/*************************************************************************/
/*  os_uwp.cpp                                                           */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
/*                      https://godotengine.org                          */
/*************************************************************************/
/* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur.                 */
/* Copyright (c) 2014-2020 Godot Engine contributors (cf. AUTHORS.md).   */
/*                                                                       */
/* Permission is hereby granted, free of charge, to any person obtaining */
/* a copy of this software and associated documentation files (the       */
/* "Software"), to deal in the Software without restriction, including   */
/* without limitation the rights to use, copy, modify, merge, publish,   */
/* distribute, sublicense, and/or sell copies of the Software, and to    */
/* permit persons to whom the Software is furnished to do so, subject to */
/* the following conditions:                                             */
/*                                                                       */
/* The above copyright notice and this permission notice shall be        */
/* included in all copies or substantial portions of the Software.       */
/*                                                                       */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
/*************************************************************************/

// Must include Winsock before windows.h (included by os_uwp.h)
#include "drivers/unix/net_socket_posix.h"

#include "os_uwp.h"

#include "core/io/marshalls.h"
#include "core/project_settings.h"
#include "drivers/gles2/rasterizer_gles2.h"
#include "drivers/unix/ip_unix.h"
#include "drivers/windows/dir_access_windows.h"
#include "drivers/windows/file_access_windows.h"
#include "drivers/windows/mutex_windows.h"
#include "drivers/windows/rw_lock_windows.h"
#include "drivers/windows/semaphore_windows.h"
#include "main/main.h"
#include "platform/windows/windows_terminal_logger.h"
#include "servers/audio_server.h"
#include "servers/rendering/rendering_server_raster.h"
#include "servers/rendering/rendering_server_wrap_mt.h"
#include "thread_uwp.h"

#include <ppltasks.h>
#include <wrl.h>

using namespace Windows::ApplicationModel::Core;
using namespace Windows::ApplicationModel::Activation;
using namespace Windows::UI::Core;
using namespace Windows::UI::Input;
using namespace Windows::UI::Popups;
using namespace Windows::Foundation;
using namespace Windows::Graphics::Display;
using namespace Microsoft::WRL;
using namespace Windows::UI::ViewManagement;
using namespace Windows::Devices::Input;
using namespace Windows::Devices::Sensors;
using namespace Windows::ApplicationModel::DataTransfer;
using namespace concurrency;

int OS_UWP::get_video_driver_count() const {
	return 2;
}

Size2 OS_UWP::get_window_size() const {
	Size2 size;
	size.width = video_mode.width;
	size.height = video_mode.height;
	return size;
}

int OS_UWP::get_current_video_driver() const {
	return video_driver_index;
}

void OS_UWP::set_window_size(const Size2 p_size) {
	Windows::Foundation::Size new_size;
	new_size.Width = p_size.width;
	new_size.Height = p_size.height;

	ApplicationView ^ view = ApplicationView::GetForCurrentView();

	if (view->TryResizeView(new_size)) {
		video_mode.width = p_size.width;
		video_mode.height = p_size.height;
	}
}

void OS_UWP::set_window_fullscreen(bool p_enabled) {
	ApplicationView ^ view = ApplicationView::GetForCurrentView();

	video_mode.fullscreen = view->IsFullScreenMode;

	if (video_mode.fullscreen == p_enabled)
		return;

	if (p_enabled) {
		video_mode.fullscreen = view->TryEnterFullScreenMode();

	} else {
		view->ExitFullScreenMode();
		video_mode.fullscreen = false;
	}
}

bool OS_UWP::is_window_fullscreen() const {
	return ApplicationView::GetForCurrentView()->IsFullScreenMode;
}

void OS_UWP::set_keep_screen_on(bool p_enabled) {
	if (is_keep_screen_on() == p_enabled)
		return;

	if (p_enabled)
		display_request->RequestActive();
	else
		display_request->RequestRelease();

	OS::set_keep_screen_on(p_enabled);
}

void OS_UWP::initialize_core() {
	last_button_state = 0;

	//RedirectIOToConsole();

	ThreadUWP::make_default();
	RWLockWindows::make_default();

	FileAccess::make_default<FileAccessWindows>(FileAccess::ACCESS_RESOURCES);
	FileAccess::make_default<FileAccessWindows>(FileAccess::ACCESS_USERDATA);
	FileAccess::make_default<FileAccessWindows>(FileAccess::ACCESS_FILESYSTEM);
	DirAccess::make_default<DirAccessWindows>(DirAccess::ACCESS_RESOURCES);
	DirAccess::make_default<DirAccessWindows>(DirAccess::ACCESS_USERDATA);
	DirAccess::make_default<DirAccessWindows>(DirAccess::ACCESS_FILESYSTEM);

	NetSocketPosix::make_default();

	// We need to know how often the clock is updated
	if (!QueryPerformanceFrequency((LARGE_INTEGER *)&ticks_per_second))
		ticks_per_second = 1000;
	// If timeAtGameStart is 0 then we get the time since
	// the start of the computer when we call GetGameTime()
	ticks_start = 0;
	ticks_start = get_ticks_usec();

	IP_Unix::make_default();

	cursor_shape = CURSOR_ARROW;
}

bool OS_UWP::can_draw() const {
	return !minimized;
};

void OS_UWP::set_window(Windows::UI::Core::CoreWindow ^ p_window) {
	window = p_window;
}

void OS_UWP::screen_size_changed() {
	gl_context->reset();
};

Error OS_UWP::initialize(const VideoMode &p_desired, int p_video_driver, int p_audio_driver) {
	main_loop = nullptr;
	outside = true;

	// FIXME: Hardcoded for now, add Vulkan support.
	p_video_driver = VIDEO_DRIVER_GLES2;
	ContextEGL_UWP::Driver opengl_api_type = ContextEGL_UWP::GLES_2_0;

	bool gl_initialization_error = false;

	gl_context = memnew(ContextEGL_UWP(window, opengl_api_type));

	if (gl_context->initialize() != OK) {
		memdelete(gl_context);
		gl_context = nullptr;
		gl_initialization_error = true;
	}

	if (opengl_api_type == ContextEGL_UWP::GLES_2_0) {
		if (RasterizerGLES2::is_viable() == OK) {
			RasterizerGLES2::register_config();
			RasterizerGLES2::make_current();
		} else {
			gl_initialization_error = true;
		}
	}

	if (gl_initialization_error) {
		OS::get_singleton()->alert("Your video card driver does not support any of the supported OpenGL versions.\n"
								   "Please update your drivers or if you have a very old or integrated GPU upgrade it.",
				"Unable to initialize video driver");
		return ERR_UNAVAILABLE;
	}

	video_driver_index = p_video_driver;
	gl_context->make_current();
	gl_context->set_use_vsync(video_mode.use_vsync);

	VideoMode vm;
	vm.width = gl_context->get_window_width();
	vm.height = gl_context->get_window_height();
	vm.resizable = false;

	ApplicationView ^ view = ApplicationView::GetForCurrentView();
	vm.fullscreen = view->IsFullScreenMode;

	view->SetDesiredBoundsMode(ApplicationViewBoundsMode::UseVisible);
	view->PreferredLaunchWindowingMode = ApplicationViewWindowingMode::PreferredLaunchViewSize;

	if (p_desired.fullscreen != view->IsFullScreenMode) {
		if (p_desired.fullscreen) {
			vm.fullscreen = view->TryEnterFullScreenMode();

		} else {
			view->ExitFullScreenMode();
			vm.fullscreen = false;
		}
	}

	Windows::Foundation::Size desired;
	desired.Width = p_desired.width;
	desired.Height = p_desired.height;

	view->PreferredLaunchViewSize = desired;

	if (view->TryResizeView(desired)) {
		vm.width = view->VisibleBounds.Width;
		vm.height = view->VisibleBounds.Height;
	}

	set_video_mode(vm);

	rendering_server = memnew(RenderingServerRaster);
	// FIXME: Reimplement threaded rendering
	if (get_render_thread_mode() != RENDER_THREAD_UNSAFE) {
		rendering_server = memnew(RenderingServerWrapMT(rendering_server, false));
	}

	rendering_server->init();

	input = memnew(InputDefault);

	joypad = ref new JoypadUWP(input);
	joypad->register_events();

	AudioDriverManager::initialize(p_audio_driver);

	managed_object->update_clipboard();

	Clipboard::ContentChanged += ref new EventHandler<Platform::Object ^>(managed_object, &ManagedType::on_clipboard_changed);

	accelerometer = Accelerometer::GetDefault();
	if (accelerometer != nullptr) {
		// 60 FPS
		accelerometer->ReportInterval = (1.0f / 60.0f) * 1000;
		accelerometer->ReadingChanged +=
				ref new TypedEventHandler<Accelerometer ^, AccelerometerReadingChangedEventArgs ^>(managed_object, &ManagedType::on_accelerometer_reading_changed);
	}

	magnetometer = Magnetometer::GetDefault();
	if (magnetometer != nullptr) {
		// 60 FPS
		magnetometer->ReportInterval = (1.0f / 60.0f) * 1000;
		magnetometer->ReadingChanged +=
				ref new TypedEventHandler<Magnetometer ^, MagnetometerReadingChangedEventArgs ^>(managed_object, &ManagedType::on_magnetometer_reading_changed);
	}

	gyrometer = Gyrometer::GetDefault();
	if (gyrometer != nullptr) {
		// 60 FPS
		gyrometer->ReportInterval = (1.0f / 60.0f) * 1000;
		gyrometer->ReadingChanged +=
				ref new TypedEventHandler<Gyrometer ^, GyrometerReadingChangedEventArgs ^>(managed_object, &ManagedType::on_gyroscope_reading_changed);
	}

	_ensure_user_data_dir();

	if (is_keep_screen_on())
		display_request->RequestActive();

	set_keep_screen_on(GLOBAL_DEF("display/window/energy_saving/keep_screen_on", true));

	return OK;
}

void OS_UWP::set_clipboard(const String &p_text) {
	DataPackage ^ clip = ref new DataPackage();
	clip->RequestedOperation = DataPackageOperation::Copy;
	clip->SetText(ref new Platform::String((const wchar_t *)p_text.c_str()));

	Clipboard::SetContent(clip);
};

String OS_UWP::get_clipboard() const {
	if (managed_object->clipboard != nullptr)
		return managed_object->clipboard->Data();
	else
		return "";
};

void OS_UWP::input_event(const Ref<InputEvent> &p_event) {
	input->parse_input_event(p_event);
};

void OS_UWP::delete_main_loop() {
	if (main_loop)
		memdelete(main_loop);
	main_loop = nullptr;
}

void OS_UWP::set_main_loop(MainLoop *p_main_loop) {
	input->set_main_loop(p_main_loop);
	main_loop = p_main_loop;
}

void OS_UWP::finalize() {
	if (main_loop)
		memdelete(main_loop);

	main_loop = nullptr;

	rendering_server->finish();
	memdelete(rendering_server);
#ifdef OPENGL_ENABLED
	if (gl_context)
		memdelete(gl_context);
#endif

	memdelete(input);

	joypad = nullptr;
}

void OS_UWP::finalize_core() {
	NetSocketPosix::cleanup();
}

void OS_UWP::alert(const String &p_alert, const String &p_title) {
	Platform::String ^ alert = ref new Platform::String(p_alert.c_str());
	Platform::String ^ title = ref new Platform::String(p_title.c_str());

	MessageDialog ^ msg = ref new MessageDialog(alert, title);

	UICommand ^ close = ref new UICommand("Close", ref new UICommandInvokedHandler(managed_object, &OS_UWP::ManagedType::alert_close));
	msg->Commands->Append(close);
	msg->DefaultCommandIndex = 0;

	managed_object->alert_close_handle = true;

	msg->ShowAsync();
}

void OS_UWP::ManagedType::alert_close(IUICommand ^ command) {
	alert_close_handle = false;
}

void OS_UWP::ManagedType::on_clipboard_changed(Platform::Object ^ sender, Platform::Object ^ ev) {
	update_clipboard();
}

void OS_UWP::ManagedType::update_clipboard() {
	DataPackageView ^ data = Clipboard::GetContent();

	if (data->Contains(StandardDataFormats::Text)) {
		create_task(data->GetTextAsync()).then([this](Platform::String ^ clipboard_content) {
			this->clipboard = clipboard_content;
		});
	}
}

void OS_UWP::ManagedType::on_accelerometer_reading_changed(Accelerometer ^ sender, AccelerometerReadingChangedEventArgs ^ args) {
	AccelerometerReading ^ reading = args->Reading;

	os->input->set_accelerometer(Vector3(
			reading->AccelerationX,
			reading->AccelerationY,
			reading->AccelerationZ));
}

void OS_UWP::ManagedType::on_magnetometer_reading_changed(Magnetometer ^ sender, MagnetometerReadingChangedEventArgs ^ args) {
	MagnetometerReading ^ reading = args->Reading;

	os->input->set_magnetometer(Vector3(
			reading->MagneticFieldX,
			reading->MagneticFieldY,
			reading->MagneticFieldZ));
}

void OS_UWP::ManagedType::on_gyroscope_reading_changed(Gyrometer ^ sender, GyrometerReadingChangedEventArgs ^ args) {
	GyrometerReading ^ reading = args->Reading;

	os->input->set_magnetometer(Vector3(
			reading->AngularVelocityX,
			reading->AngularVelocityY,
			reading->AngularVelocityZ));
}

void OS_UWP::set_mouse_mode(MouseMode p_mode) {
	if (p_mode == MouseMode::MOUSE_MODE_CAPTURED) {
		CoreWindow::GetForCurrentThread()->SetPointerCapture();

	} else {
		CoreWindow::GetForCurrentThread()->ReleasePointerCapture();
	}

	if (p_mode == MouseMode::MOUSE_MODE_CAPTURED || p_mode == MouseMode::MOUSE_MODE_HIDDEN) {
		CoreWindow::GetForCurrentThread()->PointerCursor = nullptr;

	} else {
		CoreWindow::GetForCurrentThread()->PointerCursor = ref new CoreCursor(CoreCursorType::Arrow, 0);
	}

	mouse_mode = p_mode;

	SetEvent(mouse_mode_changed);
}

OS_UWP::MouseMode OS_UWP::get_mouse_mode() const {
	return mouse_mode;
}

Point2 OS_UWP::get_mouse_position() const {
	return Point2(old_x, old_y);
}

int OS_UWP::get_mouse_button_state() const {
	return last_button_state;
}

void OS_UWP::set_window_title(const String &p_title) {
}

void OS_UWP::set_video_mode(const VideoMode &p_video_mode, int p_screen) {
	video_mode = p_video_mode;
}

OS::VideoMode OS_UWP::get_video_mode(int p_screen) const {
	return video_mode;
}

void OS_UWP::get_fullscreen_mode_list(List<VideoMode> *p_list, int p_screen) const {
}

String OS_UWP::get_name() const {
	return "UWP";
}

OS::Date OS_UWP::get_date(bool utc) const {
	SYSTEMTIME systemtime;
	if (utc)
		GetSystemTime(&systemtime);
	else
		GetLocalTime(&systemtime);

	Date date;
	date.day = systemtime.wDay;
	date.month = Month(systemtime.wMonth);
	date.weekday = Weekday(systemtime.wDayOfWeek);
	date.year = systemtime.wYear;
	date.dst = false;
	return date;
}

OS::Time OS_UWP::get_time(bool utc) const {
	SYSTEMTIME systemtime;
	if (utc)
		GetSystemTime(&systemtime);
	else
		GetLocalTime(&systemtime);

	Time time;
	time.hour = systemtime.wHour;
	time.min = systemtime.wMinute;
	time.sec = systemtime.wSecond;
	return time;
}

OS::TimeZoneInfo OS_UWP::get_time_zone_info() const {
	TIME_ZONE_INFORMATION info;
	bool daylight = false;
	if (GetTimeZoneInformation(&info) == TIME_ZONE_ID_DAYLIGHT)
		daylight = true;

	TimeZoneInfo ret;
	if (daylight) {
		ret.name = info.DaylightName;
	} else {
		ret.name = info.StandardName;
	}

	// Bias value returned by GetTimeZoneInformation is inverted of what we expect
	// For example on GMT-3 GetTimeZoneInformation return a Bias of 180, so invert the value to get -180
	ret.bias = -info.Bias;
	return ret;
}

uint64_t OS_UWP::get_unix_time() const {
	FILETIME ft;
	SYSTEMTIME st;
	GetSystemTime(&st);
	SystemTimeToFileTime(&st, &ft);

	SYSTEMTIME ep;
	ep.wYear = 1970;
	ep.wMonth = 1;
	ep.wDayOfWeek = 4;
	ep.wDay = 1;
	ep.wHour = 0;
	ep.wMinute = 0;
	ep.wSecond = 0;
	ep.wMilliseconds = 0;
	FILETIME fep;
	SystemTimeToFileTime(&ep, &fep);

	return (*(uint64_t *)&ft - *(uint64_t *)&fep) / 10000000;
};

void OS_UWP::delay_usec(uint32_t p_usec) const {
	int msec = p_usec < 1000 ? 1 : p_usec / 1000;

	// no Sleep()
	WaitForSingleObjectEx(GetCurrentThread(), msec, false);
}

uint64_t OS_UWP::get_ticks_usec() const {
	uint64_t ticks;
	uint64_t time;
	// This is the number of clock ticks since start
	QueryPerformanceCounter((LARGE_INTEGER *)&ticks);
	// Divide by frequency to get the time in seconds
	time = ticks * 1000000L / ticks_per_second;
	// Subtract the time at game start to get
	// the time since the game started
	time -= ticks_start;
	return time;
}

void OS_UWP::process_events() {
	joypad->process_controllers();
	process_key_events();
}

void OS_UWP::process_key_events() {
	for (int i = 0; i < key_event_pos; i++) {
		KeyEvent &kev = key_event_buffer[i];

		Ref<InputEventKey> key_event;
		key_event.instance();
		key_event->set_alt(kev.alt);
		key_event->set_shift(kev.shift);
		key_event->set_control(kev.control);
		key_event->set_echo(kev.echo);
		key_event->set_keycode(kev.keycode);
		key_event->set_physical_keycode(kev.physical_keycode);
		key_event->set_unicode(kev.unicode);
		key_event->set_pressed(kev.pressed);

		input_event(key_event);
	}
	key_event_pos = 0;
}

void OS_UWP::queue_key_event(KeyEvent &p_event) {
	// This merges Char events with the previous Key event, so
	// the unicode can be retrieved without sending duplicate events.
	if (p_event.type == KeyEvent::MessageType::CHAR_EVENT_MESSAGE && key_event_pos > 0) {
		KeyEvent &old = key_event_buffer[key_event_pos - 1];
		ERR_FAIL_COND(old.type != KeyEvent::MessageType::KEY_EVENT_MESSAGE);

		key_event_buffer[key_event_pos - 1].unicode = p_event.unicode;
		return;
	}

	ERR_FAIL_COND(key_event_pos >= KEY_EVENT_BUFFER_SIZE);

	key_event_buffer[key_event_pos++] = p_event;
}

void OS_UWP::set_cursor_shape(CursorShape p_shape) {
	ERR_FAIL_INDEX(p_shape, CURSOR_MAX);

	if (cursor_shape == p_shape)
		return;

	static const CoreCursorType uwp_cursors[CURSOR_MAX] = {
		CoreCursorType::Arrow,
		CoreCursorType::IBeam,
		CoreCursorType::Hand,
		CoreCursorType::Cross,
		CoreCursorType::Wait,
		CoreCursorType::Wait,
		CoreCursorType::Arrow,
		CoreCursorType::Arrow,
		CoreCursorType::UniversalNo,
		CoreCursorType::SizeNorthSouth,
		CoreCursorType::SizeWestEast,
		CoreCursorType::SizeNortheastSouthwest,
		CoreCursorType::SizeNorthwestSoutheast,
		CoreCursorType::SizeAll,
		CoreCursorType::SizeNorthSouth,
		CoreCursorType::SizeWestEast,
		CoreCursorType::Help
	};

	CoreWindow::GetForCurrentThread()->PointerCursor = ref new CoreCursor(uwp_cursors[p_shape], 0);

	cursor_shape = p_shape;
}

OS::CursorShape OS_UWP::get_cursor_shape() const {
	return cursor_shape;
}

void OS_UWP::set_custom_mouse_cursor(const RES &p_cursor, CursorShape p_shape, const Vector2 &p_hotspot) {
	// TODO
}

Error OS_UWP::execute(const String &p_path, const List<String> &p_arguments, bool p_blocking, ProcessID *r_child_id, String *r_pipe, int *r_exitcode, bool read_stderr, Mutex *p_pipe_mutex) {
	return FAILED;
};

Error OS_UWP::kill(const ProcessID &p_pid) {
	return FAILED;
};

Error OS_UWP::set_cwd(const String &p_cwd) {
	return FAILED;
}

String OS_UWP::get_executable_path() const {
	return "";
}

void OS_UWP::set_icon(const Ref<Image> &p_icon) {
}

bool OS_UWP::has_environment(const String &p_var) const {
	return false;
};

String OS_UWP::get_environment(const String &p_var) const {
	return "";
};

bool OS_UWP::set_environment(const String &p_var, const String &p_value) const {
	return false;
}

String OS_UWP::get_stdin_string(bool p_block) {
	return String();
}

void OS_UWP::move_window_to_foreground() {
}

Error OS_UWP::shell_open(String p_uri) {
	return FAILED;
}

String OS_UWP::get_locale() const {
#if WINAPI_FAMILY == WINAPI_FAMILY_PHONE_APP // this should work on phone 8.1, but it doesn't
	return "en";
#else
	Platform::String ^ language = Windows::Globalization::Language::CurrentInputMethodLanguageTag;
	return String(language->Data()).replace("-", "_");
#endif
}

void OS_UWP::release_rendering_thread() {
	gl_context->release_current();
}

void OS_UWP::make_rendering_thread() {
	gl_context->make_current();
}

void OS_UWP::swap_buffers() {
	gl_context->swap_buffers();
}

bool OS_UWP::has_touchscreen_ui_hint() const {
	TouchCapabilities ^ tc = ref new TouchCapabilities();
	return tc->TouchPresent != 0 || UIViewSettings::GetForCurrentView()->UserInteractionMode == UserInteractionMode::Touch;
}

bool OS_UWP::has_virtual_keyboard() const {
	return UIViewSettings::GetForCurrentView()->UserInteractionMode == UserInteractionMode::Touch;
}

void OS_UWP::show_virtual_keyboard(const String &p_existing_text, const Rect2 &p_screen_rect, int p_max_input_length, int p_cursor_start, int p_cursor_end) {
	InputPane ^ pane = InputPane::GetForCurrentView();
	pane->TryShow();
}

void OS_UWP::hide_virtual_keyboard() {
	InputPane ^ pane = InputPane::GetForCurrentView();
	pane->TryHide();
}

static String format_error_message(DWORD id) {
	LPWSTR messageBuffer = nullptr;
	size_t size = FormatMessageW(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
			nullptr, id, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), (LPWSTR)&messageBuffer, 0, nullptr);

	String msg = "Error " + itos(id) + ": " + String(messageBuffer, size);

	LocalFree(messageBuffer);

	return msg;
}

Error OS_UWP::open_dynamic_library(const String p_path, void *&p_library_handle, bool p_also_set_library_path) {
	String full_path = "game/" + p_path;
	p_library_handle = (void *)LoadPackagedLibrary(full_path.c_str(), 0);
	ERR_FAIL_COND_V_MSG(!p_library_handle, ERR_CANT_OPEN, "Can't open dynamic library: " + full_path + ", error: " + format_error_message(GetLastError()) + ".");
	return OK;
}

Error OS_UWP::close_dynamic_library(void *p_library_handle) {
	if (!FreeLibrary((HMODULE)p_library_handle)) {
		return FAILED;
	}
	return OK;
}

Error OS_UWP::get_dynamic_library_symbol_handle(void *p_library_handle, const String p_name, void *&p_symbol_handle, bool p_optional) {
	p_symbol_handle = (void *)GetProcAddress((HMODULE)p_library_handle, p_name.utf8().get_data());
	if (!p_symbol_handle) {
		if (!p_optional) {
			ERR_FAIL_V_MSG(ERR_CANT_RESOLVE, "Can't resolve symbol " + p_name + ", error: " + String::num(GetLastError()) + ".");
		} else {
			return ERR_CANT_RESOLVE;
		}
	}
	return OK;
}

void OS_UWP::run() {
	if (!main_loop)
		return;

	main_loop->init();

	uint64_t last_ticks = get_ticks_usec();

	int frames = 0;
	uint64_t frame = 0;

	while (!force_quit) {
		CoreWindow::GetForCurrentThread()->Dispatcher->ProcessEvents(CoreProcessEventsOption::ProcessAllIfPresent);
		if (managed_object->alert_close_handle)
			continue;
		process_events(); // get rid of pending events
		if (Main::iteration())
			break;
	};

	main_loop->finish();
}

MainLoop *OS_UWP::get_main_loop() const {
	return main_loop;
}

String OS_UWP::get_user_data_dir() const {
	Windows::Storage::StorageFolder ^ data_folder = Windows::Storage::ApplicationData::Current->LocalFolder;

	return String(data_folder->Path->Data()).replace("\\", "/");
}

bool OS_UWP::_check_internal_feature_support(const String &p_feature) {
	return p_feature == "pc";
}

OS_UWP::OS_UWP() {
	key_event_pos = 0;
	force_quit = false;
	alt_mem = false;
	gr_mem = false;
	shift_mem = false;
	control_mem = false;
	meta_mem = false;
	minimized = false;

	pressrc = 0;
	old_invalid = true;
	mouse_mode = MOUSE_MODE_VISIBLE;
#ifdef STDOUT_FILE
	stdo = fopen("stdout.txt", "wb");
#endif

	gl_context = nullptr;

	display_request = ref new Windows::System::Display::DisplayRequest();

	managed_object = ref new ManagedType;
	managed_object->os = this;

	mouse_mode_changed = CreateEvent(nullptr, TRUE, FALSE, L"os_mouse_mode_changed");

	AudioDriverManager::add_driver(&audio_driver);

	Vector<Logger *> loggers;
	loggers.push_back(memnew(WindowsTerminalLogger));
	_set_logger(memnew(CompositeLogger(loggers)));
}

OS_UWP::~OS_UWP() {
#ifdef STDOUT_FILE
	fclose(stdo);
#endif
}