text: /**
   * Copyright (c) Microsoft Corporation.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   * http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  async function downloadBrowser(browser) {
    const browserType = require('.')[browser];
    let progressBar = null;
    let lastDownloadedBytes = 0;
    function onProgress(downloadedBytes, totalBytes) {
      if (!progressBar) {
        const ProgressBar = require('progress');
        progressBar = new ProgressBar(`Downloading ${browser} ${browserType._revision} - ${toMegabytes(totalBytes)} [:bar] :percent :etas `, {
          complete: '=',
          incomplete: ' ',
          width: 20,
          total: totalBytes,
        });
      }
      const delta = downloadedBytes - lastDownloadedBytes;
      lastDownloadedBytes = downloadedBytes;
      progressBar.tick(delta);
    }
  
    const fetcher = browserType._createBrowserFetcher();
    const revisionInfo = fetcher.revisionInfo();
    // Do nothing if the revision is already downloaded.
    if (revisionInfo.local)
      return revisionInfo;
    await fetcher.download(revisionInfo.revision, onProgress);
    logPolitely(`${browser} downloaded to ${revisionInfo.folderPath}`);
    return revisionInfo;
  }
  
  
  function toMegabytes(bytes) {
    const mb = bytes / 1024 / 1024;
    return `${Math.round(mb * 10) / 10} Mb`;
  }
  
  function logPolitely(toBeLogged) {
    const logLevel = process.env.npm_config_loglevel;
    const logLevelDisplay = ['silent', 'error', 'warn'].indexOf(logLevel) > -1;
  
    if (!logLevelDisplay)
      console.log(toBeLogged);
  }
  
  module.exports = {downloadBrowser};
  