Can a ac unit be installed in a 2002 ford focus that came without one?

I bought a 2002 ford focus that was advertised as having ac.

I bought it from a mechanic who has other focus's that he could pull one out of.

Is this something a resourceful mechanic could do?

I really like this car and would like to keep it.Can a ac unit be installed in a 2002 ford focus that came without one?it is something a mechanic should be able to do