I think whoever installed the drain in my shower used parts for a kitchen sink. Help!

[amateurplumber]

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.

 

[Mr_David]

It looks right. That is a Tubular tub waste and overflow with a tubular trap
Replace it with an all glue fitting type including the p-trap.
Slip joint tubular is easier to install but to many joints can loosen up and fail.

don't get the ones with the cable that operates the drain plug. You'll just be replacing it again down the road.

search tub waste and overflow. tons of stuff to filter through.

 

[amateurplumber]

Thanks! The drain/flange seem to be either plastic or extremely flimsy metal. I do see the pvc it is on is threaded, though. Should i just break off the column thing and then use the tool I bought to unscrew the flange and just replace that? I just cant understand how this is even allowed, though...I just built a shower and the diameter of the pvc i used is larger and there's actually space for the water to drain. If you look at the photos, there's maybe a 1/2" under it for water to escape.