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 { ServerOptions } from '../../types/ConfigurationData';
   7 import {
   8   ProcedureName,
   9   Protocol,
  10   ProtocolResponse,
  11   ProtocolVersion,
  12   RequestPayload,
  13   ResponseStatus,
  14 } from '../../types/UIProtocol';
  15 import Configuration from '../../utils/Configuration';
  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(private options?: ServerOptions) {
  30     super();
  31     this.server = new Server(this.requestListener.bind(this) as RequestListener);
  32     this.responseHandlers = new Map<string, responseHandler>();
  33   }
  34
  35   public start(): void {
  36     if ((this.server as Server).listening === false) {
  37       (this.server as Server).listen(this.options ?? Configuration.getUIServer().options);
  38     }
  39   }
  40
  41   public stop(): void {
  42     this.chargingStations.clear();
  43     this.responseHandlers.clear();
  44   }
  45
  46   // eslint-disable-next-line @typescript-eslint/no-unused-vars
  47   public sendRequest(request: string): void {
  48     // This is intentionally left blank
  49   }
  50
  51   public sendResponse(response: string): void {
  52     const [uuid, payload] = JSON.parse(response) as ProtocolResponse;
  53     const statusCode = this.responseStatusToStatusCode(payload.status);
  54     if (this.responseHandlers.has(uuid) === true) {
  55       const { res } = this.responseHandlers.get(uuid);
  56       res.writeHead(statusCode, { 'Content-Type': 'application/json' });
  57       res.write(JSON.stringify(payload));
  58       res.end();
  59       this.responseHandlers.delete(uuid);
  60     } else {
  61       logger.error(
  62         `${this.logPrefix()} ${moduleName}.sendResponse: Response for unknown request: ${response}`
  63       );
  64     }
  65   }
  66
  67   public logPrefix(modName?: string, methodName?: string): string {
  68     const logMsg =
  69       modName && methodName ? ` UI HTTP Server | ${modName}.${methodName}:` : ' UI HTTP Server |';
  70     return Utils.logPrefix(logMsg);
  71   }
  72
  73   private requestListener(req: IncomingMessage, res: ServerResponse): void {
  74     // Expected request URL pathname: /ui/:version/:procedureName
  75     const [protocol, version, procedureName] = req.url?.split('/').slice(1) as [
  76       Protocol,
  77       ProtocolVersion,
  78       ProcedureName
  79     ];
  80     const uuid = Utils.generateUUID();
  81     this.responseHandlers.set(uuid, { procedureName, res });
  82     try {
  83       if (UIServiceUtils.isProtocolSupported(protocol, version) === false) {
  84         throw new BaseError(`Unsupported UI protocol version: '/${protocol}/${version}'`);
  85       }
  86       req.on('error', (error) => {
  87         logger.error(
  88           `${this.logPrefix(moduleName, 'requestListener.req.onerror')} Error on HTTP request:`,
  89           error
  90         );
  91       });
  92       if (!this.uiServices.has(version)) {
  93         this.uiServices.set(version, UIServiceFactory.getUIServiceImplementation(version, this));
  94       }
  95       if (req.method === 'POST') {
  96         const bodyBuffer = [];
  97         req
  98           .on('data', (chunk) => {
  99             bodyBuffer.push(chunk);
 100           })
 101           .on('end', () => {
 102             const body = JSON.parse(Buffer.concat(bodyBuffer).toString()) as RequestPayload;
 103             this.uiServices
 104               .get(version)
 105               .requestHandler(this.buildProtocolRequest(uuid, procedureName, body ?? {}))
 106               .catch(() => {
 107                 this.sendResponse(
 108                   this.buildProtocolResponse(uuid, { status: ResponseStatus.FAILURE })
 109                 );
 110               });
 111           });
 112       } else {
 113         throw new BaseError(`Unsupported HTTP method: '${req.method}'`);
 114       }
 115     } catch (error) {
 116       logger.error(
 117         `${this.logPrefix(moduleName, 'requestListener')} Handle HTTP request error:`,
 118         error
 119       );
 120       this.sendResponse(this.buildProtocolResponse(uuid, { status: ResponseStatus.FAILURE }));
 121     }
 122   }
 123
 124   private responseStatusToStatusCode(status: ResponseStatus): StatusCodes {
 125     switch (status) {
 126       case ResponseStatus.SUCCESS:
 127         return StatusCodes.OK;
 128       case ResponseStatus.FAILURE:
 129         return StatusCodes.BAD_REQUEST;
 130       default:
 131         return StatusCodes.INTERNAL_SERVER_ERROR;
 132     }
 133   }
 134 }