A321 pilot reported increasing engine vibration in cruise and an engine stall message displayed. Flight crew performed inflight engine shutdown; diverted and landed safely.

Narrative

In Cruise at FL 320 we had an advisory on the N2 Vib indication; flashing at 4.7; as I was reaching for my QRH to look up the engine advisory information; an ECAM message was displayed; ENG 1 Stall. We followed the ECAM procedures and immediately declared an emergency and requested a lower altitude. At an initial altitude of FL 240; we realized that we needed lower due to aircraft performance and descended to FL 180. During the decent with the #1 engine at idle; engine parameters normal except for the N2 Vib in the 4-5 range. As we continued to run checklists the vibration increased to a limit where we made the decision to shut down the #1 engine. A call to dispatch was made to notify them of our situation and our diversion airport and requested WX and Notams. Flight Attendants briefed and passengers notified. A normal landing with ARFF present in ZZZ and requested ARFF to follow us to the gate as well. Logbook entries made for inflight shutdown of the #1 engine and overweight landing. Overweight; wet runways and possible ice accretion is why we decided on ZZZ. More available runway length.