2000 Toyota Celica Ran out of oil

My car was making a little pinging noise for about 3 weeks, then the noise got really bad. So I decided to take it to the shop to find out that I'm an idiot. My car had 1 quart(maybe) of oil in it, including what was drained from the oil filter itself. They changed the oil and added lucas. The noise has almost gone away, but there is some light pinging when the car is idling. Is my engine ruined? I haven't been driving it b/c I assume it will go out any day now.

The mechanic said he thought the loud noise was actually the chain on the timing belt, because there was so little oil in the car that there was not enough oil pressure to keep it tight.