My question involves labor and employment law for the state of:Illinois

I work at a neighbourhood pool thats extremely corrupt. Everyone there is either high,hungover,or tipsy when their working. On many occasions I've seen people buying drugs there. I may have bought drugs there once. The head guard dislikes me and decided to get me fired for it. They said they're not firing me but they aren't going to give me any more hours to work(basically the same thing, right?)I never admitted to buying drugs and that head guard never actually saw me buy any drugs or anything. The head guard also once came there drunk(not when she was working)and her top fell off and she kept walking around. Is it legal for them to fire me based on hearsay? I would like to know if they did anything wrong so I can try and get my job back. I believe I have been wrongfully terminated.