{-# LANGUAGE BangPatterns #-}
{-# LANGUAGE MagicHash #-}
{-# LANGUAGE OverloadedStrings #-}
-- |
-- Module       : Data.ByteString.Base16
-- Copyright 	: (c) 2020 Emily Pillmore
-- License	: BSD-style
--
-- Maintainer	: Emily Pillmore <emilypi@cohomolo.gy>
-- Stability	: Experimental
-- Portability	: portable
--
-- This module contains the combinators implementing the
-- RFC 4648 specification for the Base16 encoding including
-- unpadded and lenient variants
--
module Data.ByteString.Base16
( encodeBase16
, encodeBase16'
, decodeBase16
, isBase16
, isValidBase16
) where


import Data.ByteString (ByteString)
import Data.ByteString.Base16.Internal
import Data.ByteString.Base16.Internal.Head
import Data.Either
import Data.Text (Text)
import qualified Data.Text.Encoding as T


-- | Encode a 'ByteString' value as Base16 'Text' with padding.
--
-- See: <https://tools.ietf.org/html/rfc4648#section-4 RFC-4648 section 4>
--
encodeBase16 :: ByteString -> Text
encodeBase16 = T.decodeUtf8 . encodeBase16'
{-# INLINE encodeBase16 #-}

-- | Encode a 'ByteString' value as a Base16 'ByteString'  value with padding.
--
-- See: <https://tools.ietf.org/html/rfc4648#section-4 RFC-4648 section 4>
--
encodeBase16' :: ByteString -> ByteString
encodeBase16' = encodeBase16_
{-# INLINE encodeBase16' #-}

-- | Decode a padded Base16-encoded 'ByteString' value.
--
-- See: <https://tools.ietf.org/html/rfc4648#section-4 RFC-4648 section 4>
--
decodeBase16 :: ByteString -> Either Text ByteString
decodeBase16 = decodeBase16_
{-# INLINE decodeBase16 #-}

-- | Tell whether a 'ByteString' value is base16 encoded.
--
isBase16 :: ByteString -> Bool
isBase16 bs = isValidBase16 bs && isRight (decodeBase16 bs)
{-# INLINE isBase16 #-}

-- | Tell whether a 'ByteString' value is a valid Base16 format.
--
-- This will not tell you whether or not this is a correct Base16 representation,
-- only that it conforms to the correct shape. To check whether it is a true
-- Base16 encoded 'ByteString' value, use 'isBase16'.
--
isValidBase16 :: ByteString -> Bool
isValidBase16 = validateBase16 "0123456789abcdef"
{-# INLINE isValidBase16 #-}