/* Distributed under the OSI-approved BSD 3-Clause License.  See accompanying

   file LICENSE.rst or https://cmake.org/licensing for details.  */

#include "cmFileTime.h"

#include <ctime>

#include <string>

// Use a platform-specific API to get file times efficiently.

#if !defined(_WIN32) || defined(__CYGWIN__)

#  include "cm_sys_stat.h"

#else

#  include <windows.h>

#  include "cmsys/Encoding.hxx"

#endif

bool cmFileTime::Load(std::string const& fileName)

{

#if !defined(_WIN32) || defined(__CYGWIN__)

  // POSIX version.  Use the stat function.

  struct stat fst;

  if (::stat(fileName.c_str(), &fst) != 0) {

    return false;

  }

#  if CMake_STAT_HAS_ST_MTIM

  // Nanosecond resolution

  this->Time = fst.st_mtim.tv_sec * UtPerS + fst.st_mtim.tv_nsec;

#  elif CMake_STAT_HAS_ST_MTIMESPEC

  // Nanosecond resolution

  this->Time = fst.st_mtimespec.tv_sec * UtPerS + fst.st_mtimespec.tv_nsec;

#  else

  // Second resolution

  this->Time = fst.st_mtime * UtPerS;

#  endif

#else

  // Windows version.  Get the modification time from extended file attributes.

  WIN32_FILE_ATTRIBUTE_DATA fdata;

  if (!GetFileAttributesExW(cmsys::Encoding::ToWide(fileName).c_str(),

                            GetFileExInfoStandard, &fdata)) {

    return false;

  }

  // Copy the file time to the output location.

  using uint64 = unsigned long long;

  this->Time = static_cast<TimeType>(

    (uint64(fdata.ftLastWriteTime.dwHighDateTime) << 32) +

    fdata.ftLastWriteTime.dwLowDateTime);

#endif

  return true;

}