Move the UI WS protocol version handling is protocol header

[e-mobility-charging-stations-simulator.git] / src / charging-station / UIWebSocketServices / AbstractUIService.ts

import { ProtocolCommand, ProtocolRequestHandler } from '../../types/UIProtocol';

import BaseError from '../../exception/BaseError';
import UIWebSocketServer from '../UIWebSocketServer';
import logger from '../../utils/Logger';

export default abstract class AbstractUIService {
  public readonly chargingStations: Set<string>;
  protected readonly uiWebSocketServer: UIWebSocketServer;
  protected readonly messageHandlers: Map<ProtocolCommand, ProtocolRequestHandler>;

  constructor(uiWebSocketServer: UIWebSocketServer) {
    this.chargingStations = new Set<string>();
    this.uiWebSocketServer = uiWebSocketServer;
    // TODO: Move the shared service code to AbstractUIService
    this.messageHandlers = new Map<ProtocolCommand, ProtocolRequestHandler>([
      [ProtocolCommand.LIST_CHARGING_STATIONS, this.handleListChargingStations.bind(this)],
    ]);
  }

  public async handleMessage(command: ProtocolCommand, payload: Record<string, unknown>): Promise<void> {
    let messageResponse: Record<string, unknown>;
    if (this.messageHandlers.has(command)) {
      try {
        // Call the method to build the message response
        messageResponse = await this.messageHandlers.get(command)(payload) as Record<string, unknown>;
      } catch (error) {
        // Log
        logger.error(this.uiWebSocketServer.logPrefix() + ' Handle message error: %j', error);
        throw error;
      }
    } else {
      // Throw exception
      throw new BaseError(`${command} is not implemented to handle message payload ${JSON.stringify(payload, null, 2)}`);
    }
    // Send the built message response
    this.uiWebSocketServer.broadcastToClients(this.buildProtocolMessage(command, messageResponse));
  }

  protected buildProtocolMessage(
      command: ProtocolCommand,
      payload: Record<string, unknown>,
  ): string {
    return JSON.stringify([command, payload]);
  }

  protected handleListChargingStations(): Set<string> {
    return this.chargingStations;
  }
}