Hmm yeah i'm going with tie as well .
Oda will make it like that to show how much Luffy has grown , also i don't know if Shanks would fight him seriously tbh
Shanks I Emperor with power and crew to stop Kaido, War at Marineford and all pirates that dare to fight him. He should be close or equall to Whitebeards strenght.
In friendly match Shanks would not kill Luffy but beat him up pretty bad, as enemies there is a big chance that Luffy would get wrecked in not so long time. I believe that Luffy is stil below Admiral level of strenght as it is for now, Shanks seems as strong as them if not stronger by some margin.
Shanks is clear winner.