Looks a bit like a slightly angrier version of an L-39.
It fills the same role for the Russians as the A-10 does for us. It’s actually pretty fearsome in the ground attack role though the A-10 is significantly better.
When the A-X competition that resulted in the A-10 was being let out for bidding, Northrop’s proposal had a similar idea of what would be a good ground attack aircraft. Some people think that Sukhoi’s design borrows considerably from it: https://en.wikipedia.org/wiki/Northrop_YA-9
https://www.popularmechanics.com/military/aviation/a24303/russia-sukhoi-su-25-a-10/