Unfortunately, Turkey did a political Blunder by Acquiring the S-400. Turkey had the option of buying F-35 but after S-400. I don't think so that US will give any country which Operates S-400.
The problem is that the US isn’t going to give the F-35 to a country that buys large amounts of Russian military equipment. I mean, they wouldn’t even allow for Turkey, a NATO ally, to get the F-35 because of the whole S-400 or F-35 issue and Turkey was even helping in funding and getting/making parts for the F-35 project.
Turkey had no other option left and hence they decided to go for S-400 and signed a contract with Russia for the S-400 air defence system in April 2017. Unfortunately now ,I don't think so that Turkey can use these S-400. I had heard news that Turkey's S-400 are just lying Idle.
Now after S-400 , Turkey has decided that it will develop an Indigenous Air Defense System for itself.