Suggestion: Integrated Sleep/Shutdown Timer
Flux is great for helping with sleep, and Nightshift doesn't begin to compare.
However, I haven't been able to find a good method or app to shutdown/sleep my Mac at the end of a movie.
My suggestion is to integrate a shutdown/sleep function into video players (I use VLC). When the file ends, the screen of computer turn off, allowing peaceful, uninterrupted and light free sleep.