How to track watched movies/series?

Question

Do it yourself

There is a server where the film library is stored, there is a Dune HD tv-301 set-top box through which all this is viewed via LAN.
And now the task arose, but is it possible somehow to track what I looked at and what else is not? The fact is that the server automatically uploads new serials to the shared folder and sometimes confusion begins about what I have already seen and what not ...
Maybe someone faced such a task?