{-# LANGUAGE OverloadedStrings #-}
-- |
-- Module       : Data.Text.Encoding.Base32.Hex
-- Copyright 	: (c) 2019 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 Base32-Hex encoding including
-- unpadded and lenient variants
module Data.Text.Encoding.Base32.Hex
( encodeBase32
, decodeBase32
, encodeBase32Unpadded
, decodeBase32Unpadded
-- , decodeBase32Lenient
, isBase32Hex
, isValidBase32Hex
) where


import qualified Data.ByteString.Base32.Hex as B32U

import Data.Text (Text)
import qualified Data.Text.Encoding as T

-- | Encode a 'Text' value in Base32hex with padding.
--
-- See: <https://tools.ietf.org/html/rfc4648#section-5 RFC-4648 section 5>
--
encodeBase32 :: Text -> Text
encodeBase32 = B32U.encodeBase32 . T.encodeUtf8
{-# INLINE encodeBase32 #-}

-- | Decode a padded Base32hex-encoded 'Text' value.
--
-- See: <https://tools.ietf.org/html/rfc4648#section-4 RFC-4648 section 4>
--
decodeBase32 :: Text -> Either Text Text
decodeBase32 = fmap T.decodeUtf8 . B32U.decodeBase32 . T.encodeUtf8
{-# INLINE decodeBase32 #-}

-- | Encode a 'Text' value in Base32hex without padding.
--
-- See: <https://tools.ietf.org/html/rfc4648#section-3.2 RFC-4648 section 3.2>
--
encodeBase32Unpadded :: Text -> Text
encodeBase32Unpadded = B32U.encodeBase32Unpadded . T.encodeUtf8
{-# INLINE encodeBase32Unpadded #-}

-- | Decode an arbitrarily padded Base32hex encoded 'Text' value
--
-- See: <https://tools.ietf.org/html/rfc4648#section-4 RFC-4648 section 4>
--
decodeBase32Unpadded :: Text -> Either Text Text
decodeBase32Unpadded = fmap T.decodeUtf8
    . B32U.decodeBase32Unpadded
    . T.encodeUtf8
{-# INLINE decodeBase32Unpadded #-}

-- -- -- | Leniently decode an unpadded Base32hex-encoded 'Text'. This function
-- -- -- will not generate parse errors. If input data contains padding chars,
-- -- -- then the input will be parsed up until the first pad character.
-- -- --
-- -- -- __Note:__ This is not RFC 4648-compliant.
-- -- --
-- -- decodeBase32Lenient :: Text -> Text
-- -- decodeBase32Lenient = T.decodeUtf8
-- --     . B32U.decodeBase32Lenient
-- --     . T.encodeUtf8
-- -- {-# INLINE decodeBase32Lenient #-}

-- | Tell whether a 'Text' value is Base32hex-encoded.
--
isBase32Hex :: Text -> Bool
isBase32Hex = B32U.isBase32Hex . T.encodeUtf8
{-# INLINE isBase32Hex #-}

-- | Tell whether a 'Text' value is a valid Base32hex format.
--
-- This will not tell you whether or not this is a correct Base32hex representation,
-- only that it conforms to the correct shape. To check whether it is a true
-- Base32 encoded 'Text' value, use 'isBase32Hex'.
--
isValidBase32Hex :: Text -> Bool
isValidBase32Hex = B32U.isValidBase32Hex . T.encodeUtf8
{-# INLINE isValidBase32Hex #-}