{-# LANGUAGE CPP #-}
#if __GLASGOW_HASKELL__ >= 702
{-# LANGUAGE Trustworthy #-}
#endif

-- |
-- Module      : Data.ByteString.Base64
-- Copyright   : (c) 2010 Bryan O'Sullivan
--
-- License     : BSD-style
-- Maintainer  : Emily Pillmore <emilypi@cohomolo.gy>,
--               Herbert Valerio Riedel <hvr@gnu.org>,
--               Mikhail Glushenkov <mikhail.glushenkov@gmail.com>
-- Stability   : experimental
-- Portability : GHC
--
-- Fast and efficient encoding and decoding of base64-encoded strings.
--
-- @since 0.1.0.0
module Data.ByteString.Base64
  ( encode
  , decode
  , decodeLenient
  ) where

import Data.ByteString.Base64.Internal
import qualified Data.ByteString as B
import Data.ByteString.Internal (ByteString(..))
import Data.Word (Word8)
import Foreign.ForeignPtr (ForeignPtr)

-- | Encode a string into base64 form.  The result will always be a
-- multiple of 4 bytes in length.
encode :: ByteString -> ByteString
encode :: ByteString -> ByteString
encode ByteString
s = Padding -> EncodeTable -> ByteString -> ByteString
encodeWith Padding
Padded (ByteString -> EncodeTable
mkEncodeTable ByteString
alphabet) ByteString
s

-- | Decode a base64-encoded string. This function strictly follows
-- the specification in
-- <http://tools.ietf.org/rfc/rfc4648 RFC 4648>.
--
-- (Note: this means that even @"\\n"@ and @"\\r\\n"@ as line breaks are rejected
-- rather than ignored.  If you are using this in the context of a
-- standard that overrules RFC 4648 such as HTTP multipart mime bodies,
-- consider using 'decodeLenient'.)
decode :: ByteString -> Either String ByteString
decode :: ByteString -> Either String ByteString
decode ByteString
s = Padding
-> ForeignPtr Word8 -> ByteString -> Either String ByteString
decodeWithTable Padding
Padded ForeignPtr Word8
decodeFP ByteString
s

-- | Decode a base64-encoded string.  This function is lenient in
-- following the specification from
-- <http://tools.ietf.org/rfc/rfc4648 RFC 4648>, and will not
-- generate parse errors no matter how poor its input.
decodeLenient :: ByteString -> ByteString
decodeLenient :: ByteString -> ByteString
decodeLenient ByteString
s = ForeignPtr Word8 -> ByteString -> ByteString
decodeLenientWithTable ForeignPtr Word8
decodeFP ByteString
s

alphabet :: ByteString
alphabet :: ByteString
alphabet = [Word8] -> ByteString
B.pack ([Word8] -> ByteString) -> [Word8] -> ByteString
forall a b. (a -> b) -> a -> b
$ [Word8
65..Word8
90] [Word8] -> [Word8] -> [Word8]
forall a. [a] -> [a] -> [a]
++ [Word8
97..Word8
122] [Word8] -> [Word8] -> [Word8]
forall a. [a] -> [a] -> [a]
++ [Word8
48..Word8
57] [Word8] -> [Word8] -> [Word8]
forall a. [a] -> [a] -> [a]
++ [Word8
43,Word8
47]
{-# NOINLINE alphabet #-}

decodeFP :: ForeignPtr Word8
#if MIN_VERSION_bytestring(0,11,0)
BS ForeignPtr Word8
decodeFP Int
_ =
#else
PS decodeFP _ _ =
#endif
  [Word8] -> ByteString
B.pack ([Word8] -> ByteString) -> [Word8] -> ByteString
forall a b. (a -> b) -> a -> b
$ Int -> Word8 -> [Word8]
forall a. Int -> a -> [a]
replicate Int
43 Word8
forall a. Integral a => a
x
    [Word8] -> [Word8] -> [Word8]
forall a. [a] -> [a] -> [a]
++ [Word8
62,Word8
forall a. Integral a => a
x,Word8
forall a. Integral a => a
x,Word8
forall a. Integral a => a
x,Word8
63]
    [Word8] -> [Word8] -> [Word8]
forall a. [a] -> [a] -> [a]
++ [Word8
52..Word8
61]
    [Word8] -> [Word8] -> [Word8]
forall a. [a] -> [a] -> [a]
++ [Word8
forall a. Integral a => a
x,Word8
forall a. Integral a => a
x,Word8
forall a. Integral a => a
x,Word8
forall a. Integral a => a
done,Word8
forall a. Integral a => a
x,Word8
forall a. Integral a => a
x,Word8
forall a. Integral a => a
x]
    [Word8] -> [Word8] -> [Word8]
forall a. [a] -> [a] -> [a]
++ [Word8
0..Word8
25]
    [Word8] -> [Word8] -> [Word8]
forall a. [a] -> [a] -> [a]
++ [Word8
forall a. Integral a => a
x,Word8
forall a. Integral a => a
x,Word8
forall a. Integral a => a
x,Word8
forall a. Integral a => a
x,Word8
forall a. Integral a => a
x,Word8
forall a. Integral a => a
x]
    [Word8] -> [Word8] -> [Word8]
forall a. [a] -> [a] -> [a]
++ [Word8
26..Word8
51]
    [Word8] -> [Word8] -> [Word8]
forall a. [a] -> [a] -> [a]
++ Int -> Word8 -> [Word8]
forall a. Int -> a -> [a]
replicate Int
133 Word8
forall a. Integral a => a
x
{-# NOINLINE decodeFP #-}

x :: Integral a => a
x :: forall a. Integral a => a
x = a
255
{-# INLINE x #-}