Go Web Server for Remotely Powering on a Desktop Computer with a Raspberry Pi
hjr265.me
hjr265.me
So the first post the author made starts with bad assumptions and leads to needless engineering. Cool project, nonetheless.
If you're in the OS, both of those solutions are easy. The machine can be in a suspended or powered off state. Presumably you could WoL it, remote in, then do whatever you wish.
A remote shutdown sounds like a return of Back Orifice.
So hard power off = shutdown, reset = restart?