    {-# LANGUAGE DataKinds #-}
    -- |
    -- Module       : Data.Text.Encoding.Base64.URL
    -- Copyright    : (c) 2019-2023 Emily Pillmore
    -- License      : BSD-style
    --
    -- Maintainer   : Emily Pillmore <emilypi@cohomolo.gy>
    -- Stability    : stable
    -- Portability  : non-portable
    --
    -- This module contains 'Data.Text.Text'-valued combinators for
    -- implementing the RFC 4648 specification of the Base64url
    -- encoding format. This includes strictly padded/unpadded and lenient decoding
    -- variants, as well as internal and external validation for canonicity.
    --
    module Data.Text.Encoding.Base64.URL
    ( -- * Encoding
      encodeBase64
    , encodeBase64Unpadded
      -- * Decoding
    , decodeBase64
    , decodeBase64Untyped
    , decodeBase64UntypedWith
    , decodeBase64Unpadded
    , decodeBase64UnpaddedUntyped
    , decodeBase64UnpaddedUntypedWith
    , decodeBase64Padded
    , decodeBase64PaddedUntyped
    , decodeBase64PaddedUntypedWith
    , decodeBase64Lenient
      -- * Validation
    , isBase64Url
    , isValidBase64Url
    ) where

    import Data.Base64.Types

    import Data.Bifunctor (first)
    import Data.ByteString (ByteString)
    import qualified Data.ByteString.Base64.URL as B64U

    import Data.Text (Text)
    import qualified Data.Text.Encoding as T
    import Data.Text.Encoding.Base64.Error

    -- $setup
    --
    -- >>> import Data.Base64.Types
    -- >>> :set -XOverloadedStrings
    -- >>> :set -XTypeApplications
    -- >>> :set -XDataKinds
    --

    -- | Encode a 'Text' value in Base64url with padding.
    --
    -- See: <https://tools.ietf.org/html/rfc4648#section-5 RFC-4648 section 5>
    --
    -- === __Examples__:
    --
    -- >>> encodeBase64 "<<?>>"
    -- "PDw_Pj4="
    --
    encodeBase64 :: Text -> Base64 'UrlPadded Text
    encodeBase64 :: Text -> Base64 'UrlPadded Text
    encodeBase64 = ByteString -> Base64 'UrlPadded Text
    B64U.encodeBase64 (ByteString -> Base64 'UrlPadded Text)
    -> (Text -> ByteString) -> Text -> Base64 'UrlPadded Text
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . Text -> ByteString
    T.encodeUtf8
    {-# INLINE encodeBase64 #-}

    -- | Decode a Base64url encoded 'Text' value, either padded or unpadded.
    -- The correct decoding function is dispatched based on the existence of padding.
    --
    -- For typed values:
    --   - If a padded value is required, use 'decodeBase64Padded'
    --   - If an unpadded value is required, use 'decodeBase64Unpadded'
    --
    -- See: <https://tools.ietf.org/html/rfc4648#section-4 RFC-4648 section 4>
    --
    -- === __Examples__:
    --
    -- >>> decodeBase64 $ assertBase64 @'UrlPadded "PDw_Pj4="
    -- "<<?>>"
    --
    -- >>> decodeBase64 $ assertBase64 @'UrlUnpadded "PDw_Pj4"
    -- "<<?>>"
    --
    decodeBase64 :: UrlAlphabet k => Base64 k Text -> Text
    decodeBase64 :: forall (k :: Alphabet). UrlAlphabet k => Base64 k Text -> Text
    decodeBase64 = ByteString -> Text
    T.decodeUtf8 (ByteString -> Text)
    -> (Base64 k Text -> ByteString) -> Base64 k Text -> Text
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . Base64 k ByteString -> ByteString
    forall (k :: Alphabet).
    UrlAlphabet k =>
    Base64 k ByteString -> ByteString
    B64U.decodeBase64 (Base64 k ByteString -> ByteString)
    -> (Base64 k Text -> Base64 k ByteString)
    -> Base64 k Text
    -> ByteString
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . (Text -> ByteString) -> Base64 k Text -> Base64 k ByteString
    forall a b. (a -> b) -> Base64 k a -> Base64 k b
    forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
    fmap Text -> ByteString
    T.encodeUtf8
    {-# INLINE decodeBase64 #-}

    -- | Decode an untyped Base64url encoded 'Text' 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-encoded values are optionally padded.
    --
    -- For a decoder that fails to decode untyped values of incorrect size:
    --   - If a padded value is required, use 'decodeBase64PaddedUntyped'
    --   - If an unpadded value is required, use 'decodeBase64UnpaddedUntyped'
    --
    -- See: <https://tools.ietf.org/html/rfc4648#section-4 RFC-4648 section 4>
    --
    -- === __Examples__:
    --
    -- >>> decodeBase64Untyped "PDw_Pj4="
    -- Right "<<?>>"
    --
    -- >>> decodeBase64Untyped "PDw_Pj4"
    -- Right "<<?>>"
    --
    -- >>> decodeBase64Untyped "PDw-Pg="
    -- Left "Base64-encoded bytestring has invalid padding"
    --
    -- >>> decodeBase64Untyped "PDw-Pg"
    -- Right "<<>>"
    --
    decodeBase64Untyped :: Text -> Either Text Text
    decodeBase64Untyped :: Text -> Either Text Text
    decodeBase64Untyped = (ByteString -> Text) -> Either Text ByteString -> Either Text Text
    forall a b. (a -> b) -> Either Text a -> Either Text b
    forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
    fmap ByteString -> Text
    T.decodeUtf8
      (Either Text ByteString -> Either Text Text)
    -> (Text -> Either Text ByteString) -> Text -> Either Text Text
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . ByteString -> Either Text ByteString
    B64U.decodeBase64Untyped
      (ByteString -> Either Text ByteString)
    -> (Text -> ByteString) -> Text -> Either Text ByteString
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . Text -> ByteString
    T.encodeUtf8
    {-# inline decodeBase64Untyped #-}

    -- | Attempt to decode an untyped 'ByteString' value as Base64url, converting from
    -- 'ByteString' to 'Text' 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__:
    --
    -- @
    -- 'decodeBase64UntypedWith' 'T.decodeUtf8''
    --   :: 'Text' -> 'Either' ('Base64Error' 'UnicodeException') 'Text'
    -- @
    --
    decodeBase64UntypedWith
        :: (ByteString -> Either err Text)
          -- ^ convert a bytestring to text (e.g. 'T.decodeUtf8'')
        -> ByteString
          -- ^ Input text to decode
        -> Either (Base64Error err) Text
    decodeBase64UntypedWith :: forall err.
    (ByteString -> Either err Text)
    -> ByteString -> Either (Base64Error err) Text
    decodeBase64UntypedWith ByteString -> Either err Text
    f ByteString
    t = case ByteString -> Either Text ByteString
    B64U.decodeBase64Untyped ByteString
    t of
      Left Text
    de -> Base64Error err -> Either (Base64Error err) Text
    forall a b. a -> Either a b
    Left (Base64Error err -> Either (Base64Error err) Text)
    -> Base64Error err -> Either (Base64Error err) Text
    forall a b. (a -> b) -> a -> b
    $ Text -> Base64Error err
    forall e. Text -> Base64Error e
    DecodeError Text
    de
      Right ByteString
    a -> (err -> Base64Error err)
    -> Either err Text -> Either (Base64Error err) Text
    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 (ByteString -> Either err Text
    f ByteString
    a)
    {-# INLINE decodeBase64UntypedWith #-}

    -- | Encode a 'Text' value in Base64url without padding.
    --
    -- See: <https://tools.ietf.org/html/rfc4648#section-3.2 RFC-4648 section 3.2>
    --
    -- === __Examples__:
    --
    -- >>> encodeBase64Unpadded "<<?>>"
    -- "PDw_Pj4"
    --
    encodeBase64Unpadded :: Text -> Base64 'UrlUnpadded Text
    encodeBase64Unpadded :: Text -> Base64 'UrlUnpadded Text
    encodeBase64Unpadded = ByteString -> Base64 'UrlUnpadded Text
    B64U.encodeBase64Unpadded (ByteString -> Base64 'UrlUnpadded Text)
    -> (Text -> ByteString) -> Text -> Base64 'UrlUnpadded Text
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . Text -> ByteString
    T.encodeUtf8
    {-# INLINE encodeBase64Unpadded #-}

    -- | Decode an unpadded Base64url encoded 'Text' value.
    --
    -- See: <https://tools.ietf.org/html/rfc4648#section-4 RFC-4648 section 4>
    --
    -- === __Examples__:
    --
    -- >>> decodeBase64Unpadded $ assertBase64 @'UrlUnpadded "PDw_Pj4"
    -- "<<?>>"
    --
    decodeBase64Unpadded :: Base64 'UrlUnpadded Text -> Text
    decodeBase64Unpadded :: Base64 'UrlUnpadded Text -> Text
    decodeBase64Unpadded = ByteString -> Text
    T.decodeUtf8
      (ByteString -> Text)
    -> (Base64 'UrlUnpadded Text -> ByteString)
    -> Base64 'UrlUnpadded Text
    -> Text
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . Base64 'UrlUnpadded ByteString -> ByteString
    B64U.decodeBase64Unpadded
      (Base64 'UrlUnpadded ByteString -> ByteString)
    -> (Base64 'UrlUnpadded Text -> Base64 'UrlUnpadded ByteString)
    -> Base64 'UrlUnpadded Text
    -> ByteString
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . (Text -> ByteString)
    -> Base64 'UrlUnpadded Text -> Base64 'UrlUnpadded ByteString
    forall a b.
    (a -> b) -> Base64 'UrlUnpadded a -> Base64 'UrlUnpadded b
    forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
    fmap Text -> ByteString
    T.encodeUtf8
    {-# INLINE decodeBase64Unpadded #-}

    -- | Decode a unpadded, untyped Base64url-encoded 'Text' 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 'decodeBase64PaddedUntyped'
    --
    -- See: <https://tools.ietf.org/html/rfc4648#section-4 RFC-4648 section 4>
    --
    -- === __Examples__:
    --
    -- >>> decodeBase64UnpaddedUntyped "PDw_Pj4"
    -- Right "<<?>>"
    --
    -- >>> decodeBase64UnpaddedUntyped "PDw-Pg="
    -- Left "Base64-encoded bytestring has invalid padding"
    --
    -- >>> decodeBase64UnpaddedUntyped "PDw-Pg"
    -- Right "<<>>"
    --
    decodeBase64UnpaddedUntyped :: Text -> Either Text Text
    decodeBase64UnpaddedUntyped :: Text -> Either Text Text
    decodeBase64UnpaddedUntyped = (ByteString -> Text) -> Either Text ByteString -> Either Text Text
    forall a b. (a -> b) -> Either Text a -> Either Text b
    forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
    fmap ByteString -> Text
    T.decodeUtf8
      (Either Text ByteString -> Either Text Text)
    -> (Text -> Either Text ByteString) -> Text -> Either Text Text
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . ByteString -> Either Text ByteString
    B64U.decodeBase64UnpaddedUntyped
      (ByteString -> Either Text ByteString)
    -> (Text -> ByteString) -> Text -> Either Text ByteString
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . Text -> ByteString
    T.encodeUtf8
    {-# inline decodeBase64UnpaddedUntyped #-}

    -- | Attempt to decode an untyped, unpadded 'ByteString' value as Base64url, converting from
    -- 'ByteString' to 'Text' 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>
    --
    -- === __Example__:
    --
    -- @
    -- 'decodeBase64UnpaddedUntypedWith' 'T.decodeUtf8''
    --   :: 'ByteString' -> 'Either' ('Base64Error' 'UnicodeException') 'Text'
    -- @
    --
    decodeBase64UnpaddedUntypedWith
        :: (ByteString -> Either err Text)
          -- ^ convert a bytestring to text (e.g. 'T.decodeUtf8'')
        -> ByteString
          -- ^ Input text to decode
        -> Either (Base64Error err) Text
    decodeBase64UnpaddedUntypedWith :: forall err.
    (ByteString -> Either err Text)
    -> ByteString -> Either (Base64Error err) Text
    decodeBase64UnpaddedUntypedWith ByteString -> Either err Text
    f ByteString
    t = case ByteString -> Either Text ByteString
    B64U.decodeBase64UnpaddedUntyped ByteString
    t of
      Left Text
    de -> Base64Error err -> Either (Base64Error err) Text
    forall a b. a -> Either a b
    Left (Base64Error err -> Either (Base64Error err) Text)
    -> Base64Error err -> Either (Base64Error err) Text
    forall a b. (a -> b) -> a -> b
    $ Text -> Base64Error err
    forall e. Text -> Base64Error e
    DecodeError Text
    de
      Right ByteString
    a -> (err -> Base64Error err)
    -> Either err Text -> Either (Base64Error err) Text
    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 (ByteString -> Either err Text
    f ByteString
    a)
    {-# INLINE decodeBase64UnpaddedUntypedWith #-}

    -- | Decode a padded Base64url encoded 'Text' value
    --
    -- See: <https://tools.ietf.org/html/rfc4648#section-4 RFC-4648 section 4>
    --
    -- === __Examples__:
    --
    -- >>> decodeBase64Padded $ assertBase64 @'UrlPadded "PDw_Pj4="
    -- "<<?>>"
    --
    decodeBase64Padded :: Base64 'UrlPadded Text -> Text
    decodeBase64Padded :: Base64 'UrlPadded Text -> Text
    decodeBase64Padded = ByteString -> Text
    T.decodeUtf8
      (ByteString -> Text)
    -> (Base64 'UrlPadded Text -> ByteString)
    -> Base64 'UrlPadded Text
    -> Text
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . Base64 'UrlPadded ByteString -> ByteString
    B64U.decodeBase64Padded
      (Base64 'UrlPadded ByteString -> ByteString)
    -> (Base64 'UrlPadded Text -> Base64 'UrlPadded ByteString)
    -> Base64 'UrlPadded Text
    -> ByteString
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . (Text -> ByteString)
    -> Base64 'UrlPadded Text -> Base64 'UrlPadded ByteString
    forall a b. (a -> b) -> Base64 'UrlPadded a -> Base64 'UrlPadded b
    forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
    fmap Text -> ByteString
    T.encodeUtf8
    {-# INLINE decodeBase64Padded #-}

    -- | Decode an untyped, padded Base64url encoded 'Text' value
    --
    -- For a decoder that fails on padded input, use 'decodeBase64UnpaddedUntyped'
    --
    -- See: <https://tools.ietf.org/html/rfc4648#section-4 RFC-4648 section 4>
    --
    -- === __Examples__:
    --
    -- >>> decodeBase64PaddedUntyped "PDw_Pj4="
    -- Right "<<?>>"
    --
    decodeBase64PaddedUntyped :: Text -> Either Text Text
    decodeBase64PaddedUntyped :: Text -> Either Text Text
    decodeBase64PaddedUntyped = (ByteString -> Text) -> Either Text ByteString -> Either Text Text
    forall a b. (a -> b) -> Either Text a -> Either Text b
    forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
    fmap ByteString -> Text
    T.decodeUtf8
      (Either Text ByteString -> Either Text Text)
    -> (Text -> Either Text ByteString) -> Text -> Either Text Text
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . ByteString -> Either Text ByteString
    B64U.decodeBase64PaddedUntyped
      (ByteString -> Either Text ByteString)
    -> (Text -> ByteString) -> Text -> Either Text ByteString
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . Text -> ByteString
    T.encodeUtf8
    {-# inline decodeBase64PaddedUntyped #-}

    -- | Attempt to decode a padded, untyped 'ByteString' value as Base64url, converting from
    -- 'ByteString' to 'Text' 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>
    --
    -- === __Example__:
    --
    -- @
    -- 'decodeBase64PaddedWith' 'T.decodeUtf8''
    --   :: 'ByteString' -> 'Either' ('Base64Error' 'UnicodeException') 'Text'
    -- @
    --
    decodeBase64PaddedUntypedWith
        :: (ByteString -> Either err Text)
          -- ^ convert a bytestring to text (e.g. 'T.decodeUtf8'')
        -> ByteString
          -- ^ Input text to decode
        -> Either (Base64Error err) Text
    decodeBase64PaddedUntypedWith :: forall err.
    (ByteString -> Either err Text)
    -> ByteString -> Either (Base64Error err) Text
    decodeBase64PaddedUntypedWith ByteString -> Either err Text
    f ByteString
    t = case ByteString -> Either Text ByteString
    B64U.decodeBase64PaddedUntyped ByteString
    t of
      Left Text
    de -> Base64Error err -> Either (Base64Error err) Text
    forall a b. a -> Either a b
    Left (Base64Error err -> Either (Base64Error err) Text)
    -> Base64Error err -> Either (Base64Error err) Text
    forall a b. (a -> b) -> a -> b
    $ Text -> Base64Error err
    forall e. Text -> Base64Error e
    DecodeError Text
    de
      Right ByteString
    a -> (err -> Base64Error err)
    -> Either err Text -> Either (Base64Error err) Text
    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 (ByteString -> Either err Text
    f ByteString
    a)
    {-# INLINE decodeBase64PaddedUntypedWith #-}

    -- | Leniently decode an untyped Base64url-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.
    --
    -- === __Examples__:
    --
    -- >>> decodeBase64Lenient "PDw_Pj4="
    -- "<<?>>"
    --
    -- >>> decodeBase64Lenient "PDw_%%%$}Pj4"
    -- "<<?>>"
    --
    decodeBase64Lenient :: Text -> Text
    decodeBase64Lenient :: Text -> Text
    decodeBase64Lenient = ByteString -> Text
    T.decodeUtf8
        (ByteString -> Text) -> (Text -> ByteString) -> Text -> Text
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . ByteString -> ByteString
    B64U.decodeBase64Lenient
        (ByteString -> ByteString)
    -> (Text -> ByteString) -> Text -> ByteString
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . Text -> ByteString
    T.encodeUtf8
    {-# INLINE decodeBase64Lenient #-}

    -- | Tell whether an untyped 'Text' value is Base64url-encoded.
    --
    -- === __Examples__:
    --
    -- >>> isBase64Url "PDw_Pj4="
    -- True
    --
    -- >>> isBase64Url "PDw_Pj4"
    -- True
    --
    -- >>> isBase64Url "PDw_Pj"
    -- False
    --
    isBase64Url :: Text -> Bool
    isBase64Url :: Text -> Bool
    isBase64Url = ByteString -> Bool
    B64U.isBase64Url (ByteString -> Bool) -> (Text -> ByteString) -> Text -> Bool
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . Text -> ByteString
    T.encodeUtf8
    {-# INLINE isBase64Url #-}

    -- | Tell whether an untyped 'Text' 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 'Text' value, use 'isBase64Url'.
    --
    -- === __Examples__:
    --
    -- >>> isValidBase64Url "PDw_Pj4="
    -- True
    --
    -- >>> isValidBase64Url "PDw_Pj"
    -- True
    --
    -- >>> isValidBase64Url "%"
    -- False
    --
    isValidBase64Url :: Text -> Bool
    isValidBase64Url :: Text -> Bool
    isValidBase64Url = ByteString -> Bool
    B64U.isValidBase64Url (ByteString -> Bool) -> (Text -> ByteString) -> Text -> Bool
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . Text -> ByteString
    T.encodeUtf8
    {-# INLINE isValidBase64Url #-}