Chat export parameter customisation (#7647)

* use export settings and hide fields

Signed-off-by: Kerry Archibald <kerrya@element.io>

* fix exporter tests

Signed-off-by: Kerry Archibald <kerrya@element.io>

* test ExportDialog with settings

Signed-off-by: Kerry Archibald <kerrya@element.io>

* tidy debugs, rename setting to Parameters

Signed-off-by: Kerry Archibald <kerrya@element.io>

* use reasonable 100gb limit

Signed-off-by: Kerry Archibald <kerrya@element.io>

* use normal setting instead of UIFeature

Signed-off-by: Kerry Archibald <kerrya@element.io>

* use a customisation

Signed-off-by: Kerry Archibald <kerrya@element.io>

* move validateNumberInRange to utils

Signed-off-by: Kerry Archibald <kerrya@element.io>

* use nullish coalesce

Signed-off-by: Kerry Archibald <kerrya@element.io>

* use 8gb size limit for customisation

Signed-off-by: Kerry Archibald <kerrya@element.io>

* update comments

Signed-off-by: Kerry Archibald <kerrya@element.io>

src/customisations/ChatExport.ts

@@ -0,0 +1,52 @@
+/*
+Copyright 2022 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import { ExportFormat, ExportType } from "../utils/exportUtils/exportUtils";
+
+export type ForceChatExportParameters = {
+    format?: ExportFormat;
+    range?: ExportType;
+    // must be < 10**8
+    // only used when range is 'LastNMessages'
+    // default is 100
+    numberOfMessages?: number;
+    includeAttachments?: boolean;
+    // maximum size of exported archive
+    // must be > 0 and < 8000
+    sizeMb?: number;
+};
+
+/**
+ * Force parameters in room chat export
+ * fields returned here are forced
+ * and not allowed to be edited in the chat export form
+ */
+const getForceChatExportParameters = (): ForceChatExportParameters => {
+    return {};
+};
+
+// This interface summarises all available customisation points and also marks
+// them all as optional. This allows customisers to only define and export the
+// customisations they need while still maintaining type safety.
+export interface IChatExportCustomisations {
+    getForceChatExportParameters?: typeof getForceChatExportParameters;
+}
+
+// A real customisation module will define and export one or more of the
+// customisation points that make up `IChatExportCustomisations`.
+export default {
+    getForceChatExportParameters,
+} as IChatExportCustomisations;