signal-desktop/ts/main/challengeMain.ts

// Copyright 2021 Signal Messenger, LLC
// SPDX-License-Identifier: AGPL-3.0-only

import type { IpcMainEvent } from 'electron';
import { ipcMain as ipc } from 'electron';

import * as log from '../logging/log';
import type { IPCRequest, IPCResponse, ChallengeResponse } from '../challenge';

export class ChallengeMainHandler {
  private handlers: Array<(response: ChallengeResponse) => void> = [];

  constructor() {
    this.initialize();
  }

  public handleCaptcha(captcha: string): void {
    const response: ChallengeResponse = { captcha };

    const { handlers } = this;
    this.handlers = [];

    log.info(
      'challengeMain.handleCaptcha: sending captcha response to ' +
        `${handlers.length} handlers`,
      response
    );
    for (const resolve of handlers) {
      resolve(response);
    }
  }

  private async onRequest(
    event: IpcMainEvent,
    request: IPCRequest
  ): Promise<void> {
    const logId = `challengeMain.onRequest(${request.reason})`;
    log.info(`${logId}: received challenge request, waiting for response`);

    const start = Date.now();

    const data = await new Promise<ChallengeResponse>(resolve => {
      this.handlers.push(resolve);
    });

    const duration = Date.now() - start;
    log.info(`${logId}: got response after ${duration}ms`);

    const ipcResponse: IPCResponse = {
      seq: request.seq,
      data,
    };
    event.sender.send('challenge:response', ipcResponse);
  }

  private initialize(): void {
    ipc.on('challenge:request', (event, request) => {
      this.onRequest(event, request);
    });
  }
}