fix: fix OCPP message sending promise leak

[e-mobility-charging-stations-simulator.git] / ui / web / src / composables / UIClient.ts

import {
  ProcedureName,
  type ProtocolResponse,
  type RequestPayload,
  type ResponsePayload,
  ResponseStatus,
} from '@/types';
import config from '@/assets/config';

type ResponseHandler = {
  procedureName: ProcedureName;
  resolve: (value: ResponsePayload | PromiseLike<ResponsePayload>) => void;
  reject: (reason?: unknown) => void;
};

export class UIClient {
  private static instance: UIClient | null = null;

  private ws!: WebSocket;
  private responseHandlers: Map<string, ResponseHandler>;

  private constructor() {
    this.openWS();
    this.responseHandlers = new Map<string, ResponseHandler>();
  }

  public static getInstance() {
    if (UIClient.instance === null) {
      UIClient.instance = new UIClient();
    }
    return UIClient.instance;
  }

  public registerWSonOpenListener(listener: (event: Event) => void) {
    this.ws.addEventListener('open', listener);
  }

  public async startSimulator(): Promise<ResponsePayload> {
    return this.sendRequest(ProcedureName.START_SIMULATOR, {});
  }

  public async stopSimulator(): Promise<ResponsePayload> {
    return this.sendRequest(ProcedureName.STOP_SIMULATOR, {});
  }

  public async listChargingStations(): Promise<ResponsePayload> {
    return this.sendRequest(ProcedureName.LIST_CHARGING_STATIONS, {});
  }

  public async startChargingStation(hashId: string): Promise<ResponsePayload> {
    return this.sendRequest(ProcedureName.START_CHARGING_STATION, { hashIds: [hashId] });
  }

  public async stopChargingStation(hashId: string): Promise<ResponsePayload> {
    return this.sendRequest(ProcedureName.STOP_CHARGING_STATION, { hashIds: [hashId] });
  }

  public async openConnection(hashId: string): Promise<ResponsePayload> {
    return this.sendRequest(ProcedureName.OPEN_CONNECTION, {
      hashIds: [hashId],
    });
  }

  public async closeConnection(hashId: string): Promise<ResponsePayload> {
    return this.sendRequest(ProcedureName.CLOSE_CONNECTION, {
      hashIds: [hashId],
    });
  }

  public async startTransaction(
    hashId: string,
    connectorId: number,
    idTag: string | undefined,
  ): Promise<ResponsePayload> {
    return this.sendRequest(ProcedureName.START_TRANSACTION, {
      hashIds: [hashId],
      connectorId,
      idTag,
    });
  }

  public async stopTransaction(
    hashId: string,
    transactionId: number | undefined,
  ): Promise<ResponsePayload> {
    return this.sendRequest(ProcedureName.STOP_TRANSACTION, {
      hashIds: [hashId],
      transactionId,
    });
  }

  public async startAutomaticTransactionGenerator(
    hashId: string,
    connectorId: number,
  ): Promise<ResponsePayload> {
    return this.sendRequest(ProcedureName.START_AUTOMATIC_TRANSACTION_GENERATOR, {
      hashIds: [hashId],
      connectorIds: [connectorId],
    });
  }

  public async stopAutomaticTransactionGenerator(
    hashId: string,
    connectorId: number,
  ): Promise<ResponsePayload> {
    return this.sendRequest(ProcedureName.STOP_AUTOMATIC_TRANSACTION_GENERATOR, {
      hashIds: [hashId],
      connectorIds: [connectorId],
    });
  }

  private openWS(): void {
    this.ws = new WebSocket(
      `ws://${config.uiServer.host}:${config.uiServer.port}`,
      config.uiServer.protocol,
    );
    this.ws.onmessage = this.responseHandler.bind(this);
    this.ws.onerror = (errorEvent) => {
      console.error('WebSocket error: ', errorEvent);
    };
    this.ws.onclose = (closeEvent) => {
      console.info('WebSocket closed: ', closeEvent);
    };
  }

  private setResponseHandler(
    id: string,
    procedureName: ProcedureName,
    resolve: (value: ResponsePayload | PromiseLike<ResponsePayload>) => void,
    reject: (reason?: unknown) => void,
  ): void {
    this.responseHandlers.set(id, { procedureName, resolve, reject });
  }

  private getResponseHandler(id: string): ResponseHandler | undefined {
    return this.responseHandlers.get(id);
  }

  private deleteResponseHandler(id: string): boolean {
    return this.responseHandlers.delete(id);
  }

  private async sendRequest(
    command: ProcedureName,
    data: RequestPayload,
  ): Promise<ResponsePayload> {
    return new Promise<ResponsePayload>((resolve, reject) => {
      const uuid = crypto.randomUUID();
      const msg = JSON.stringify([uuid, command, data]);

      if (this.ws.readyState !== WebSocket.OPEN) {
        this.openWS();
      }
      if (this.ws.readyState === WebSocket.OPEN) {
        const sendTimeout = setTimeout(() => {
          this.deleteResponseHandler(uuid);
          return reject(new Error(`Send request '${command}' message timeout`));
        }, 60 * 1000);
        try {
          this.ws.send(msg);
          this.setResponseHandler(uuid, command, resolve, reject);
        } catch (error) {
          this.deleteResponseHandler(uuid);
          reject(error);
        } finally {
          clearTimeout(sendTimeout);
        }
      } else {
        throw new Error(`Send request '${command}' message: connection not opened`);
      }
    });
  }

  private responseHandler(messageEvent: MessageEvent<string>): void {
    const response = JSON.parse(messageEvent.data) as ProtocolResponse;

    if (Array.isArray(response) === false) {
      throw new Error(`Response not an array: ${JSON.stringify(response, undefined, 2)}`);
    }

    const [uuid, responsePayload] = response;

    if (this.responseHandlers.has(uuid) === true) {
      const { procedureName, resolve, reject } = this.getResponseHandler(uuid)!;
      switch (responsePayload.status) {
        case ResponseStatus.SUCCESS:
          resolve(responsePayload);
          break;
        case ResponseStatus.FAILURE:
          reject(responsePayload);
          break;
        default:
          console.error(
            `Response status for procedure '${procedureName}' not supported: '${responsePayload.status}'`,
          );
      }
      this.deleteResponseHandler(uuid);
    } else {
      throw new Error(`Not a response to a request: ${JSON.stringify(response, undefined, 2)}`);
    }
  }
}