What happened?

So I asked for your theories on the storyline. This time I'm going to ask, what happened to the animatronics? In the first restaurant there were two, SpringTrap and Golden Freddy. What happened to cause them to get bought and replaced? Also what did they do to SpringTrap and why not keep him but keep Golden Freddy? And how has SpringTrap survived 30 years? Also how come Foxy is out of order? And why is his jaw hinges damaged? Answer me as to what happened to them!