convert ReplayDetectionEntry to typescript

src/matrix/e2ee/megolm/decryption/ReplayDetectionEntry.ts

@@ -14,11 +14,24 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
+import type {TimelineEvent} from "../../../storage/types";
+
 export class ReplayDetectionEntry {
-    constructor(sessionId, messageIndex, event) {
+    public readonly sessionId: string;
+    public readonly messageIndex: number;
+    public readonly event: TimelineEvent;
+
+    constructor(sessionId: string, messageIndex: number, event: TimelineEvent) {
         this.sessionId = sessionId;
         this.messageIndex = messageIndex;
-        this.eventId = event.event_id;
-        this.timestamp = event.origin_server_ts;
+        this.event = event;
+    }
+
+    get eventId(): string {
+        return this.event.event_id;
+    }
+
+    get timestamp(): number {
+        return this.event.origin_server_ts;
     }
 }