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