doesn't look too good...electrical things just won't work without their smoke, and once the smoke escapes it's nearly impossible to put it back in.
starters are usually bolt-off/bolt-on. Slight possibility it could be rebuilt -- that's a lot cheaper than new, just look for a starter/alternator rebuild shop in your area.
Don't rule out the possibility that the solenoid burned up & saved the starter. couple ways to figure it out...measure the voltage at the starter motor terminal with key turned to "start" -- if you get 12V (plus or minus half a volt or so) then the starter is bad; but if there's no voltage at the starter and the solenoid is clicking, replace the solenoid. No voltmeter, you can always just use a jumper cable to power the starter directly from the battery -- just be prepared for a spark shower.
I won't even ask about how it happened..........

almost forgot: once you get it running, ya might want to make sure your battery is still charging, on the chance that you blew out the rectifier -- kinda doubt it though.