return;
  80     }
  81     // Expected request URL pathname: /ui/:version/:procedureName
  82     const [protocol, version, procedureName] = req.url?.split('/').slice(1) as [
  83       Protocol,
  84       ProtocolVersion,
  85       ProcedureName
  86     ];
  87     const uuid = Utils.generateUUID();
  88     this.responseHandlers.set(uuid, { procedureName, res });
  89     try {
  90       if (UIServiceUtils.isProtocolAndVersionSupported(protocol, version) === false) {
  91         throw new BaseError(`Unsupported UI protocol version: '/${protocol}/${version}'`);
  92       }
  93       req.on('error', (error) => {
  94         logger.error(
  95           `${this.logPrefix(moduleName, 'requestListener.req.onerror')} Error on HTTP request:`,
  96           error
  97         );
  98       });
  99       if (this.uiServices.has(version) === false) {
 100         this.uiServices.set(version, UIServiceFactory.getUIServiceImplementation(version, this));
 101       }
 102       if (req.method === 'POST') {
 103         const bodyBuffer = [];
 104         req
 105           .on('data', (chunk) => {
 106             bodyBuffer.push(chunk);
 107           })
 108           .on('end', () => {
 109             const body = JSON.parse(Buffer.concat(bodyBuffer).toString()) as RequestPayload;
 110             this.uiServices
 111               .get(version)
 112               .requestHandler(this.buildProtocolRequest(uuid, procedureName, body ?? {}))
 113               .catch(() => {
 114                 this.sendResponse(
 115                   this.buildProtocolResponse(uuid, { status: ResponseStatus.FAILURE })
 116                 );
 117               });
 118           });
 119       } else {
 120         throw new BaseError(`Unsupported HTTP method: '${req.method}'`);
 121       }
 122     } catch (error) {
 123       logger.error(
 124         `${this.logPrefix(moduleName, 'requestListener')} Handle HTTP request error:`,
 125         error
 126       );
 127       this.sendResponse(this.buildProtocolResponse(uuid, { status: ResponseStatus.FAILURE }));
 128     }
 129   }
 130
 131   private authenticate(req: IncomingMessage): boolean {
 132     if (this.isBasicAuthEnabled() === true) {
 133       if (this.isValidBasicAuth(req) === true) {
 134         return true;
 135       }
 136       return false;
 137     }
 138     return true;
 139   }
 140
 141   private responseStatusToStatusCode(status: ResponseStatus): StatusCodes {
 142     switch (status) {
 143       case ResponseStatus.SUCCESS:
 144         return StatusCodes.OK;
 145       case ResponseStatus.FAILURE:
 146         return StatusCodes.BAD_REQUEST;
 147       default:
 148         return StatusCodes.INTERNAL_SERVER_ERROR;
 149     }
 150   }
 151 }