What's wrong with my door? ?

ight soo a few weeks ago I got robbed and thts not the problem the problem is dat my door won't close now I mean I do miss my tv and my xbox but mane I can't even close da door like last nite I had a couple ladies ova at da apartment and I was tryin to do my thang but da door wouldn't close I went to home depot and da guy said it sound like I need a new sprocket what da hell is a sprocket? Soo I google sprocket and a tommy gun came up I was like aww hell naw dis ***** wanna go to war soo I show up to home depot da next day wit my cuzins and we shoot da place up but now I don't now what a sprocket is somebody help me