    {-# LANGUAGE Trustworthy #-}
    -- |
    -- Module       : Data.Text.Short.Encoding.Base64.URL
    -- Copyright    : (c) 2019-2020 Emily Pillmore
    -- License      : BSD-style
    --
    -- Maintainer   : Emily Pillmore <emilypi@cohomolo.gy>
    -- Stability    : stable
    -- Portability  : non-portable
    --
    -- This module contains 'Data.Text.Short.ShortText'-valued combinators
    -- implementing the RFC 4648 specification for the Base64url
    -- encoding format. This includes strictly padded/unpadded and lenient
    -- decoding variants, and external + internal validations for canonicity.
    --
    module Data.Text.Short.Encoding.Base64.URL
    ( -- * Encoding
      encodeBase64
    , encodeBase64Unpadded
      -- * Decoding
    , decodeBase64
    , decodeBase64With
    , decodeBase64Unpadded
    , decodeBase64UnpaddedWith
    , decodeBase64Padded
    , decodeBase64PaddedWith
    , decodeBase64Lenient
      -- * Validation
    , isBase64Url
    , isValidBase64Url
    ) where

    import Data.Bifunctor (first)
    import qualified Data.ByteString.Base64.URL as B64U
    import Data.ByteString.Short (ShortByteString)
    import qualified Data.ByteString.Short.Base64.URL as BS64U
    import Data.Text (Text)
    import qualified Data.Text.Encoding.Base64.URL as B64TU
    import Data.Text.Encoding.Base64.Error
    import Data.Text.Short
    import Data.Text.Short.Unsafe

    -- | Encode a 'ShortText' value in Base64url with padding.
    --
    -- See: <https://tools.ietf.org/html/rfc4648#section-5 RFC-4648 section 5>
    --
    -- === __Examples__:
    --
    -- >>> encodeBase64 "<<?>>"
    -- "PDw_Pj4="
    --
    encodeBase64 :: ShortText -> ShortText
    encodeBase64 :: ShortText -> ShortText
    encodeBase64 = ByteString -> ShortText
    fromByteStringUnsafe
      (ByteString -> ShortText)
    -> (ShortText -> ByteString) -> ShortText -> ShortText
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . ByteString -> ByteString
    B64U.encodeBase64'
      (ByteString -> ByteString)
    -> (ShortText -> ByteString) -> ShortText -> ByteString
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . ShortText -> ByteString
    toByteString
    {-# INLINE encodeBase64 #-}

    -- | Decode a padded Base64url-encoded 'ShortText' value. If its length is not a multiple
    -- of 4, then padding chars will be added to fill out the input to a multiple of
    -- 4 for safe decoding as base64url encodings are optionally padded.
    --
    -- For a decoder that fails on unpadded input, use 'decodeBase64Unpadded'.
    --
    -- /Note:/ This function makes sure that decoding is total by deferring to
    -- 'T.decodeLatin1'. This will always round trip for any valid Base64-encoded
    -- text value, but it may not round trip for bad inputs. The onus is on the
    -- caller to make sure inputs are valid. If unsure, defer to `decodeBase64With`
    -- and pass in a custom decode function.
    --
    -- See: <https://tools.ietf.org/html/rfc4648#section-4 RFC-4648 section 4>
    --
    -- === __Examples__:
    --
    -- >>> decodeBase64 "PDw_Pj4="
    -- Right "<<?>>"
    --
    -- >>> decodeBase64 "PDw_Pj4"
    -- Right "<<?>>"
    --
    -- >>> decodeBase64 "PDw-Pg="
    -- Left "Base64-encoded bytestring has invalid padding"
    --
    -- >>> decodeBase64 "PDw-Pg"
    -- Right "<<>>"
    --
    decodeBase64 :: ShortText -> Either Text ShortText
    decodeBase64 :: ShortText -> Either Text ShortText
    decodeBase64 = (Text -> ShortText) -> Either Text Text -> Either Text ShortText
    forall a b. (a -> b) -> Either Text a -> Either Text b
    forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
    fmap Text -> ShortText
    fromText (Either Text Text -> Either Text ShortText)
    -> (ShortText -> Either Text Text)
    -> ShortText
    -> Either Text ShortText
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . Text -> Either Text Text
    B64TU.decodeBase64 (Text -> Either Text Text)
    -> (ShortText -> Text) -> ShortText -> Either Text Text
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . ShortText -> Text
    toText
    {-# INLINE decodeBase64 #-}

    -- | Attempt to decode a 'ShortByteString' value as Base64url, converting from
    -- 'ByteString' to 'ShortText' according to some encoding function. In practice,
    -- This is something like 'decodeUtf8'', which may produce an error.
    --
    -- See: <https://tools.ietf.org/html/rfc4648#section-4 RFC-4648 section 4>
    --
    -- === __Examples__:
    --
    -- @
    -- 'decodeBase64With' 'T.decodeUtf8''
    --   :: 'ShortByteString' -> 'Either' ('Base64Error' 'UnicodeException') 'ShortText'
    -- @
    --
    decodeBase64With
        :: (ShortByteString -> Either err ShortText)
          -- ^ convert a bytestring to text (e.g. 'T.decodeUtf8'')
        -> ShortByteString
          -- ^ Input text to decode
        -> Either (Base64Error err) ShortText
    decodeBase64With :: forall err.
    (ShortByteString -> Either err ShortText)
    -> ShortByteString -> Either (Base64Error err) ShortText
    decodeBase64With ShortByteString -> Either err ShortText
    f ShortByteString
    t = case ShortByteString -> Either Text ShortByteString
    BS64U.decodeBase64 ShortByteString
    t of
      Left Text
    de -> Base64Error err -> Either (Base64Error err) ShortText
    forall a b. a -> Either a b
    Left (Base64Error err -> Either (Base64Error err) ShortText)
    -> Base64Error err -> Either (Base64Error err) ShortText
    forall a b. (a -> b) -> a -> b
    $ Text -> Base64Error err
    forall e. Text -> Base64Error e
    DecodeError Text
    de
      Right ShortByteString
    a -> (err -> Base64Error err)
    -> Either err ShortText -> Either (Base64Error err) ShortText
    forall a b c. (a -> b) -> Either a c -> Either b c
    forall (p :: * -> * -> *) a b c.
    Bifunctor p =>
    (a -> b) -> p a c -> p b c
    first err -> Base64Error err
    forall e. e -> Base64Error e
    ConversionError (ShortByteString -> Either err ShortText
    f ShortByteString
    a)
    {-# INLINE decodeBase64With #-}

    -- | Encode a 'ShortText' value in Base64url without padding. Note that for Base64url,
    -- padding is optional. If you call this function, you will simply be encoding
    -- as Base64url and stripping padding chars from the output.
    --
    -- See: <https://tools.ietf.org/html/rfc4648#section-3.2 RFC-4648 section 3.2>
    --
    -- === __Examples__:
    --
    -- >>> encodeBase64Unpadded "<<?>>"
    -- "PDw_Pj4"
    --
    encodeBase64Unpadded :: ShortText -> ShortText
    encodeBase64Unpadded :: ShortText -> ShortText
    encodeBase64Unpadded = ByteString -> ShortText
    fromByteStringUnsafe
      (ByteString -> ShortText)
    -> (ShortText -> ByteString) -> ShortText -> ShortText
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . ByteString -> ByteString
    B64U.encodeBase64Unpadded'
      (ByteString -> ByteString)
    -> (ShortText -> ByteString) -> ShortText -> ByteString
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . ShortText -> ByteString
    toByteString
    {-# INLINE encodeBase64Unpadded #-}

    -- | Decode an unpadded Base64url encoded 'ShortText' value.
    --
    -- /Note:/ This function makes sure that decoding is total by deferring to
    -- 'T.decodeLatin1'. This will always round trip for any valid Base64-encoded
    -- text value, but it may not round trip for bad inputs. The onus is on the
    -- caller to make sure inputs are valid. If unsure, defer to `decodeBase64UnpaddedWith`
    -- and pass in a custom decode function.
    --
    -- See: <https://tools.ietf.org/html/rfc4648#section-4 RFC-4648 section 4>
    --
    -- === __Examples__:
    --
    -- >>> decodeBase64Unpadded "PDw_Pj4"
    -- Right "<<?>>"
    --
    -- >>> decodeBase64Unpadded "PDw_Pj4="
    -- Left "Base64-encoded bytestring has invalid padding"
    --
    decodeBase64Unpadded :: ShortText -> Either Text ShortText
    decodeBase64Unpadded :: ShortText -> Either Text ShortText
    decodeBase64Unpadded = (Text -> ShortText) -> Either Text Text -> Either Text ShortText
    forall a b. (a -> b) -> Either Text a -> Either Text b
    forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
    fmap Text -> ShortText
    fromText (Either Text Text -> Either Text ShortText)
    -> (ShortText -> Either Text Text)
    -> ShortText
    -> Either Text ShortText
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . Text -> Either Text Text
    B64TU.decodeBase64Unpadded (Text -> Either Text Text)
    -> (ShortText -> Text) -> ShortText -> Either Text Text
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . ShortText -> Text
    toText
    {-# INLINE decodeBase64Unpadded #-}

    -- | Attempt to decode an unpadded 'ShortByteString' value as Base64url, converting from
    -- 'ShortByteString' to 'ShortText' according to some encoding function. In practice,
    -- This is something like 'decodeUtf8'', which may produce an error.
    --
    -- See: <https://tools.ietf.org/html/rfc4648#section-4 RFC-4648 section 4>
    --
    -- === __Examples__:
    --
    -- @
    -- 'decodeBase64UnpaddedWith' 'T.decodeUtf8''
    --   :: 'ShortByteString' -> 'Either' ('Base64Error' 'UnicodeException') 'ShortText'
    -- @
    --
    decodeBase64UnpaddedWith
        :: (ShortByteString -> Either err ShortText)
          -- ^ convert a bytestring to text (e.g. 'T.decodeUtf8'')
        -> ShortByteString
          -- ^ Input text to decode
        -> Either (Base64Error err) ShortText
    decodeBase64UnpaddedWith :: forall err.
    (ShortByteString -> Either err ShortText)
    -> ShortByteString -> Either (Base64Error err) ShortText
    decodeBase64UnpaddedWith ShortByteString -> Either err ShortText
    f ShortByteString
    t = case ShortByteString -> Either Text ShortByteString
    BS64U.decodeBase64Unpadded ShortByteString
    t of
      Left Text
    de -> Base64Error err -> Either (Base64Error err) ShortText
    forall a b. a -> Either a b
    Left (Base64Error err -> Either (Base64Error err) ShortText)
    -> Base64Error err -> Either (Base64Error err) ShortText
    forall a b. (a -> b) -> a -> b
    $ Text -> Base64Error err
    forall e. Text -> Base64Error e
    DecodeError Text
    de
      Right ShortByteString
    a -> (err -> Base64Error err)
    -> Either err ShortText -> Either (Base64Error err) ShortText
    forall a b c. (a -> b) -> Either a c -> Either b c
    forall (p :: * -> * -> *) a b c.
    Bifunctor p =>
    (a -> b) -> p a c -> p b c
    first err -> Base64Error err
    forall e. e -> Base64Error e
    ConversionError (ShortByteString -> Either err ShortText
    f ShortByteString
    a)
    {-# INLINE decodeBase64UnpaddedWith #-}

    -- | Decode an padded Base64url encoded 'ShortText' value
    --
    -- /Note:/ This function makes sure that decoding is total by deferring to
    -- 'T.decodeLatin1'. This will always round trip for any valid Base64-encoded
    -- text value, but it may not round trip for bad inputs. The onus is on the
    -- caller to make sure inputs are valid. If unsure, defer to `decodeBase64PaddedWith`
    -- and pass in a custom decode function.
    --
    -- See: <https://tools.ietf.org/html/rfc4648#section-4 RFC-4648 section 4>
    --
    -- === __Examples__:
    --
    -- >>> decodeBase64Padded "PDw_Pj4="
    -- Right "<<?>>"
    --
    -- >>> decodeBase64Padded "PDw_Pj4"
    -- Left "Base64-encoded bytestring requires padding"
    --
    decodeBase64Padded :: ShortText -> Either Text ShortText
    decodeBase64Padded :: ShortText -> Either Text ShortText
    decodeBase64Padded = (Text -> ShortText) -> Either Text Text -> Either Text ShortText
    forall a b. (a -> b) -> Either Text a -> Either Text b
    forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
    fmap Text -> ShortText
    fromText (Either Text Text -> Either Text ShortText)
    -> (ShortText -> Either Text Text)
    -> ShortText
    -> Either Text ShortText
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . Text -> Either Text Text
    B64TU.decodeBase64Padded (Text -> Either Text Text)
    -> (ShortText -> Text) -> ShortText -> Either Text Text
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . ShortText -> Text
    toText
    {-# INLINE decodeBase64Padded #-}

    -- | Attempt to decode a padded 'ShortByteString' value as Base64url, converting from
    -- 'ByteString' to 'ShortText' according to some encoding function. In practice,
    -- This is something like 'decodeUtf8'', which may produce an error.
    --
    -- See: <https://tools.ietf.org/html/rfc4648#section-4 RFC-4648 section 4>
    --
    -- === __Examples__:
    --
    -- @
    -- 'decodeBase64With' 'T.decodeUtf8''
    --   :: 'ShortByteString' -> 'Either' ('Base64Error' 'UnicodeException') 'ShortText'
    -- @
    --
    decodeBase64PaddedWith
        :: (ShortByteString -> Either err ShortText)
          -- ^ convert a bytestring to text (e.g. 'T.decodeUtf8'')
        -> ShortByteString
          -- ^ Input text to decode
        -> Either (Base64Error err) ShortText
    decodeBase64PaddedWith :: forall err.
    (ShortByteString -> Either err ShortText)
    -> ShortByteString -> Either (Base64Error err) ShortText
    decodeBase64PaddedWith ShortByteString -> Either err ShortText
    f ShortByteString
    t = case ShortByteString -> Either Text ShortByteString
    BS64U.decodeBase64Padded ShortByteString
    t of
      Left Text
    de -> Base64Error err -> Either (Base64Error err) ShortText
    forall a b. a -> Either a b
    Left (Base64Error err -> Either (Base64Error err) ShortText)
    -> Base64Error err -> Either (Base64Error err) ShortText
    forall a b. (a -> b) -> a -> b
    $ Text -> Base64Error err
    forall e. Text -> Base64Error e
    DecodeError Text
    de
      Right ShortByteString
    a -> (err -> Base64Error err)
    -> Either err ShortText -> Either (Base64Error err) ShortText
    forall a b c. (a -> b) -> Either a c -> Either b c
    forall (p :: * -> * -> *) a b c.
    Bifunctor p =>
    (a -> b) -> p a c -> p b c
    first err -> Base64Error err
    forall e. e -> Base64Error e
    ConversionError (ShortByteString -> Either err ShortText
    f ShortByteString
    a)
    {-# INLINE decodeBase64PaddedWith #-}

    -- | Leniently decode an unpadded Base64url-encoded 'ShortText'. 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.
    --
    -- === __Examples__:
    --
    -- >>> decodeBase64Lenient "PDw_Pj4="
    -- "<<?>>"
    --
    -- >>> decodeBase64Lenient "PDw_%%%$}Pj4"
    -- "<<?>>"
    --
    decodeBase64Lenient :: ShortText -> ShortText
    decodeBase64Lenient :: ShortText -> ShortText
    decodeBase64Lenient = Text -> ShortText
    fromText (Text -> ShortText)
    -> (ShortText -> Text) -> ShortText -> ShortText
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . Text -> Text
    B64TU.decodeBase64Lenient (Text -> Text) -> (ShortText -> Text) -> ShortText -> Text
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . ShortText -> Text
    toText
    {-# INLINE decodeBase64Lenient #-}

    -- | Tell whether a 'ShortText' value is Base64url-encoded.
    --
    -- === __Examples__:
    --
    -- >>> isBase64Url "PDw_Pj4="
    -- True
    --
    -- >>> isBase64Url "PDw_Pj4"
    -- True
    --
    -- >>> isBase64Url "PDw_Pj"
    -- False
    --
    isBase64Url :: ShortText -> Bool
    isBase64Url :: ShortText -> Bool
    isBase64Url = ByteString -> Bool
    B64U.isBase64Url (ByteString -> Bool)
    -> (ShortText -> ByteString) -> ShortText -> Bool
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . ShortText -> ByteString
    toByteString
    {-# INLINE isBase64Url #-}

    -- | Tell whether a 'ShortText' value is a valid Base64url format.
    --
    -- This will not tell you whether or not this is a correct Base64url representation,
    -- only that it conforms to the correct shape. To check whether it is a true
    -- Base64 encoded 'ShortText' value, use 'isBase64Url'.
    --
    -- === __Examples__:
    --
    -- >>> isValidBase64Url "PDw_Pj4="
    -- True
    --
    -- >>> isValidBase64Url "PDw_Pj"
    -- True
    --
    -- >>> isValidBase64Url "%"
    -- False
    --
    isValidBase64Url :: ShortText -> Bool
    isValidBase64Url :: ShortText -> Bool
    isValidBase64Url = ByteString -> Bool
    B64U.isValidBase64Url (ByteString -> Bool)
    -> (ShortText -> ByteString) -> ShortText -> Bool
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . ShortText -> ByteString
    toByteString
    {-# INLINE isValidBase64Url #-}