//    OpenVPN -- An application to securely tunnel IP networks
//               over a single port, with support for SSL/TLS-based
//               session authentication and key exchange,
//               packet encryption, packet authentication, and
//               packet compression.
//
//    Copyright (C) 2012-2020 OpenVPN Inc.
//
//    This program is free software: you can redistribute it and/or modify
//    it under the terms of the GNU Affero General Public License Version 3
//    as published by the Free Software Foundation.
//
//    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 Affero General Public License for more details.
//
//    You should have received a copy of the GNU Affero General Public License
//    along with this program in the COPYING file.
//    If not, see <http://www.gnu.org/licenses/>.

#pragma once

#include <string>

#include <openvpn/common/platform.hpp>

#if !defined(OPENVPN_PLATFORM_WIN)
#include <sys/types.h> // for open(), ftruncate()
#include <sys/stat.h>  // for open()
#include <fcntl.h>     // for open()
#include <unistd.h>    // for write(), ftruncate()
#include <errno.h>
#endif

#include <openvpn/common/exception.hpp>
#include <openvpn/common/size.hpp>
#include <openvpn/buffer/buffer.hpp>

#if !defined(OPENVPN_PLATFORM_WIN)
#include <openvpn/common/scoped_fd.hpp>
#include <openvpn/common/write.hpp>
#include <openvpn/common/strerror.hpp>
#endif

namespace openvpn {

#if defined(OPENVPN_PLATFORM_WIN)

  inline void write_private(const std::string& path, const void *buf, size_t count)
  {
    OPENVPN_THROW_EXCEPTION("write_private('" << path << "') : not implemented on Windows yet");
  }

#else

  inline void write_private(const std::string& path, const void *buf, ssize_t count)
  {
    ScopedFD fd(::open(path.c_str(), O_WRONLY|O_CREAT|O_CLOEXEC, S_IRUSR|S_IWUSR));
    if (!fd.defined())
      {
	const int eno = errno;
	OPENVPN_THROW_EXCEPTION(path << " : open error : " << strerror_str(eno));
      }
    if (::ftruncate(fd(), 0) < 0)
      {
	const int eno = errno;
	OPENVPN_THROW_EXCEPTION(path << " : truncate error : " << strerror_str(eno));
      }
    const ssize_t len = write_retry(fd(), buf, count);
    if (len == -1)
      {
	const int eno = errno;
	OPENVPN_THROW_EXCEPTION(path << " : write error : " << strerror_str(eno));
      }
    else if (len != count)
      OPENVPN_THROW_EXCEPTION(path << " : unexpected write size");
    if (!fd.close())
      {
	const int eno = errno;
	OPENVPN_THROW_EXCEPTION(path << " : close error : " << strerror_str(eno));
      }
  }

#endif

  inline void write_private(const std::string& path, const Buffer& buf)
  {
    write_private(path, buf.c_data(), buf.size());
  }

  inline void write_private(const std::string& path, const std::string& str)
  {
    write_private(path, str.c_str(), str.length());
  }

}