/* Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
   file LICENSE.rst or https://cmake.org/licensing for details.  */
#include "cmFileTimes.h"

#include <utility>

#include <cm/memory>

#include "cmsys/Status.hxx"

#include "cm_sys_stat.h"

#if defined(_WIN32)
#  include <windows.h>

#  include "cmSystemTools.h"
#else
#  include <cerrno>

#  include <utime.h>
#endif

#if defined(_WIN32) &&                                                        \
  (defined(_MSC_VER) || defined(__WATCOMC__) || defined(__MINGW32__))
#  include <io.h>
#endif

#ifdef _WIN32
class cmFileTimes::WindowsHandle
{
public:
  WindowsHandle(HANDLE h)
    : handle_(h)
  {
  }
  ~WindowsHandle()
  {
    if (this->handle_ != INVALID_HANDLE_VALUE) {
      CloseHandle(this->handle_);
    }
  }
  explicit operator bool() const
  {
    return this->handle_ != INVALID_HANDLE_VALUE;
  }
  bool operator!() const { return this->handle_ == INVALID_HANDLE_VALUE; }
  operator HANDLE() const { return this->handle_; }

private:
  HANDLE handle_;
};
#endif

class cmFileTimes::Times
{
public:
#if defined(_WIN32) && !defined(__CYGWIN__)
  FILETIME timeCreation;
  FILETIME timeLastAccess;
  FILETIME timeLastWrite;
#else
  struct utimbuf timeBuf;
#endif
};

cmFileTimes::cmFileTimes() = default;
cmFileTimes::cmFileTimes(std::string const& fileName)
{
  this->Load(fileName);
}
cmFileTimes::~cmFileTimes() = default;

cmsys::Status cmFileTimes::Load(std::string const& fileName)
{
  std::unique_ptr<Times> ptr;
  if (this->IsValid()) {
    // Invalidate this and reuse times
    ptr.swap(this->times);
  } else {
    ptr = cm::make_unique<Times>();
  }

#if defined(_WIN32) && !defined(__CYGWIN__)
  cmFileTimes::WindowsHandle handle =
    CreateFileW(cmSystemTools::ConvertToWindowsExtendedPath(fileName).c_str(),
                GENERIC_READ, FILE_SHARE_READ, 0, OPEN_EXISTING,
                FILE_FLAG_BACKUP_SEMANTICS, 0);
  if (!handle) {
    return cmsys::Status::Windows_GetLastError();
  }
  if (!GetFileTime(handle, &ptr->timeCreation, &ptr->timeLastAccess,
                   &ptr->timeLastWrite)) {
    return cmsys::Status::Windows_GetLastError();
  }
#else
  struct stat st;
  if (stat(fileName.c_str(), &st) < 0) {
    return cmsys::Status::POSIX_errno();
  }
  ptr->timeBuf.actime = st.st_atime;
  ptr->timeBuf.modtime = st.st_mtime;
#endif
  // Accept times
  this->times = std::move(ptr);
  return cmsys::Status::Success();
}

cmsys::Status cmFileTimes::Store(std::string const& fileName) const
{
  if (!this->IsValid()) {
    return cmsys::Status::POSIX(EINVAL);
  }

#if defined(_WIN32) && !defined(__CYGWIN__)
  cmFileTimes::WindowsHandle handle = CreateFileW(
    cmSystemTools::ConvertToWindowsExtendedPath(fileName).c_str(),
    FILE_WRITE_ATTRIBUTES, 0, 0, OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, 0);
  if (!handle) {
    return cmsys::Status::Windows_GetLastError();
  }
  if (SetFileTime(handle, &this->times->timeCreation,
                  &this->times->timeLastAccess,
                  &this->times->timeLastWrite) == 0) {
    return cmsys::Status::Windows_GetLastError();
  }
#else
  if (utime(fileName.c_str(), &this->times->timeBuf) < 0) {
    return cmsys::Status::POSIX_errno();
  }
#endif
  return cmsys::Status::Success();
}

cmsys::Status cmFileTimes::Copy(std::string const& fromFile,
                                std::string const& toFile)
{
  cmFileTimes fileTimes;
  cmsys::Status load_status = fileTimes.Load(fromFile);
  if (!load_status) {
    return load_status;
  }
  return fileTimes.Store(toFile);
}