Make use of js-sdk roomNameGenerator to handle i18n for generated room names (#9209)

* Make use of js-sdk roomNameGenerator to handle i18n for generated room names

* DRY

* Make tsc happier

* Update MatrixClientPeg.ts

src/MatrixClientPeg.ts

@@ -17,7 +17,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import { ICreateClientOpts, PendingEventOrdering } from 'matrix-js-sdk/src/matrix';
+import { ICreateClientOpts, PendingEventOrdering, RoomNameState, RoomNameType } from 'matrix-js-sdk/src/matrix';
 import { IStartClientOpts, MatrixClient } from 'matrix-js-sdk/src/client';
 import { MemoryStore } from 'matrix-js-sdk/src/store/memory';
 import * as utils from 'matrix-js-sdk/src/utils';
@@ -37,6 +37,7 @@ import IdentityAuthClient from './IdentityAuthClient';
 import { crossSigningCallbacks, tryToUnlockSecretStorageWithDehydrationKey } from './SecurityManager';
 import SecurityCustomisations from "./customisations/Security";
 import CryptoStoreTooNewDialog from "./components/views/dialogs/CryptoStoreTooNewDialog";
+import { _t } from "./languageHandler";
 
 export interface IMatrixClientCreds {
     homeserverUrl: string;
@@ -278,6 +279,48 @@ class MatrixClientPegClass implements IMatrixClientPeg {
         return matches[1];
     }
 
+    private namesToRoomName(names: string[], count: number): string | undefined {
+        const countWithoutMe = count - 1;
+        if (!names.length) {
+            return _t("Empty room");
+        }
+        if (names.length === 1 && countWithoutMe <= 1) {
+            return names[0];
+        }
+    }
+
+    private memberNamesToRoomName(names: string[], count: number): string {
+        const name = this.namesToRoomName(names, count);
+        if (name) return name;
+
+        if (names.length === 2 && count === 2) {
+            return _t("%(user1)s and %(user2)s", {
+                user1: names[0],
+                user2: names[1],
+            });
+        }
+        return _t("%(user)s and %(count)s others", {
+            user: names[0],
+            count: count - 1,
+        });
+    }
+
+    private inviteeNamesToRoomName(names: string[], count: number): string {
+        const name = this.namesToRoomName(names, count);
+        if (name) return name;
+
+        if (names.length === 2 && count === 2) {
+            return _t("Inviting %(user1)s and %(user2)s", {
+                user1: names[0],
+                user2: names[1],
+            });
+        }
+        return _t("Inviting %(user)s and %(count)s others", {
+            user: names[0],
+            count: count - 1,
+        });
+    }
+
     private createClient(creds: IMatrixClientCreds): void {
         const opts: ICreateClientOpts = {
             baseUrl: creds.homeserverUrl,
@@ -299,16 +342,34 @@ class MatrixClientPegClass implements IMatrixClientPeg {
                 verificationMethods.RECIPROCATE_QR_CODE,
             ],
             identityServer: new IdentityAuthClient(),
-            cryptoCallbacks: {},
+            // These are always installed regardless of the labs flag so that cross-signing features
+            // can toggle on without reloading and also be accessed immediately after login.
+            cryptoCallbacks: { ...crossSigningCallbacks },
+            roomNameGenerator: (_: string, state: RoomNameState) => {
+                switch (state.type) {
+                    case RoomNameType.Generated:
+                        switch (state.subtype) {
+                            case "Inviting":
+                                return this.inviteeNamesToRoomName(state.names, state.count);
+                            default:
+                                return this.memberNamesToRoomName(state.names, state.count);
+                        }
+                    case RoomNameType.EmptyRoom:
+                        if (state.oldName) {
+                            return _t("Empty room (was %(oldName)s)", {
+                                oldName: state.oldName,
+                            });
+                        } else {
+                            return _t("Empty room");
+                        }
+                    default:
+                        return null;
+                }
+            },
         };
 
-        // These are always installed regardless of the labs flag so that
-        // cross-signing features can toggle on without reloading and also be
-        // accessed immediately after login.
-        Object.assign(opts.cryptoCallbacks, crossSigningCallbacks);
         if (SecurityCustomisations.getDehydrationKey) {
-            opts.cryptoCallbacks.getDehydrationKey =
-                SecurityCustomisations.getDehydrationKey;
+            opts.cryptoCallbacks!.getDehydrationKey = SecurityCustomisations.getDehydrationKey;
         }
 
         this.matrixClient = createMatrixClient(opts);
@@ -319,7 +380,7 @@ class MatrixClientPegClass implements IMatrixClientPeg {
 
         this.matrixClient.setGuest(Boolean(creds.guest));
 
-        const notifTimelineSet = new EventTimelineSet(null, {
+        const notifTimelineSet = new EventTimelineSet(undefined, {
             timelineSupport: true,
             pendingEvents: false,
         });