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   ProtocolVersion,
  10 } from '../../../types/UIProtocol';
  11 import logger from '../../../utils/Logger';
  12 import Utils from '../../../utils/Utils';
  13 import { AbstractUIServer } from '../AbstractUIServer';
  14
  15 export default abstract class AbstractUIService {
  16   protected readonly version: ProtocolVersion;
  17   protected readonly uiServer: AbstractUIServer;
  18   protected readonly messageHandlers: Map<ProtocolCommand, ProtocolRequestHandler>;
  19
  20   constructor(uiServer: AbstractUIServer, version: ProtocolVersion) {
  21     this.version = version;
  22     this.uiServer = uiServer;
  23     this.messageHandlers = new Map<ProtocolCommand, ProtocolRequestHandler>([
  24       [ProtocolCommand.LIST_CHARGING_STATIONS, this.handleListChargingStations.bind(this)],
  25     ]);
  26   }
  27
  28   public async messageHandler(request: RawData): Promise<void> {
  29     let command: ProtocolCommand;
  30     let payload: JsonType;
  31     const protocolRequest = JSON.parse(request.toString()) as ProtocolRequest;
  32     if (Utils.isIterable(protocolRequest)) {
  33       [command, payload] = protocolRequest;
  34     } else {
  35       throw new BaseError('UI protocol request is not iterable');
  36     }
  37     let messageResponse: JsonType;
  38     if (this.messageHandlers.has(command)) {
  39       try {
  40         // Call the message handler to build the message response
  41         messageResponse = (await this.messageHandlers.get(command)(payload)) as JsonType;
  42       } catch (error) {
  43         // Log
  44         logger.error(this.uiServer.logPrefix() + ' Handle message error: %j', error);
  45         throw error;
  46       }
  47     } else {
  48       // Throw exception
  49       throw new BaseError(
  50         `${command} is not implemented to handle message payload ${JSON.stringify(
  51           payload,
  52           null,
  53           2
  54         )}`
  55       );
  56     }
  57     // Send the message response
  58     this.uiServer.sendResponse(this.buildProtocolMessage(command, messageResponse));
  59   }
  60
  61   protected buildProtocolMessage(command: ProtocolCommand, payload: JsonType): string {
  62     return JSON.stringify([command, payload]);
  63   }
  64
  65   private handleListChargingStations(): JsonType {
  66     return Array.from(this.uiServer.chargingStations);
  67   }
  68 }