module Data.SortingNetwork.ComparesSpec (
  spec,
) where

import Control.Monad
import Control.Monad.ST
import Data.SortingNetwork.Compares (oddEvenMerge, optimal)
import Data.SortingNetwork.MutableVector (unsafeSortBy)
import Data.SortingNetwork.Types (MkPairs)
import Data.SortingNetwork.Common (isSorted)
import qualified Data.Vector as V
import Test.Hspec

sortViaVector :: Ord a => MkPairs -> [a] -> [a]
sortViaVector mkPairs xs = runST do
  v <- V.unsafeThaw (V.fromList xs)
  unsafeSortBy mkPairs compare v
  vFin <- V.unsafeFreeze v
  pure $ V.toList vFin

{-
  TODO: test is now disabled - end-to-end testing with TH is faster as there are no vector overhead.
  plus we are getting almost the same coverage - we just need to verify that the sequence of compare-and-swap
  operation does sort.
 -}
spec :: Spec
spec = when False do
  forM_
    [ ("optimal", optimal)
    , ("oddEvenMerge", oddEvenMerge)
    ]
    \(tag, mkPairs) ->
      describe tag do
        describe "0-1 principle" do
          forM_ [2 .. 16] \n -> specify ("n = " <> show n) do
            let inputs :: [] [Bool]
                inputs = replicateM n [False, True]
            forM_ inputs \inp ->
              sortViaVector mkPairs inp `shouldSatisfy` isSorted