wba/frontend/src/js/arvados/collection/wb-download-file.js

import makeArvadosRequest from 'make-arvados-request';

function wbDownloadFile(arvHost, arvToken,
  manifestReader, path) {

  const file = manifestReader.getFile(path);
  const name = path.split('/').reverse()[0];
  const blockRefs = file[0];

  let prom = makeArvadosRequest(arvHost, arvToken,
    '/arvados/v1/keep_services');
  prom = prom.then(xhr => {
    const services = xhr.response['items'];
    const proxies = services.filter(svc => (svc.service_type === 'proxy'));
    const n = Math.floor(Math.random() * proxies.length);
    const proxy = proxies[n];
    const blocks = [];

    let prom_2 = new Promise(accept => accept());

    for (let i = 0; i < blockRefs.length; i++) {
      const [ locator, position, size ] = blockRefs[i];

      const prom_1 = makeArvadosRequest(
        proxy.service_host + ':' + proxy.service_port,
        arvToken,
        '/' + locator,
        { 'useSsl': proxy.service_ssl_flag,
          'responseType': 'arraybuffer' }
      );

      prom_2 = prom_2.then(() => prom_1);

      prom_2 = prom_2.then(xhr => (blocks.push(xhr.response.slice(position,
        position + size))));
    }

    prom_2 = prom_2.then(() => blocks);

    return prom_2;
  });



  /* prom = prom.then(() => {
    const blob = new Blob(blocks);
    const url = window.URL.createObjectURL(blob);
    const a = document.createElement('a');
    a.href = url;
    a.download = name;
    a.click();
  }); */

  return prom;
}

export default wbDownloadFile;