#include "common/common_pch.h"

#include <Qt>
#if QT_VERSION >= QT_VERSION_CHECK(5, 9, 0)
# include <QOperatingSystemVersion>
#endif
#include <QScreen>
#include <QSettings>
#include <QString>
#include <QStringList>

#include "common/fs_sys_helpers.h"
#include "common/version.h"
#include "mkvtoolnix-gui/app.h"
#include "mkvtoolnix-gui/util/installation_checker.h"
#include "mkvtoolnix-gui/util/system_information.h"

namespace mtx { namespace gui { namespace Util {

using namespace mtx::gui;

namespace {

void
gatherGeneralInfo(QStringList &info) {
  InstallationChecker checker;
  checker.runChecks();

  info << Q("# MKVToolNix") << Q("");
  info << Q("## General") << Q("");

  info << Q("* MKVToolNix GUI version: %1").arg(Q(get_current_version().to_string()));
  info << Q("* mkvmerge version: %1").arg(checker.mkvmergeVersion().isEmpty() ? Q("unknown") : checker.mkvmergeVersion());
  info << Q("* Installation path: %1").arg(App::applicationDirPath());

  info << Q("") << Q("## Installation problems") << Q("");

  auto problems = checker.problems();
  if (problems.isEmpty()) {
    info << Q("No problems were found with the installation.");
    return;
  }

  for (auto const &problem : problems) {
    auto name = problem.first == InstallationChecker::ProblemType::FileNotFound                 ? Q("FileNotFound")
              : problem.first == InstallationChecker::ProblemType::MkvmergeNotFound             ? Q("MkvmergeNotFound")
              : problem.first == InstallationChecker::ProblemType::MkvmergeCannotBeExecuted     ? Q("MkvmergeCannotBeExecuted")
              : problem.first == InstallationChecker::ProblemType::MkvmergeVersionNotRecognized ? Q("MkvmergeVersionNotRecognized")
              : problem.first == InstallationChecker::ProblemType::MkvmergeVersionDiffers       ? Q("MkvmergeVersionDiffers")
              :                                                                                   Q("unknown");
    info << Q("* Type: %1, info: %2").arg(name).arg(problem.second.isEmpty() ? Q("—") : problem.second);
  }
}

void
gatherOperatingSystemInfo(QStringList &info) {
  info << Q("") << Q("## Operating system");

#if QT_VERSION >= QT_VERSION_CHECK(5, 9, 0)
  auto versionInfo = QOperatingSystemVersion::current();
  auto versionNum  = QStringList{};

  if (versionInfo.majorVersion() != -1)
    versionNum << QString::number(versionInfo.majorVersion());
  if (versionInfo.minorVersion() != -1)
    versionNum << QString::number(versionInfo.minorVersion());
  if (versionInfo.microVersion() != -1)
    versionNum << QString::number(versionInfo.microVersion());

  auto osName    = versionInfo.name();
  auto osVersion = versionNum.join(Q("."));

#elif defined(SYS_WINDOWS)
  auto osName    = Q("Windows");
  auto osVersion = QString{};

#elif defined(SYS_LINUX)
  auto osName    = Q("Linux");
  auto osVersion = QString{};

#elif defined(SYS_APPLE)
  auto osName    = Q("macOS");
  auto osVersion = QString{};

#else
  auto osName    = Q("unknown");
  auto osVersion = QString{};
#endif

  info << Q("* Name: %1").arg(osName);
  info << Q("* Version: %1").arg(osVersion.isEmpty() ? Q("unknown") : osVersion);
}

void
gatherScreenInfo(QStringList &info) {
  info << Q("") << Q("## Screens");

  int idx = 0;
  for (auto const &screen : App::screens()) {
    info << Q("") << Q("### Screen %1").arg(idx++) << Q("");
    info << Q("* Device pixel ratio: %1").arg(screen->devicePixelRatio());
    info << Q("* Logical DPI: %1x%2").arg(screen->logicalDotsPerInchX()).arg(screen->logicalDotsPerInchX());
    info << Q("* Physical DPI: %1x%2").arg(screen->physicalDotsPerInchX()).arg(screen->physicalDotsPerInchX());
    info << Q("* Physical size: %1x%2").arg(screen->physicalSize().width()).arg(screen->physicalSize().height());
    info << Q("* Virtual size: %1x%2").arg(screen->virtualSize().width()).arg(screen->virtualSize().height());
    info << Q("* Geometry: %1x%2@%3x%4").arg(screen->geometry().width()).arg(screen->geometry().height()).arg(screen->geometry().x()).arg(screen->geometry().y());
  }

#if defined(SYS_WINDOWS)
  QSettings reg{Q("HKEY_CURRENT_USER\\Control Panel\\Desktop"), QSettings::NativeFormat};

  info << Q("") << Q("### Desktop scaling settings") << Q("");

  info << Q("* Scaling mode (`Win8DpiScaling`): %1").arg(reg.value("Win8DpiScaling", "not set").toString());
  info << Q("* Scaling override (`DesktopDPIOverride`): %1").arg(reg.value("DesktopDPIOverride", "not set").toString());
  info << Q("* System-wide scale factor (`LogPixels`): %1").arg(reg.value("LogPixels", "not set").toString());
#endif
}

void
gatherQtInfo(QStringList &info) {
  info << Q("") << Q("# Qt") << Q("");

  info << Q("* Version: %1.%2.%3").arg((QT_VERSION >> 16) & 0xff).arg((QT_VERSION >> 8) & 0xff).arg(QT_VERSION & 0xff);

  info << Q("") << Q("## Environment variables") << Q("");

  auto keys = QStringList{} << Q("QT_AUTO_SCREEN_SCALE_FACTOR") << Q("QT_SCALE_FACTOR") << Q("QT_SCREEN_SCALE_FACTORS") << Q("QT_DEVICE_PIXEL_RATIO");
  for (auto const &name : keys)
    info << Q("* `%1=%2`").arg(name).arg(Q(mtx::sys::get_environment_variable(to_utf8(name))));
}

} // anonymous namespace

QString
gatherSystemInformation() {
  QStringList info;

  gatherGeneralInfo(info);

  info << Q("") << Q("# System");

  gatherOperatingSystemInfo(info);
  gatherScreenInfo(info);
  gatherQtInfo(info);

  return info.join(Q("\n"));
}

}}}
