fix: Move content into to frontend directory

Doing this BEFORE the merge prevents a lot of merge conflicts.

Signed-off-by: Tilman Vatteroth <git@tilmanvatteroth.de>

frontend/src/components/editor-page/document-bar/revisions/utils.ts

@@ -0,0 +1,42 @@
+/*
+ * SPDX-FileCopyrightText: 2022 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+import type { RevisionDetails } from '../../../../api/revisions/types'
+import { getUser } from '../../../../api/users'
+import type { UserInfo } from '../../../../api/users/types'
+import { download } from '../../../common/download/download'
+
+const DISPLAY_MAX_USERS_PER_REVISION = 9
+
+/**
+ * Downloads a given revision's content as markdown document in the browser.
+ *
+ * @param noteId The id of the note from which to download the revision.
+ * @param revision The revision details object containing the content to download.
+ */
+export const downloadRevision = (noteId: string, revision: RevisionDetails | null): void => {
+  if (!revision) {
+    return
+  }
+  download(revision.content, `${noteId}-${revision.createdAt}.md`, 'text/markdown')
+}
+
+/**
+ * Fetches user details for the given usernames while returning a maximum of 9 users.
+ *
+ * @param usernames The list of usernames to fetch.
+ * @throws {Error} in case the user-data request failed.
+ * @return An array of user details.
+ */
+export const getUserDataForRevision = async (usernames: string[]): Promise<UserInfo[]> => {
+  const users: UserInfo[] = []
+  const usersToFetch = Math.min(usernames.length, DISPLAY_MAX_USERS_PER_REVISION) - 1
+  for (let i = 0; i <= usersToFetch; i++) {
+    const user = await getUser(usernames[i])
+    users.push(user)
+  }
+  return users
+}