Chunk loading and unloading

Okay so i want to unload chunks from a player if they are not looking in the direction of which those chunks are located but i also want to load the chunks that the player is see currently how would i go about this?

 

Before anyone else helps you, what code have you used in previous attempts?

 

nothing cause i cant come up with a way to find which chunk(s) the player is looking at

 

okay, get the player's facing direction and figure out what chunk they are currently in. Based on the direction, the x/z chunk coordinates will increase and/or decrease