interface Base64 exposes [ fromBytes, fromStr, toBytes, toStr ] imports [ Base64.Decode, Base64.Encode ]

# base 64 encoding from a sequence of bytes
fromBytes : List U8 -> Result Str [ InvalidInput ]*
fromBytes = \bytes ->
    when Base64.Decode.fromBytes bytes is
        Ok v -> Ok v
        Err _ -> Err InvalidInput

# base 64 encoding from a string 
fromStr : Str -> Result Str [ InvalidInput ]*
fromStr = \str ->
    fromBytes (Str.toUtf8 str)

# base64-encode bytes to the original 
toBytes : Str -> Result (List U8) [ InvalidInput ]*
toBytes = \str ->
    Ok (Base64.Encode.toBytes str)

toStr : Str -> Result Str [ InvalidInput ]*
toStr = \str ->
    when toBytes str is
        Ok bytes ->
            when Str.fromUtf8 bytes is
                Ok v -> Ok v
                Err _ -> Err InvalidInput

        Err _ -> Err InvalidInput