The entire point of this is that it restores the ship to the original blueprint state.
You would need some kind of UI to go along with this in order to select a certain blueprint, and there would have to be some kind of system to where the final ship (after repairs) can\'t be more than, say, twice the mass of the existing (damaged) ship - that prevents someone from abusing this and building a small fighter, then telling the repair dock to build it a massive ship, and then just providing some power and some time, essentially getting a free titan.
That brings me to another point - any kind of repair dock should consume a heck of a lot of power, and should take more time to build the larger the ship is - say, 1 minute per mass up to 50, then one minute per 100 mass up to, say 5000, then 1 minute per 500 mass from 5000 upward. That makes a 5k mass ship take not quite 2 hours to fully reconstruct, and a 20k mass ship take just over two hours. There should also be a limit to how much time it takes to repair, and the limit should be about four hours. Anything over that would simply just not be worth the wait.