{-# LANGUAGE ScopedTypeVariables #-}

module HaskellWorks.Data.EliasFanoSpec (spec) where

import Data.Word
import HaskellWorks.Data.AtIndex
import HaskellWorks.Data.EliasFano
import HaskellWorks.Hspec.Hedgehog
import Hedgehog
import Test.Hspec

import qualified Data.Vector.Storable                          as DVS
import qualified HaskellWorks.Data.PackedVector.PackedVector64 as PV
import qualified Hedgehog.Gen                                  as G
import qualified Hedgehog.Range                                as R

{-# ANN module ("HLint: Ignore Redundant do" :: String) #-}

spec :: Spec
spec = describe "HaskellWorks.Data.EliasFanoSpec" $ do
  it "List to EliasFano" $ requireTest $ do
    ws <- forAll $ pure $ [2, 3, 5, 7, 11, 13, 24]
    let actual = fromListWord64 ws
    let expected = EliasFano
          { efBucketBits  = DVS.fromList [4443]
          , efLoSegments  = PV.fromList 2 [2, 3, 1, 3, 3, 1, 0]
          , efLoBitCount  = 2
          , efCount       = 7
          }
    actual === expected
  it "hiSegment <-> bucketBits round trip" $ requireProperty $ do
    vs <- forAll $ G.list (R.linear 1 100) (G.word64 (R.linear 0 20))
    ws <- forAll $ pure $ drop 1 $ scanl (+) 0 vs
    maxW <- forAll $ pure $ last ws
    bucketBitsToHiSegment (hiSegmentToBucketBits maxW ws) === ws
  it "List to EliasFano" $ requireTest $ do
    ws <- forAll $ pure $ EliasFano
          { efBucketBits  = DVS.fromList [4443]
          , efLoSegments  = PV.fromList 2 [2, 3, 1, 3, 3, 1, 0]
          , efLoBitCount  = 2
          , efCount       = 7
          }
    let actual = toListWord64 ws
    let expected = [2, 3, 5, 7, 11, 13, 24]
    actual === expected
  it "List to EliasFano 2" $ requireTest $ do
    let ws =  [    0,    5,    6,   14,   20,   29,   39,   51
              ,   52,   60,   64,   71,   76,   87,   97,  103
              ,  122,  135,  233,  245,  657,  662,  663,  671
              ,  676,  684,  690,  701,  709,  725,  734,  755
              ,  783,  796,  834,  841,  842,  845,  855,  861
              ,  883,  888,  910,  917,  925,  936,  945,  962
              ,  982,  998, 1019, 1028, 1029, 1040, 1044, 1048
              , 1057, 1066, 1075, 1080, 1090, 1097, 1098, 1102
              , 1117, 1121, 1136, 1141, 1142, 1148, 1157, 1167
              , 1168, 1173, 1184, 1189, 1201, 1205, 1216, 1225
              , 1226, 1231, 1244, 1249, 1250, 1253, 1257, 1262
              , 1274, 1279, 1280, 1283, 1289, 1294, 1315, 1320
              , 1321, 1324, 1330, 1335, 1346, 1351, 1352, 1355
              , 1362, 1367, 1403, 1414, 1423, 1424, 1427, 1438
              , 1446, 1447, 1452, 1477, 1482, 1483, 1486, 1493
              , 1498, 1529, 1533, 1534, 1537, 1544, 1549, 1581
              ]
    let ef = fromListWord64 ws :: EliasFano
    _ <- forAll $ pure ef
    let actual = toListWord64 ef
    let expected = ws
    actual === expected
  it "Round trip" $ requireProperty $ do
    vs <- forAll $ G.list (R.linear 0 100) (G.word64 (R.linear 1 20))
    ws <- forAll $ pure $ drop 1 $ scanl (+) 0 vs
    ef :: EliasFano <- forAll $ pure $ fromListWord64 ws
    let actual = toListWord64 ef
    actual === (ws :: [Word64])
  it "atIndex" $ requireTest $ do
    ef <- forAll $ pure $ EliasFano
          { efBucketBits  = DVS.fromList [4443]
          , efLoSegments  = PV.fromList 2 [2, 3, 1, 3, 3, 1, 0]
          , efLoBitCount  = 2
          , efCount       = 7
          }
    let actual = fmap (atIndex ef) [0 .. end ef - 1]
    let expected = [2, 3, 5, 7, 11, 13, 24]
    actual === expected