module Data.Array.Parallel.PArray (
  PArray, Elt, Random(..),

  length, empty, replicate, singleton,
  zip, unzip, enumFromTo, fromList, nf
) where

import Data.Array.Parallel.Lifted.PArray
import Data.Array.Parallel.Lifted.Instances
import Data.Array.Parallel.Lifted.Combinators
import Data.Array.Parallel.Lifted.Prim
import qualified Data.Array.Parallel.Unlifted as U

import Data.Array.Parallel.Base ( showsApp )

import qualified System.Random as R

import Prelude hiding ( length, replicate, zip, unzip, enumFromTo )

class Elt a where
  pa :: PA a

instance Elt Int where
  pa = dPA_Int

instance Elt Double where
  pa = dPA_Double

instance (Elt a, Elt b) => Elt (a,b) where
  pa = dPA_2 pa pa

instance (Elt a, Elt b, Elt c) => Elt (a,b,c) where
  pa = dPA_3 pa pa pa

instance (Elt a, Elt b, Elt c, Elt d) => Elt (a,b,c,d) where
  pa = dPA_4 pa pa pa pa

instance (Elt a, Elt b, Elt c, Elt d, Elt e) => Elt (a,b,c,d,e) where
  pa = dPA_5 pa pa pa pa pa

length :: Elt a => PArray a -> Int
{-# INLINE length #-}
length = lengthPA_v pa

empty :: Elt a => PArray a
{-# INLINE empty #-}
empty = emptyPA pa

replicate :: Elt a => Int -> a -> PArray a
{-# INLINE replicate #-}
replicate = replicatePA_v pa

singleton :: Elt a => a -> PArray a
{-# INLINE singleton #-}
singleton = singletonPA_v pa

zip :: (Elt a, Elt b) => PArray a -> PArray b -> PArray (a,b)
{-# INLINE zip #-}
zip = zipPA_v pa pa

unzip :: (Elt a, Elt b) => PArray (a,b) -> (PArray a, PArray b)
{-# INLINE unzip #-}
unzip = unzipPA_v pa pa

enumFromTo :: Int -> Int -> PArray Int
{-# INLINE enumFromTo #-}
enumFromTo = enumFromToPA_v

fromList :: Elt a => [a] -> PArray a
{-# INLINE fromList #-}
fromList = fromListPA pa

toList :: Elt a => PArray a -> [a]
toList xs = [indexPA_v pa xs i | i <- [0 .. length xs - 1]]

nf :: Elt a => PArray a -> ()
nf = nfPA pa

instance (Elt a, Show a) => Show (PArray a) where
  showsPrec n xs = showsApp n "fromList<PArray>" (toList xs)

class Random a where
  randoms  :: R.RandomGen g => Int -> g -> PArray a
  randomRs :: R.RandomGen g => Int -> (a, a) -> g -> PArray a

prim_randoms :: (PrimPA a, R.Random a, R.RandomGen g) => Int -> g -> PArray a
prim_randoms n = fromUArrPA' . U.randoms n

prim_randomRs :: (PrimPA a, R.Random a, R.RandomGen g) => Int -> (a, a) -> g -> PArray a
prim_randomRs n r = fromUArrPA' . U.randomRs n r

instance Random Int where
  randoms = prim_randoms
  randomRs = prim_randomRs

instance Random Double where
  randoms = prim_randoms
  randomRs = prim_randomRs