{-# LANGUAGE FlexibleInstances #-}

module Hash where

import Types

import qualified Data.ByteString as B
import qualified Data.ByteString.Char8 as C8
import qualified Crypto.Hash as H

class Hashable a where
	hash :: a -> HashPointer

instance Hashable B.ByteString where
	-- Encodes the SHA256 using base16 format
	hash = HashPointer SHA256 . Val . C8.pack . show . sha256

instance Hashable Val where
	hash (Val v) = hash v

sha256 :: B.ByteString -> H.Digest H.SHA256
sha256 = H.hash

-- | Hash the concacenation of the hashes.
instance Hashable [HashPointer] where
	hash = hash . B.concat . map (val . hashValue)

instance Hashable a => Hashable (Activity a) where
	hash (Activity a (Just p) s) = hash [hash a, p, hash s]
	hash (Activity a Nothing s) = hash [hash a, hash s]

instance Hashable Entered where
	hash v = hash [hash (enteredData v), hash (echoData v)]

instance Hashable Seen where
	hash v = hash [hash (seenData v)]

instance Hashable Signature where
	hash (Signature s) = hash s