module Quipper103 where
import System.Random
import Quipper
import Quipper.Libraries.Simulation

c_r :: Int -> [Qubit] -> Qubit -> Circ ([Qubit], Qubit)
c_r k [] q = return ([], q)
c_r k (x:xs) q = do
  q <- rGate k q `controlled` x
  (xs, q) <- c_r (k+1) xs q
  return (x:xs, q)


phi_a :: [Qubit] -> Qubit -> Circ ([Qubit], Qubit)
phi_a qs q = do
  q <- hadamard q
  (qs, q) <- c_r 2 qs q
  return (qs, q)


phiCirc = print_generic Preview phi_a [qubit, qubit, qubit, qubit, qubit, qubit, qubit] qubit

qft :: [Qubit] -> Circ [Qubit]
qft [] = return []
qft (x:xs) = do
  (xs, x) <- phi_a xs x
  xs <- qft xs
  return (x:xs)

qftCirc = print_generic Preview qft $ replicate 5 qubit

qftAdder :: [Qubit] -> [Qubit] -> Circ ([Qubit], [Qubit])
qftAdder as bs = 
  with_computed qft' cbs
  where qft' = do
          as <- qft as
          return (as, bs)
        cbs ([], []) = return ([], [])
        cbs (a:as', b:bs') = do
          (b:bs', a) <- c_r 1 (b:bs') a
          (as', bs') <- cbs (as', bs')
          return (a:as', b:bs')

qftAdderCirc = print_generic Preview qftAdder (replicate 5 qubit) (replicate 5 qubit)

testQFTAdder :: IO ()
testQFTAdder = do 
  g <- newStdGen
  let x = sim_generic (0.0 :: Double) qftAdder [False, True, True, True] [False, True, True, True]
  putStrLn $ show x