/*
This file is part of Telegram Desktop,
the official desktop application for the Telegram messaging service.

For license and copyright information please follow this link:
https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
*/
#include "ui/platform/linux/ui_linux_wayland_integration.h"

#include "base/platform/base_platform_info.h"
#include "waylandshells/xdg_shell.h"

#include <QtGui/QWindow>

// private headers are using keywords :(
#ifdef QT_NO_KEYWORDS
#define signals Q_SIGNALS
#define slots Q_SLOTS
#endif // QT_NO_KEYWORDS

#include <private/qguiapplication_p.h>
#include <private/qwaylandintegration_p.h>
#include <private/qwaylanddisplay_p.h>
#include <private/qwaylandwindow_p.h>
#include <private/qwaylandshellsurface_p.h>

#include <connection_thread.h>
#include <registry.h>

Q_DECLARE_METATYPE(QMargins);

using QtWaylandClient::QWaylandIntegration;
using QtWaylandClient::QWaylandWindow;
using namespace KWayland::Client;

namespace Ui {
namespace Platform {

struct WaylandIntegration::Private {
	std::unique_ptr<ConnectionThread> connection;
	Registry registry;
	QEventLoop interfacesLoop;
	bool interfacesAnnounced = false;
};

WaylandIntegration::WaylandIntegration()
: _private(std::make_unique<Private>()) {
	_private->connection = std::unique_ptr<ConnectionThread>{
		ConnectionThread::fromApplication(),
	};

	_private->registry.create(_private->connection.get());
	_private->registry.setup();

	QObject::connect(
		_private->connection.get(),
		&ConnectionThread::connectionDied,
		&_private->registry,
		&Registry::destroy);

	QObject::connect(
		&_private->registry,
		&Registry::interfacesAnnounced,
		[=] {
			_private->interfacesAnnounced = true;
			if (_private->interfacesLoop.isRunning()) {
				_private->interfacesLoop.quit();
			}
		});
}

WaylandIntegration::~WaylandIntegration() = default;

WaylandIntegration *WaylandIntegration::Instance() {
	if (!::Platform::IsWayland()) return nullptr;
	static WaylandIntegration instance;
	return &instance;
}

void WaylandIntegration::waitForInterfaceAnnounce() {
	Expects(!_private->interfacesLoop.isRunning());
	if (!_private->interfacesAnnounced) {
		_private->interfacesLoop.exec();
	}
}

bool WaylandIntegration::xdgDecorationSupported() {
	return _private->registry.hasInterface(
		Registry::Interface::XdgDecorationUnstableV1);
}

bool WaylandIntegration::windowExtentsSupported() {
	// initialize shell integration before querying
	if (const auto integration = static_cast<QWaylandIntegration*>(
		QGuiApplicationPrivate::platformIntegration())) {
		integration->shellIntegration();
	}
	return WaylandShells::XdgShell();
}

void WaylandIntegration::setWindowExtents(
		QWindow *window,
		const QMargins &extents) {
	window->setProperty(
		"_desktopApp_waylandCustomMargins",
		QVariant::fromValue<QMargins>(extents));
}

void WaylandIntegration::unsetWindowExtents(QWindow *window) {
	window->setProperty(
		"_desktopApp_waylandCustomMargins",
		QVariant());
}

bool WaylandIntegration::showWindowMenu(QWindow *window) {
	if (const auto waylandWindow = static_cast<QWaylandWindow*>(
		window->handle())) {
		if (const auto seat = waylandWindow->display()->lastInputDevice()) {
			if (const auto shellSurface = waylandWindow->shellSurface()) {
				return shellSurface->showWindowMenu(seat);
			}
		}
	}

	return false;
}

} // namespace Platform
} // namespace Ui