/*
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 "platform/linux/linux_gtk_integration.h"

#ifdef DESKTOP_APP_DISABLE_DBUS_INTEGRATION
#error "GTK integration depends on D-Bus integration."
#endif // DESKTOP_APP_DISABLE_DBUS_INTEGRATION

#include "base/platform/linux/base_linux_gtk_integration.h"
#include "base/platform/linux/base_linux_gtk_integration_p.h"
#include "base/platform/linux/base_linux_glibmm_helper.h"
#include "base/platform/linux/base_linux_dbus_utilities.h"
#include "base/platform/base_platform_info.h"
#include "platform/linux/linux_gtk_integration_p.h"
#include "platform/linux/linux_gdk_helper.h"
#include "platform/linux/linux_gtk_open_with_dialog.h"
#include "platform/linux/linux_wayland_integration.h"
#include "webview/webview_interface.h"
#include "window/window_controller.h"
#include "core/application.h"

#include <QtCore/QProcess>

#include <private/qguiapplication_p.h>
#include <giomm.h>

#include <sys/mman.h>
#include <sys/stat.h>
#include <fcntl.h>

namespace Platform {
namespace internal {

using namespace Platform::Gtk;
using BaseGtkIntegration = base::Platform::GtkIntegration;

namespace {

constexpr auto kService = "org.telegram.desktop.GtkIntegration-%1"_cs;
constexpr auto kObjectPath = "/org/telegram/desktop/GtkIntegration"_cs;
constexpr auto kInterface = "org.telegram.desktop.GtkIntegration"_cs;
constexpr auto kPropertiesInterface = "org.freedesktop.DBus.Properties"_cs;
constexpr auto kGifcShmId = "tdesktop-gtk-gifc"_cs;

constexpr auto kIntrospectionXML = R"INTROSPECTION(<node>
	<interface name='org.telegram.desktop.GtkIntegration'>
		<method name='Load'>
			<arg type='s' name='allowed-backends' direction='in'/>
		</method>
		<method name='ShowOpenWithDialog'>
			<arg type='s' name='parent' direction='in'/>
			<arg type='s' name='filepath' direction='in'/>
		</method>
		<method name='GetImageFromClipboard'>
			<arg type='h' name='shm-descriptor' direction='out'/>
			<arg type='i' name='shm-size' direction='out'/>
		</method>
		<signal name='OpenWithDialogResponse'>
			<arg type='b' name='result' direction='out'/>
		</signal>
	</interface>
</node>)INTROSPECTION"_cs;

bool GetImageFromClipboardSupported() {
	return (gtk_clipboard_get != nullptr)
		&& (gtk_clipboard_wait_for_contents != nullptr)
		&& (gtk_clipboard_wait_for_image != nullptr)
		&& (gtk_selection_data_targets_include_image != nullptr)
		&& (gtk_selection_data_free != nullptr)
		&& (gdk_pixbuf_get_pixels != nullptr)
		&& (gdk_pixbuf_get_width != nullptr)
		&& (gdk_pixbuf_get_height != nullptr)
		&& (gdk_pixbuf_get_rowstride != nullptr)
		&& (gdk_pixbuf_get_has_alpha != nullptr)
		&& (gdk_atom_intern != nullptr);
}

} // namespace

class GtkIntegration::Private {
public:
	Private()
	: dbusConnection([] {
		try {
			return Gio::DBus::Connection::get_sync(
				Gio::DBus::BusType::BUS_TYPE_SESSION);
		} catch (...) {
			return Glib::RefPtr<Gio::DBus::Connection>();
		}
	}())
	, interfaceVTable(sigc::mem_fun(this, &Private::handleMethodCall))
	, serviceName(kService.utf16().arg(getpid()).toStdString()) {
	}

	void handleMethodCall(
		const Glib::RefPtr<Gio::DBus::Connection> &connection,
		const Glib::ustring &sender,
		const Glib::ustring &object_path,
		const Glib::ustring &interface_name,
		const Glib::ustring &method_name,
		const Glib::VariantContainerBase &parameters,
		const Glib::RefPtr<Gio::DBus::MethodInvocation> &invocation);

	const Glib::RefPtr<Gio::DBus::Connection> dbusConnection;
	const Gio::DBus::InterfaceVTable interfaceVTable;
	Glib::RefPtr<Gio::DBus::NodeInfo> introspectionData;
	Glib::ustring serviceName;
	Glib::ustring parentDBusName;
	bool remoting = true;
	uint registerId = 0;
	uint parentServiceWatcherId = 0;
};

void GtkIntegration::Private::handleMethodCall(
		const Glib::RefPtr<Gio::DBus::Connection> &connection,
		const Glib::ustring &sender,
		const Glib::ustring &object_path,
		const Glib::ustring &interface_name,
		const Glib::ustring &method_name,
		const Glib::VariantContainerBase &parameters,
		const Glib::RefPtr<Gio::DBus::MethodInvocation> &invocation) {
	if (sender != parentDBusName) {
		Gio::DBus::Error error(
			Gio::DBus::Error::ACCESS_DENIED,
			"Access denied.");

		invocation->return_error(error);
	}

	try {
		const auto integration = Instance();
		if (!integration) {
			throw std::exception();
		}

		auto parametersCopy = parameters;

		if (method_name == "Load") {
			const auto allowedBackends = base::Platform::GlibVariantCast<
				Glib::ustring>(parametersCopy.get_child(0));

			integration->load(QString::fromStdString(allowedBackends));
			invocation->return_value({});
			return;
		} else if (method_name == "ShowOpenWithDialog") {
			const auto parent = base::Platform::GlibVariantCast<
				Glib::ustring>(parametersCopy.get_child(0));

			const auto filepath = base::Platform::GlibVariantCast<
				Glib::ustring>(parametersCopy.get_child(1));

			const auto dialog = File::internal::CreateGtkOpenWithDialog(
				QString::fromStdString(parent),
				QString::fromStdString(filepath)).release();

			if (dialog) {
				dialog->response(
				) | rpl::start_with_next([=](bool response) {
					try {
						connection->emit_signal(
							std::string(kObjectPath),
							std::string(kInterface),
							"OpenWithDialogResponse",
							parentDBusName,
							base::Platform::MakeGlibVariant(std::tuple{
								response,
							}));
					} catch (...) {
					}

					delete dialog;
				}, dialog->lifetime());

				invocation->return_value({});
				return;
			}
		} else if (method_name == "GetImageFromClipboard") {
			const auto image = integration->getImageFromClipboard();
			if (!image.isNull()) {
				const auto bitsPerSample = 8;
				const auto channels = image.hasAlphaChannel() ? 4 : 3;

				QVector<uchar> dataVector(
						image.constBits(),
						image.constBits() + image.sizeInBytes());

				QByteArray streamData;
				QDataStream stream(&streamData, QIODevice::WriteOnly);
				stream
					<< image.width()
					<< image.height()
					<< image.bytesPerLine()
					<< image.hasAlphaChannel()
					<< bitsPerSample
					<< channels
					<< dataVector;

				const auto fd = shm_open(
					kGifcShmId.utf8().constData(),
					O_RDWR | O_CREAT,
					S_IRUSR | S_IWUSR);

				if (fd == -1) {
					throw std::exception();
				}

				const auto fdGuard = gsl::finally([&] {
					close(fd);
					shm_unlink(kGifcShmId.utf8().constData());
				});

				if (ftruncate(fd, streamData.size())) {
					throw std::exception();
				}

				const auto mapped = mmap(
					nullptr,
					streamData.size(),
					PROT_WRITE,
					MAP_SHARED,
					fd,
					0);

				if (mapped == MAP_FAILED) {
					throw std::exception();
				}

				const auto mappedGuard = gsl::finally([&] {
					munmap(mapped, streamData.size());
				});

				memcpy(mapped, streamData.constData(), streamData.size());

				const auto fdList = Gio::UnixFDList::create();
				fdList->append(fd);

				invocation->return_value(
					Glib::VariantContainerBase::create_tuple({
						Glib::wrap(g_variant_new_handle(0)),
						Glib::Variant<int>::create(streamData.size()),
					}),
					fdList);

				return;
			}
		}
	} catch (...) {
	}

	Gio::DBus::Error error(
		Gio::DBus::Error::UNKNOWN_METHOD,
		"Method does not exist.");

	invocation->return_error(error);
}

GtkIntegration::GtkIntegration()
: _private(std::make_unique<Private>()) {
}

GtkIntegration::~GtkIntegration() {
	if (_private->dbusConnection) {
		if (_private->parentServiceWatcherId != 0) {
			_private->dbusConnection->signal_unsubscribe(
				_private->parentServiceWatcherId);
		}

		if (_private->registerId != 0) {
			_private->dbusConnection->unregister_object(
				_private->registerId);
		}
	}
}

GtkIntegration *GtkIntegration::Instance() {
	if (!BaseGtkIntegration::Instance()) {
		return nullptr;
	}

	static GtkIntegration instance;
	return &instance;
}

void GtkIntegration::load(const QString &allowedBackends) {
	static bool Loaded = false;
	Expects(!Loaded);

	if (_private->remoting) {
		if (!_private->dbusConnection) {
			return;
		}

		try {
			auto reply = _private->dbusConnection->call_sync(
				std::string(kObjectPath),
				std::string(kInterface),
				"Load",
				base::Platform::MakeGlibVariant(std::tuple{
					Glib::ustring(allowedBackends.toStdString()),
				}),
				_private->serviceName);
		} catch (...) {
		}

		return;
	}

	BaseGtkIntegration::Instance()->load(allowedBackends, true);
	if (!BaseGtkIntegration::Instance()->loaded()) {
		return;
	}

	auto &lib = BaseGtkIntegration::Instance()->library();

	LOAD_GTK_SYMBOL(lib, gtk_widget_show);
	LOAD_GTK_SYMBOL(lib, gtk_widget_get_window);
	LOAD_GTK_SYMBOL(lib, gtk_widget_realize);
	LOAD_GTK_SYMBOL(lib, gtk_widget_destroy);
	LOAD_GTK_SYMBOL(lib, gtk_clipboard_get);
	LOAD_GTK_SYMBOL(lib, gtk_clipboard_wait_for_contents);
	LOAD_GTK_SYMBOL(lib, gtk_clipboard_wait_for_image);
	LOAD_GTK_SYMBOL(lib, gtk_selection_data_targets_include_image);
	LOAD_GTK_SYMBOL(lib, gtk_selection_data_free);

	LOAD_GTK_SYMBOL(lib, gdk_atom_intern);

	LOAD_GTK_SYMBOL(lib, gdk_pixbuf_get_has_alpha);
	LOAD_GTK_SYMBOL(lib, gdk_pixbuf_get_pixels);
	LOAD_GTK_SYMBOL(lib, gdk_pixbuf_get_width);
	LOAD_GTK_SYMBOL(lib, gdk_pixbuf_get_height);
	LOAD_GTK_SYMBOL(lib, gdk_pixbuf_get_rowstride);

	GdkHelperLoad(lib);

	LOAD_GTK_SYMBOL(lib, gtk_app_chooser_dialog_new);
	LOAD_GTK_SYMBOL(lib, gtk_app_chooser_get_app_info);
	LOAD_GTK_SYMBOL(lib, gtk_app_chooser_get_type);

	Loaded = true;
}

int GtkIntegration::exec(const QString &parentDBusName, int ppid) {
	_private->remoting = false;
	_private->serviceName = kService.utf16().arg(ppid).toStdString();
	_private->parentDBusName = parentDBusName.toStdString();

	_private->introspectionData = Gio::DBus::NodeInfo::create_for_xml(
		std::string(kIntrospectionXML));

	_private->registerId = _private->dbusConnection->register_object(
		std::string(kObjectPath),
		_private->introspectionData->lookup_interface(),
		_private->interfaceVTable);

	const auto app = Gio::Application::create(_private->serviceName);
	app->hold();
	_private->parentServiceWatcherId = base::Platform::DBus::RegisterServiceWatcher(
		_private->dbusConnection,
		parentDBusName.toStdString(),
		[=](
			const Glib::ustring &service,
			const Glib::ustring &oldOwner,
			const Glib::ustring &newOwner) {
			if (!newOwner.empty()) {
				return;
			}
			app->quit();
		});
	return app->run(0, nullptr);
}

bool GtkIntegration::showOpenWithDialog(const QString &filepath) const {
	const auto parent = [&] {
		if (const auto activeWindow = Core::App().activeWindow()) {
			if (const auto integration = WaylandIntegration::Instance()) {
				if (const auto handle = integration->nativeHandle(
					activeWindow->widget()->windowHandle())
					; !handle.isEmpty()) {
					return qsl("wayland:") + handle;
				}
			} else if (Platform::IsX11()) {
				return qsl("x11:") + QString::number(
					activeWindow->widget()->winId(),
					16);
			}
		}
		return QString();
	}();

	if (_private->remoting) {
		if (!_private->dbusConnection) {
			return false;
		}

		try {
			_private->dbusConnection->call_sync(
				std::string(kObjectPath),
				std::string(kInterface),
				"ShowOpenWithDialog",
				base::Platform::MakeGlibVariant(std::tuple{
					Glib::ustring(parent.toStdString()),
					Glib::ustring(filepath.toStdString()),
				}),
				_private->serviceName);

			const auto context = Glib::MainContext::create();
			const auto loop = Glib::MainLoop::create(context);
			g_main_context_push_thread_default(context->gobj());
			const auto contextGuard = gsl::finally([&] {
				g_main_context_pop_thread_default(context->gobj());
			});
			bool result = false;

			const auto signalId = _private->dbusConnection->signal_subscribe(
				[&](
					const Glib::RefPtr<Gio::DBus::Connection> &connection,
					const Glib::ustring &sender_name,
					const Glib::ustring &object_path,
					const Glib::ustring &interface_name,
					const Glib::ustring &signal_name,
					Glib::VariantContainerBase parameters) {
					try {
						auto parametersCopy = parameters;

						result = base::Platform::GlibVariantCast<bool>(
								parametersCopy.get_child(0));

						loop->quit();
					} catch (...) {
					}
				},
				_private->serviceName,
				std::string(kInterface),
				"OpenWithDialogResponse",
				std::string(kObjectPath));

			const auto signalGuard = gsl::finally([&] {
				if (signalId != 0) {
					_private->dbusConnection->signal_unsubscribe(signalId);
				}
			});

			if (signalId != 0) {
				QWindow window;
				QGuiApplicationPrivate::showModalWindow(&window);
				loop->run();
				QGuiApplicationPrivate::hideModalWindow(&window);
			}

			return result;
		} catch (...) {
		}

		return false;
	}

	const auto dialog = File::internal::CreateGtkOpenWithDialog(
		parent,
		filepath);

	if (!dialog) {
		return false;
	}

	const auto context = Glib::MainContext::create();
	const auto loop = Glib::MainLoop::create(context);
	g_main_context_push_thread_default(context->gobj());
	bool result = false;

	dialog->response(
	) | rpl::start_with_next([&](bool response) {
		result = response;
		loop->quit();
	}, dialog->lifetime());

	QWindow window;
	QGuiApplicationPrivate::showModalWindow(&window);
	loop->run();
	g_main_context_pop_thread_default(context->gobj());
	QGuiApplicationPrivate::hideModalWindow(&window);

	return result;
}

QImage GtkIntegration::getImageFromClipboard() const {
	QImage data;

	if (_private->remoting) {
		if (!_private->dbusConnection) {
			return data;
		}

		try {
			Glib::RefPtr<Gio::UnixFDList> outFdList;

			auto reply = _private->dbusConnection->call_sync(
				std::string(kObjectPath),
				std::string(kInterface),
				"GetImageFromClipboard",
				{},
				{},
				outFdList,
				_private->serviceName);

			const auto streamSize = base::Platform::GlibVariantCast<int>(
				reply.get_child(1));

			const auto mapped = mmap(
				nullptr,
				streamSize,
				PROT_READ,
				MAP_SHARED,
				outFdList->get(0),
				0);

			if (mapped == MAP_FAILED) {
				return data;
			}

			QByteArray streamData;
			streamData.resize(streamSize);
			memcpy(streamData.data(), mapped, streamData.size());
			munmap(mapped, streamData.size());

			int imageWidth = 0;
			int imageHeight = 0;
			int imageBytesPerLine = 0;
			bool imageHasAlphaChannel = false;
			int imageBitsPerSample = 0;
			int imageChannels = 0;
			QVector<uchar> imageData;

			QDataStream stream(streamData);
			stream
				>> imageWidth
				>> imageHeight
				>> imageBytesPerLine
				>> imageHasAlphaChannel
				>> imageBitsPerSample
				>> imageChannels
				>> imageData;

			data = QImage(
				imageData.data(),
				imageWidth,
				imageHeight,
				imageBytesPerLine,
				imageHasAlphaChannel
					? QImage::Format_RGBA8888
					: QImage::Format_RGB888).copy();

			return data;
		} catch (...) {
		}

		return data;
	}

	if (!GetImageFromClipboardSupported()) {
		return data;
	}

	const auto clipboard = gtk_clipboard_get(GDK_SELECTION_CLIPBOARD);
	if (!clipboard) {
		return data;
	}

	auto gsel = gtk_clipboard_wait_for_contents(
		clipboard,
		gdk_atom_intern("TARGETS", true));

	if (gsel) {
		if (gtk_selection_data_targets_include_image(gsel, false)) {
			auto img = gtk_clipboard_wait_for_image(clipboard);

			if (img) {
				data = QImage(
					gdk_pixbuf_get_pixels(img),
					gdk_pixbuf_get_width(img),
					gdk_pixbuf_get_height(img),
					gdk_pixbuf_get_rowstride(img),
					gdk_pixbuf_get_has_alpha(img)
						? QImage::Format_RGBA8888
						: QImage::Format_RGB888).copy();

				g_object_unref(img);
			}
		}

		gtk_selection_data_free(gsel);
	}

	return data;
}

QString GtkIntegration::AllowedBackends() {
	return Platform::IsWayland()
		? qsl("wayland,x11")
		: Platform::IsX11()
			? qsl("x11,wayland")
			: QString();
}

int GtkIntegration::Exec(
		Type type,
		const QString &parentDBusName,
		int ppid,
		uint instanceNumber) {
	Glib::init();
	Gio::init();

	if (type == Type::Base) {
		if (const auto integration = BaseGtkIntegration::Instance()) {
			return integration->exec(parentDBusName, ppid);
		}
	} else if (type == Type::Webview) {
		if (const auto instance = Webview::CreateInstance({})) {
			return instance->exec(
				parentDBusName.toStdString(),
				ppid,
				instanceNumber);
		}
	} else if (type == Type::TDesktop) {
		if (const auto integration = Instance()) {
			return integration->exec(parentDBusName, ppid);
		}
	}

	return 1;
}

void GtkIntegration::Start(Type type) {
	if (type != Type::Base && type != Type::TDesktop) {
		return;
	}

	const auto dbusName = [] {
		try {
			static const auto connection = Gio::DBus::Connection::get_sync(
				Gio::DBus::BusType::BUS_TYPE_SESSION);

			return QString::fromStdString(connection->get_unique_name());
		} catch (...) {
			return QString();
		}
	}();

	if (dbusName.isEmpty()) {
		return;
	}

	QProcess::startDetached(cExeDir() + cExeName(), {
		(type == Type::Base)
			? qsl("-basegtkintegration")
			: qsl("-gtkintegration"),
		dbusName,
		QString::number(getpid()),
	});
}

void GtkIntegration::Autorestart(Type type) {
	if (type != Type::Base && type != Type::TDesktop) {
		return;
	}

	try {
		static const auto connection = Gio::DBus::Connection::get_sync(
			Gio::DBus::BusType::BUS_TYPE_SESSION);

		const auto baseServiceName = [] {
			if (const auto integration = BaseGtkIntegration::Instance()) {
				return integration->serviceName();
			}
			return QString();
		}();

		base::Platform::DBus::RegisterServiceWatcher(
			connection,
			(type == Type::Base)
				? baseServiceName.toStdString()
				: kService.utf16().arg(getpid()).toStdString(),
			[=](
				const Glib::ustring &service,
				const Glib::ustring &oldOwner,
				const Glib::ustring &newOwner) {
				if (newOwner.empty()) {
					Start(type);
				} else {
					if (type == Type::Base) {
						if (const auto integration = BaseGtkIntegration::Instance()) {
							integration->load(AllowedBackends());
						}
					} else if (type == Type::TDesktop) {
						if (const auto integration = Instance()) {
							integration->load(AllowedBackends());
						}
					}
				}
			});
	} catch (...) {
	}
}

} // namespace internal
} // namespace Platform