{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE ScopedTypeVariables #-}

module Test.Hashing where

import Control.Monad (void)

import qualified Data.ByteString.Unsafe as BS
import Foreign hiding (void)
import Foreign.C
import LibSodium.Bindings.GenericHashing (cryptoGenericHash, cryptoGenericHashBytes)
import qualified Sel.Hashing as Hashing
import Test.Tasty
import Test.Tasty.HUnit

spec :: TestTree
spec =
  testGroup
    "Generic hashing tests"
    [ testCase "cryptoGenericHash without key" testCryptoGenericHashWithoutKey
    , testCase "cryptoGenericHash with key" testCryptoGenericHashWithKey
    , testCase "Multi-part hashing" testMultipartHahsing
    ]

testCryptoGenericHashWithoutKey :: Assertion
testCryptoGenericHashWithoutKey = do
  expected <- Hashing.hashToHexByteString <$> Hashing.hashByteString Nothing "test test"
  assertEqual
    "Hashed test string is consistent without key"
    expected
    "7f3dc1170e7017a1643d84d102429c4c7aec4ca99c016c32af18af997fed51f1"

testCryptoGenericHashWithKey :: Assertion
testCryptoGenericHashWithKey =
  let key = "af7d1575690407317bf93723a8d1dca5"
      msg = "Test Test" :: String
   in withCStringLen msg $ \(cString, cstringLength) ->
        allocaBytes (fromIntegral cryptoGenericHashBytes) $ \outPtr ->
          BS.unsafeUseAsCStringLen key $ \(keyPtr, keyLength) -> do
            void $
              cryptoGenericHash
                outPtr
                cryptoGenericHashBytes
                (castPtr cString :: Ptr CUChar)
                (fromIntegral cstringLength)
                (castPtr keyPtr)
                (fromIntegral keyLength)
            out <- peekCStringLen (castPtr outPtr, cstringLength)
            assertEqual
              "Hashed test string is consistent with key"
              "<|1"
              out

testMultipartHahsing :: Assertion
testMultipartHahsing = do
  hashKey <- Hashing.newHashKey
  expectedHash <- Hashing.hashByteString (Just hashKey) "test test"
  actualHash <- Hashing.withMultipart (Just hashKey) $ \multipartState -> do
    let message1 = "test "
    Hashing.updateMultipart multipartState message1
    let message2 = "test"
    Hashing.updateMultipart multipartState message2
  assertEqual
    "Hash remains the same when using multipart"
    (Hashing.hashToHexByteString expectedHash)
    (Hashing.hashToHexByteString actualHash)