1996 Mercury Tracer is it the alternator?

1996 Mercury Tracer 4 cyl Automatic 128800 miles

i was driving my car today and all of a sudden the rpm gauge, radio, and heat just quit on me. Then started working. When I left to go home, the car lights dimmed, inside and out, the battery light, and check engine light, and airbag light came on, then all of the lights went out and the car died. Is it the alternator or the crank shaft, or the battery?