I am searching for an idiom for a chaotic and irregular bedroom. Consider a situation that your mother enters your bedroom and encounters with that scene. At that situation, what does she say?
She might say "This place is a tip!" or a "dump". (A tip being a rubbish dump, UK.) Or "What a shambles!"
I can think of several words, such as pigsty, but they are not actually idioms.
It is perhaps not "politically correct", but "It looks as though a bomb has gone off in here!" is a known saying.