Puff of smoke came BEFORE you turned on the a/c, right? And car was running fine, no stumbles or hesitation, temp a-ok.
ck the underside of your hood, too. see if there's any wet, oily type spray on the black paint of the hood. If so, waterpump going out, may be dripping, too, onto that all important opti.
So, from what you're saying, the a/c running great, but you lost power to a great extent. No, it's not normal. Belt or pulley seizing? That's a wild guess.
Others will chime in.