{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE Trustworthy         #-}
module Network.Tox.Crypto.KeySpec where

import           Test.Hspec
import           Test.QuickCheck

import qualified Crypto.Saltine.Class     as Sodium
import           Data.Binary              (Binary)
import           Data.ByteString          (ByteString)
import qualified Data.ByteString          as ByteString
import qualified Data.MessagePack.Result  as R
import           Data.Proxy               (Proxy (..))
import           Data.Typeable            (Typeable)
import qualified Network.Tox.Binary       as Binary
import           Network.Tox.Crypto.Key   (Key (..))
import qualified Network.Tox.Crypto.Key   as Key
import           Network.Tox.EncodingSpec
import qualified Text.Read                as Read


readMaybe :: String -> Maybe Key.PublicKey
readMaybe = Read.readMaybe


decodeM :: Monad m => ByteString -> m Key.PublicKey
decodeM = Key.decode


keyToInteger :: String -> Integer
keyToInteger string =
  Key.keyToInteger (read string :: Key.PublicKey)


encodeDecodePublicKey :: Key.PublicKey -> Expectation
encodeDecodePublicKey key =
  Sodium.decode (Sodium.encode key) `shouldBe` Just key


localEncodingSpec
  :: (Typeable a, Read a, Show a, Binary a, Arbitrary a, Eq a)
  => Proxy a -> Spec
localEncodingSpec proxy =
  describe (Binary.typeName proxy) $ do
    binarySpec proxy
    readShowSpec proxy


spec :: Spec
spec = do
  -- PublicKey for RPC tests.
  rpcSpec (Proxy :: Proxy Key.PublicKey)

  -- All others only local tests.
  localEncodingSpec (Proxy :: Proxy Key.CombinedKey)
  localEncodingSpec (Proxy :: Proxy Key.Nonce)
  localEncodingSpec (Proxy :: Proxy Key.PublicKey)
  localEncodingSpec (Proxy :: Proxy Key.SecretKey)

  describe "IsEncoding" $
    it "decodes encoded public keys correctly" $
      property encodeDecodePublicKey

  describe "read" $ do
    it "decodes valid hex string to PublicKey" $
      let
        actual = readMaybe "\"0100000000000000000000000000000000000000000000000000000000000010\""
        Just expected = Sodium.decode $ ByteString.pack [1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0x10]
      in
      actual `shouldBe` (Just $ Key expected)

    it "decodes empty string to Nothing" $ do
      let actual = readMaybe ""
      actual `shouldBe` Nothing
      case decodeM ByteString.empty of
        R.Failure msg -> msg `shouldStartWith` "unable to decode"
        R.Success val -> expectationFailure $ "unexpected success: " ++ show val

    it "decodes valid hex string of wrong length to Nothing" $
      let actual = readMaybe "\"0110\"" in
      actual `shouldBe` Nothing

  describe "keyToInteger" $ do
    it "converts keys to Integer in big endian" $ do
      keyToInteger "\"fe00000000000000000000000000000000000000000000000000000000000000\""
        `shouldBe`  0xfe00000000000000000000000000000000000000000000000000000000000000
      keyToInteger "\"00000000000000000000000000000000000000000000000000000000000000fe\""
        `shouldBe`  0x00000000000000000000000000000000000000000000000000000000000000fe

    it "encodes all keys to positive Integers" $
      property $ \key ->
        Key.keyToInteger (key :: Key.PublicKey) `shouldSatisfy` (0 <=)