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 messageId: string;
  30     let command: ProtocolCommand;
  31     let payload: JsonType;
  32     const protocolRequest = JSON.parse(request.toString()) as ProtocolRequest;
  33     if (Utils.isIterable(protocolRequest)) {
  34       [messageId, command, payload] = protocolRequest;
  35     } else {
  36       throw new BaseError('UI protocol request is not iterable');
  37     }
  38     let messageResponse: JsonType;
  39     if (this.messageHandlers.has(command)) {
  40       try {
  41         // Call the message handler to build the message response
  42         messageResponse = (await this.messageHandlers.get(command)(payload)) as JsonType;
  43       } catch (error) {
  44         // Log
  45         logger.error(this.uiServer.logPrefix() + ' Handle message error: %j', error);
  46         throw error;
  47       }
  48     } else {
  49       // Throw exception
  50       throw new BaseError(
  51         `${command} is not implemented to handle message payload ${JSON.stringify(
  52           payload,
  53           null,
  54           2
  55         )}`
  56       );
  57     }
  58     // Send the message response
  59     this.uiServer.sendResponse(this.buildProtocolMessage(messageId, command, messageResponse));
  60   }
  61
  62   protected buildProtocolMessage(
  63     messageId: string,
  64     command: ProtocolCommand,
  65     payload: JsonType
  66   ): string {
  67     return JSON.stringify([messageId, command, payload]);
  68   }
  69
  70   private handleListChargingStations(): JsonType {
  71     return Array.from(this.uiServer.chargingStations);
  72   }
  73 }