#include "fallout76savegame.h"

#ifdef _WIN32
#include <Windows.h>
#else
#include <QDateTime>
#include <QTimeZone>

using SYSTEMTIME = _SYSTEMTIME;

static void FileTimeToSystemTime(const FILETIME* ft, SYSTEMTIME* st)
{
  const uint64_t ticks = (static_cast<uint64_t>(ft->dwHighDateTime) << 32) |
                         static_cast<uint64_t>(ft->dwLowDateTime);
  const int64_t unixSecs = static_cast<int64_t>(ticks / 10000000ULL) - 11644473600LL;
  const uint64_t remainderHns = ticks % 10000000ULL;

  const QDateTime dt = QDateTime::fromSecsSinceEpoch(unixSecs, QTimeZone::UTC);
  const QDate d      = dt.date();
  const QTime t      = dt.time();

  st->wYear         = static_cast<uint16_t>(d.year());
  st->wMonth        = static_cast<uint16_t>(d.month());
  st->wDayOfWeek    = static_cast<uint16_t>(d.dayOfWeek() % 7);
  st->wDay          = static_cast<uint16_t>(d.day());
  st->wHour         = static_cast<uint16_t>(t.hour());
  st->wMinute       = static_cast<uint16_t>(t.minute());
  st->wSecond       = static_cast<uint16_t>(t.second());
  st->wMilliseconds = static_cast<uint16_t>(remainderHns / 10000);
}
#endif

#include "gamefallout76.h"

Fallout76SaveGame::Fallout76SaveGame(QString const& fileName, GameFallout76 const* game)
    : GamebryoSaveGame(fileName, game, true)
{
  FileWrapper file(fileName, "FO76_SAVEGAME");

  FILETIME ftime;
  fetchInformationFields(file, m_PCName, m_PCLevel, m_PCLocation, m_SaveNumber, ftime);

  // A file time is a 64-bit value that represents the number of 100-nanosecond
  // intervals that have elapsed since 12:00 A.M. January 1, 1601 Coordinated Universal
  // Time (UTC). So we need to convert that to something useful
  SYSTEMTIME ctime;
  ::FileTimeToSystemTime(&ftime, &ctime);

  setCreationTime(ctime);
}

void Fallout76SaveGame::fetchInformationFields(FileWrapper& file, QString playerName,
                                               unsigned short playerLevel,
                                               QString playerLocation,
                                               unsigned long saveNumber,
                                               FILETIME& creationTime) const
{

  file.skip<unsigned long>();  // header size
  file.skip<uint32_t>();       // header version
  file.read(saveNumber);

  file.read(playerName);

  unsigned long temp;
  file.read(temp);
  playerLevel = static_cast<unsigned short>(temp);
  file.read(playerLocation);

  QString ignore;
  file.read(ignore);  // playtime as ascii hh.mm.ss
  file.read(ignore);  // race name (i.e. BretonRace)

  file.skip<unsigned short>();  // Player gender (0 = male)
  file.skip<float>(2);          // experience gathered, experience required

  FILETIME ftime;
  file.read(ftime);
}

std::unique_ptr<GamebryoSaveGame::DataFields> Fallout76SaveGame::fetchDataFields() const
{

  FileWrapper file(getFilepath(), "TESV_SAVEGAME");  // 10bytes
  {

    FILETIME ftime;
    fetchInformationFields(file, m_PCName, m_PCLevel, m_PCLocation, m_SaveNumber,
                           ftime);
  }

  std::unique_ptr<DataFields> fields = std::make_unique<DataFields>();

  file.readImage(384, true);

  uint8_t saveGameVersion = file.readChar();
  QString ignore;
  file.read(ignore);      // game version
  file.skip<uint32_t>();  // plugin info size

  file.readPlugins();
  if (saveGameVersion >= 68) {
    file.readLightPlugins();
  }

  return fields;
}