{-# LANGUAGE FlexibleContexts #-}
module Graphics.Image.Interface.VectorSpec (spec) where

import           Graphics.Image.ColorSpace
import           Graphics.Image.Interface        as I
import           Graphics.Image.Interface.Vector as I
import           Graphics.Image.InterfaceSpec    ()
import           Test.Hspec
import           Test.QuickCheck

prop_fromToIx :: Positive Int -> (NonNegative Int, NonNegative Int) -> Bool
prop_fromToIx (Positive n) (NonNegative i, NonNegative j) =
  (i, j `mod` n) == toIx n (fromIx n (i, j `mod` n))

prop_toFromIx :: Positive Int -> NonNegative Int -> Bool
prop_toFromIx (Positive n) (NonNegative k) = k == fromIx n (toIx n k)

prop_doubleTranspose :: Image VU Y Word8 -> Bool
prop_doubleTranspose img = I.transpose (I.transpose img) == img


spec :: Spec
spec = do
  describe "Vector Index Properties" $ do
    it "fromToIx" $ property $ prop_fromToIx
    it "toFromIx" $ property $ prop_toFromIx
  describe "Interface Properties" $ do
    it "transpose . transpose" $ property prop_doubleTranspose