How long does it take for apple to repair a phone?

I have to send my iPhone 6 in for repairs. I dropped it in water and the right side of the screen is fading and twitching black, and the power button doesn't work (although the home button does and I can turn it on). Approximately how long would it take for me to get it back?

Depends on lots of things.

Shipping method and distance
Degree of damage
Acquiring parts if they're not in stock
Workload
Availability of technicians