Signal-Desktop/ts/util/downloadAttachment.ts

// Copyright 2020 Signal Messenger, LLC
// SPDX-License-Identifier: AGPL-3.0-only

import {
  AttachmentPointerClass,
  DownloadAttachmentType,
} from '../textsecure.d';

type AttachmentData = AttachmentPointerClass & {
  id?: string;
};

export async function downloadAttachment(
  attachmentData: AttachmentData
): Promise<DownloadAttachmentType | null> {
  let downloaded;
  try {
    if (attachmentData.id) {
      // eslint-disable-next-line no-param-reassign
      attachmentData.cdnId = attachmentData.id;
    }
    downloaded = await window.textsecure.messageReceiver.downloadAttachment(
      attachmentData
    );
  } catch (error) {
    // Attachments on the server expire after 30 days, then start returning 404
    if (error && error.code === 404) {
      return null;
    }

    throw error;
  }

  return downloaded;
}