// =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
// Mobius Forensic Toolkit
// Copyright (C) 2008,2009,2010,2011,2012,2013,2014,2015,2016,2017,2018,2019,2020,2021,2022,2023,2024 Eduardo Aguiar
//
// This program is free software; you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by the
// Free Software Foundation; either version 2, or (at your option) any later
// version.
//
// This program is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General
// Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
// =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
#include "util.h"
#include <mobius/exception.inc>
#include <mutex>
#include <stdexcept>

namespace
{
// =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
// Internal variables and constants
// =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
//! \brief Mininum libgcrypt version needed
static constexpr const char *LIBGCRYPT_MIN_VERSION = "1.9.0";

//! \brief Is libgcrypt initialized?
static std::once_flag is_libgcrypt_initialized_;

// =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
//! \brief Initialize libgcrypt
// =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
static void
_init_libgcrypt ()
{
  if (!gcry_check_version (LIBGCRYPT_MIN_VERSION))
    throw std::runtime_error (mobius::MOBIUS_EXCEPTION_MSG ("libgcrypt too old"));

  gcry_control (GCRYCTL_INITIALIZATION_FINISHED, 0);
}

} // namespace


namespace mobius::crypt::gcrypt
{
// =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
//! \brief Initialize libgcrypt
// =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
void
init ()
{
  std::call_once (is_libgcrypt_initialized_, _init_libgcrypt);

  if (!gcry_control (GCRYCTL_INITIALIZATION_FINISHED_P))
    throw std::runtime_error (MOBIUS_EXCEPTION_MSG ("libgcrypt has not been initialized"));
}

// =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
//! \brief Get libgcrypt error message
//! \param err Error number
//! \return Error message
// =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
std::string
get_error_message (gcry_error_t err)
{
  const char *text = gcry_strerror (err);

  if (text)
    return text;

  return "libgcrypt error " + std::to_string (err);
}

} // namespace mobius::crypt::gcrypt