/*  PCSX2 - PS2 Emulator for PCs
 *  Copyright (C) 2002-2022  PCSX2 Dev Team
 *
 *  PCSX2 is free software: you can redistribute it and/or modify it under the terms
 *  of the GNU Lesser General Public License as published by the Free Software Found-
 *  ation, either version 3 of the License, or (at your option) any later version.
 *
 *  PCSX2 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 General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along with PCSX2.
 *  If not, see <http://www.gnu.org/licenses/>.
 */

#include "PrecompiledHeader.h"

#include <cmath>
#include <csignal>

#include "common/Assertions.h"
#include "common/Console.h"
#include "common/CrashHandler.h"
#include "common/Exceptions.h"
#include "common/FileSystem.h"
#include "common/Path.h"
#include "common/SettingsWrapper.h"
#include "common/StringUtil.h"
#include "common/Timer.h"

#include "pcsx2/CDVD/CDVD.h"
#include "pcsx2/CDVD/CDVDcommon.h"
#include "pcsx2/Counters.h"
#include "pcsx2/DebugTools/Debug.h"
#include "pcsx2/Frontend/CommonHost.h"
#include "pcsx2/Frontend/FullscreenUI.h"
#include "pcsx2/Frontend/GameList.h"
#include "pcsx2/Frontend/InputManager.h"
#include "pcsx2/Frontend/ImGuiManager.h"
#include "pcsx2/Frontend/LogSink.h"
#include "pcsx2/GS.h"
#include "pcsx2/GS/GS.h"
#include "pcsx2/GSDumpReplayer.h"
#include "pcsx2/HostDisplay.h"
#include "pcsx2/HostSettings.h"
#include "pcsx2/INISettingsInterface.h"
#include "pcsx2/PAD/Host/PAD.h"
#include "pcsx2/PerformanceMetrics.h"
#include "pcsx2/VMManager.h"

#include <QtCore/QTimer>
#include <QtWidgets/QApplication>
#include <QtWidgets/QMessageBox>
#include <QtGui/QClipboard>
#include <QtGui/QInputMethod>

#include "fmt/core.h"

#include "DisplayWidget.h"
#include "GameList/GameListWidget.h"
#include "MainWindow.h"
#include "QtHost.h"
#include "QtUtils.h"
#include "svnrev.h"

#ifdef ENABLE_ACHIEVEMENTS
#include "Frontend/Achievements.h"
#endif

static constexpr u32 SETTINGS_SAVE_DELAY = 1000;

EmuThread* g_emu_thread = nullptr;

//////////////////////////////////////////////////////////////////////////
// Local function declarations
//////////////////////////////////////////////////////////////////////////
namespace QtHost {
static void PrintCommandLineVersion();
static void PrintCommandLineHelp(const std::string_view& progname);
static std::shared_ptr<VMBootParameters>& AutoBoot(std::shared_ptr<VMBootParameters>& autoboot);
static bool ParseCommandLineOptions(const QStringList& args, std::shared_ptr<VMBootParameters>& autoboot);
static bool InitializeConfig();
static void SaveSettings();
static void HookSignals();
}

//////////////////////////////////////////////////////////////////////////
// Local variable declarations
//////////////////////////////////////////////////////////////////////////
const IConsoleWriter* PatchesCon = &Console;
static std::unique_ptr<QTimer> s_settings_save_timer;
static std::unique_ptr<INISettingsInterface> s_base_settings_interface;
static bool s_batch_mode = false;
static bool s_nogui_mode = false;
static bool s_start_fullscreen_ui = false;
static bool s_start_fullscreen_ui_fullscreen = false;

//////////////////////////////////////////////////////////////////////////
// CPU Thread
//////////////////////////////////////////////////////////////////////////

EmuThread::EmuThread(QThread* ui_thread)
	: QThread()
	, m_ui_thread(ui_thread)
{
}

EmuThread::~EmuThread() = default;

bool EmuThread::isOnEmuThread() const
{
	return QThread::currentThread() == this;
}

void EmuThread::start()
{
	pxAssertRel(!g_emu_thread, "Emu thread does not exist");

	g_emu_thread = new EmuThread(QThread::currentThread());
	g_emu_thread->QThread::start();
	g_emu_thread->m_started_semaphore.acquire();
	g_emu_thread->moveToThread(g_emu_thread);
}

void EmuThread::stop()
{
	pxAssertRel(g_emu_thread, "Emu thread exists");
	pxAssertRel(!g_emu_thread->isOnEmuThread(), "Not called on the emu thread");

	QMetaObject::invokeMethod(g_emu_thread, &EmuThread::stopInThread, Qt::QueuedConnection);
	while (g_emu_thread->isRunning())
		QApplication::processEvents(QEventLoop::ExcludeUserInputEvents, 1);
}

void EmuThread::stopInThread()
{
	if (VMManager::HasValidVM())
		destroyVM();

	if (m_run_fullscreen_ui)
		stopFullscreenUI();

	m_event_loop->quit();
	m_shutdown_flag.store(true);
}

bool EmuThread::confirmMessage(const QString& title, const QString& message)
{
	if (!isOnEmuThread())
	{
		// This is definitely deadlock risky, but unlikely to happen (why would GS be confirming?).
		bool result = false;
		QMetaObject::invokeMethod(g_emu_thread, "confirmMessage", Qt::BlockingQueuedConnection,
			Q_RETURN_ARG(bool, result), Q_ARG(const QString&, title), Q_ARG(const QString&, message));
		return result;
	}

	// Easy if there's no VM.
	if (!VMManager::HasValidVM())
		return emit messageConfirmed(title, message);

	// Preemptively pause/set surfaceless on the emu thread, because it can't run while the popup is open.
	const bool was_paused = (VMManager::GetState() == VMState::Paused);
	const bool was_fullscreen = isFullscreen();
	if (!was_paused)
		VMManager::SetPaused(true);
	if (was_fullscreen)
		setSurfaceless(true);

	// This won't return until the user confirms one way or another.
	const bool result = emit messageConfirmed(title, message);

	// Resume VM after confirming.
	if (was_fullscreen)
		setSurfaceless(false);
	if (!was_paused)
		VMManager::SetPaused(false);

	return result;
}

void EmuThread::startFullscreenUI(bool fullscreen)
{
	if (!isOnEmuThread())
	{
		QMetaObject::invokeMethod(this, "startFullscreenUI", Qt::QueuedConnection, Q_ARG(bool, fullscreen));
		return;
	}

	if (VMManager::HasValidVM())
		return;

	m_run_fullscreen_ui = true;
	if (fullscreen)
		m_is_fullscreen = true;

	if (!GetMTGS().WaitForOpen())
	{
		m_run_fullscreen_ui = false;
		return;
	}

	// poll more frequently so we don't lose events
	stopBackgroundControllerPollTimer();
	startBackgroundControllerPollTimer();
}

void EmuThread::stopFullscreenUI()
{
	if (!isOnEmuThread())
	{
		QMetaObject::invokeMethod(this, &EmuThread::stopFullscreenUI, Qt::QueuedConnection);

		// wait until the host display is gone
		while (g_host_display)
			QApplication::processEvents(QEventLoop::ExcludeUserInputEvents, 1);

		return;
	}

	if (!g_host_display)
		return;

	pxAssertRel(!VMManager::HasValidVM(), "VM is not valid at FSUI shutdown time");
	m_run_fullscreen_ui = false;
	GetMTGS().WaitForClose();
}

void EmuThread::startVM(std::shared_ptr<VMBootParameters> boot_params)
{
	if (!isOnEmuThread())
	{
		QMetaObject::invokeMethod(this, "startVM", Qt::QueuedConnection,
			Q_ARG(std::shared_ptr<VMBootParameters>, boot_params));
		return;
	}

	pxAssertRel(!VMManager::HasValidVM(), "VM is shut down");

	// Determine whether to start fullscreen or not.
	if (boot_params->fullscreen.has_value())
		m_is_fullscreen = boot_params->fullscreen.value();
	else
		m_is_fullscreen = Host::GetBaseBoolSettingValue("UI", "StartFullscreen", false);

	if (!VMManager::Initialize(*boot_params))
		return;

	if (!Host::GetBoolSettingValue("UI", "StartPaused", false))
	{
		// This will come back and call OnVMResumed().
		VMManager::SetState(VMState::Running);
	}
	else
	{
		// When starting paused, redraw the window, so there's at least something there.
		redrawDisplayWindow();
		Host::OnVMPaused();
	}

	m_event_loop->quit();
}

void EmuThread::resetVM()
{
	if (!isOnEmuThread())
	{
		QMetaObject::invokeMethod(this, &EmuThread::resetVM, Qt::QueuedConnection);
		return;
	}

	VMManager::Reset();
}

void EmuThread::setVMPaused(bool paused)
{
	if (!isOnEmuThread())
	{
		QMetaObject::invokeMethod(this, "setVMPaused", Qt::QueuedConnection, Q_ARG(bool, paused));
		return;
	}

	VMManager::SetPaused(paused);
}

void EmuThread::shutdownVM(bool save_state /* = true */)
{
	if (!isOnEmuThread())
	{
		QMetaObject::invokeMethod(this, "shutdownVM", Qt::QueuedConnection, Q_ARG(bool, save_state));
		return;
	}

	const VMState state = VMManager::GetState();
	if (state == VMState::Paused)
		m_event_loop->quit();
	else if (state != VMState::Running)
		return;

	m_save_state_on_shutdown = save_state;
	VMManager::SetState(VMState::Stopping);
}

void EmuThread::loadState(const QString& filename)
{
	if (!isOnEmuThread())
	{
		QMetaObject::invokeMethod(this, "loadState", Qt::QueuedConnection, Q_ARG(const QString&, filename));
		return;
	}

	if (!VMManager::HasValidVM())
		return;

	VMManager::LoadState(filename.toUtf8().constData());
}

void EmuThread::loadStateFromSlot(qint32 slot)
{
	if (!isOnEmuThread())
	{
		QMetaObject::invokeMethod(this, "loadStateFromSlot", Qt::QueuedConnection, Q_ARG(qint32, slot));
		return;
	}

	if (!VMManager::HasValidVM())
		return;

	VMManager::LoadStateFromSlot(slot);
}

void EmuThread::saveState(const QString& filename)
{
	if (!isOnEmuThread())
	{
		QMetaObject::invokeMethod(this, "saveState", Qt::QueuedConnection, Q_ARG(const QString&, filename));
		return;
	}

	if (!VMManager::HasValidVM())
		return;

	if (!VMManager::SaveState(filename.toUtf8().constData()))
	{
		// this one is usually the result of a user-chosen path, so we can display a message box safely here
		Console.Error("Failed to save state");
	}
}

void EmuThread::saveStateToSlot(qint32 slot)
{
	if (!isOnEmuThread())
	{
		QMetaObject::invokeMethod(this, "saveStateToSlot", Qt::QueuedConnection, Q_ARG(qint32, slot));
		return;
	}

	if (!VMManager::HasValidVM())
		return;

	VMManager::SaveStateToSlot(slot);
}

void EmuThread::run()
{
	// Qt-specific initialization.
	m_event_loop = new QEventLoop();
	m_started_semaphore.release();
	connectSignals();

	// Common host initialization (VM setup, etc).
	CommonHost::CPUThreadInitialize();

	// Start background polling because the VM won't do it for us.
	createBackgroundControllerPollTimer();
	startBackgroundControllerPollTimer();

	// Main CPU thread loop.
	while (!m_shutdown_flag.load())
	{
		if (!VMManager::HasValidVM())
		{
			m_event_loop->exec();
			continue;
		}

		executeVM();
	}

	// Teardown in reverse order.
	stopBackgroundControllerPollTimer();
	destroyBackgroundControllerPollTimer();
	CommonHost::CPUThreadShutdown();

	// Move back to the UI thread, since we're no longer running.
	moveToThread(m_ui_thread);
	deleteLater();
}

void EmuThread::destroyVM()
{
	m_last_speed = 0.0f;
	m_last_game_fps = 0.0f;
	m_last_video_fps = 0.0f;
	m_last_internal_width = 0;
	m_last_internal_height = 0;
	m_was_paused_by_focus_loss = false;
	VMManager::Shutdown(m_save_state_on_shutdown);
	m_save_state_on_shutdown = false;
}

void EmuThread::executeVM()
{
	for (;;)
	{
		switch (VMManager::GetState())
		{
			case VMState::Initializing:
				pxFailRel("Shouldn't be in the starting state state");
				continue;

			case VMState::Paused:
				m_event_loop->exec();
				continue;

			case VMState::Running:
				m_event_loop->processEvents(QEventLoop::AllEvents);
				VMManager::Execute();
				continue;

			case VMState::Stopping:
				destroyVM();
				m_event_loop->processEvents(QEventLoop::AllEvents);
				return;

			default:
				continue;
		}
	}
}

void EmuThread::createBackgroundControllerPollTimer()
{
	pxAssert(!m_background_controller_polling_timer);
	m_background_controller_polling_timer = new QTimer(this);
	m_background_controller_polling_timer->setSingleShot(false);
	m_background_controller_polling_timer->setTimerType(Qt::CoarseTimer);
	connect(m_background_controller_polling_timer, &QTimer::timeout, this, &EmuThread::doBackgroundControllerPoll);
}

void EmuThread::destroyBackgroundControllerPollTimer()
{
	delete m_background_controller_polling_timer;
	m_background_controller_polling_timer = nullptr;
}

void EmuThread::startBackgroundControllerPollTimer()
{
	if (m_background_controller_polling_timer->isActive())
		return;

	m_background_controller_polling_timer->start(FullscreenUI::IsInitialized() ?
													 FULLSCREEN_UI_CONTROLLER_POLLING_INTERVAL :
                                                     BACKGROUND_CONTROLLER_POLLING_INTERVAL);
}

void EmuThread::stopBackgroundControllerPollTimer()
{
	if (!m_background_controller_polling_timer->isActive())
		return;

	m_background_controller_polling_timer->stop();
}

void EmuThread::doBackgroundControllerPoll()
{
	InputManager::PollSources();
}

void EmuThread::toggleFullscreen()
{
	if (!isOnEmuThread())
	{
		QMetaObject::invokeMethod(this, &EmuThread::toggleFullscreen, Qt::QueuedConnection);
		return;
	}

	setFullscreen(!m_is_fullscreen);
}

void EmuThread::setFullscreen(bool fullscreen)
{
	if (!isOnEmuThread())
	{
		QMetaObject::invokeMethod(this, "setFullscreen", Qt::QueuedConnection, Q_ARG(bool, fullscreen));
		return;
	}

	if (!GetMTGS().IsOpen() || m_is_fullscreen == fullscreen)
		return;

	// This will call back to us on the MTGS thread.
	m_is_fullscreen = fullscreen;
	GetMTGS().UpdateDisplayWindow();
	GetMTGS().WaitGS();

	// If we're using exclusive fullscreen, the refresh rate may have changed.
	UpdateVSyncRate();
}

void EmuThread::setSurfaceless(bool surfaceless)
{
	if (!isOnEmuThread())
	{
		QMetaObject::invokeMethod(this, "setSurfaceless", Qt::QueuedConnection, Q_ARG(bool, surfaceless));
		return;
	}

	if (!GetMTGS().IsOpen() || m_is_surfaceless == surfaceless)
		return;

	// If we went surfaceless and were running the fullscreen UI, stop MTGS running idle.
	// Otherwise, we'll keep trying to present to nothing.
	GetMTGS().SetRunIdle(!surfaceless && m_run_fullscreen_ui);

	// This will call back to us on the MTGS thread.
	m_is_surfaceless = surfaceless;
	GetMTGS().UpdateDisplayWindow();
	GetMTGS().WaitGS();
}

void EmuThread::applySettings()
{
	if (!isOnEmuThread())
	{
		QMetaObject::invokeMethod(this, &EmuThread::applySettings, Qt::QueuedConnection);
		return;
	}

	VMManager::ApplySettings();
}

void EmuThread::reloadGameSettings()
{
	if (!isOnEmuThread())
	{
		QMetaObject::invokeMethod(this, &EmuThread::reloadGameSettings, Qt::QueuedConnection);
		return;
	}

	// this will skip applying settings when they're not active
	VMManager::ReloadGameSettings();
}

void EmuThread::updateEmuFolders()
{
	if (!isOnEmuThread())
	{
		QMetaObject::invokeMethod(this, &EmuThread::updateEmuFolders, Qt::QueuedConnection);
		return;
	}

	Host::Internal::UpdateEmuFolders();
}

void EmuThread::connectSignals()
{
	connect(qApp, &QGuiApplication::applicationStateChanged, this, &EmuThread::onApplicationStateChanged);
}

void EmuThread::loadSettings(SettingsInterface& si, std::unique_lock<std::mutex>& lock)
{
	m_verbose_status = si.GetBoolValue("UI", "VerboseStatusBar", false);
	m_pause_on_focus_loss = si.GetBoolValue("UI", "PauseOnFocusLoss", false);
}

void Host::LoadSettings(SettingsInterface& si, std::unique_lock<std::mutex>& lock)
{
	CommonHost::LoadSettings(si, lock);
	g_emu_thread->loadSettings(si, lock);
}

void EmuThread::checkForSettingChanges(const Pcsx2Config& old_config)
{
	QMetaObject::invokeMethod(g_main_window, &MainWindow::checkForSettingChanges, Qt::QueuedConnection);

	if (g_host_display)
	{
		const bool render_to_main = shouldRenderToMain();
		if (!m_is_fullscreen && m_is_rendering_to_main != render_to_main)
		{
			m_is_rendering_to_main = render_to_main;
			GetMTGS().UpdateDisplayWindow();
			GetMTGS().WaitGS();
		}
	}

	updatePerformanceMetrics(true);
}

void Host::CheckForSettingsChanges(const Pcsx2Config& old_config)
{
	CommonHost::CheckForSettingsChanges(old_config);
	g_emu_thread->checkForSettingChanges(old_config);
}

bool EmuThread::shouldRenderToMain() const
{
	return !Host::GetBaseBoolSettingValue("UI", "RenderToSeparateWindow", false) && !QtHost::InNoGUIMode();
}

void EmuThread::toggleSoftwareRendering()
{
	if (!isOnEmuThread())
	{
		QMetaObject::invokeMethod(this, &EmuThread::toggleSoftwareRendering, Qt::QueuedConnection);
		return;
	}

	if (!VMManager::HasValidVM())
		return;

	GetMTGS().ToggleSoftwareRendering();
}

void EmuThread::switchRenderer(GSRendererType renderer)
{
	if (!isOnEmuThread())
	{
		QMetaObject::invokeMethod(this, "switchRenderer", Qt::QueuedConnection, Q_ARG(GSRendererType, renderer));
		return;
	}

	if (!VMManager::HasValidVM())
		return;

	GetMTGS().SwitchRenderer(renderer);
}

void EmuThread::changeDisc(CDVD_SourceType source, const QString& path)
{
	if (!isOnEmuThread())
	{
		QMetaObject::invokeMethod(this, "changeDisc", Qt::QueuedConnection, Q_ARG(CDVD_SourceType, source), Q_ARG(const QString&, path));
		return;
	}

	if (!VMManager::HasValidVM())
		return;

	VMManager::ChangeDisc(source, path.toStdString());
}

void EmuThread::reloadPatches()
{
	if (!isOnEmuThread())
	{
		QMetaObject::invokeMethod(this, &EmuThread::reloadPatches, Qt::QueuedConnection);
		return;
	}

	if (!VMManager::HasValidVM())
		return;

	VMManager::ReloadPatches(true, true);
}

void EmuThread::reloadInputSources()
{
	if (!isOnEmuThread())
	{
		QMetaObject::invokeMethod(this, &EmuThread::reloadInputSources, Qt::QueuedConnection);
		return;
	}

	std::unique_lock<std::mutex> lock = Host::GetSettingsLock();
	SettingsInterface* si = Host::GetSettingsInterface();
	SettingsInterface* bindings_si = Host::GetSettingsInterfaceForBindings();
	InputManager::ReloadSources(*si, lock);

	// skip loading bindings if we're not running, since it'll get done on startup anyway
	if (VMManager::HasValidVM())
		InputManager::ReloadBindings(*si, *bindings_si);
}

void EmuThread::reloadInputBindings()
{
	if (!isOnEmuThread())
	{
		QMetaObject::invokeMethod(this, &EmuThread::reloadInputBindings, Qt::QueuedConnection);
		return;
	}

	// skip loading bindings if we're not running, since it'll get done on startup anyway
	if (!VMManager::HasValidVM())
		return;

	auto lock = Host::GetSettingsLock();
	SettingsInterface* si = Host::GetSettingsInterface();
	SettingsInterface* bindings_si = Host::GetSettingsInterfaceForBindings();
	InputManager::ReloadBindings(*si, *bindings_si);
}

void EmuThread::requestDisplaySize(float scale)
{
	if (!isOnEmuThread())
	{
		QMetaObject::invokeMethod(this, "requestDisplaySize", Qt::QueuedConnection, Q_ARG(float, scale));
		return;
	}

	if (!VMManager::HasValidVM())
		return;

	VMManager::RequestDisplaySize(scale);
}

void EmuThread::enumerateInputDevices()
{
	if (!isOnEmuThread())
	{
		QMetaObject::invokeMethod(this, &EmuThread::enumerateInputDevices, Qt::QueuedConnection);
		return;
	}

	const std::vector<std::pair<std::string, std::string>> devs(InputManager::EnumerateDevices());
	QList<QPair<QString, QString>> qdevs;
	qdevs.reserve(devs.size());
	for (const std::pair<std::string, std::string>& dev : devs)
		qdevs.emplace_back(QString::fromStdString(dev.first), QString::fromStdString(dev.second));

	onInputDevicesEnumerated(qdevs);
}

void EmuThread::enumerateVibrationMotors()
{
	if (!isOnEmuThread())
	{
		QMetaObject::invokeMethod(this, &EmuThread::enumerateVibrationMotors, Qt::QueuedConnection);
		return;
	}

	const std::vector<InputBindingKey> motors(InputManager::EnumerateMotors());
	QList<InputBindingKey> qmotors;
	qmotors.reserve(motors.size());
	for (InputBindingKey key : motors)
		qmotors.push_back(key);

	onVibrationMotorsEnumerated(qmotors);
}

void EmuThread::connectDisplaySignals(DisplayWidget* widget)
{
	widget->disconnect(this);

	connect(widget, &DisplayWidget::windowResizedEvent, this, &EmuThread::onDisplayWindowResized);
	connect(widget, &DisplayWidget::windowRestoredEvent, this, &EmuThread::redrawDisplayWindow);
}

void EmuThread::onDisplayWindowResized(int width, int height, float scale)
{
	if (!g_host_display)
		return;

	GetMTGS().ResizeDisplayWindow(width, height, scale);
}

void EmuThread::onApplicationStateChanged(Qt::ApplicationState state)
{
	// NOTE: This is executed on the emu thread, not UI thread.
	if (!m_pause_on_focus_loss || !VMManager::HasValidVM())
		return;

	const bool focus_loss = (state != Qt::ApplicationActive);
	if (focus_loss)
	{
		if (!m_was_paused_by_focus_loss && VMManager::GetState() == VMState::Running)
		{
			m_was_paused_by_focus_loss = true;
			VMManager::SetPaused(true);
		}
	}
	else
	{
		if (m_was_paused_by_focus_loss)
		{
			m_was_paused_by_focus_loss = false;
			if (VMManager::GetState() == VMState::Paused)
				VMManager::SetPaused(false);
		}
	}
}

void EmuThread::redrawDisplayWindow()
{
	if (!isOnEmuThread())
	{
		QMetaObject::invokeMethod(this, &EmuThread::redrawDisplayWindow, Qt::QueuedConnection);
		return;
	}

	// If we're running, we're going to re-present anyway.
	if (!VMManager::HasValidVM() || VMManager::GetState() == VMState::Running)
		return;

	GetMTGS().RunOnGSThread([]() { GetMTGS().PresentCurrentFrame(); });
}

void EmuThread::runOnCPUThread(const std::function<void()>& func)
{
	func();
}

void EmuThread::queueSnapshot(quint32 gsdump_frames)
{
	if (!isOnEmuThread())
	{
		QMetaObject::invokeMethod(this, "queueSnapshot", Qt::QueuedConnection, Q_ARG(quint32, gsdump_frames));
		return;
	}

	if (!VMManager::HasValidVM())
		return;

	GetMTGS().RunOnGSThread([gsdump_frames]() {
		GSQueueSnapshot(std::string(), gsdump_frames);
	});
}

void EmuThread::updateDisplay()
{
	pxAssertRel(!isOnEmuThread(), "Not on emu thread");

	// finished with the display for now
	g_host_display->DoneCurrent();

	// but we should get it back after this call
	onUpdateDisplayRequested(m_is_fullscreen, !m_is_fullscreen && m_is_rendering_to_main, m_is_surfaceless);
	if (!g_host_display->MakeCurrent())
	{
		pxFailRel("Failed to recreate context after updating");
		return;
	}
}

bool EmuThread::acquireHostDisplay(RenderAPI api)
{
	pxAssertRel(!g_host_display, "Host display does not exist on create");
	m_is_rendering_to_main = shouldRenderToMain();
	m_is_surfaceless = false;

	g_host_display = HostDisplay::CreateForAPI(api);
	if (!g_host_display)
		return false;

	DisplayWidget* widget = emit onCreateDisplayRequested(m_is_fullscreen, m_is_rendering_to_main);
	if (!widget)
	{
		g_host_display.reset();
		return false;
	}

	connectDisplaySignals(widget);

	if (!g_host_display->MakeCurrent())
	{
		Console.Error("Failed to make render context current");
		releaseHostDisplay();
		return false;
	}

	if (!g_host_display->SetupDevice() || !ImGuiManager::Initialize())
	{
		Console.Error("Failed to initialize device/imgui");
		releaseHostDisplay();
		return false;
	}

	Console.WriteLn(Color_StrongGreen, "%s Graphics Driver Info:", HostDisplay::RenderAPIToString(g_host_display->GetRenderAPI()));
	Console.Indent().WriteLn(g_host_display->GetDriverInfo());

	if (m_run_fullscreen_ui && !FullscreenUI::Initialize())
	{
		Console.Error("Failed to initialize fullscreen UI");
		releaseHostDisplay();
		m_run_fullscreen_ui = false;
		return false;
	}

	return true;
}

void EmuThread::releaseHostDisplay()
{
	ImGuiManager::Shutdown();

	g_host_display.reset();
	emit onDestroyDisplayRequested();
}

bool Host::AcquireHostDisplay(RenderAPI api)
{
	return g_emu_thread->acquireHostDisplay(api);
}

void Host::ReleaseHostDisplay()
{
	g_emu_thread->releaseHostDisplay();
}

VsyncMode Host::GetEffectiveVSyncMode()
{
	// Force vsync on when running big picture UI, and paused or no VM.
	if (g_emu_thread->isRunningFullscreenUI())
	{
		const VMState state = VMManager::GetState();
		if (state == VMState::Shutdown || state == VMState::Paused)
			return VsyncMode::On;
	}

	// Force vsync off when not running at 100% speed.
	if (EmuConfig.GS.LimitScalar != 1.0f)
		return VsyncMode::Off;

	// Otherwise use the config setting.
	return EmuConfig.GS.VsyncEnable;
}

bool Host::BeginPresentFrame(bool frame_skip)
{
	if (!g_host_display->BeginPresent(frame_skip))
	{
		// if we're skipping a frame, we need to reset imgui's state, since
		// we won't be calling EndPresentFrame().
		ImGuiManager::NewFrame();
		return false;
	}

	return true;
}

void Host::EndPresentFrame()
{
	if (GSDumpReplayer::IsReplayingDump())
		GSDumpReplayer::RenderUI();

	FullscreenUI::Render();
	ImGuiManager::RenderOSD();
	g_host_display->EndPresent();
	ImGuiManager::NewFrame();
}

void Host::ResizeHostDisplay(u32 new_window_width, u32 new_window_height, float new_window_scale)
{
	g_host_display->ResizeWindow(new_window_width, new_window_height, new_window_scale);
	ImGuiManager::WindowResized();

	// if we're paused, re-present the current frame at the new window size.
	if (VMManager::GetState() == VMState::Paused)
		GetMTGS().PresentCurrentFrame();
}

void Host::RequestResizeHostDisplay(s32 width, s32 height)
{
	g_emu_thread->onResizeDisplayRequested(width, height);
}

void Host::UpdateHostDisplay()
{
	g_emu_thread->updateDisplay();
	ImGuiManager::WindowResized();

	// if we're paused, re-present the current frame at the new window size.
	if (VMManager::GetState() == VMState::Paused)
		GetMTGS().PresentCurrentFrame();
}

void Host::OnVMStarting()
{
	CommonHost::OnVMStarting();
	g_emu_thread->stopBackgroundControllerPollTimer();
	emit g_emu_thread->onVMStarting();
}

void Host::OnVMStarted()
{
	CommonHost::OnVMStarted();
	emit g_emu_thread->onVMStarted();
}

void Host::OnVMDestroyed()
{
	CommonHost::OnVMDestroyed();
	emit g_emu_thread->onVMStopped();
	g_emu_thread->startBackgroundControllerPollTimer();
}

void Host::OnVMPaused()
{
	CommonHost::OnVMPaused();
	g_emu_thread->startBackgroundControllerPollTimer();
	emit g_emu_thread->onVMPaused();
}

void Host::OnVMResumed()
{
	CommonHost::OnVMResumed();

	// exit the event loop when we eventually return
	g_emu_thread->getEventLoop()->quit();
	g_emu_thread->stopBackgroundControllerPollTimer();

	// if we were surfaceless (view->game list, system->unpause), get our display widget back
	if (g_emu_thread->isSurfaceless())
		g_emu_thread->setSurfaceless(false);

	emit g_emu_thread->onVMResumed();
}

void Host::OnGameChanged(const std::string& disc_path, const std::string& game_serial, const std::string& game_name, u32 game_crc)
{
	CommonHost::OnGameChanged(disc_path, game_serial, game_name, game_crc);
	emit g_emu_thread->onGameChanged(QString::fromStdString(disc_path), QString::fromStdString(game_serial), QString::fromStdString(game_name), game_crc);
}

void EmuThread::updatePerformanceMetrics(bool force)
{
	if (m_verbose_status && VMManager::HasValidVM())
	{
		std::string gs_stat_str;
		GSgetTitleStats(gs_stat_str);

		QString gs_stat;
		if (THREAD_VU1)
		{
			gs_stat =
				QStringLiteral("%1 | EE: %2% | VU: %3% | GS: %4%")
					.arg(gs_stat_str.c_str())
					.arg(PerformanceMetrics::GetCPUThreadUsage(), 0, 'f', 0)
					.arg(PerformanceMetrics::GetVUThreadUsage(), 0, 'f', 0)
					.arg(PerformanceMetrics::GetGSThreadUsage(), 0, 'f', 0);
		}
		else
		{
			gs_stat = QStringLiteral("%1 | EE: %2% | GS: %3%")
						  .arg(gs_stat_str.c_str())
						  .arg(PerformanceMetrics::GetCPUThreadUsage(), 0, 'f', 0)
						  .arg(PerformanceMetrics::GetGSThreadUsage(), 0, 'f', 0);
		}

		QMetaObject::invokeMethod(g_main_window->getStatusVerboseWidget(), "setText", Qt::QueuedConnection, Q_ARG(const QString&, gs_stat));
	}

	const GSRendererType renderer = GSConfig.Renderer;
	const float speed = std::round(PerformanceMetrics::GetSpeed());
	const float gfps = std::round(PerformanceMetrics::GetInternalFPS());
	const float vfps = std::round(PerformanceMetrics::GetFPS());
	int iwidth, iheight;
	GSgetInternalResolution(&iwidth, &iheight);

	if (iwidth != m_last_internal_width || iheight != m_last_internal_height ||
		speed != m_last_speed || gfps != m_last_game_fps || vfps != m_last_video_fps ||
		renderer != m_last_renderer || force)
	{
		if (iwidth == 0 && iheight == 0)
		{
			// if we don't have width/height yet, we're not going to have fps either.
			// and we'll probably be <100% due to compiling. so just leave it blank for now.
			QString blank;
			QMetaObject::invokeMethod(g_main_window->getStatusRendererWidget(), "setText", Qt::QueuedConnection, Q_ARG(const QString&, blank));
			QMetaObject::invokeMethod(g_main_window->getStatusResolutionWidget(), "setText", Qt::QueuedConnection, Q_ARG(const QString&, blank));
			QMetaObject::invokeMethod(g_main_window->getStatusFPSWidget(), "setText", Qt::QueuedConnection, Q_ARG(const QString&, blank));
			QMetaObject::invokeMethod(g_main_window->getStatusVPSWidget(), "setText", Qt::QueuedConnection, Q_ARG(const QString&, blank));
			return;
		}
		else
		{
			if (renderer != m_last_renderer || force)
			{
				QMetaObject::invokeMethod(g_main_window->getStatusRendererWidget(), "setText", Qt::QueuedConnection,
					Q_ARG(const QString&, QString::fromUtf8(Pcsx2Config::GSOptions::GetRendererName(renderer))));
				m_last_renderer = renderer;
			}
			if (iwidth != m_last_internal_width || iheight != m_last_internal_height || force)
			{
				QMetaObject::invokeMethod(g_main_window->getStatusResolutionWidget(), "setText", Qt::QueuedConnection,
					Q_ARG(const QString&, tr("%1x%2")
											  .arg(iwidth)
											  .arg(iheight)));
				m_last_internal_width = iwidth;
				m_last_internal_height = iheight;
			}

			if (gfps != m_last_game_fps || force)
			{
				QMetaObject::invokeMethod(g_main_window->getStatusFPSWidget(), "setText", Qt::QueuedConnection,
					Q_ARG(const QString&, tr("Game: %1 FPS")
											  .arg(gfps, 0, 'f', 0)));
				m_last_game_fps = gfps;
			}

			if (speed != m_last_speed || vfps != m_last_video_fps || force)
			{
				QMetaObject::invokeMethod(g_main_window->getStatusVPSWidget(), "setText", Qt::QueuedConnection,
					Q_ARG(const QString&, tr("Video: %1 FPS (%2%)")
											  .arg(vfps, 0, 'f', 0)
											  .arg(speed, 0, 'f', 0)));
				m_last_speed = speed;
				m_last_video_fps = vfps;
			}
		}
	}
}

void Host::OnPerformanceMetricsUpdated()
{
	g_emu_thread->updatePerformanceMetrics(false);
}

void Host::OnSaveStateLoading(const std::string_view& filename)
{
	emit g_emu_thread->onSaveStateLoading(QtUtils::StringViewToQString(filename));
}

void Host::OnSaveStateLoaded(const std::string_view& filename, bool was_successful)
{
	emit g_emu_thread->onSaveStateLoaded(QtUtils::StringViewToQString(filename), was_successful);
}

void Host::OnSaveStateSaved(const std::string_view& filename)
{
	emit g_emu_thread->onSaveStateSaved(QtUtils::StringViewToQString(filename));
}

#ifdef ENABLE_ACHIEVEMENTS
void Host::OnAchievementsRefreshed()
{
	u32 game_id = 0;
	u32 achievement_count = 0;
	u32 max_points = 0;

	QString game_info;

	if (Achievements::HasActiveGame())
	{
		game_id = Achievements::GetGameID();
		achievement_count = Achievements::GetAchievementCount();
		max_points = Achievements::GetMaximumPointsForGame();

		game_info = qApp->translate("EmuThread",
							"Game ID: %1\n"
							"Game Title: %2\n"
							"Achievements: %5 (%6)\n\n")
						.arg(game_id)
						.arg(QString::fromStdString(Achievements::GetGameTitle()))
						.arg(achievement_count)
						.arg(qApp->translate("EmuThread", "%n points", "", max_points));

		const std::string rich_presence_string(Achievements::GetRichPresenceString());
		if (!rich_presence_string.empty())
			game_info.append(QString::fromStdString(rich_presence_string));
		else
			game_info.append(qApp->translate("EmuThread", "Rich presence inactive or unsupported."));
	}
	else
	{
		game_info = qApp->translate("EmuThread", "Game not loaded or no RetroAchievements available.");
	}

	emit g_emu_thread->onAchievementsRefreshed(game_id, game_info, achievement_count, max_points);
}
#endif

void Host::CPUThreadVSync()
{
	g_emu_thread->getEventLoop()->processEvents(QEventLoop::AllEvents);
	CommonHost::CPUThreadVSync();
}

void Host::RunOnCPUThread(std::function<void()> function, bool block /* = false */)
{
	if (g_emu_thread->isOnEmuThread())
	{
		// probably shouldn't ever happen, but just in case..
		function();
		return;
	}

	QMetaObject::invokeMethod(g_emu_thread, "runOnCPUThread",
		block ? Qt::BlockingQueuedConnection : Qt::QueuedConnection,
		Q_ARG(const std::function<void()>&, std::move(function)));
}

void Host::RefreshGameListAsync(bool invalidate_cache)
{
	QMetaObject::invokeMethod(g_main_window, "refreshGameList", Qt::QueuedConnection,
		Q_ARG(bool, invalidate_cache));
}

void Host::CancelGameListRefresh()
{
	QMetaObject::invokeMethod(g_main_window, "cancelGameListRefresh", Qt::BlockingQueuedConnection);
}

void Host::RequestExit(bool save_state_if_running)
{
	if (VMManager::HasValidVM())
		g_emu_thread->shutdownVM(save_state_if_running);

	QMetaObject::invokeMethod(g_main_window, "requestExit", Qt::QueuedConnection);
}

void Host::RequestVMShutdown(bool allow_confirm, bool allow_save_state, bool default_save_state)
{
	if (!VMManager::HasValidVM())
		return;

	// Run it on the host thread, that way we get the confirm prompt (if enabled).
	QMetaObject::invokeMethod(g_main_window, "requestShutdown", Qt::QueuedConnection,
		Q_ARG(bool, allow_confirm), Q_ARG(bool, allow_save_state),
		Q_ARG(bool, default_save_state), Q_ARG(bool, false));
}

bool Host::IsFullscreen()
{
	return g_emu_thread->isFullscreen();
}

void Host::SetFullscreen(bool enabled)
{
	g_emu_thread->setFullscreen(enabled);
}

alignas(16) static SysMtgsThread s_mtgs_thread;

SysMtgsThread& GetMTGS()
{
	return s_mtgs_thread;
}

bool QtHost::InitializeConfig()
{
	if (!CommonHost::InitializeCriticalFolders())
	{
		QMessageBox::critical(nullptr, QStringLiteral("PCSX2"),
			QStringLiteral("One or more critical directories are missing, your installation may be incomplete."));
		return false;
	}

	const std::string path(Path::Combine(EmuFolders::Settings, "PCSX2.ini"));
	Console.WriteLn("Loading config from %s.", path.c_str());

	s_base_settings_interface = std::make_unique<INISettingsInterface>(std::move(path));
	Host::Internal::SetBaseSettingsLayer(s_base_settings_interface.get());
	if (!s_base_settings_interface->Load() || !CommonHost::CheckSettingsVersion())
	{
		// If the config file doesn't exist, assume this is a new install and don't prompt to overwrite.
		if (FileSystem::FileExists(s_base_settings_interface->GetFileName().c_str()) &&
			QMessageBox::question(nullptr, QStringLiteral("PCSX2"),
				QStringLiteral("Settings failed to load, or are the incorrect version. Clicking Yes will reset all settings to defaults. Do you want to continue?")) != QMessageBox::Yes)
		{
			return false;
		}

		CommonHost::SetDefaultSettings(*s_base_settings_interface, true, true, true, true, true);
		SaveSettings();
	}

	CommonHost::SetBlockSystemConsole(QtHost::InNoGUIMode());
	CommonHost::LoadStartupSettings();
	return true;
}

void Host::SetDefaultUISettings(SettingsInterface& si)
{
	si.SetBoolValue("UI", "InhibitScreensaver", true);
	si.SetBoolValue("UI", "ConfirmShutdown", true);
	si.SetBoolValue("UI", "StartPaused", false);
	si.SetBoolValue("UI", "PauseOnFocusLoss", false);
	si.SetBoolValue("UI", "StartFullscreen", false);
	si.SetBoolValue("UI", "DoubleClickTogglesFullscreen", true);
	si.SetBoolValue("UI", "HideMouseCursor", false);
	si.SetBoolValue("UI", "RenderToSeparateWindow", false);
	si.SetBoolValue("UI", "HideMainWindowWhenRunning", false);
	si.SetBoolValue("UI", "DisableWindowResize", false);
	si.SetStringValue("UI", "Theme", MainWindow::DEFAULT_THEME_NAME);
}

void QtHost::SaveSettings()
{
	pxAssertRel(!g_emu_thread->isOnEmuThread(), "Saving should happen on the UI thread.");

	{
		auto lock = Host::GetSettingsLock();
		if (!s_base_settings_interface->Save())
			Console.Error("Failed to save settings.");
	}

	s_settings_save_timer->deleteLater();
	s_settings_save_timer.release();
}

void Host::CommitBaseSettingChanges()
{
	if (!QtHost::IsOnUIThread())
	{
		QtHost::RunOnUIThread(&Host::CommitBaseSettingChanges);
		return;
	}

	auto lock = Host::GetSettingsLock();
	if (s_settings_save_timer)
		return;

	s_settings_save_timer = std::make_unique<QTimer>();
	s_settings_save_timer->connect(s_settings_save_timer.get(), &QTimer::timeout, &QtHost::SaveSettings);
	s_settings_save_timer->setSingleShot(true);
	s_settings_save_timer->start(SETTINGS_SAVE_DELAY);
}

bool QtHost::InBatchMode()
{
	return s_batch_mode;
}

bool QtHost::InNoGUIMode()
{
	return s_nogui_mode;
}

bool QtHost::IsOnUIThread()
{
	QThread* ui_thread = qApp->thread();
	return (QThread::currentThread() == ui_thread);
}

void QtHost::RunOnUIThread(const std::function<void()>& func, bool block /*= false*/)
{
	// main window always exists, so it's fine to attach it to that.
	QMetaObject::invokeMethod(g_main_window, "runOnUIThread",
		block ? Qt::BlockingQueuedConnection : Qt::QueuedConnection,
		Q_ARG(const std::function<void()>&, func));
}

bool Host::RequestResetSettings(bool folders, bool core, bool controllers, bool hotkeys, bool ui)
{
	{
		auto lock = Host::GetSettingsLock();
		CommonHost::SetDefaultSettings(*s_base_settings_interface.get(), folders, core, controllers, hotkeys, ui);
	}
	Host::CommitBaseSettingChanges();

	g_emu_thread->applySettings();
	if (folders)
		g_emu_thread->updateEmuFolders();

	return true;
}

QString QtHost::GetAppNameAndVersion()
{
	QString ret;
	if constexpr (!PCSX2_isReleaseVersion && GIT_TAGGED_COMMIT)
	{
		ret = QStringLiteral("PCSX2 Nightly - " GIT_TAG);
	}
	else if constexpr (PCSX2_isReleaseVersion)
	{
#define APPNAME_STRINGIZE(x) #x
		ret = QStringLiteral("PCSX2 "
			APPNAME_STRINGIZE(PCSX2_VersionHi) "."
			APPNAME_STRINGIZE(PCSX2_VersionMid) "."
			APPNAME_STRINGIZE(PCSX2_VersionLo));
#undef APPNAME_STRINGIZE
	}
	else
	{
		return QStringLiteral("PCSX2 " GIT_REV);
	}

	return ret;
}

QString QtHost::GetAppConfigSuffix()
{
#if defined(PCSX2_DEBUG)
	return QStringLiteral(" [Debug]");
#elif defined(PCSX2_DEVBUILD)
	return QStringLiteral(" [Devel]");
#else
	return QString();
#endif
}

QString QtHost::GetResourcesBasePath()
{
	return QString::fromStdString(EmuFolders::Resources);
}

std::optional<std::vector<u8>> Host::ReadResourceFile(const char* filename)
{
	const std::string path(Path::Combine(EmuFolders::Resources, filename));
	std::optional<std::vector<u8>> ret(FileSystem::ReadBinaryFile(path.c_str()));
	if (!ret.has_value())
		Console.Error("Failed to read resource file '%s'", filename);
	return ret;
}

std::optional<std::string> Host::ReadResourceFileToString(const char* filename)
{
	const std::string path(Path::Combine(EmuFolders::Resources, filename));
	std::optional<std::string> ret(FileSystem::ReadFileToString(path.c_str()));
	if (!ret.has_value())
		Console.Error("Failed to read resource file to string '%s'", filename);
	return ret;
}

std::optional<std::time_t> Host::GetResourceFileTimestamp(const char* filename)
{
	const std::string path(Path::Combine(EmuFolders::Resources, filename));
	FILESYSTEM_STAT_DATA sd;
	if (!FileSystem::StatFile(filename, &sd))
		return std::nullopt;

	return sd.ModificationTime;
}

void Host::ReportErrorAsync(const std::string_view& title, const std::string_view& message)
{
	if (!title.empty() && !message.empty())
	{
		Console.Error("ReportErrorAsync: %.*s: %.*s",
			static_cast<int>(title.size()), title.data(),
			static_cast<int>(message.size()), message.data());
	}
	else if (!message.empty())
	{
		Console.Error("ReportErrorAsync: %.*s",
			static_cast<int>(message.size()), message.data());
	}

	QMetaObject::invokeMethod(g_main_window, "reportError", Qt::QueuedConnection,
		Q_ARG(const QString&, title.empty() ? QString() : QString::fromUtf8(title.data(), title.size())),
		Q_ARG(const QString&, message.empty() ? QString() : QString::fromUtf8(message.data(), message.size())));
}

bool Host::ConfirmMessage(const std::string_view& title, const std::string_view& message)
{
	const QString qtitle(QString::fromUtf8(title.data(), title.size()));
	const QString qmessage(QString::fromUtf8(message.data(), message.size()));
	return g_emu_thread->confirmMessage(qtitle, qmessage);
}

void Host::OpenURL(const std::string_view& url)
{
	QtHost::RunOnUIThread([url = QtUtils::StringViewToQString(url)]() {
		QtUtils::OpenURL(g_main_window, QUrl(url));
	});
}

bool Host::CopyTextToClipboard(const std::string_view& text)
{
	QtHost::RunOnUIThread([text = QtUtils::StringViewToQString(text)]() {
		QClipboard* clipboard = QGuiApplication::clipboard();
		if (clipboard)
			clipboard->setText(text);
	});
	return true;
}

void Host::BeginTextInput()
{
	QInputMethod* method = qApp->inputMethod();
	if (method)
		QMetaObject::invokeMethod(method, "show", Qt::QueuedConnection);
}

void Host::EndTextInput()
{
	QInputMethod* method = qApp->inputMethod();
	if (method)
		QMetaObject::invokeMethod(method, "hide", Qt::QueuedConnection);
}

void Host::OnInputDeviceConnected(const std::string_view& identifier, const std::string_view& device_name)
{
	emit g_emu_thread->onInputDeviceConnected(
		identifier.empty() ? QString() : QString::fromUtf8(identifier.data(), identifier.size()),
		device_name.empty() ? QString() : QString::fromUtf8(device_name.data(), device_name.size()));
}

void Host::OnInputDeviceDisconnected(const std::string_view& identifier)
{
	emit g_emu_thread->onInputDeviceDisconnected(
		identifier.empty() ? QString() : QString::fromUtf8(identifier.data(), identifier.size()));
}

//////////////////////////////////////////////////////////////////////////
// Hotkeys
//////////////////////////////////////////////////////////////////////////

BEGIN_HOTKEY_LIST(g_host_hotkeys)
END_HOTKEY_LIST()


//////////////////////////////////////////////////////////////////////////
// Interface Stuff
//////////////////////////////////////////////////////////////////////////

static void SignalHandler(int signal)
{
	// First try the normal (graceful) shutdown/exit.
	static bool graceful_shutdown_attempted = false;
	if (!graceful_shutdown_attempted && g_main_window)
	{
		std::fprintf(stderr, "Received CTRL+C, attempting graceful shutdown. Press CTRL+C again to force.\n");
		graceful_shutdown_attempted = true;

		// This could be a bit risky invoking from a signal handler... hopefully it's okay.
		QMetaObject::invokeMethod(g_main_window, &MainWindow::requestExit, Qt::QueuedConnection);
		return;
	}

	std::signal(signal, SIG_DFL);

	// MacOS is missing std::quick_exit() despite it being C++11...
#ifndef __APPLE__
	std::quick_exit(1);
#else
	_Exit(1);
#endif
}

void QtHost::HookSignals()
{
	std::signal(SIGINT, SignalHandler);
	std::signal(SIGTERM, SignalHandler);

#ifdef __linux__
	// Ignore SIGCHLD by default on Linux, since we kick off aplay asynchronously.
	struct sigaction sa_chld = {};
	sigemptyset(&sa_chld.sa_mask);
	sa_chld.sa_flags = SA_SIGINFO | SA_RESTART | SA_NOCLDSTOP | SA_NOCLDWAIT;
	sigaction(SIGCHLD, &sa_chld, nullptr);
#endif
}

void QtHost::PrintCommandLineVersion()
{
	CommonHost::InitializeEarlyConsole();
	std::fprintf(stderr, "%s\n", (GetAppNameAndVersion() + GetAppConfigSuffix()).toUtf8().constData());
	std::fprintf(stderr, "https://pcsx2.net/\n");
	std::fprintf(stderr, "\n");
}

void QtHost::PrintCommandLineHelp(const std::string_view& progname)
{
	PrintCommandLineVersion();
	fmt::print(stderr, "Usage: {} [parameters] [--] [boot filename]\n", progname);
	std::fprintf(stderr, "\n");
	std::fprintf(stderr, "  -help: Displays this information and exits.\n");
	std::fprintf(stderr, "  -version: Displays version information and exits.\n");
	std::fprintf(stderr, "  -batch: Enables batch mode (exits after shutting down).\n");
	std::fprintf(stderr, "  -nogui: Hides main window while running (implies batch mode).\n");
	std::fprintf(stderr, "  -elf <file>: Overrides the boot ELF with the specified filename.\n");
	std::fprintf(stderr, "  -disc <path>: Uses the specified host DVD drive as a source.\n");
	std::fprintf(stderr, "  -bios: Starts the BIOS (System Menu/OSDSYS).\n");
	std::fprintf(stderr, "  -fastboot: Force fast boot for provided filename.\n");
	std::fprintf(stderr, "  -slowboot: Force slow boot for provided filename.\n");
	std::fprintf(stderr, "  -state <index>: Loads specified save state by index.\n");
	std::fprintf(stderr, "  -statefile <filename>: Loads state from the specified filename.\n");
	std::fprintf(stderr, "  -fullscreen: Enters fullscreen mode immediately after starting.\n");
	std::fprintf(stderr, "  -nofullscreen: Prevents fullscreen mode from triggering if enabled.\n");
	std::fprintf(stderr, "  -earlyconsolelog: Forces logging of early console messages to console.\n");
#ifdef ENABLE_RAINTEGRATION
	std::fprintf(stderr, "  -raintegration: Use RAIntegration instead of built-in achievement support.\n");
#endif
	std::fprintf(stderr, "  --: Signals that no more arguments will follow and the remaining\n"
						 "    parameters make up the filename. Use when the filename contains\n"
						 "    spaces or starts with a dash.\n");
	std::fprintf(stderr, "\n");
}

std::shared_ptr<VMBootParameters>& QtHost::AutoBoot(std::shared_ptr<VMBootParameters>& autoboot)
{
	if (!autoboot)
		autoboot = std::make_shared<VMBootParameters>();

	return autoboot;
}

bool QtHost::ParseCommandLineOptions(const QStringList& args, std::shared_ptr<VMBootParameters>& autoboot)
{
	bool no_more_args = false;

	if (args.empty())
	{
		// Nothing to do here.
		return true;
	}

	for (auto it = std::next(args.begin()); it != args.end(); ++it)
	{
		if (!no_more_args)
		{
#define CHECK_ARG(str) (*it == str)
#define CHECK_ARG_PARAM(str) (*it == str && std::next(it) != args.end())

			if (CHECK_ARG(QStringLiteral("-help")))
			{
				PrintCommandLineHelp(args.front().toStdString());
				return false;
			}
			else if (CHECK_ARG(QStringLiteral("-version")))
			{
				PrintCommandLineVersion();
				return false;
			}
			else if (CHECK_ARG(QStringLiteral("-batch")))
			{
				s_batch_mode = true;
				continue;
			}
			else if (CHECK_ARG(QStringLiteral("-nogui")))
			{
				s_batch_mode = true;
				s_nogui_mode = true;
				continue;
			}
			else if (CHECK_ARG(QStringLiteral("-fastboot")))
			{
				AutoBoot(autoboot)->fast_boot = true;
				continue;
			}
			else if (CHECK_ARG(QStringLiteral("-slowboot")))
			{
				AutoBoot(autoboot)->fast_boot = false;
				continue;
			}
			else if (CHECK_ARG_PARAM(QStringLiteral("-state")))
			{
				AutoBoot(autoboot)->state_index = (++it)->toInt();
				continue;
			}
			else if (CHECK_ARG_PARAM(QStringLiteral("-statefile")))
			{
				AutoBoot(autoboot)->save_state = (++it)->toStdString();
				continue;
			}
			else if (CHECK_ARG_PARAM(QStringLiteral("-elf")))
			{
				AutoBoot(autoboot)->elf_override = (++it)->toStdString();
				continue;
			}
			else if (CHECK_ARG_PARAM(QStringLiteral("-disc")))
			{
				AutoBoot(autoboot)->source_type = CDVD_SourceType::Disc;
				AutoBoot(autoboot)->filename = (++it)->toStdString();
				continue;
			}
			else if (CHECK_ARG(QStringLiteral("-bios")))
			{
				AutoBoot(autoboot)->source_type = CDVD_SourceType::NoDisc;
				continue;
			}
			else if (CHECK_ARG(QStringLiteral("-fullscreen")))
			{
				AutoBoot(autoboot)->fullscreen = true;
				s_start_fullscreen_ui_fullscreen = true;
				continue;
			}
			else if (CHECK_ARG(QStringLiteral("-nofullscreen")))
			{
				AutoBoot(autoboot)->fullscreen = false;
				continue;
			}
			else if (CHECK_ARG(QStringLiteral("-earlyconsolelog")))
			{
				CommonHost::InitializeEarlyConsole();
				continue;
			}
			else if (CHECK_ARG(QStringLiteral("-bigpicture")))
			{
				s_start_fullscreen_ui = true;
				continue;
			}
#ifdef ENABLE_RAINTEGRATION
			else if (CHECK_ARG(QStringLiteral("-raintegration")))
			{
				Achievements::SwitchToRAIntegration();
				continue;
			}
#endif
			else if (CHECK_ARG(QStringLiteral("--")))
			{
				no_more_args = true;
				continue;
			}
			else if ((*it)[0] == '-')
			{
				QMessageBox::critical(nullptr, QStringLiteral("Error"), QStringLiteral("Unknown parameter: '%1'").arg(*it));
				return false;
			}

#undef CHECK_ARG
#undef CHECK_ARG_PARAM
		}

		if (!AutoBoot(autoboot)->filename.empty())
			AutoBoot(autoboot)->filename += ' ';

		AutoBoot(autoboot)->filename += it->toStdString();
	}

	// check autoboot parameters, if we set something like fullscreen without a bios
	// or disc, we don't want to actually start.
	if (autoboot && !autoboot->source_type.has_value() && autoboot->filename.empty() && autoboot->elf_override.empty())
	{
		CommonHost::InitializeEarlyConsole();
		Console.Warning("Skipping autoboot due to no boot parameters.");
		autoboot.reset();
	}

	// if we don't have autoboot, we definitely don't want batch mode (because that'll skip
	// scanning the game list).
	if (s_batch_mode && !s_start_fullscreen_ui && !autoboot)
	{
		QMessageBox::critical(nullptr, QStringLiteral("Error"), s_nogui_mode ?
			QStringLiteral("Cannot use no-gui mode, because no boot filename was specified.") :
			QStringLiteral("Cannot use batch mode, because no boot filename was specified."));
		return false;
	}

	return true;
}

#ifndef _WIN32

// See note in EarlyHardwareChecks.cpp as to why we don't do this on Windows.
static bool PerformEarlyHardwareChecks()
{
	// NOTE: No point translating this message, because the configuration isn't loaded yet, so we
	// won't know which language to use, and loading the configuration uses float instructions.
	const char* error;
	if (VMManager::PerformEarlyHardwareChecks(&error))
		return true;

	QMessageBox::critical(nullptr, QStringLiteral("Hardware Check Failed"), QString::fromUtf8(error));
	return false;
}

#endif

static void RegisterTypes()
{
	qRegisterMetaType<std::optional<bool>>();
	qRegisterMetaType<std::function<void()>>("std::function<void()>");
	qRegisterMetaType<std::shared_ptr<VMBootParameters>>();
	qRegisterMetaType<GSRendererType>();
	qRegisterMetaType<InputBindingKey>();
	qRegisterMetaType<CDVD_SourceType>();
	qRegisterMetaType<const GameList::Entry*>();
}

int main(int argc, char* argv[])
{
	CrashHandler::Install();

	QGuiApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
	QGuiApplication::setAttribute(Qt::AA_UseHighDpiPixmaps);
	QGuiApplication::setHighDpiScaleFactorRoundingPolicy(Qt::HighDpiScaleFactorRoundingPolicy::PassThrough);
	RegisterTypes();

	QApplication app(argc, argv);

#ifndef _WIN32
	if (!PerformEarlyHardwareChecks())
		return EXIT_FAILURE;
#endif

	std::shared_ptr<VMBootParameters> autoboot;
	if (!QtHost::ParseCommandLineOptions(app.arguments(), autoboot))
		return EXIT_FAILURE;

	// Bail out if we can't find any config.
	if (!QtHost::InitializeConfig())
		return EXIT_FAILURE;

	// Set theme before creating any windows.
	MainWindow::updateApplicationTheme();
	MainWindow* main_window = new MainWindow(QApplication::style()->objectName());

	// Start up the CPU thread.
	QtHost::HookSignals();
	EmuThread::start();

	// Create all window objects, the emuthread might still be starting up at this point.
	main_window->initialize();

	// When running in batch mode, ensure game list is loaded, but don't scan for any new files.
	if (!s_batch_mode)
		main_window->refreshGameList(false);
	else
		GameList::Refresh(false, true);

	// Don't bother showing the window in no-gui mode.
	if (!s_nogui_mode)
		main_window->show();

	// Initialize big picture mode if requested.
	if (s_start_fullscreen_ui)
		g_emu_thread->startFullscreenUI(s_start_fullscreen_ui_fullscreen);

	// Skip the update check if we're booting a game directly.
	if (autoboot)
		g_emu_thread->startVM(std::move(autoboot));
	else if (!s_nogui_mode)
		main_window->startupUpdateCheck();

	// This doesn't return until we exit.
	const int result = app.exec();

	// Shutting down.
	EmuThread::stop();
	if (g_main_window)
	{
		g_main_window->close();
		delete g_main_window;
	}

	// Ensure emulog is flushed.
	if (emuLog)
	{
		std::fclose(emuLog);
		emuLog = nullptr;
	}

	return result;
}