[Gekidou MM-45790] Create File Options Menu for Tablet View (#6531)

app/utils/files.tsx

@@ -0,0 +1,44 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+import {ChannelModel} from '@app/database/models/server';
+import {fileToGalleryItem} from '@utils/gallery';
+
+export const getNumberFileMenuOptions = (canDownloadFiles: boolean, publicLinkEnabled: boolean) => {
+    let numberItems = 1;
+    numberItems += canDownloadFiles ? 1 : 0;
+    numberItems += publicLinkEnabled ? 1 : 0;
+    return numberItems;
+};
+
+// return an object with key:value of channelID:channelDisplayName
+export const getChannelNamesWithID = (fileChannels: ChannelModel[]) => {
+    return fileChannels.reduce<{[id: string]: string | undefined}>((acc, v) => {
+        acc[v.id] = v.displayName;
+        return acc;
+    }, {});
+};
+
+// return array of fileInfos (image and non-image) sorted by create_at date
+export const getOrderedFileInfos = (fileInfos: FileInfo[]) => {
+    return fileInfos.sort((a: FileInfo, b: FileInfo) => {
+        return (b.create_at || 0) - (a.create_at || 0);
+    });
+};
+
+// returns object with keys of fileInfo.id and value of the ordered index from
+// orderedFilesForGallery
+export const getFileInfosIndexes = (orderedFilesForGallery: FileInfo[]) => {
+    return orderedFilesForGallery.reduce<{[id: string]: number | undefined}>((acc, v, idx) => {
+        if (v.id) {
+            acc[v.id] = idx;
+        }
+        return acc;
+    }, {});
+};
+
+// return ordered FileInfo[] converted to GalleryItemType[]
+export const getOrderedGalleryItems = (orderedFileInfos: FileInfo[]) => {
+    return orderedFileInfos.map((f) => fileToGalleryItem(f, f.user_id));
+};
+