/*
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/win/tray_win.h"

#include "base/invoke_queued.h"
#include "base/qt_signal_producer.h"
#include "core/application.h"
#include "lang/lang_keys.h"
#include "main/main_session.h"
#include "storage/localstorage.h"
#include "ui/painter.h"
#include "ui/ui_utility.h"
#include "ui/widgets/popup_menu.h"
#include "window/window_controller.h"
#include "window/window_session_controller.h"
#include "styles/style_window.h"

#include <qpa/qplatformscreen.h>
#include <qpa/qplatformsystemtrayicon.h>
#include <qpa/qplatformtheme.h>
#include <private/qguiapplication_p.h>
#include <private/qhighdpiscaling_p.h>
#include <QSvgRenderer>

namespace Platform {

namespace {

constexpr auto kTooltipDelay = crl::time(10000);

[[nodiscard]] std::optional<bool> IsDarkTaskbar() {
	static const auto kSystemVersion = QOperatingSystemVersion::current();
	static const auto kDarkModeAddedVersion = QOperatingSystemVersion(
		QOperatingSystemVersion::Windows,
		10,
		0,
		18282);
	static const auto kSupported = (kSystemVersion >= kDarkModeAddedVersion);
	if (!kSupported) {
		return std::nullopt;
	}

	const auto keyName = L""
		"Software\\Microsoft\\Windows\\CurrentVersion\\Themes\\Personalize";
	const auto valueName = L"SystemUsesLightTheme";
	auto key = HKEY();
	auto result = RegOpenKeyEx(HKEY_CURRENT_USER, keyName, 0, KEY_READ, &key);
	if (result != ERROR_SUCCESS) {
		return std::nullopt;
	}

	DWORD value = 0, type = 0, size = sizeof(value);
	result = RegQueryValueEx(key, valueName, 0, &type, (LPBYTE)&value, &size);
	RegCloseKey(key);
	if (result != ERROR_SUCCESS) {
		return std::nullopt;
	}

	return (value == 0);
}

[[nodiscard]] QImage MonochromeIconFor(int size, bool darkMode) {
	Expects(size > 0);

	static const auto Content = [&] {
		auto f = QFile(u":/gui/icons/tray/monochrome.svg"_q);
		f.open(QIODevice::ReadOnly);
		return f.readAll();
	}();
	static auto Mask = QImage();
	static auto Size = 0;
	if (Mask.isNull() || Size != size) {
		Size = size;
		Mask = QImage(size, size, QImage::Format_ARGB32_Premultiplied);
		Mask.fill(Qt::transparent);
		auto p = QPainter(&Mask);
		QSvgRenderer(Content).render(&p, QRectF(0, 0, size, size));
	}
	static auto Colored = QImage();
	static auto ColoredDark = QImage();
	auto &use = darkMode ? ColoredDark : Colored;
	if (use.size() != Mask.size()) {
		const auto color = darkMode ? 255 : 0;
		const auto alpha = darkMode ? 255 : 228;
		use = style::colorizeImage(Mask, { color, color, color, alpha });
	}
	return use;
}

[[nodiscard]] QImage MonochromeWithDot(QImage image, style::color color) {
	auto p = QPainter(&image);
	auto hq = PainterHighQualityEnabler(p);
	const auto xm = image.width() / 16.;
	const auto ym = image.height() / 16.;
	p.setBrush(color);
	p.setPen(Qt::NoPen);
	p.drawEllipse(QRectF( // cx=3.9, cy=12.7, r=2.2
		1.7 * xm,
		10.5 * ym,
		4.4 * xm,
		4.4 * ym));
	return image;
}

[[nodiscard]] QImage ImageIconWithCounter(
		Window::CounterLayerArgs &&args,
		bool supportMode,
		bool smallIcon,
		bool monochrome) {
	static auto ScaledLogo = base::flat_map<int, QImage>();
	static auto ScaledLogoNoMargin = base::flat_map<int, QImage>();
	static auto ScaledLogoDark = base::flat_map<int, QImage>();
	static auto ScaledLogoLight = base::flat_map<int, QImage>();

	const auto darkMode = IsDarkTaskbar();
	auto &scaled = (monochrome && darkMode)
		? (*darkMode
			? ScaledLogoDark
			: ScaledLogoLight)
		: smallIcon
		? ScaledLogoNoMargin
		: ScaledLogo;

	auto result = [&] {
		if (const auto it = scaled.find(args.size); it != scaled.end()) {
			return it->second;
		} else if (monochrome && darkMode) {
			return MonochromeIconFor(args.size, *darkMode);
		}
		return scaled.emplace(
			args.size,
			(smallIcon
				? Window::LogoNoMargin()
				: Window::Logo()
			).scaledToWidth(args.size, Qt::SmoothTransformation)
		).first->second;
	}();
	if ((!monochrome || !darkMode) && supportMode) {
		Window::ConvertIconToBlack(result);
	}
	if (!args.count) {
		return result;
	} else if (smallIcon) {
		if (monochrome && darkMode) {
			return MonochromeWithDot(std::move(result), args.bg);
		}
		return Window::WithSmallCounter(std::move(result), std::move(args));
	}
	QPainter p(&result);
	const auto half = args.size / 2;
	args.size = half;
	p.drawPixmap(
		half,
		half,
		Ui::PixmapFromImage(Window::GenerateCounterLayer(std::move(args))));
	return result;
}

} // namespace

Tray::Tray() {
}

void Tray::createIcon() {
	if (!_icon) {
		if (const auto theme = QGuiApplicationPrivate::platformTheme()) {
			_icon.reset(theme->createPlatformSystemTrayIcon());
		}
		if (!_icon) {
			return;
		}
		_icon->init();
		updateIcon();
		_icon->updateToolTip(AppName.utf16());

		using Reason = QPlatformSystemTrayIcon::ActivationReason;
		base::qt_signal_producer(
			_icon.get(),
			&QPlatformSystemTrayIcon::activated
		) | rpl::filter(
			rpl::mappers::_1 != Reason::Context
		) | rpl::map_to(
			rpl::empty
		) | rpl::start_to_stream(_iconClicks, _lifetime);

		base::qt_signal_producer(
			_icon.get(),
			&QPlatformSystemTrayIcon::contextMenuRequested
		) | rpl::filter([=] {
			return _menu != nullptr;
		}) | rpl::start_with_next([=](
				QPoint globalNativePosition,
				const QPlatformScreen *screen) {
			_aboutToShowRequests.fire({});
			const auto position = QHighDpi::fromNativePixels(
				globalNativePosition,
				screen ? screen->screen() : nullptr);
			InvokeQueued(_menu.get(), [=] {
				_menu->popup(position);
			});
		}, _lifetime);
	} else {
		updateIcon();
	}
}

void Tray::destroyIcon() {
	_icon = nullptr;
}

void Tray::updateIcon() {
	if (!_icon) {
		return;
	}
	const auto controller = Core::App().activePrimaryWindow();
	const auto session = !controller
		? nullptr
		: !controller->sessionController()
		? nullptr
		: &controller->sessionController()->session();

	// Force Qt to use right icon size, not the larger one.
	QIcon forTrayIcon;
	forTrayIcon.addPixmap(
		Tray::IconWithCounter(
			CounterLayerArgs(
				GetSystemMetrics(SM_CXSMICON),
				Core::App().unreadBadge(),
				Core::App().unreadBadgeMuted()),
			true,
			Core::App().settings().trayIconMonochrome(),
			session && session->supportMode()));
	_icon->updateIcon(forTrayIcon);
}

void Tray::createMenu() {
	if (!_menu) {
		_menu = base::make_unique_q<Ui::PopupMenu>(nullptr);
		_menu->deleteOnHide(false);
	}
}

void Tray::destroyMenu() {
	_menu = nullptr;
	_actionsLifetime.destroy();
}

void Tray::addAction(rpl::producer<QString> text, Fn<void()> &&callback) {
	if (!_menu) {
		return;
	}

	// If we try to activate() window before the _menu is hidden,
	// then the window will be shown in semi-active state (Qt bug).
	// It will receive input events, but it will be rendered as inactive.
	auto callbackLater = crl::guard(_menu.get(), [=] {
		using namespace rpl::mappers;
		_callbackFromTrayLifetime = _menu->shownValue(
		) | rpl::filter(!_1) | rpl::take(1) | rpl::start_with_next([=] {
			callback();
		});
	});

	const auto action = _menu->addAction(QString(), std::move(callbackLater));
	std::move(
		text
	) | rpl::start_with_next([=](const QString &text) {
		action->setText(text);
	}, _actionsLifetime);
}

void Tray::showTrayMessage() const {
	if (!cSeenTrayTooltip() && _icon) {
		_icon->showMessage(
			AppName.utf16(),
			tr::lng_tray_icon_text(tr::now),
			QIcon(),
			QPlatformSystemTrayIcon::Information,
			kTooltipDelay);
		cSetSeenTrayTooltip(true);
		Local::writeSettings();
	}
}

bool Tray::hasTrayMessageSupport() const {
	return !cSeenTrayTooltip();
}

rpl::producer<> Tray::aboutToShowRequests() const {
	return _aboutToShowRequests.events();
}

rpl::producer<> Tray::showFromTrayRequests() const {
	return rpl::never<>();
}

rpl::producer<> Tray::hideToTrayRequests() const {
	return rpl::never<>();
}

rpl::producer<> Tray::iconClicks() const {
	return _iconClicks.events();
}

bool Tray::hasIcon() const {
	return _icon;
}

rpl::lifetime &Tray::lifetime() {
	return _lifetime;
}

Window::CounterLayerArgs Tray::CounterLayerArgs(
		int size,
		int counter,
		bool muted) {
	return Window::CounterLayerArgs{
		.size = size,
		.count = counter,
		.bg = muted ? st::trayCounterBgMute : st::trayCounterBg,
		.fg = st::trayCounterFg,
	};
}

QPixmap Tray::IconWithCounter(
		Window::CounterLayerArgs &&args,
		bool smallIcon,
		bool monochrome,
		bool supportMode) {
	return Ui::PixmapFromImage(ImageIconWithCounter(
		std::move(args),
		supportMode,
		smallIcon,
		monochrome));
}

bool HasMonochromeSetting() {
	return IsDarkTaskbar().has_value();
}

} // namespace Platform