import log from '../log.js';
import { retrieveStudyMetadata } from './retrieveStudyMetadata';

/**
 * Retrieves metaData for multiple studies at once.
 *
 * This function calls retrieveStudyMetadata several times, asynchronously,
 * and waits for all of the results to be returned.
 *
 * @param studyInstanceUids The UIDs of the Studies to be retrieved
 * @return Promise
 */
export default function retrieveStudiesMetadata(
  server,
  studyInstanceUids,
  seriesInstanceUids
) {
  // Create an empty array to store the Promises for each metaData retrieval call
  const promises = [];

  // Loop through the array of studyInstanceUids
  studyInstanceUids.forEach(function(studyInstanceUid) {
    // Send the call and resolve or reject the related promise based on its outcome
    const promise = retrieveStudyMetadata(
      server,
      studyInstanceUid,
      seriesInstanceUids
    );

    // Add the current promise to the array of promises
    promises.push(promise);
  });

  // When all of the promises are complete, this callback runs
  const promise = Promise.all(promises);

  // Warn the error on console if some retrieval failed
  promise.catch(error => log.warn(error));

  return promise;
}