I think whoever installed the drain in my shower used parts for a kitchen sink. How do I fix it?

[Amateurplumber1]

I noticed there was a small leak in the ceiling so I removed the access panel for my tub/shower that said genius (thankfully) installed and everything looks wrong. I narrowed down (pretty sure) the leak to water getting behind the flange in my tub drain. I have a lot of experience with plumbing so I dont think this should be too difficult and the ceiling is already kind of messed up so I don't mind opening it up, but...can anyone verify what the hell is actually going on?

I'd really appreciate any tips or advice! Here are some pics of this disaster. I'm really not sure how water was even able to drain properly with it being set up the way it is. Thanks a ton.

 

[Dj2]

Try tightening the 4 nuts with an adjustable wrench after you verify that they all have slip joint rings inside in the right direction. Also make sure it's properly vented.

OR...since the set up is in a concealed place, replace your set up with a trap that you glue without slip joints.