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