src/charging-station/ui-server/ui-services/AbstractUIService.ts

   1 import { RawData } from 'ws';
   2
   3 import BaseError from '../../../exception/BaseError';
   4 import { JsonType } from '../../../types/JsonType';
   5 import {
   6   ProcedureName,
   7   ProtocolRequest,
   8   ProtocolRequestHandler,
   9   ProtocolResponse,
  10   ProtocolVersion,
  11   ResponsePayload,
  12   ResponseStatus,
  13 } from '../../../types/UIProtocol';
  14 import logger from '../../../utils/Logger';
  15 import Utils from '../../../utils/Utils';
  16 import Bootstrap from '../../Bootstrap';
  17 import WorkerBroadcastChannel from '../../WorkerBroadcastChannel';
  18 import { AbstractUIServer } from '../AbstractUIServer';
  19
  20 const moduleName = 'AbstractUIService';
  21
  22 export default abstract class AbstractUIService {
  23   protected readonly version: ProtocolVersion;
  24   protected readonly uiServer: AbstractUIServer;
  25   protected readonly messageHandlers: Map<ProcedureName, ProtocolRequestHandler>;
  26   protected workerBroadcastChannel: WorkerBroadcastChannel;
  27
  28   constructor(uiServer: AbstractUIServer, version: ProtocolVersion) {
  29     this.version = version;
  30     this.uiServer = uiServer;
  31     this.messageHandlers = new Map<ProcedureName, ProtocolRequestHandler>([
  32       [ProcedureName.LIST_CHARGING_STATIONS, this.handleListChargingStations.bind(this)],
  33       [ProcedureName.START_SIMULATOR, this.handleStartSimulator.bind(this)],
  34       [ProcedureName.STOP_SIMULATOR, this.handleStopSimulator.bind(this)],
  35     ]);
  36     this.workerBroadcastChannel = new WorkerBroadcastChannel();
  37   }
  38
  39   public async messageHandler(request: RawData): Promise<void> {
  40     let messageId: string;
  41     let command: ProcedureName;
  42     let requestPayload: JsonType;
  43     let responsePayload: ResponsePayload;
  44     try {
  45       [messageId, command, requestPayload] = this.dataValidation(request);
  46
  47       if (this.messageHandlers.has(command) === false) {
  48         // Throw exception
  49         throw new BaseError(
  50           `${command} is not implemented to handle message payload ${JSON.stringify(
  51             requestPayload,
  52             null,
  53             2
  54           )}`
  55         );
  56       }
  57       // Call the message handler to build the response payload
  58       responsePayload = (await this.messageHandlers.get(command)(
  59         requestPayload
  60       )) as ResponsePayload;
  61     } catch (error) {
  62       // Log
  63       logger.error(
  64         `${this.uiServer.logPrefix(moduleName, 'messageHandler')} Handle message error:`,
  65         error
  66       );
  67       // Send the message response failure
  68       this.uiServer.sendResponse(
  69         this.buildProtocolResponse(messageId ?? 'error', {
  70           status: ResponseStatus.FAILURE,
  71           command,
  72           requestPayload,
  73           errorMessage: (error as Error).message,
  74           errorStack: (error as Error).stack,
  75         })
  76       );
  77       throw error;
  78     }
  79
  80     // Send the message response success
  81     this.uiServer.sendResponse(this.buildProtocolResponse(messageId, responsePayload));
  82   }
  83
  84   protected buildProtocolResponse(messageId: string, payload: ResponsePayload): string {
  85     return JSON.stringify([messageId, payload] as ProtocolResponse);
  86   }
  87
  88   // Validate the raw data received from the WebSocket
  89   // TODO: should probably be moved to the ws verify clients callback
  90   private dataValidation(rawData: RawData): ProtocolRequest {
  91     logger.debug(
  92       `${this.uiServer.logPrefix(
  93         moduleName,
  94         'dataValidation'
  95       )} Raw data received: ${rawData.toString()}`
  96     );
  97     const data = JSON.parse(rawData.toString()) as JsonType[];
  98
  99     if (Utils.isIterable(data) === false) {
 100       throw new BaseError('UI protocol request is not iterable');
 101     }
 102
 103     if (data.length !== 3) {
 104       throw new BaseError('UI protocol request is malformed');
 105     }
 106
 107     return data as ProtocolRequest;
 108   }
 109
 110   private handleListChargingStations(): JsonType {
 111     return {
 112       status: ResponseStatus.SUCCESS,
 113       ...Array.from(this.uiServer.chargingStations.values()),
 114     } as JsonType;
 115   }
 116
 117   private async handleStartSimulator(): Promise<ResponsePayload> {
 118     await Bootstrap.getInstance().start();
 119     return { status: ResponseStatus.SUCCESS };
 120   }
 121
 122   private async handleStopSimulator(): Promise<ResponsePayload> {
 123     await Bootstrap.getInstance().stop();
 124     return { status: ResponseStatus.SUCCESS };
 125   }
 126 }