Victim is gonna survive. He allegedly stole this kids visor (i'm assuming he did it), then stood there and chose to not fight or run. Not saying he deserved what he got, but he learned some valuable lessons that day.
As far as the assailant goes hes 17 and was on some overkill shyt. But what did he really do? Knock dude out and break his nose? Okay scare the fukk outta him, put him in a diversion program, have him pay some restitution. Don't send him to prison for some serious violent crime and turn him into a real savage. Even the time hes doing in jail with his current custody level is gonna fukk him up. There is some REAL psychos in there. And living around them will have you thinking thats normal after a while.
Honestly if this woulda happened in a secluded spot the reaction would not have been the same. Other kid woulda got up with a broken nose. Walked that shyt off. Took the L cuz he knows hes a thief. But because its on camera everyones

omg hes a brute.
its a 17 year old. Teach him his lesson. Don't make an example outta him.