spring is what gives the car its ride height so my guess is most likely a spring (as long as the tire isnt flat or something isnt obviously bent or broken on that side). shock might need to be fixed too but its independent from what u explained.
Mine sits high on one side at the rear 2, but it has new struts, going to be doing the springs as well, hoping it sits flat then........
haha ya i just realized i said the wrong thing, i meant spring (its now edited). but ya as long as u have no broken components on the front left its the spring