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

module HaskellWorks.Data.RankSelect.Base.Rank0Spec
  ( genRank0UpTo8Spec
  , genRank0UpTo16Spec
  , 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.PopCount0
import           HaskellWorks.Data.Positioning
import           HaskellWorks.Data.RankSelect.Base.Rank0
import           HaskellWorks.Data.RankSelect.Base.Select0
import           Test.Hspec
import           Test.QuickCheck

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

genRank0UpTo8Spec :: forall s. (Typeable s, BitRead s, Rank0 s) => s -> Spec
genRank0UpTo8Spec _ = describe ("Generically up to 8 bits for " ++ show (typeOf (undefined :: s))) $ do
  it "rank0 10010010 over [0..8] should be 001223445" $ do
    let bs = fromJust (bitRead "10010010") :: s
    fmap (rank0 bs) [0..8] `shouldBe` [0, 0, 1, 2, 2, 3, 4, 4, 5]

genRank0UpTo16Spec :: forall s. (Typeable s, BitRead s, Rank0 s) => s -> Spec
genRank0UpTo16Spec _ = describe ("Generically up to 16 bits for " ++ show (typeOf (undefined :: s))) $ do
  it "rank0 11011010 00000000 over [0..16]" $ do
    let bs = fromJust $ bitRead "11011010 00000000" :: s
    fmap (rank0 bs) [0..16] `shouldBe` [0, 0, 0, 1, 1, 1, 2, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]
  it "rank0 11011010 10000000 over [0..16]" $ do
    let bs = fromJust $ bitRead "11011010 10000000" :: s
    fmap (rank0 bs) [0..16] `shouldBe` [0, 0, 0, 1, 1, 1, 2, 2, 3, 3, 4, 5, 6, 7, 8, 9, 10]

spec :: Spec
spec = describe "HaskellWorks.Data.RankSelect.InternalSpec" $ do
  genRank0UpTo8Spec (undefined :: Word8)
  genRank0UpTo8Spec (undefined :: Word16)
  genRank0UpTo8Spec (undefined :: Word32)
  genRank0UpTo8Spec (undefined :: Word64)
  genRank0UpTo8Spec (undefined :: [Word8])
  genRank0UpTo16Spec (undefined :: [Word8])
  genRank0UpTo8Spec (undefined :: [Word16])
  genRank0UpTo16Spec (undefined :: [Word16])
  genRank0UpTo8Spec (undefined :: [Word32])
  genRank0UpTo16Spec (undefined :: [Word32])
  genRank0UpTo8Spec (undefined :: [Word64])
  genRank0UpTo16Spec (undefined :: [Word64])
  genRank0UpTo8Spec (undefined :: DV.Vector Word8)
  genRank0UpTo16Spec (undefined :: DV.Vector Word8)
  genRank0UpTo8Spec (undefined :: DV.Vector Word16)
  genRank0UpTo16Spec (undefined :: DV.Vector Word16)
  genRank0UpTo8Spec (undefined :: DV.Vector Word32)
  genRank0UpTo16Spec (undefined :: DV.Vector Word32)
  genRank0UpTo8Spec (undefined :: DV.Vector Word64)
  genRank0UpTo16Spec (undefined :: DV.Vector Word64)
  genRank0UpTo8Spec (undefined :: DVS.Vector Word8)
  genRank0UpTo16Spec (undefined :: DVS.Vector Word8)
  genRank0UpTo8Spec (undefined :: DVS.Vector Word16)
  genRank0UpTo16Spec (undefined :: DVS.Vector Word16)
  genRank0UpTo8Spec (undefined :: DVS.Vector Word32)
  genRank0UpTo16Spec (undefined :: DVS.Vector Word32)
  genRank0UpTo8Spec (undefined :: DVS.Vector Word64)
  genRank0UpTo16Spec (undefined :: DVS.Vector Word64)
  describe "Different word sizes give the same rank0" $ do
    it "when comparing Word16 and Word64 over bits 0-7" $
      forAll (choose (0, 8 :: Count)) $ \(i :: Count) (w :: Word8) ->
        rank0 w i == rank0 (fromIntegral w :: Word64) i
    it "when comparing Word16 and Word64 over bits 0-15" $ property $
      forAll (choose (0, 16 :: Count)) $ \(i :: Count) (w :: Word16) ->
        rank0 w i == rank0 (fromIntegral w :: Word64) i
    it "when comparing Word32 and Word64 over bits 0-31" $ property $
      forAll (choose (0, 32 :: Count)) $ \(i :: Count) (w :: Word32) ->
        rank0 w i == rank0 (fromIntegral w :: Word64) i
    it "when comparing Word32 and Word64 over bits 32-64" $ property $
      forAll (choose (0, 32 :: Count)) $ \(i :: Count) (v :: Word32) (w :: Word32) ->
        let v64 = fromIntegral v :: Word64 in
        let w64 = fromIntegral w :: Word64 in
        rank0 v i + popCount0 w == rank0 ((v64 .<. 32) .|. w64) (i + 32)
    it "when comparing select1 for Word64 form a galois connection" $ property $
      forAll (choose (0, 32 :: Count)) $ \(i :: Count) (w :: Word32) ->
        1 <= i && i <= popCount0 w ==>
          rank0 w (select0 w i) == i && select0 w (rank0 w (fromIntegral i)) <= fromIntegral i