import Stripe.Signature

-- base
import Control.Monad   (unless)
import Data.Foldable   (for_)
import Data.Word       (Word8)
import Numeric.Natural (Natural)
import System.Exit     (exitFailure)

-- base16-bytestring
import qualified Data.ByteString.Base16 as Base16

-- bytestring
import qualified Data.ByteString
import qualified Data.ByteString.Char8

-- stripe-concepts
import Stripe.Concepts (WebhookSecretKey (..))

-- text
import qualified Data.Text

data Failure = Failure String

main :: IO ()
main =
    unless (null failures) $ do
        for_ failures $ \(Failure x) -> putStrLn ("🔥 " ++ x)
        exitFailure

failures :: [Failure]
failures = parseFailures ++ validationFailures

parseFailures :: [Failure]
parseFailures =
    case parseSig (Data.Text.pack test_string) of
        Nothing -> [Failure "Signature parsing failed"]
        Just sig ->
            case sigTime sig == test_time of
                True -> []
                False -> [Failure $ "sigTime: " ++ show (sigTime sig)]
            ++
            case (Data.ByteString.unpack <$> sigV1 sig) == [test_v1Bytes] of
                True -> []
                False -> [Failure $ "sigV1: " ++ show (Data.ByteString.unpack <$> sigV1 sig)]

  where
    test_string :: String
    test_string =
        "t=1492774577,v1=5257a869e7ecebeda32affa62cdca3fa51cad7e\
        \77a0e56ff536d0ce8e108d8bd,v0=6ffbb59b2300aae63f27240606\
        \9a9788598b792a944a07aba816edb039989a39"

    test_time :: Natural
    test_time = 1492774577

    test_v1Bytes :: [Word8]
    test_v1Bytes =
        [82,87,168,105,231,236,235,237,163,42,255,166,44,220,163,250
        ,81,202,215,231,122,14,86,255,83,109,12,232,225,8,216,189]

validationFailures :: [Failure]
validationFailures =
    case Base16.decode (Data.ByteString.Char8.pack "f89c0a0e96fa6304a7ebd5ecaf13bc1beb859577cd7cafb7bdbc43c3bc2f6afa") of
        Left _ -> [Failure "Digest decoding failed"]
        Right d ->
            case isSigValid Sig{ sigTime = 123, sigV1 = [d] } (WebhookSecretKey (Data.ByteString.Char8.pack "secret")) (Data.ByteString.Char8.pack "hello") of
                True -> []
                False -> [Failure "isSigValid rejects a valid signature"]
            ++
            case isSigValid Sig{ sigTime = 123, sigV1 = [d] } (WebhookSecretKey (Data.ByteString.Char8.pack "secret")) (Data.ByteString.Char8.pack "hello!") of
                False -> []
                True -> [Failure "isSigValid accepts an invalid signature"]
            ++
            case isSigValid Sig{ sigTime = 123, sigV1 = [Data.ByteString.Char8.pack "whatever", d] } (WebhookSecretKey (Data.ByteString.Char8.pack "secret")) (Data.ByteString.Char8.pack "hello") of
                True -> []
                False -> [Failure "isSigValid should accept if *any* of the sigs are valid"]