{-# OPTIONS_GHC -fno-warn-incomplete-patterns #-}
{-# LANGUAGE ScopedTypeVariables #-}

module HaskellWorks.Data.RankSelect.Base.Rank1Spec
  ( genRank1UpTo8Spec
  , genRank1UpTo16Spec
  , spec
  ) where

import           Data.Maybe
import           Data.Typeable
import qualified Data.Vector                                                as DV
import qualified Data.Vector.Storable                                       as DVS
import           Data.Word
import           HaskellWorks.Data.Bits.BitRead
import           HaskellWorks.Data.Bits.BitWise
import           HaskellWorks.Data.Bits.PopCount.PopCount1
import           HaskellWorks.Data.Positioning
import           HaskellWorks.Data.RankSelect.Base.Rank1
import           HaskellWorks.Data.RankSelect.Base.Select1
import           Test.Hspec
import           Test.QuickCheck

{-# ANN module ("HLint: ignore Redundant do" :: String) #-}
{-# ANN module ("HLint: ignore Reduce duplication"  :: String) #-}

genRank1UpTo8Spec :: forall s. (Typeable s, BitRead s, Rank1 s) => s -> Spec
genRank1UpTo8Spec _ = describe ("Generically up to 8 bits for " ++ show (typeOf (undefined :: s))) $ do
  it "rank1 10010010 over [0..8] should be 011122233" $ do
    let bs = fromJust (bitRead "10010010") :: s
    fmap (rank1 bs) [0..8] `shouldBe` [0, 1, 1, 1, 2, 2, 2, 3, 3]

genRank1UpTo16Spec :: forall s. (Typeable s, BitRead s, Rank1 s) => s -> Spec
genRank1UpTo16Spec _ = describe ("Generically up to 16 bits for " ++ show (typeOf (undefined :: s))) $ do
  it "rank1 11011010 00000000 over [0..9]" $ do
    let bs = fromJust $ bitRead "11011010 00000000" :: s
    fmap (rank1 bs) [0..16] `shouldBe` [0, 1, 2, 2, 3, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5]
  it "rank1 11011010 10000000 over [0..9]" $ do
    let bs = fromJust $ bitRead "11011010 10000000" :: s
    fmap (rank1 bs) [0..16] `shouldBe` [0, 1, 2, 2, 3, 4, 4, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6]

spec :: Spec
spec = describe "HaskellWorks.Data.RankSelect.InternalSpec" $ do
  genRank1UpTo8Spec (undefined :: Word8)
  genRank1UpTo8Spec (undefined :: Word16)
  genRank1UpTo8Spec (undefined :: Word32)
  genRank1UpTo8Spec (undefined :: Word64)
  genRank1UpTo8Spec (undefined :: [Word8])
  genRank1UpTo16Spec (undefined :: [Word8])
  genRank1UpTo8Spec (undefined :: [Word16])
  genRank1UpTo16Spec (undefined :: [Word16])
  genRank1UpTo8Spec (undefined :: [Word32])
  genRank1UpTo16Spec (undefined :: [Word32])
  genRank1UpTo8Spec (undefined :: [Word64])
  genRank1UpTo16Spec (undefined :: [Word64])
  genRank1UpTo8Spec (undefined :: DV.Vector Word8)
  genRank1UpTo16Spec (undefined :: DV.Vector Word8)
  genRank1UpTo8Spec (undefined :: DV.Vector Word16)
  genRank1UpTo16Spec (undefined :: DV.Vector Word16)
  genRank1UpTo8Spec (undefined :: DV.Vector Word32)
  genRank1UpTo16Spec (undefined :: DV.Vector Word32)
  genRank1UpTo8Spec (undefined :: DV.Vector Word64)
  genRank1UpTo16Spec (undefined :: DV.Vector Word64)
  genRank1UpTo8Spec (undefined :: DVS.Vector Word8)
  genRank1UpTo16Spec (undefined :: DVS.Vector Word8)
  genRank1UpTo8Spec (undefined :: DVS.Vector Word16)
  genRank1UpTo16Spec (undefined :: DVS.Vector Word16)
  genRank1UpTo8Spec (undefined :: DVS.Vector Word32)
  genRank1UpTo16Spec (undefined :: DVS.Vector Word32)
  genRank1UpTo8Spec (undefined :: DVS.Vector Word64)
  genRank1UpTo16Spec (undefined :: DVS.Vector Word64)
  describe "For Word8-Word64" $ do
    it "rank1 for Word16 and Word64 should give same answer for bits 0-7" $
      forAll (choose (0, 8)) $ \(i :: Count) (w :: Word8) ->
        rank1 w i == rank1 (fromIntegral w :: Word64) i
    it "rank1 for Word16 and Word64 should give same answer for bits 0-15" $
      forAll (choose (0, 16)) $ \(i :: Count) (w :: Word16) ->
        rank1 w i == rank1 (fromIntegral w :: Word64) i
    it "rank1 for Word32 and Word64 should give same answer for bits 0-31" $
      forAll (choose (0, 32)) $ \(i :: Count) (w :: Word32) ->
        rank1 w i == rank1 (fromIntegral w :: Word64) i
    it "rank1 for Word32 and Word64 should give same answer for bits 32-64" $
      forAll (choose (0, 32)) $ \(i :: Count) (v :: Word32) (w :: Word32) ->
        let v64 = fromIntegral v :: Word64 in
        let w64 = fromIntegral w :: Word64 in
        rank1 v i + popCount1 w == rank1 ((v64 .<. 32) .|. w64) (i + 32)
    it "rank1 and select1 for Word64 form a galois connection" $
      forAll (choose (0, 32)) $ \(i :: Count) (w :: Word32) -> 1 <= i && i <= popCount1 w ==>
        rank1 w (select1 w i) == i && select1 w (rank1 w (fromIntegral i)) <= fromIntegral i