mCaptcha/templates/widget/js/index.ts

/*
 * mCaptcha is a PoW based DoS protection software.
 * This is the frontend web component of the mCaptcha system
 * Copyright © 2021 Aravinth Manivnanan <realaravinth@batsense.net>.
 *
 * Use of this source code is governed by Apache 2.0 or MIT license.
 * You shoud have received a copy of MIT and Apache 2.0 along with
 * this program. If not, see <https://spdx.org/licenses/MIT.html> for
 * MIT or <http://www.apache.org/licenses/LICENSE-2.0> for Apache.
 */

import prove from './prove';
import fetchPoWConfig from './fetchPoWConfig';
import sendWork from './sendWork';
import sendToParent from './sendToParent';
import * as CONST from './const';

import '../main.scss';

let LOCK = false;

/** add  mcaptcha widget element to DOM */
export const registerVerificationEventHandler = () => {
  const verificationContainer = <HTMLElement>(
    document.querySelector('.widget__verification-container')
  );
  verificationContainer.style.display = 'flex';
  CONST.btn().addEventListener('click', e => solveCaptchaRunner(e));
};

export const solveCaptchaRunner = async (e: Event) => {
  if (LOCK) {
    e.preventDefault();
    return;
  }

  try {
    LOCK = true;
    if (CONST.btn().checked == false) {
      CONST.messageText().before();
      LOCK = false;
      return;
    }
    e.preventDefault();
    // steps:

    // 1. show during
    CONST.messageText().during();
    // 1. get config
    const config = await fetchPoWConfig();
    // 2. prove work
    const proof = await prove(config);
    // 3. submit work
    const token = await sendWork(proof);
    // 4. send token
    sendToParent(token);
    // 5. mark checkbox checked
    CONST.btn().checked = true;
    CONST.messageText().after();
    LOCK = false;
  } catch (e) {
    CONST.messageText().error();
    console.error(e);
    LOCK = false;
  }
};

registerVerificationEventHandler();