Wait until 2030, but the main question is: What's the point? If an AI is capable of doing this, then it can also "generate" movies ad-hoc, so each movie is customized to individuals. I personally think that would result in so many alternate realities that the human race cannot handle.
possible right now. Training data is film transcript + online reviews. 1000s if not 10000s of reviews available per film. Plug novel transcript into model, spit out review predictions!