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   ProtocolCommand,
   7   ProtocolRequest,
   8   ProtocolRequestHandler,
   9 } from '../../../types/UIProtocol';
  10 import logger from '../../../utils/Logger';
  11 import Utils from '../../../utils/Utils';
  12 import { AbstractUIServer } from '../AbstractUIServer';
  13
  14 export default abstract class AbstractUIService {
  15   protected readonly uiServer: AbstractUIServer;
  16   protected readonly messageHandlers: Map<ProtocolCommand, ProtocolRequestHandler>;
  17
  18   constructor(uiServer: AbstractUIServer) {
  19     this.uiServer = uiServer;
  20     this.messageHandlers = new Map<ProtocolCommand, ProtocolRequestHandler>([
  21       [ProtocolCommand.LIST_CHARGING_STATIONS, this.handleListChargingStations.bind(this)],
  22     ]);
  23   }
  24
  25   public async messageHandler(request: RawData): Promise<void> {
  26     let command: ProtocolCommand;
  27     let payload: JsonType;
  28     const protocolRequest = JSON.parse(request.toString()) as ProtocolRequest;
  29     if (Utils.isIterable(protocolRequest)) {
  30       [command, payload] = protocolRequest;
  31     } else {
  32       throw new BaseError('UI protocol request is not iterable');
  33     }
  34     let messageResponse: JsonType;
  35     if (this.messageHandlers.has(command)) {
  36       try {
  37         // Call the message handler to build the message response
  38         messageResponse = (await this.messageHandlers.get(command)(payload)) as JsonType;
  39       } catch (error) {
  40         // Log
  41         logger.error(this.uiServer.logPrefix() + ' Handle message error: %j', error);
  42         throw error;
  43       }
  44     } else {
  45       // Throw exception
  46       throw new BaseError(
  47         `${command} is not implemented to handle message payload ${JSON.stringify(
  48           payload,
  49           null,
  50           2
  51         )}`
  52       );
  53     }
  54     // Send the message response
  55     this.uiServer.sendResponse(this.buildProtocolMessage(command, messageResponse));
  56   }
  57
  58   protected buildProtocolMessage(command: ProtocolCommand, payload: JsonType): string {
  59     return JSON.stringify([command, payload]);
  60   }
  61
  62   private handleListChargingStations(): JsonType {
  63     return Array.from(this.uiServer.chargingStations);
  64   }
  65 }