// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//

/*
   Portions from http://www.adp-gmbh.ch/cpp/common/base64.html
   Copyright notice:

   base64.cpp and base64.h

   Copyright (C) 2004-2008 René Nyffenegger

   This source code is provided 'as-is', without any express or implied
   warranty. In no event will the author be held liable for any damages
   arising from the use of this software.

   Permission is granted to anyone to use this software for any purpose,
   including commercial applications, and to alter it and redistribute it
   freely, subject to the following restrictions:

   1. The origin of this source code must not be misrepresented; you must not
      claim that you wrote the original source code. If you use this source code
      in a product, an acknowledgment in the product documentation would be
      appreciated but is not required.

   2. Altered source versions must be plainly marked as such, and must not be
      misrepresented as being the original source code.

   3. This notice may not be removed or altered from any source distribution.

   René Nyffenegger rene.nyffenegger@adp-gmbh.ch

*/

#pragma once

#include <cstddef>
#include <cstdint>
#include <string>
#include <string_view>

namespace xrpl {

namespace base64 {

/**
 * Returns the maximum number of characters needed to base64-encode @p nBytes bytes.
 *
 * @param nBytes Number of input bytes.
 * @return Size of the encoded string, including padding.
 */
constexpr std::size_t
encodedSize(std::size_t const nBytes)
{
    return 4 * ((nBytes + 2) / 3);
}

/**
 * Returns the maximum number of bytes a base64 string of @p numChars characters
 * decodes to.
 *
 * @param numChars Number of base64 characters.
 * @return Upper bound on the number of decoded bytes.
 */
constexpr std::size_t
decodedSize(std::size_t const numChars)
{
    return ((numChars / 4) * 3) + 2;
}

}  // namespace base64

std::string
base64Encode(std::uint8_t const* data, std::size_t len);

inline std::string
base64Encode(std::string_view s)
{
    return base64Encode(reinterpret_cast<std::uint8_t const*>(s.data()), s.size());
}

std::string
base64Decode(std::string_view data);

}  // namespace xrpl