/*
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 "chat_helpers/stickers_list_widget.h"

#include "data/data_document.h"
#include "data/data_document_media.h"
#include "data/data_session.h"
#include "data/data_channel.h"
#include "data/data_file_origin.h"
#include "data/data_cloud_file.h"
#include "data/data_changes.h"
#include "chat_helpers/send_context_menu.h" // SendMenu::FillSendMenu
#include "chat_helpers/stickers_lottie.h"
#include "ui/widgets/buttons.h"
#include "ui/widgets/popup_menu.h"
#include "ui/effects/animations.h"
#include "ui/effects/ripple_animation.h"
#include "ui/image/image.h"
#include "ui/cached_round_corners.h"
#include "lottie/lottie_multi_player.h"
#include "lottie/lottie_single_player.h"
#include "lottie/lottie_animation.h"
#include "boxes/stickers_box.h"
#include "inline_bots/inline_bot_result.h"
#include "storage/storage_account.h"
#include "lang/lang_keys.h"
#include "mainwindow.h"
#include "dialogs/dialogs_layout.h"
#include "boxes/sticker_set_box.h"
#include "boxes/stickers_box.h"
#include "boxes/confirm_box.h"
#include "window/window_session_controller.h" // GifPauseReason.
#include "main/main_session.h"
#include "main/main_session_settings.h"
#include "apiwrap.h"
#include "api/api_toggling_media.h" // Api::ToggleFavedSticker
#include "styles/style_chat_helpers.h"
#include "styles/style_window.h"

#include <QtWidgets/QApplication>

namespace ChatHelpers {
namespace {

constexpr auto kInlineItemsMaxPerRow = 5;
constexpr auto kSearchRequestDelay = 400;
constexpr auto kRecentDisplayLimit = 20;
constexpr auto kPreloadOfficialPages = 4;
constexpr auto kOfficialLoadLimit = 40;

using Data::StickersSet;
using Data::StickersPack;
using Data::StickersSetThumbnailView;

bool SetInMyList(MTPDstickerSet::Flags flags) {
	return (flags & MTPDstickerSet::Flag::f_installed_date)
		&& !(flags & MTPDstickerSet::Flag::f_archived);
}

} // namespace

struct StickerIcon {
	StickerIcon(uint64 setId) : setId(setId) {
	}
	StickerIcon(
		not_null<StickersSet*> set,
		DocumentData *sticker,
		int pixw,
		int pixh)
	: setId(set->id)
	, set(set)
	, sticker(sticker)
	, pixw(pixw)
	, pixh(pixh) {
	}

	void ensureMediaCreated() const {
		if (!sticker) {
			return;
		} else if (set->hasThumbnail()) {
			if (!thumbnailMedia) {
				thumbnailMedia = set->createThumbnailView();
				set->loadThumbnail();
			}
		} else if (!stickerMedia) {
			stickerMedia = sticker->createMediaView();
			stickerMedia->thumbnailWanted(sticker->stickerSetOrigin());
		}
	}

	uint64 setId = 0;
	StickersSet *set = nullptr;
	mutable std::unique_ptr<Lottie::SinglePlayer> lottie;
	mutable QPixmap savedFrame;
	DocumentData *sticker = nullptr;
	ChannelData *megagroup = nullptr;
	mutable std::shared_ptr<StickersSetThumbnailView> thumbnailMedia;
	mutable std::shared_ptr<Data::DocumentMedia> stickerMedia;
	mutable std::shared_ptr<Data::CloudImageView> megagroupUserpic;
	int pixw = 0;
	int pixh = 0;
	mutable rpl::lifetime lifetime;

};

class StickersListWidget::Footer : public TabbedSelector::InnerFooter {
public:
	explicit Footer(not_null<StickersListWidget*> parent);

	void preloadImages();
	void validateSelectedIcon(
		uint64 setId,
		ValidateIconAnimations animations);
	void refreshIcons(ValidateIconAnimations animations);
	bool hasOnlyFeaturedSets() const;

	void leaveToChildEvent(QEvent *e, QWidget *child) override;

	void stealFocus();
	void returnFocus();
	void setLoading(bool loading);

	void clearHeavyData();

protected:
	void paintEvent(QPaintEvent *e) override;
	void resizeEvent(QResizeEvent *e) override;
	void mousePressEvent(QMouseEvent *e) override;
	void mouseMoveEvent(QMouseEvent *e) override;
	void mouseReleaseEvent(QMouseEvent *e) override;
	bool eventHook(QEvent *e) override;

	void processHideFinished() override;

private:
	enum class SpecialOver {
		None,
		Search,
		Settings,
	};
	using OverState = std::variant<SpecialOver, int>;

	template <typename Callback>
	void enumerateVisibleIcons(Callback callback);

	bool iconsAnimationCallback(crl::time now);
	void setSelectedIcon(
		int newSelected,
		ValidateIconAnimations animations);
	void validateIconLottieAnimation(const StickerIcon &icon);

	void refreshIconsGeometry(ValidateIconAnimations animations);
	void updateSelected();
	void updateSetIcon(uint64 setId);
	void finishDragging();
	void paintStickerSettingsIcon(Painter &p) const;
	void paintSearchIcon(Painter &p) const;
	void paintSetIcon(Painter &p, const StickerIcon &icon, int x) const;
	void paintSelectionBar(Painter &p) const;
	void paintLeftRightFading(Painter &p) const;

	void initSearch();
	void toggleSearch(bool visible);
	void resizeSearchControls();
	void scrollByWheelEvent(not_null<QWheelEvent*> e);

	const not_null<StickersListWidget*> _pan;

	static constexpr auto kVisibleIconsCount = 8;

	std::vector<StickerIcon> _icons;
	OverState _iconOver = SpecialOver::None;
	int _iconSel = 0;
	OverState _iconDown = SpecialOver::None;
	bool _iconsDragging = false;
	Ui::Animations::Basic _iconsAnimation;
	QPoint _iconsMousePos, _iconsMouseDown;
	int _iconsLeft = 0;
	int _iconsRight = 0;
	int _iconsTop = 0;
	int _iconsStartX = 0;
	int _iconsMax = 0;
	anim::value _iconsX;
	anim::value _iconSelX;
	crl::time _iconsStartAnim = 0;

	bool _horizontal = false;

	bool _searchShown = false;
	object_ptr<Ui::InputField> _searchField = { nullptr };
	object_ptr<Ui::CrossButton> _searchCancel = { nullptr };
	QPointer<QWidget> _focusTakenFrom;

};

auto StickersListWidget::PrepareStickers(
	const QVector<DocumentData*> &pack)
-> std::vector<Sticker> {
	return ranges::views::all(
		pack
	) | ranges::views::transform([](DocumentData *document) {
		return Sticker{ document };
	}) | ranges::to_vector;
}

StickersListWidget::Set::Set(
	uint64 id,
	StickersSet *set,
	MTPDstickerSet::Flags flags,
	const QString &title,
	const QString &shortName,
	int count,
	bool externalLayout,
	std::vector<Sticker> &&stickers)
: id(id)
, set(set)
, flags(flags)
, title(title)
, shortName(shortName)
, stickers(std::move(stickers))
, count(count)
, externalLayout(externalLayout) {
}

StickersListWidget::Set::Set(Set &&other) = default;
StickersListWidget::Set &StickersListWidget::Set::operator=(
	Set &&other) = default;
StickersListWidget::Set::~Set() = default;


void StickersListWidget::Sticker::ensureMediaCreated() {
	if (documentMedia) {
		return;
	}
	documentMedia = document->createMediaView();
}

StickersListWidget::Footer::Footer(not_null<StickersListWidget*> parent)
: InnerFooter(parent)
, _pan(parent)
, _iconsAnimation([=](crl::time now) {
	return iconsAnimationCallback(now);
}) {
	setMouseTracking(true);

	_iconsLeft = _iconsRight = st::emojiCategorySkip + st::stickerIconWidth;

	_pan->session().downloaderTaskFinished(
	) | rpl::start_with_next([=] {
		update();
	}, lifetime());
}

void StickersListWidget::Footer::clearHeavyData() {
	const auto count = int(_icons.size());
	const auto iconsX = qRound(_iconsX.current());
	const auto first = floorclamp(iconsX, st::stickerIconWidth, 0, count);
	const auto last = ceilclamp(
		iconsX + width(),
		st::stickerIconWidth,
		0,
		count);
	for (auto i = 0; i != count; ++i) {
		auto &icon = _icons[i];
		icon.lottie = nullptr;
		icon.lifetime.destroy();
		icon.stickerMedia = nullptr;
		if (i < first || i >= last) {
			// Not visible icon.
			icon.savedFrame = QPixmap();
		}
	}
}

void StickersListWidget::Footer::initSearch() {
	_searchField.create(
		this,
		st::gifsSearchField,
		tr::lng_stickers_search_sets());
	_searchCancel.create(this, st::gifsSearchCancel);
	_searchField->show();
	_searchCancel->show(anim::type::instant);

	const auto cancelSearch = [=] {
		if (_searchField->getLastText().isEmpty()) {
			toggleSearch(false);
		} else {
			_searchField->setText(QString());
		}
	};
	connect(_searchField, &Ui::InputField::submitted, [=] {
		_pan->sendSearchRequest();
	});
	connect(_searchField, &Ui::InputField::cancelled, cancelSearch);
	connect(_searchField, &Ui::InputField::changed, [=] {
		_pan->searchForSets(_searchField->getLastText());
	});
	_searchCancel->setClickedCallback(cancelSearch);

	resizeSearchControls();
}

void StickersListWidget::Footer::toggleSearch(bool visible) {
	if (_searchShown == visible) {
		return;
	}
	_searchShown = visible;
	if (_searchShown) {
		initSearch();
		stealFocus();
	} else if (_searchField) {
		returnFocus();
		_searchField.destroy();
		_searchCancel.destroy();
		_focusTakenFrom = nullptr;
	}
	update();
}

void StickersListWidget::Footer::stealFocus() {
	if (_searchField) {
		if (!_focusTakenFrom) {
			_focusTakenFrom = QApplication::focusWidget();
		}
		_searchField->setFocus();
	}
}

void StickersListWidget::Footer::returnFocus() {
	if (_searchField && _focusTakenFrom) {
		if (_searchField->hasFocus()) {
			_focusTakenFrom->setFocus();
		}
		_focusTakenFrom = nullptr;
	}
}

template <typename Callback>
void StickersListWidget::Footer::enumerateVisibleIcons(Callback callback) {
	auto iconsX = qRound(_iconsX.current());
	auto index = iconsX / st::stickerIconWidth;
	auto x = _iconsLeft - (iconsX % st::stickerIconWidth);
	auto first = floorclamp(iconsX, st::stickerIconWidth, 0, _icons.size());
	auto last = ceilclamp(iconsX + width(), st::stickerIconWidth, 0, _icons.size());
	for (auto index = first; index != last; ++index) {
		callback(_icons[index], x);
		x += st::stickerIconWidth;
	}
}

void StickersListWidget::Footer::preloadImages() {
	enumerateVisibleIcons([](const StickerIcon &icon, int x) {
		if (const auto sticker = icon.sticker) {
			Assert(icon.set != nullptr);
			if (icon.set->hasThumbnail()) {
				icon.set->loadThumbnail();
			} else {
				sticker->loadThumbnail(sticker->stickerSetOrigin());
			}
		}
	});
}

void StickersListWidget::Footer::validateSelectedIcon(
		uint64 setId,
		ValidateIconAnimations animations) {
	auto favedIconIndex = -1;
	auto newSelected = -1;
	for (auto i = 0, l = int(_icons.size()); i != l; ++i) {
		if (_icons[i].setId == setId
			|| (_icons[i].setId == Data::Stickers::FavedSetId
				&& setId == Data::Stickers::RecentSetId)) {
			newSelected = i;
			break;
		} else if (_icons[i].setId == Data::Stickers::FavedSetId) {
			favedIconIndex = i;
		}
	}
	setSelectedIcon(
		(newSelected >= 0
			? newSelected
			: (favedIconIndex >= 0) ? favedIconIndex : 0),
		animations);
}

void StickersListWidget::Footer::setSelectedIcon(
		int newSelected,
		ValidateIconAnimations animations) {
	if (_iconSel == newSelected) {
		return;
	}
	_iconSel = newSelected;
	auto iconSelXFinal = _iconSel * st::stickerIconWidth;
	if (animations == ValidateIconAnimations::Full) {
		_iconSelX.start(iconSelXFinal);
	} else {
		_iconSelX = anim::value(iconSelXFinal, iconSelXFinal);
	}
	auto iconsCountForCentering = (2 * _iconSel + 1);
	auto iconsWidthForCentering = iconsCountForCentering
		* st::stickerIconWidth;
	auto iconsXFinal = std::clamp(
		(_iconsLeft + iconsWidthForCentering + _iconsRight - width()) / 2,
		0,
		_iconsMax);
	if (animations == ValidateIconAnimations::None) {
		_iconsX = anim::value(iconsXFinal, iconsXFinal);
		_iconsAnimation.stop();
	} else {
		_iconsX.start(iconsXFinal);
		_iconsStartAnim = crl::now();
		_iconsAnimation.start();
	}
	updateSelected();
	update();
}

void StickersListWidget::Footer::processHideFinished() {
	_iconOver = _iconDown = SpecialOver::None;
	_iconsStartAnim = 0;
	_iconsAnimation.stop();
	_iconsX.finish();
	_iconSelX.finish();
	_horizontal = false;
}

void StickersListWidget::Footer::leaveToChildEvent(QEvent *e, QWidget *child) {
	_iconsMousePos = QCursor::pos();
	updateSelected();
}

void StickersListWidget::Footer::setLoading(bool loading) {
	if (_searchCancel) {
		_searchCancel->setLoadingAnimation(loading);
	}
}

void StickersListWidget::Footer::paintEvent(QPaintEvent *e) {
	Painter p(this);

	paintSearchIcon(p);

	if (_icons.empty() || _searchShown) {
		return;
	}

	if (!hasOnlyFeaturedSets()) {
		paintStickerSettingsIcon(p);
	}

	auto clip = QRect(
		_iconsLeft,
		_iconsTop,
		width() - _iconsLeft - _iconsRight,
		st::emojiFooterHeight);
	if (rtl()) {
		clip.moveLeft(width() - _iconsLeft - clip.width());
	}
	p.setClipRect(clip);

	enumerateVisibleIcons([&](const StickerIcon &icon, int x) {
		paintSetIcon(p, icon, x);
	});

	paintSelectionBar(p);
	paintLeftRightFading(p);
}

void StickersListWidget::Footer::paintSelectionBar(Painter &p) const {
	auto selxrel = _iconsLeft + qRound(_iconSelX.current());
	auto selx = selxrel - qRound(_iconsX.current());
	if (rtl()) {
		selx = width() - selx - st::stickerIconWidth;
	}
	p.fillRect(
		selx,
		_iconsTop + st::emojiFooterHeight - st::stickerIconPadding,
		st::stickerIconWidth,
		st::stickerIconSel,
		st::stickerIconSelColor);
}

void StickersListWidget::Footer::paintLeftRightFading(Painter &p) const {
	auto o_left = std::clamp(
		_iconsX.current() / st::stickerIconLeft.width(),
		0.,
		1.);
	if (o_left > 0) {
		p.setOpacity(o_left);
		st::stickerIconLeft.fill(p, style::rtlrect(_iconsLeft, _iconsTop, st::stickerIconLeft.width(), st::emojiFooterHeight, width()));
		p.setOpacity(1.);
	}
	auto o_right = std::clamp(
		(_iconsMax - _iconsX.current()) / st::stickerIconRight.width(),
		0.,
		1.);
	if (o_right > 0) {
		p.setOpacity(o_right);
		st::stickerIconRight.fill(p, style::rtlrect(width() - _iconsRight - st::stickerIconRight.width(), _iconsTop, st::stickerIconRight.width(), st::emojiFooterHeight, width()));
		p.setOpacity(1.);
	}
}

void StickersListWidget::Footer::resizeEvent(QResizeEvent *e) {
	if (_searchField) {
		resizeSearchControls();
	}
	refreshIconsGeometry(ValidateIconAnimations::None);
}

void StickersListWidget::Footer::resizeSearchControls() {
	Expects(_searchField != nullptr);
	Expects(_searchCancel != nullptr);

	const auto fieldWidth = width()
		- st::gifsSearchFieldPosition.x()
		- st::gifsSearchCancelPosition.x()
		- st::gifsSearchCancel.width;
	_searchField->resizeToWidth(fieldWidth);
	_searchField->moveToLeft(st::gifsSearchFieldPosition.x(), st::gifsSearchFieldPosition.y());
	_searchCancel->moveToRight(st::gifsSearchCancelPosition.x(), st::gifsSearchCancelPosition.y());
}

void StickersListWidget::Footer::mousePressEvent(QMouseEvent *e) {
	if (e->button() != Qt::LeftButton) {
		return;
	}
	_iconsMousePos = e ? e->globalPos() : QCursor::pos();
	updateSelected();

	if (_iconOver == SpecialOver::Settings) {
		Ui::show(Box<StickersBox>(
			_pan->controller(),
			(hasOnlyFeaturedSets()
				? StickersBox::Section::Featured
				: StickersBox::Section::Installed)));
	} else if (_iconOver == SpecialOver::Search) {
		toggleSearch(true);
	} else {
		_iconDown = _iconOver;
		_iconsMouseDown = _iconsMousePos;
		_iconsStartX = qRound(_iconsX.current());
	}
}

void StickersListWidget::Footer::mouseMoveEvent(QMouseEvent *e) {
	_iconsMousePos = e ? e->globalPos() : QCursor::pos();
	updateSelected();

	if (!_iconsDragging
		&& !_icons.empty()
		&& v::is<int>(_iconDown)) {
		if ((_iconsMousePos - _iconsMouseDown).manhattanLength() >= QApplication::startDragDistance()) {
			_iconsDragging = true;
		}
	}
	if (_iconsDragging) {
		auto newX = std::clamp(
			(rtl() ? -1 : 1) * (_iconsMouseDown.x() - _iconsMousePos.x())
				+ _iconsStartX,
			0,
			_iconsMax);
		if (newX != qRound(_iconsX.current())) {
			_iconsX = anim::value(newX, newX);
			_iconsStartAnim = 0;
			_iconsAnimation.stop();
			update();
		}
	}
}

void StickersListWidget::Footer::mouseReleaseEvent(QMouseEvent *e) {
	if (_icons.empty()) {
		return;
	}

	const auto wasDown = std::exchange(_iconDown, SpecialOver::None);

	_iconsMousePos = e ? e->globalPos() : QCursor::pos();
	if (_iconsDragging) {
		finishDragging();
		return;
	}

	updateSelected();
	if (wasDown == _iconOver) {
		if (const auto index = std::get_if<int>(&_iconOver)) {
			_iconSelX = anim::value(
				*index * st::stickerIconWidth,
				*index * st::stickerIconWidth);
			_pan->showStickerSet(_icons[*index].setId);
		}
	}
}

void StickersListWidget::Footer::finishDragging() {
	auto newX = std::clamp(
		_iconsStartX + _iconsMouseDown.x() - _iconsMousePos.x(),
		0,
		_iconsMax);
	if (newX != qRound(_iconsX.current())) {
		_iconsX = anim::value(newX, newX);
		_iconsStartAnim = 0;
		_iconsAnimation.stop();
		update();
	}
	_iconsDragging = false;
	updateSelected();
}

bool StickersListWidget::Footer::eventHook(QEvent *e) {
	if (e->type() == QEvent::TouchBegin) {
	} else if (e->type() == QEvent::Wheel) {
		if (!_icons.empty()
			&& v::is<int>(_iconOver)
			&& (_iconDown == SpecialOver::None)) {
			scrollByWheelEvent(static_cast<QWheelEvent*>(e));
		}
	}
	return InnerFooter::eventHook(e);
}

void StickersListWidget::Footer::scrollByWheelEvent(
		not_null<QWheelEvent*> e) {
	auto horizontal = (e->angleDelta().x() != 0);
	auto vertical = (e->angleDelta().y() != 0);
	if (horizontal) {
		_horizontal = true;
	}
	auto newX = qRound(_iconsX.current());
	if (/*_horizontal && */horizontal) {
		newX = std::clamp(
			newX - (rtl() ? -1 : 1) * (e->pixelDelta().x()
				? e->pixelDelta().x()
				: e->angleDelta().x()),
			0,
			_iconsMax);
	} else if (/*!_horizontal && */vertical) {
		newX = std::clamp(
			newX - (e->pixelDelta().y()
				? e->pixelDelta().y()
				: e->angleDelta().y()),
			0,
			_iconsMax);
	}
	if (newX != qRound(_iconsX.current())) {
		_iconsX = anim::value(newX, newX);
		_iconsStartAnim = 0;
		_iconsAnimation.stop();
		updateSelected();
		update();
	}
}

void StickersListWidget::Footer::updateSelected() {
	if (_iconDown != SpecialOver::None) {
		return;
	}

	auto p = mapFromGlobal(_iconsMousePos);
	auto x = p.x(), y = p.y();
	if (rtl()) x = width() - x;
	const auto settingsLeft = width() - _iconsRight;
	const auto searchLeft = _iconsLeft - st::stickerIconWidth;
	auto newOver = OverState(SpecialOver::None);
	if (x >= searchLeft
		&& x < searchLeft + st::stickerIconWidth
		&& y >= _iconsTop
		&& y < _iconsTop + st::emojiFooterHeight) {
		newOver = SpecialOver::Search;
	} else if (x >= settingsLeft
		&& x < settingsLeft + st::stickerIconWidth
		&& y >= _iconsTop
		&& y < _iconsTop + st::emojiFooterHeight) {
		if (!_icons.empty() && !hasOnlyFeaturedSets()) {
			newOver = SpecialOver::Settings;
		}
	} else if (!_icons.empty()) {
		if (y >= _iconsTop
			&& y < _iconsTop + st::emojiFooterHeight
			&& x >= _iconsLeft
			&& x < width() - _iconsRight) {
			x += qRound(_iconsX.current()) - _iconsLeft;
			if (x < _icons.size() * st::stickerIconWidth) {
				newOver = qFloor(x / st::stickerIconWidth);
			}
		}
	}
	if (newOver != _iconOver) {
		if (newOver == SpecialOver::None) {
			setCursor(style::cur_default);
		} else if (_iconOver == SpecialOver::None) {
			setCursor(style::cur_pointer);
		}
		_iconOver = newOver;
	}
}

void StickersListWidget::Footer::refreshIcons(
		ValidateIconAnimations animations) {
	auto icons = _pan->fillIcons();

	auto indices = base::flat_map<uint64, int>();
	indices.reserve(_icons.size());
	auto index = 0;
	for (const auto &entry : _icons) {
		indices.emplace(entry.setId, index++);
	}

	for (auto &now : icons) {
		if (const auto i = indices.find(now.setId); i != end(indices)) {
			auto &was = _icons[i->second];
			if (now.sticker == was.sticker) {
				now.lottie = std::move(was.lottie);
				now.lifetime = std::move(was.lifetime);
				now.savedFrame = std::move(was.savedFrame);
			}
		}
	}

	_icons = std::move(icons);
	refreshIconsGeometry(animations);
}

void StickersListWidget::Footer::refreshIconsGeometry(
		ValidateIconAnimations animations) {
	_iconOver = _iconDown = SpecialOver::None;
	_iconsX.finish();
	_iconSelX.finish();
	_iconsStartAnim = 0;
	_iconsAnimation.stop();
	_iconsMax = std::max(
		_iconsLeft + int(_icons.size()) * st::stickerIconWidth + _iconsRight - width(),
		0);
	if (_iconsX.current() > _iconsMax) {
		_iconsX = anim::value(_iconsMax, _iconsMax);
	}
	updateSelected();
	_pan->validateSelectedIcon(animations);
	update();
}

bool StickersListWidget::Footer::hasOnlyFeaturedSets() const {
	return (_icons.size() == 1)
		&& (_icons[0].setId == Data::Stickers::FeaturedSetId);
}

void StickersListWidget::Footer::paintStickerSettingsIcon(Painter &p) const {
	const auto settingsLeft = width() - _iconsRight;
	st::stickersSettings.paint(p, settingsLeft + (st::stickerIconWidth - st::stickersSettings.width()) / 2, _iconsTop + st::emojiCategory.iconPosition.y(), width());
}

void StickersListWidget::Footer::paintSearchIcon(Painter &p) const {
	const auto searchLeft = _iconsLeft - st::stickerIconWidth;
	st::stickersSearch.paint(p, searchLeft + (st::stickerIconWidth - st::stickersSearch.width()) / 2, _iconsTop + st::emojiCategory.iconPosition.y(), width());
}

void StickersListWidget::Footer::validateIconLottieAnimation(
		const StickerIcon &icon) {
	icon.ensureMediaCreated();
	if (icon.lottie
		|| !icon.sticker
		|| !HasLottieThumbnail(
			icon.thumbnailMedia.get(),
			icon.stickerMedia.get())) {
		return;
	}
	auto player = LottieThumbnail(
		icon.thumbnailMedia.get(),
		icon.stickerMedia.get(),
		StickerLottieSize::StickersFooter,
		QSize(
			st::stickerIconWidth - 2 * st::stickerIconPadding,
			st::emojiFooterHeight - 2 * st::stickerIconPadding
		) * cIntRetinaFactor(),
		_pan->getLottieRenderer());
	if (!player) {
		return;
	}
	icon.lottie = std::move(player);

	const auto id = icon.setId;
	icon.lottie->updates(
	) | rpl::start_with_next([=] {
		updateSetIcon(id);
	}, icon.lifetime);
}

void StickersListWidget::Footer::updateSetIcon(uint64 setId) {
	enumerateVisibleIcons([&](const StickerIcon &icon, int x) {
		if (icon.setId != setId) {
			return;
		}
		update(x, _iconsTop, st::stickerIconWidth, st::emojiFooterHeight);
	});
}

void StickersListWidget::Footer::paintSetIcon(
		Painter &p,
		const StickerIcon &icon,
		int x) const {
	if (icon.sticker) {
		icon.ensureMediaCreated();
		const_cast<Footer*>(this)->validateIconLottieAnimation(icon);
		const auto origin = icon.sticker->stickerSetOrigin();
		const auto thumb = icon.thumbnailMedia
			? icon.thumbnailMedia->image()
			: icon.stickerMedia
			? icon.stickerMedia->thumbnail()
			: nullptr;
		if (!icon.lottie
			|| (!icon.lottie->ready() && !icon.savedFrame.isNull())) {
			const auto pixmap = !icon.savedFrame.isNull()
				? icon.savedFrame
				: (!icon.lottie && thumb)
				? thumb->pix(icon.pixw, icon.pixh)
				: QPixmap();
			if (pixmap.isNull()) {
				return;
			} else if (icon.savedFrame.isNull()) {
				icon.savedFrame = pixmap;
			}
			p.drawPixmapLeft(
				x + (st::stickerIconWidth - icon.pixw) / 2,
				_iconsTop + (st::emojiFooterHeight - icon.pixh) / 2,
				width(),
				pixmap);
		} else if (icon.lottie->ready()) {
			const auto frame = icon.lottie->frame();
			const auto size = frame.size() / cIntRetinaFactor();
			if (icon.savedFrame.isNull()) {
				icon.savedFrame = QPixmap::fromImage(frame, Qt::ColorOnly);
				icon.savedFrame.setDevicePixelRatio(cRetinaFactor());
			}
			p.drawImage(
				QRect(
					x + (st::stickerIconWidth - size.width()) / 2,
					_iconsTop + (st::emojiFooterHeight - size.height()) / 2,
					size.width(),
					size.height()),
				frame);
			const auto paused = _pan->controller()->isGifPausedAtLeastFor(
				Window::GifPauseReason::SavedGifs);
			if (!paused) {
				icon.lottie->markFrameShown();
			}
		}
	} else if (icon.megagroup) {
		icon.megagroup->paintUserpicLeft(p, icon.megagroupUserpic, x + (st::stickerIconWidth - st::stickerGroupCategorySize) / 2, _iconsTop + (st::emojiFooterHeight - st::stickerGroupCategorySize) / 2, width(), st::stickerGroupCategorySize);
	} else {
		const auto paintedIcon = [&] {
			if (icon.setId == Data::Stickers::FeaturedSetId) {
				const auto session = &_pan->session();
				return session->data().stickers().featuredSetsUnreadCount()
					? &st::stickersTrendingUnread
					: &st::stickersTrending;
			//} else if (setId == Stickers::FavedSetId) {
			//	return &st::stickersFaved;
			}
			return &st::stickersRecent;
		}();
		paintedIcon->paint(
			p,
			x + (st::stickerIconWidth - paintedIcon->width()) / 2,
			_iconsTop + (st::emojiFooterHeight - paintedIcon->height()) / 2,
			width());
	}
}

bool StickersListWidget::Footer::iconsAnimationCallback(crl::time now) {
	if (anim::Disabled()) {
		now += st::stickerIconMove;
	}
	if (_iconsStartAnim) {
		const auto dt = (now - _iconsStartAnim) / float64(st::stickerIconMove);
		if (dt >= 1.) {
			_iconsStartAnim = 0;
			_iconsX.finish();
			_iconSelX.finish();
		} else {
			_iconsX.update(dt, anim::linear);
			_iconSelX.update(dt, anim::linear);
		}
	}

	update();

	return (_iconsStartAnim != 0);
}

StickersListWidget::StickersListWidget(
	QWidget *parent,
	not_null<Window::SessionController*> controller)
: Inner(parent, controller)
, _api(&controller->session().mtp())
, _section(Section::Stickers)
, _megagroupSetAbout(st::columnMinimalWidthThird - st::emojiScroll.width - st::emojiPanHeaderLeft)
, _addText(tr::lng_stickers_featured_add(tr::now).toUpper())
, _addWidth(st::stickersTrendingAdd.font->width(_addText))
, _settings(this, tr::lng_stickers_you_have(tr::now))
, _previewTimer([=] { showPreview(); })
, _searchRequestTimer([=] { sendSearchRequest(); }) {
	setMouseTracking(true);
	setAttribute(Qt::WA_OpaquePaintEvent);

	_settings->addClickHandler([=] {
		Ui::show(
			Box<StickersBox>(controller, StickersBox::Section::Installed));
	});

	session().downloaderTaskFinished(
	) | rpl::start_with_next([=] {
		if (isVisible()) {
			update();
			readVisibleFeatured(getVisibleTop(), getVisibleBottom());
		}
	}, lifetime());

	session().changes().peerUpdates(
		Data::PeerUpdate::Flag::StickersSet
	) | rpl::filter([=](const Data::PeerUpdate &update) {
		return (update.peer.get() == _megagroupSet);
	}) | rpl::start_with_next([=] {
		refreshStickers();
	}, lifetime());

	session().data().stickers().recentUpdated(
	) | rpl::start_with_next([=] {
		refreshRecent();
	}, lifetime());
}

Main::Session &StickersListWidget::session() const {
	return controller()->session();
}

rpl::producer<TabbedSelector::FileChosen> StickersListWidget::chosen() const {
	return _chosen.events();
}

rpl::producer<> StickersListWidget::scrollUpdated() const {
	return _scrollUpdated.events();
}

rpl::producer<> StickersListWidget::checkForHide() const {
	return _checkForHide.events();
}

object_ptr<TabbedSelector::InnerFooter> StickersListWidget::createFooter() {
	Expects(_footer == nullptr);

	auto result = object_ptr<Footer>(this);
	_footer = result;
	return result;
}

void StickersListWidget::visibleTopBottomUpdated(
		int visibleTop,
		int visibleBottom) {
	Inner::visibleTopBottomUpdated(visibleTop, visibleBottom);
	if (_section == Section::Featured) {
		checkVisibleFeatured(visibleTop, visibleBottom);
	} else {
		checkVisibleLottie();
	}
	validateSelectedIcon(ValidateIconAnimations::Full);
}

void StickersListWidget::checkVisibleFeatured(
		int visibleTop,
		int visibleBottom) {
	readVisibleFeatured(visibleTop, visibleBottom);

	const auto visibleHeight = visibleBottom - visibleTop;

	if (visibleBottom > height() - visibleHeight * kPreloadOfficialPages) {
		preloadMoreOfficial();
	}

	const auto rowHeight = featuredRowHeight();
	const auto destroyAbove = floorclamp(visibleTop - visibleHeight, rowHeight, 0, _officialSets.size());
	const auto destroyBelow = ceilclamp(visibleBottom + visibleHeight, rowHeight, 0, _officialSets.size());
	for (auto i = 0; i != destroyAbove; ++i) {
		clearHeavyIn(_officialSets[i]);
	}
	for (auto i = destroyBelow; i != _officialSets.size(); ++i) {
		clearHeavyIn(_officialSets[i]);
	}
}

void StickersListWidget::preloadMoreOfficial() {
	if (_officialRequestId) {
		return;
	}
	_officialRequestId = _api.request(MTPmessages_GetOldFeaturedStickers(
		MTP_int(_officialOffset),
		MTP_int(kOfficialLoadLimit),
		MTP_int(0)
	)).done([=](const MTPmessages_FeaturedStickers &result) {
		_officialRequestId = 0;
		result.match([&](const MTPDmessages_featuredStickersNotModified &d) {
			LOG(("Api Error: messages.featuredStickersNotModified."));
		}, [&](const MTPDmessages_featuredStickers &data) {
			const auto &list = data.vsets().v;
			_officialOffset += list.size();
			for (int i = 0, l = list.size(); i != l; ++i) {
				auto &data = list[i];
				const auto setData = data.match([&](const auto &data) {
					return data.vset().match([](const MTPDstickerSet &data) {
						return &data;
					});
				});
				const auto covers = data.match([](const MTPDstickerSetCovered &) {
					return StickersPack();
				}, [&](const MTPDstickerSetMultiCovered &data) {
					auto result = StickersPack();
					for (const auto &cover : data.vcovers().v) {
						const auto document = session().data().processDocument(cover);
						if (document->sticker()) {
							result.push_back(document);
						}
					}
					return result;
				});
				if (const auto set = session().data().stickers().feedSet(*setData)) {
					if (!covers.empty()) {
						set->covers = covers;
					}
					if (set->stickers.empty() && set->covers.empty()) {
						continue;
					}
					const auto externalLayout = true;
					appendSet(
						_officialSets,
						set->id,
						externalLayout,
						AppendSkip::Installed);
				}
			}
		});
		resizeToWidth(width());
		update();
	}).fail([=](const MTP::Error &error) {
	}).send();
}

void StickersListWidget::readVisibleFeatured(
		int visibleTop,
		int visibleBottom) {
	const auto rowHeight = featuredRowHeight();
	const auto rowFrom = floorclamp(visibleTop, rowHeight, 0, _featuredSetsCount);
	const auto rowTo = ceilclamp(visibleBottom, rowHeight, 0, _featuredSetsCount);
	for (auto i = rowFrom; i < rowTo; ++i) {
		auto &set = _officialSets[i];
		if (!(set.flags & MTPDstickerSet_ClientFlag::f_unread)) {
			continue;
		}
		if (i * rowHeight < visibleTop || (i + 1) * rowHeight > visibleBottom) {
			continue;
		}
		int count = qMin(int(set.stickers.size()), _columnCount);
		int loaded = 0;
		for (int j = 0; j < count; ++j) {
			if (!set.stickers[j].document->hasThumbnail()
				|| !set.stickers[j].document->thumbnailLoading()
				|| (set.stickers[j].documentMedia
					&& set.stickers[j].documentMedia->loaded())) {
				++loaded;
			}
		}
		if (count > 0 && loaded == count) {
			session().api().readFeaturedSetDelayed(set.id);
		}
	}
}

int StickersListWidget::featuredRowHeight() const {
	return st::stickersTrendingHeader
		+ _singleSize.height()
		+ st::stickersTrendingSkip;
}

template <typename Callback>
bool StickersListWidget::enumerateSections(Callback callback) const {
	auto info = SectionInfo();
	const auto &sets = shownSets();
	for (auto i = 0; i != sets.size(); ++i) {
		auto &set = sets[i];
		info.section = i;
		info.count = set.stickers.size();
		const auto titleSkip = set.externalLayout
			? st::stickersTrendingHeader
			: setHasTitle(set)
			? st::emojiPanHeader
			: st::stickerPanPadding;
		info.rowsTop = info.top + titleSkip;
		if (set.externalLayout) {
			info.rowsCount = 1;
			info.rowsBottom = info.top + featuredRowHeight();
		} else if (set.id == Data::Stickers::MegagroupSetId && !info.count) {
			info.rowsCount = 0;
			info.rowsBottom = info.rowsTop + _megagroupSetButtonRect.y() + _megagroupSetButtonRect.height() + st::stickerGroupCategoryAddMargin.bottom();
		} else {
			info.rowsCount = (info.count / _columnCount) + ((info.count % _columnCount) ? 1 : 0);
			info.rowsBottom = info.rowsTop + info.rowsCount * _singleSize.height();
		}
		if (!callback(info)) {
			return false;
		}
		info.top = info.rowsBottom;
	}
	return true;
}

StickersListWidget::SectionInfo StickersListWidget::sectionInfo(int section) const {
	Expects(section >= 0 && section < shownSets().size());

	auto result = SectionInfo();
	enumerateSections([searchForSection = section, &result](const SectionInfo &info) {
		if (info.section == searchForSection) {
			result = info;
			return false;
		}
		return true;
	});
	return result;
}

StickersListWidget::SectionInfo StickersListWidget::sectionInfoByOffset(int yOffset) const {
	auto result = SectionInfo();
	enumerateSections([this, &result, yOffset](const SectionInfo &info) {
		if (yOffset < info.rowsBottom || info.section == shownSets().size() - 1) {
			result = info;
			return false;
		}
		return true;
	});
	return result;
}

int StickersListWidget::countDesiredHeight(int newWidth) {
	if (newWidth <= st::stickerPanWidthMin) {
		return 0;
	}
	auto availableWidth = newWidth - (st::stickerPanPadding - st::roundRadiusSmall);
	auto columnCount = availableWidth / st::stickerPanWidthMin;
	auto singleWidth = availableWidth / columnCount;
	auto fullWidth = (st::roundRadiusSmall + newWidth + st::emojiScroll.width);
	auto rowsRight = (fullWidth - columnCount * singleWidth) / 2;
	accumulate_max(rowsRight, st::emojiScroll.width);
	_rowsLeft = fullWidth
		- columnCount * singleWidth
		- rowsRight
		- st::roundRadiusSmall;
	_singleSize = QSize(singleWidth, singleWidth);
	setColumnCount(columnCount);

	auto visibleHeight = minimalHeight();
	auto minimalHeight = (visibleHeight - st::stickerPanPadding);
	auto countResult = [this](int minimalLastHeight) {
		const auto &sets = shownSets();
		if (sets.empty()) {
			return 0;
		}
		const auto info = sectionInfo(sets.size() - 1);
		return info.top
			+ qMax(info.rowsBottom - info.top, minimalLastHeight);
	};
	const auto minimalLastHeight = (_section == Section::Stickers)
		? minimalHeight
		: 0;
	return qMax(minimalHeight, countResult(minimalLastHeight))
		+ st::stickerPanPadding;
}

void StickersListWidget::installedLocally(uint64 setId) {
	_installedLocallySets.insert(setId);
}

void StickersListWidget::notInstalledLocally(uint64 setId) {
	_installedLocallySets.remove(setId);
}

void StickersListWidget::clearInstalledLocally() {
	if (!_installedLocallySets.empty()) {
		_installedLocallySets.clear();
		refreshStickers();
	}
}

void StickersListWidget::sendSearchRequest() {
	if (_searchRequestId || _searchNextQuery.isEmpty()) {
		return;
	}

	_searchRequestTimer.cancel();
	_searchQuery = _searchNextQuery;

	auto it = _searchCache.find(_searchQuery);
	if (it != _searchCache.cend()) {
		_footer->setLoading(false);
		return;
	}

	_footer->setLoading(true);
	const auto hash = int32(0);
	_searchRequestId = _api.request(MTPmessages_SearchStickerSets(
		MTP_flags(0),
		MTP_string(_searchQuery),
		MTP_int(hash)
	)).done([=](const MTPmessages_FoundStickerSets &result) {
		searchResultsDone(result);
	}).fail([this](const MTP::Error &error) {
		// show error?
		_footer->setLoading(false);
		_searchRequestId = 0;
	}).handleAllErrors().send();
}

void StickersListWidget::searchForSets(const QString &query) {
	const auto cleaned = query.trimmed();
	if (cleaned.isEmpty()) {
		cancelSetsSearch();
		return;
	}

	if (_searchQuery != cleaned) {
		_footer->setLoading(false);
		if (const auto requestId = base::take(_searchRequestId)) {
			_api.request(requestId).cancel();
		}
		if (_searchCache.find(cleaned) != _searchCache.cend()) {
			_searchRequestTimer.cancel();
			_searchQuery = _searchNextQuery = cleaned;
		} else {
			_searchNextQuery = cleaned;
			_searchRequestTimer.callOnce(kSearchRequestDelay);
		}
		showSearchResults();
	}
}

void StickersListWidget::cancelSetsSearch() {
	_footer->setLoading(false);
	if (const auto requestId = base::take(_searchRequestId)) {
		_api.request(requestId).cancel();
	}
	_searchRequestTimer.cancel();
	_searchQuery = _searchNextQuery = QString();
	_searchCache.clear();
	refreshSearchRows(nullptr);
}

void StickersListWidget::showSearchResults() {
	refreshSearchRows();
	scrollTo(0);
}

void StickersListWidget::refreshSearchRows() {
	auto it = _searchCache.find(_searchQuery);
	auto sets = (it != end(_searchCache))
		? &it->second
		: nullptr;
	refreshSearchRows(sets);
}

void StickersListWidget::refreshSearchRows(
		const std::vector<uint64> *cloudSets) {
	clearSelection();

	const auto wasSection = _section;
	auto wasSets = base::take(_searchSets);
	const auto guard = gsl::finally([&] {
		if (_section == wasSection && _section == Section::Search) {
			takeHeavyData(_searchSets, wasSets);
		}
	});

	fillLocalSearchRows(_searchNextQuery);

	if (!cloudSets && _searchNextQuery.isEmpty()) {
		showStickerSet(!_mySets.empty()
			? _mySets[0].id
			: Data::Stickers::FeaturedSetId);
		return;
	}

	setSection(Section::Search);
	if (cloudSets) {
		fillCloudSearchRows(*cloudSets);
	}
	if (_footer) {
		_footer->refreshIcons(ValidateIconAnimations::Scroll);
	}

	_lastMousePosition = QCursor::pos();

	resizeToWidth(width());
	updateSelected();
}

void StickersListWidget::fillLocalSearchRows(const QString &query) {
	const auto searchWordsList = TextUtilities::PrepareSearchWords(query);
	if (searchWordsList.isEmpty()) {
		return;
	}
	auto searchWordInTitle = [](
			const QStringList &titleWords,
			const QString &searchWord) {
		for (const auto &titleWord : titleWords) {
			if (titleWord.startsWith(searchWord)) {
				return true;
			}
		}
		return false;
	};
	auto allSearchWordsInTitle = [&](
			const QStringList &titleWords) {
		for (const auto &searchWord : searchWordsList) {
			if (!searchWordInTitle(titleWords, searchWord)) {
				return false;
			}
		}
		return true;
	};

	const auto &sets = session().data().stickers().sets();
	for (const auto &[setId, titleWords] : _searchIndex) {
		if (allSearchWordsInTitle(titleWords)) {
			if (const auto it = sets.find(setId); it != sets.end()) {
				addSearchRow(it->second.get());
			}
		}
	}
}

void StickersListWidget::fillCloudSearchRows(
		const std::vector<uint64> &cloudSets) {
	const auto &sets = session().data().stickers().sets();
	for (const auto setId : cloudSets) {
		if (const auto it = sets.find(setId); it != sets.end()) {
			addSearchRow(it->second.get());
		}
	}
}

void StickersListWidget::addSearchRow(not_null<StickersSet*> set) {
	_searchSets.emplace_back(
		set->id,
		set,
		set->flags,
		set->title,
		set->shortName,
		set->count,
		!SetInMyList(set->flags),
		PrepareStickers(set->stickers.empty()
			? set->covers
			: set->stickers));
}

void StickersListWidget::takeHeavyData(
		std::vector<Set> &to,
		std::vector<Set> &from) {
	auto indices = base::flat_map<uint64, int>();
	indices.reserve(from.size());
	auto index = 0;
	for (const auto &set : from) {
		indices.emplace(set.id, index++);
	}
	for (auto &toSet : to) {
		const auto i = indices.find(toSet.id);
		if (i != end(indices)) {
			takeHeavyData(toSet, from[i->second]);
		}
	}
}

void StickersListWidget::takeHeavyData(Set &to, Set &from) {
	to.lottiePlayer = std::move(from.lottiePlayer);
	to.lottieLifetime = std::move(from.lottieLifetime);
	auto &toList = to.stickers;
	auto &fromList = from.stickers;
	const auto same = ranges::equal(
		toList,
		fromList,
		ranges::equal_to(),
		&Sticker::document,
		&Sticker::document);
	if (same) {
		for (auto i = 0, count = int(toList.size()); i != count; ++i) {
			takeHeavyData(toList[i], fromList[i]);
		}
	} else {
		auto indices = base::flat_map<not_null<DocumentData*>, int>();
		indices.reserve(fromList.size());
		auto index = 0;
		for (const auto &fromSticker : fromList) {
			indices.emplace(fromSticker.document, index++);
		}
		for (auto &toSticker : toList) {
			const auto i = indices.find(toSticker.document);
			if (i != end(indices)) {
				takeHeavyData(toSticker, fromList[i->second]);
			}
		}
		for (const auto &sticker : fromList) {
			if (sticker.animated) {
				to.lottiePlayer->remove(sticker.animated);
			}
		}
	}
}

void StickersListWidget::takeHeavyData(Sticker &to, Sticker &from) {
	to.documentMedia = std::move(from.documentMedia);
	to.savedFrame = std::move(from.savedFrame);
	to.animated = base::take(from.animated);
}

auto StickersListWidget::shownSets() const -> const std::vector<Set> & {
	switch (_section) {
	case Section::Featured: return _officialSets;
	case Section::Search: return _searchSets;
	case Section::Stickers: return _mySets;
	}
	Unexpected("Section in StickersListWidget.");
}

auto StickersListWidget::shownSets() -> std::vector<Set> & {
	switch (_section) {
	case Section::Featured: return _officialSets;
	case Section::Search: return _searchSets;
	case Section::Stickers: return _mySets;
	}
	Unexpected("Section in StickersListWidget.");
}

void StickersListWidget::searchResultsDone(
		const MTPmessages_FoundStickerSets &result) {
	_footer->setLoading(false);
	_searchRequestId = 0;

	if (result.type() == mtpc_messages_foundStickerSetsNotModified) {
		LOG(("API Error: "
			"messages.foundStickerSetsNotModified not expected."));
		return;
	}

	Assert(result.type() == mtpc_messages_foundStickerSets);

	auto it = _searchCache.find(_searchQuery);
	if (it == _searchCache.cend()) {
		it = _searchCache.emplace(
			_searchQuery,
			std::vector<uint64>()).first;
	}
	auto &d = result.c_messages_foundStickerSets();
	for (const auto &stickerSet : d.vsets().v) {
		const MTPDstickerSet *setData = nullptr;
		StickersPack covers;
		switch (stickerSet.type()) {
		case mtpc_stickerSetCovered: {
			auto &d = stickerSet.c_stickerSetCovered();
			if (d.vset().type() == mtpc_stickerSet) {
				setData = &d.vset().c_stickerSet();
			}
		} break;
		case mtpc_stickerSetMultiCovered: {
			auto &d = stickerSet.c_stickerSetMultiCovered();
			if (d.vset().type() == mtpc_stickerSet) {
				setData = &d.vset().c_stickerSet();
			}
			for (const auto &cover : d.vcovers().v) {
				const auto document = session().data().processDocument(cover);
				if (document->sticker()) {
					covers.push_back(document);
				}
			}
		} break;
		}
		if (!setData) continue;

		if (const auto set = session().data().stickers().feedSet(*setData)) {
			if (!covers.empty()) {
				set->covers = covers;
			}
			if (set->stickers.empty() && set->covers.empty()) {
				continue;
			}
			it->second.push_back(set->id);
		}
	}
	showSearchResults();
}

int StickersListWidget::stickersLeft() const {
	return _rowsLeft;
}

QRect StickersListWidget::stickerRect(int section, int sel) {
	auto info = sectionInfo(section);
	if (sel >= shownSets()[section].stickers.size()) {
		sel -= shownSets()[section].stickers.size();
	}
	auto countTillItem = (sel - (sel % _columnCount));
	auto rowsToSkip = (countTillItem / _columnCount) + ((countTillItem % _columnCount) ? 1 : 0);
	auto x = stickersLeft() + ((sel % _columnCount) * _singleSize.width());
	auto y = info.rowsTop + rowsToSkip * _singleSize.height();
	return QRect(QPoint(x, y), _singleSize);
}

void StickersListWidget::paintEvent(QPaintEvent *e) {
	Painter p(this);
	auto clip = e->rect();
	p.fillRect(clip, st::emojiPanBg);

	paintStickers(p, clip);
}

void StickersListWidget::paintStickers(Painter &p, QRect clip) {
	auto fromColumn = floorclamp(clip.x() - stickersLeft(), _singleSize.width(), 0, _columnCount);
	auto toColumn = ceilclamp(clip.x() + clip.width() - stickersLeft(), _singleSize.width(), 0, _columnCount);
	if (rtl()) {
		qSwap(fromColumn, toColumn);
		fromColumn = _columnCount - fromColumn;
		toColumn = _columnCount - toColumn;
	}

	auto &sets = shownSets();
	auto selectedSticker = std::get_if<OverSticker>(&_selected);
	auto selectedButton = std::get_if<OverButton>(!v::is_null(_pressed)
		? &_pressed
		: &_selected);

	if (sets.empty() && _section == Section::Search) {
		paintEmptySearchResults(p);
	}
	enumerateSections([&](const SectionInfo &info) {
		if (clip.top() >= info.rowsBottom) {
			return true;
		} else if (clip.top() + clip.height() <= info.top) {
			return false;
		}
		auto &set = sets[info.section];
		if (set.externalLayout) {
			const auto loadedCount = int(set.stickers.size());
			const auto count = (set.flags
				& MTPDstickerSet_ClientFlag::f_not_loaded)
				? set.count
				: loadedCount;

			auto widthForTitle = stickersRight() - (st::emojiPanHeaderLeft - st::roundRadiusSmall);
			if (featuredHasAddButton(info.section)) {
				auto add = featuredAddRect(info.section);
				auto selected = selectedButton ? (selectedButton->section == info.section) : false;
				auto &textBg = selected ? st::stickersTrendingAdd.textBgOver : st::stickersTrendingAdd.textBg;

				Ui::FillRoundRect(p, myrtlrect(add), textBg, ImageRoundRadius::Small);
				if (set.ripple) {
					set.ripple->paint(p, add.x(), add.y(), width());
					if (set.ripple->empty()) {
						set.ripple.reset();
					}
				}
				p.setFont(st::stickersTrendingAdd.font);
				p.setPen(selected ? st::stickersTrendingAdd.textFgOver : st::stickersTrendingAdd.textFg);
				p.drawTextLeft(add.x() - (st::stickersTrendingAdd.width / 2), add.y() + st::stickersTrendingAdd.textTop, width(), _addText, _addWidth);

				widthForTitle -= add.width() - (st::stickersTrendingAdd.width / 2);
			} else {
				auto add = featuredAddRect(info.section);
				int checkx = add.left() + (add.width() - st::stickersFeaturedInstalled.width()) / 2;
				int checky = add.top() + (add.height() - st::stickersFeaturedInstalled.height()) / 2;
				st::stickersFeaturedInstalled.paint(p, QPoint(checkx, checky), width());
			}
			if (set.flags & MTPDstickerSet_ClientFlag::f_unread) {
				widthForTitle -= st::stickersFeaturedUnreadSize + st::stickersFeaturedUnreadSkip;
			}

			auto titleText = set.title;
			auto titleWidth = st::stickersTrendingHeaderFont->width(titleText);
			if (titleWidth > widthForTitle) {
				titleText = st::stickersTrendingHeaderFont->elided(titleText, widthForTitle);
				titleWidth = st::stickersTrendingHeaderFont->width(titleText);
			}
			p.setFont(st::stickersTrendingHeaderFont);
			p.setPen(st::stickersTrendingHeaderFg);
			p.drawTextLeft(st::emojiPanHeaderLeft - st::roundRadiusSmall, info.top + st::stickersTrendingHeaderTop, width(), titleText, titleWidth);

			if (set.flags & MTPDstickerSet_ClientFlag::f_unread) {
				p.setPen(Qt::NoPen);
				p.setBrush(st::stickersFeaturedUnreadBg);

				{
					PainterHighQualityEnabler hq(p);
					p.drawEllipse(style::rtlrect(st::emojiPanHeaderLeft - st::roundRadiusSmall + titleWidth + st::stickersFeaturedUnreadSkip, info.top + st::stickersTrendingHeaderTop + st::stickersFeaturedUnreadTop, st::stickersFeaturedUnreadSize, st::stickersFeaturedUnreadSize, width()));
				}
			}

			auto statusText = (count > 0) ? tr::lng_stickers_count(tr::now, lt_count, count) : tr::lng_contacts_loading(tr::now);
			p.setFont(st::stickersTrendingSubheaderFont);
			p.setPen(st::stickersTrendingSubheaderFg);
			p.drawTextLeft(st::emojiPanHeaderLeft - st::roundRadiusSmall, info.top + st::stickersTrendingSubheaderTop, width(), statusText);

			if (info.rowsTop >= clip.y() + clip.height()) {
				return true;
			}

			for (int j = fromColumn; j < toColumn; ++j) {
				int index = j;
				if (index >= loadedCount) break;

				auto selected = selectedSticker ? (selectedSticker->section == info.section && selectedSticker->index == index) : false;
				auto deleteSelected = false;
				paintSticker(p, set, info.rowsTop, info.section, index, selected, deleteSelected);
			}
			markLottieFrameShown(set);
			return true;
		}
		if (setHasTitle(set) && clip.top() < info.rowsTop) {
			auto titleText = set.title;
			auto titleWidth = st::stickersTrendingHeaderFont->width(titleText);
			auto widthForTitle = stickersRight() - (st::emojiPanHeaderLeft - st::roundRadiusSmall);
			if (hasRemoveButton(info.section)) {
				auto remove = removeButtonRect(info.section);
				auto selected = selectedButton ? (selectedButton->section == info.section) : false;
				if (set.ripple) {
					set.ripple->paint(p, remove.x() + st::stickerPanRemoveSet.rippleAreaPosition.x(), remove.y() + st::stickerPanRemoveSet.rippleAreaPosition.y(), width());
					if (set.ripple->empty()) {
						set.ripple.reset();
					}
				}
				(selected ? st::stickerPanRemoveSet.iconOver : st::stickerPanRemoveSet.icon).paint(p, remove.topLeft() + st::stickerPanRemoveSet.iconPosition, width());

				widthForTitle -= remove.width();
			}
			if (titleWidth > widthForTitle) {
				titleText = st::stickersTrendingHeaderFont->elided(titleText, widthForTitle);
				titleWidth = st::stickersTrendingHeaderFont->width(titleText);
			}
			p.setFont(st::emojiPanHeaderFont);
			p.setPen(st::emojiPanHeaderFg);
			p.drawTextLeft(st::emojiPanHeaderLeft - st::roundRadiusSmall, info.top + st::emojiPanHeaderTop, width(), titleText, titleWidth);
		}
		if (clip.top() + clip.height() <= info.rowsTop) {
			return true;
		} else if (set.id == Data::Stickers::MegagroupSetId && set.stickers.empty()) {
			auto buttonSelected = (std::get_if<OverGroupAdd>(&_selected) != nullptr);
			paintMegagroupEmptySet(p, info.rowsTop, buttonSelected);
			return true;
		}
		auto special = (set.flags & MTPDstickerSet::Flag::f_official) != 0;
		auto fromRow = floorclamp(clip.y() - info.rowsTop, _singleSize.height(), 0, info.rowsCount);
		auto toRow = ceilclamp(clip.y() + clip.height() - info.rowsTop, _singleSize.height(), 0, info.rowsCount);
		for (int i = fromRow; i < toRow; ++i) {
			for (int j = fromColumn; j < toColumn; ++j) {
				int index = i * _columnCount + j;
				if (index >= info.count) break;

				auto selected = selectedSticker ? (selectedSticker->section == info.section && selectedSticker->index == index) : false;
				auto deleteSelected = selected && selectedSticker->overDelete;
				paintSticker(p, set, info.rowsTop, info.section, index, selected, deleteSelected);
			}
		}
		markLottieFrameShown(set);
		return true;
	});
}

void StickersListWidget::markLottieFrameShown(Set &set) {
	if (const auto player = set.lottiePlayer.get()) {
		const auto paused = controller()->isGifPausedAtLeastFor(
			Window::GifPauseReason::SavedGifs);
		if (!paused) {
			player->markFrameShown();
		}
	}
}

void StickersListWidget::checkVisibleLottie() {
	if (shownSets().empty()) {
		return;
	}
	const auto visibleTop = getVisibleTop();
	const auto visibleBottom = getVisibleBottom();
	const auto destroyAfterDistance = (visibleBottom - visibleTop) * 2;
	const auto destroyAbove = visibleTop - destroyAfterDistance;
	const auto destroyBelow = visibleBottom + destroyAfterDistance;
	enumerateSections([&](const SectionInfo &info) {
		if (destroyBelow <= info.rowsTop
			|| destroyAbove >= info.rowsBottom) {
			clearHeavyIn(shownSets()[info.section]);
		} else if ((visibleTop > info.rowsTop && visibleTop < info.rowsBottom)
			|| (visibleBottom > info.rowsTop
				&& visibleBottom < info.rowsBottom)) {
			pauseInvisibleLottieIn(info);
		}
		return true;
	});
}

void StickersListWidget::clearHeavyIn(Set &set, bool clearSavedFrames) {
	const auto player = base::take(set.lottiePlayer);
	const auto lifetime = base::take(set.lottieLifetime);
	for (auto &sticker : set.stickers) {
		if (clearSavedFrames) {
			sticker.savedFrame = QPixmap();
		}
		sticker.animated = nullptr;
		sticker.documentMedia = nullptr;
	}
}

void StickersListWidget::pauseInvisibleLottieIn(const SectionInfo &info) {
	auto &set = shownSets()[info.section];
	const auto player = set.lottiePlayer.get();
	if (!player) {
		return;
	}
	const auto pauseInRows = [&](int fromRow, int tillRow) {
		Expects(fromRow <= tillRow);

		for (auto i = fromRow; i != tillRow; ++i) {
			for (auto j = 0; j != _columnCount; ++j) {
				const auto index = i * _columnCount + j;
				if (index >= info.count) {
					break;
				}
				if (const auto animated = set.stickers[index].animated) {
					player->pause(animated);
				}
			}
		}
	};

	const auto visibleTop = getVisibleTop();
	const auto visibleBottom = getVisibleBottom();
	if (visibleTop >= info.rowsTop + _singleSize.height()
		&& visibleTop < info.rowsBottom) {
		const auto pauseHeight = (visibleTop - info.rowsTop);
		const auto pauseRows = std::min(
			pauseHeight / _singleSize.height(),
			info.rowsCount);
		pauseInRows(0, pauseRows);
	}
	if (visibleBottom > info.rowsTop
		&& visibleBottom + _singleSize.height() <= info.rowsBottom) {
		const auto pauseHeight = (info.rowsBottom - visibleBottom);
		const auto pauseRows = std::min(
			pauseHeight / _singleSize.height(),
			info.rowsCount);
		pauseInRows(info.rowsCount - pauseRows, info.rowsCount);
	}
}

void StickersListWidget::paintEmptySearchResults(Painter &p) {
	const auto iconLeft = (width() - st::stickersEmpty.width()) / 2;
	const auto iconTop = (height() / 3) - (st::stickersEmpty.height() / 2);
	st::stickersEmpty.paint(p, iconLeft, iconTop, width());

	const auto text = tr::lng_stickers_nothing_found(tr::now);
	const auto textWidth = st::normalFont->width(text);
	p.setFont(st::normalFont);
	p.setPen(st::windowSubTextFg);
	p.drawTextLeft(
		(width() - textWidth) / 2,
		iconTop + st::stickersEmpty.height() - st::normalFont->height,
		width(),
		text,
		textWidth);
}

int StickersListWidget::megagroupSetInfoLeft() const {
	return st::emojiPanHeaderLeft - st::roundRadiusSmall;
}

void StickersListWidget::paintMegagroupEmptySet(Painter &p, int y, bool buttonSelected) {
	p.setPen(st::emojiPanHeaderFg);

	auto infoLeft = megagroupSetInfoLeft();
	_megagroupSetAbout.drawLeft(p, infoLeft, y, width() - infoLeft, width());

	auto &textBg = buttonSelected
		? st::stickerGroupCategoryAdd.textBgOver
		: st::stickerGroupCategoryAdd.textBg;

	auto button = _megagroupSetButtonRect.translated(0, y);
	Ui::FillRoundRect(p, myrtlrect(button), textBg, ImageRoundRadius::Small);
	if (_megagroupSetButtonRipple) {
		_megagroupSetButtonRipple->paint(p, button.x(), button.y(), width());
		if (_megagroupSetButtonRipple->empty()) {
			_megagroupSetButtonRipple.reset();
		}
	}
	p.setFont(st::stickerGroupCategoryAdd.font);
	p.setPen(buttonSelected ? st::stickerGroupCategoryAdd.textFgOver : st::stickerGroupCategoryAdd.textFg);
	p.drawTextLeft(button.x() - (st::stickerGroupCategoryAdd.width / 2), button.y() + st::stickerGroupCategoryAdd.textTop, width(), _megagroupSetButtonText, _megagroupSetButtonTextWidth);
}

void StickersListWidget::ensureLottiePlayer(Set &set) {
	if (set.lottiePlayer) {
		return;
	}
	set.lottiePlayer = std::make_unique<Lottie::MultiPlayer>(
		Lottie::Quality::Default,
		getLottieRenderer());
	const auto raw = set.lottiePlayer.get();

	raw->updates(
	) | rpl::start_with_next([=] {
		const auto &sets = shownSets();
		enumerateSections([&](const SectionInfo &info) {
			if (shownSets()[info.section].lottiePlayer.get() == raw) {
				update(
					0,
					info.rowsTop,
					width(),
					info.rowsBottom - info.rowsTop);
				return false;
			}
			return true;
		});
	}, set.lottieLifetime);
}

void StickersListWidget::setupLottie(Set &set, int section, int index) {
	auto &sticker = set.stickers[index];
	const auto document = sticker.document;
	ensureLottiePlayer(set);

	// Document should be loaded already for the animation to be set up.
	Assert(sticker.documentMedia != nullptr);
	sticker.animated = LottieAnimationFromDocument(
		set.lottiePlayer.get(),
		sticker.documentMedia.get(),
		StickerLottieSize::StickersPanel,
		boundingBoxSize() * cIntRetinaFactor());
}

QSize StickersListWidget::boundingBoxSize() const {
	return QSize(
		_singleSize.width() - st::roundRadiusSmall * 2,
		_singleSize.height() - st::roundRadiusSmall * 2);
}

void StickersListWidget::paintSticker(Painter &p, Set &set, int y, int section, int index, bool selected, bool deleteSelected) {
	auto &sticker = set.stickers[index];
	sticker.ensureMediaCreated();
	const auto document = sticker.document;
	const auto &media = sticker.documentMedia;
	if (!document->sticker()) {
		return;
	}

	const auto isAnimated = document->sticker()->animated;
	if (isAnimated
		&& !sticker.animated
		&& media->loaded()) {
		setupLottie(set, section, index);
	}

	int row = (index / _columnCount), col = (index % _columnCount);

	auto pos = QPoint(stickersLeft() + col * _singleSize.width(), y + row * _singleSize.height());
	if (selected) {
		auto tl = pos;
		if (rtl()) tl.setX(width() - tl.x() - _singleSize.width());
		Ui::FillRoundRect(p, QRect(tl, _singleSize), st::emojiPanHover, Ui::StickerHoverCorners);
	}

	media->checkStickerSmall();

	auto w = 1;
	auto h = 1;
	if (isAnimated && !document->dimensions.isEmpty()) {
		const auto request = Lottie::FrameRequest{ boundingBoxSize() * cIntRetinaFactor() };
		const auto size = request.size(document->dimensions, true) / cIntRetinaFactor();
		w = std::max(size.width(), 1);
		h = std::max(size.height(), 1);
	} else {
		auto coef = qMin((_singleSize.width() - st::roundRadiusSmall * 2) / float64(document->dimensions.width()), (_singleSize.height() - st::roundRadiusSmall * 2) / float64(document->dimensions.height()));
		if (coef > 1) coef = 1;
		w = std::max(qRound(coef * document->dimensions.width()), 1);
		h = std::max(qRound(coef * document->dimensions.height()), 1);
	}
	auto ppos = pos + QPoint((_singleSize.width() - w) / 2, (_singleSize.height() - h) / 2);
	if (sticker.animated && sticker.animated->ready()) {
		auto request = Lottie::FrameRequest();
		request.box = boundingBoxSize() * cIntRetinaFactor();
		const auto frame = sticker.animated->frame(request);
		p.drawImage(
			QRect(ppos, frame.size() / cIntRetinaFactor()),
			frame);
		if (sticker.savedFrame.isNull()) {
			sticker.savedFrame = QPixmap::fromImage(frame, Qt::ColorOnly);
			sticker.savedFrame.setDevicePixelRatio(cRetinaFactor());
		}
		set.lottiePlayer->unpause(sticker.animated);
	} else {
		const auto image = media->getStickerSmall();
		const auto pixmap = !sticker.savedFrame.isNull()
			? sticker.savedFrame
			: image
			? image->pixSingle(
				w,
				h,
				w,
				h,
				ImageRoundRadius::None)
			: QPixmap();
		if (!pixmap.isNull()) {
			p.drawPixmapLeft(ppos, width(), pixmap);
			if (sticker.savedFrame.isNull()) {
				sticker.savedFrame = pixmap;
			}
		}
	}

	if (selected && stickerHasDeleteButton(set, index)) {
		auto xPos = pos + QPoint(_singleSize.width() - st::stickerPanDeleteIconBg.width(), 0);
		p.setOpacity(deleteSelected ? st::stickerPanDeleteOpacityBgOver : st::stickerPanDeleteOpacityBg);
		st::stickerPanDeleteIconBg.paint(p, xPos, width());
		p.setOpacity(deleteSelected ? st::stickerPanDeleteOpacityFgOver : st::stickerPanDeleteOpacityFg);
		st::stickerPanDeleteIconFg.paint(p, xPos, width());
		p.setOpacity(1.);
	}
}

int StickersListWidget::stickersRight() const {
	return stickersLeft() + (_columnCount * _singleSize.width());
}

bool StickersListWidget::featuredHasAddButton(int index) const {
	if (index < 0
		|| index >= shownSets().size()
		|| !shownSets()[index].externalLayout) {
		return false;
	}
	const auto flags = shownSets()[index].flags;
	return !SetInMyList(flags);
}

QRect StickersListWidget::featuredAddRect(int index) const {
	auto addw = _addWidth - st::stickersTrendingAdd.width;
	auto addh = st::stickersTrendingAdd.height;
	auto addx = stickersRight() - addw;
	auto addy = sectionInfo(index).top + st::stickersTrendingAddTop;
	return QRect(addx, addy, addw, addh);
}

bool StickersListWidget::hasRemoveButton(int index) const {
	if (index < 0 || index >= shownSets().size()) {
		return false;
	}
	auto &set = shownSets()[index];
	if (set.externalLayout) {
		return false;
	}
	auto flags = set.flags;
	if (!(flags & MTPDstickerSet_ClientFlag::f_special)) {
		return true;
	}
	if (set.id == Data::Stickers::MegagroupSetId) {
		Assert(_megagroupSet != nullptr);
		if (index + 1 != shownSets().size()) {
			return true;
		}
		return !set.stickers.empty() && _megagroupSet->canEditStickers();
	}
	return false;
}

QRect StickersListWidget::removeButtonRect(int index) const {
	auto buttonw = st::stickerPanRemoveSet.width;
	auto buttonh = st::stickerPanRemoveSet.height;
	auto buttonx = stickersRight() - buttonw;
	auto buttony = sectionInfo(index).top + (st::emojiPanHeader - buttonh) / 2;
	return QRect(buttonx, buttony, buttonw, buttonh);
}

void StickersListWidget::mousePressEvent(QMouseEvent *e) {
	if (e->button() != Qt::LeftButton) {
		return;
	}
	_lastMousePosition = e->globalPos();
	updateSelected();

	setPressed(_selected);
	ClickHandler::pressed();
	_previewTimer.callOnce(QApplication::startDragTime());
}

void StickersListWidget::setPressed(OverState newPressed) {
	if (auto button = std::get_if<OverButton>(&_pressed)) {
		auto &sets = shownSets();
		Assert(button->section >= 0 && button->section < sets.size());
		auto &set = sets[button->section];
		if (set.ripple) {
			set.ripple->lastStop();
		}
	} else if (std::get_if<OverGroupAdd>(&_pressed)) {
		if (_megagroupSetButtonRipple) {
			_megagroupSetButtonRipple->lastStop();
		}
	}
	_pressed = newPressed;
	if (auto button = std::get_if<OverButton>(&_pressed)) {
		auto &sets = shownSets();
		Assert(button->section >= 0 && button->section < sets.size());
		auto &set = sets[button->section];
		if (!set.ripple) {
			set.ripple = createButtonRipple(button->section);
		}
		set.ripple->add(mapFromGlobal(QCursor::pos()) - buttonRippleTopLeft(button->section));
	} else if (std::get_if<OverGroupAdd>(&_pressed)) {
		if (!_megagroupSetButtonRipple) {
			auto maskSize = _megagroupSetButtonRect.size();
			auto mask = Ui::RippleAnimation::roundRectMask(maskSize, st::roundRadiusSmall);
			_megagroupSetButtonRipple = std::make_unique<Ui::RippleAnimation>(st::stickerGroupCategoryAdd.ripple, std::move(mask), [this] {
				rtlupdate(megagroupSetButtonRectFinal());
			});
		}
		_megagroupSetButtonRipple->add(mapFromGlobal(QCursor::pos()) - myrtlrect(megagroupSetButtonRectFinal()).topLeft());
	}
}

QRect StickersListWidget::megagroupSetButtonRectFinal() const {
	auto result = QRect();
	if (_section == Section::Stickers) {
		enumerateSections([this, &result](const SectionInfo &info) {
			if (shownSets()[info.section].id == Data::Stickers::MegagroupSetId) {
				result = _megagroupSetButtonRect.translated(0, info.rowsTop);
				return false;
			}
			return true;
		});
	}
	return result;
}

std::unique_ptr<Ui::RippleAnimation> StickersListWidget::createButtonRipple(int section) {
	Expects(section >= 0 && section < shownSets().size());

	if (shownSets()[section].externalLayout) {
		auto maskSize = QSize(_addWidth - st::stickersTrendingAdd.width, st::stickersTrendingAdd.height);
		auto mask = Ui::RippleAnimation::roundRectMask(maskSize, st::roundRadiusSmall);
		return std::make_unique<Ui::RippleAnimation>(
			st::stickersTrendingAdd.ripple,
			std::move(mask),
			[this, section] { rtlupdate(featuredAddRect(section)); });
	}
	auto maskSize = QSize(st::stickerPanRemoveSet.rippleAreaSize, st::stickerPanRemoveSet.rippleAreaSize);
	auto mask = Ui::RippleAnimation::ellipseMask(maskSize);
	return std::make_unique<Ui::RippleAnimation>(
		st::stickerPanRemoveSet.ripple,
		std::move(mask),
		[this, section] { rtlupdate(removeButtonRect(section)); });
}

QPoint StickersListWidget::buttonRippleTopLeft(int section) const {
	Expects(section >= 0 && section < shownSets().size());

	if (shownSets()[section].externalLayout) {
		return myrtlrect(featuredAddRect(section)).topLeft();
	}
	return myrtlrect(removeButtonRect(section)).topLeft() + st::stickerPanRemoveSet.rippleAreaPosition;
}

void StickersListWidget::showStickerSetBox(not_null<DocumentData*> document) {
	if (document->sticker()
		&& document->sticker()->set.type() != mtpc_inputStickerSetEmpty) {
		_displayingSet = true;
		checkHideWithBox(StickerSetBox::Show(controller(), document));
	}
}

void StickersListWidget::fillContextMenu(
		not_null<Ui::PopupMenu*> menu,
		SendMenu::Type type) {
	auto selected = _selected;
	auto &sets = shownSets();
	if (v::is_null(selected) || !v::is_null(_pressed)) {
		return;
	}
	if (auto sticker = std::get_if<OverSticker>(&selected)) {
		Assert(sticker->section >= 0 && sticker->section < sets.size());
		auto &set = sets[sticker->section];
		Assert(sticker->index >= 0 && sticker->index < set.stickers.size());

		const auto document = set.stickers[sticker->index].document;
		const auto send = [=](Api::SendOptions options) {
			_chosen.fire_copy({
				.document = document,
				.options = options });
		};
		SendMenu::FillSendMenu(
			menu,
			type,
			SendMenu::DefaultSilentCallback(send),
			SendMenu::DefaultScheduleCallback(this, type, send));

		const auto toggleFavedSticker = [=] {
			Api::ToggleFavedSticker(
				document,
				Data::FileOriginStickerSet(Data::Stickers::FavedSetId, 0));
		};
		menu->addAction(
			(document->owner().stickers().isFaved(document)
				? tr::lng_faved_stickers_remove
				: tr::lng_faved_stickers_add)(tr::now),
			toggleFavedSticker);

		menu->addAction(tr::lng_context_pack_info(tr::now), [=] {
			showStickerSetBox(document);
		});

		if (const auto id = set.id; id == Data::Stickers::RecentSetId) {
			menu->addAction(tr::lng_recent_stickers_remove(tr::now), [=] {
				Api::ToggleRecentSticker(
					document,
					Data::FileOriginStickerSet(id, 0),
					false);
			});
		}
	}
}

void StickersListWidget::mouseReleaseEvent(QMouseEvent *e) {
	_previewTimer.cancel();

	auto pressed = _pressed;
	setPressed(v::null);
	if (pressed != _selected) {
		update();
	}

	auto activated = ClickHandler::unpressed();
	if (_previewShown) {
		_previewShown = false;
		return;
	}

	_lastMousePosition = e->globalPos();
	updateSelected();

	auto &sets = shownSets();
	if (!v::is_null(pressed) && pressed == _selected) {
		if (auto sticker = std::get_if<OverSticker>(&pressed)) {
			Assert(sticker->section >= 0 && sticker->section < sets.size());
			auto &set = sets[sticker->section];
			Assert(sticker->index >= 0 && sticker->index < set.stickers.size());
			if (stickerHasDeleteButton(set, sticker->index) && sticker->overDelete) {
				if (set.id == Data::Stickers::RecentSetId) {
					removeRecentSticker(sticker->section, sticker->index);
				} else if (set.id == Data::Stickers::FavedSetId) {
					removeFavedSticker(sticker->section, sticker->index);
				} else {
					Unexpected("Single sticker delete click.");
				}
				return;
			}
			const auto document = set.stickers[sticker->index].document;
			if (e->modifiers() & Qt::ControlModifier) {
				showStickerSetBox(document);
			} else {
				_chosen.fire_copy({ .document = document });
			}
		} else if (auto set = std::get_if<OverSet>(&pressed)) {
			Assert(set->section >= 0 && set->section < sets.size());
			displaySet(sets[set->section].id);
		} else if (auto button = std::get_if<OverButton>(&pressed)) {
			Assert(button->section >= 0 && button->section < sets.size());
			if (sets[button->section].externalLayout) {
				installSet(sets[button->section].id);
			} else if (sets[button->section].id == Data::Stickers::MegagroupSetId) {
				auto removeLocally = sets[button->section].stickers.empty()
					|| !_megagroupSet->canEditStickers();
				removeMegagroupSet(removeLocally);
			} else {
				removeSet(sets[button->section].id);
			}
		} else if (std::get_if<OverGroupAdd>(&pressed)) {
			Ui::show(Box<StickersBox>(controller(), _megagroupSet));
		}
	}
}

void StickersListWidget::validateSelectedIcon(
		ValidateIconAnimations animations) {
	if (_footer) {
		_footer->validateSelectedIcon(
			currentSet(getVisibleTop()),
			animations);
	}
}

void StickersListWidget::removeRecentSticker(int section, int index) {
	if ((_section != Section::Stickers)
		|| (section >= int(_mySets.size()))
		|| (_mySets[section].id != Data::Stickers::RecentSetId)) {
		return;
	}

	clearSelection();
	bool refresh = false;
	const auto &sticker = _mySets[section].stickers[index];
	const auto document = sticker.document;
	auto &recent = session().data().stickers().getRecentPack();
	for (int32 i = 0, l = recent.size(); i < l; ++i) {
		if (recent.at(i).first == document) {
			recent.removeAt(i);
			session().saveSettings();
			refresh = true;
			break;
		}
	}
	auto &sets = session().data().stickers().setsRef();
	auto it = sets.find(Data::Stickers::CustomSetId);
	if (it != sets.cend()) {
		const auto set = it->second.get();
		for (int i = 0, l = set->stickers.size(); i < l; ++i) {
			if (set->stickers.at(i) == document) {
				set->stickers.removeAt(i);
				if (set->stickers.isEmpty()) {
					sets.erase(it);
				}
				session().local().writeInstalledStickers();
				refresh = true;
				break;
			}
		}
	}
	if (refresh) {
		refreshRecentStickers();
		updateSelected();
		update();
	}
}

void StickersListWidget::removeFavedSticker(int section, int index) {
	if ((_section != Section::Stickers)
		|| (section >= int(_mySets.size()))
		|| (_mySets[section].id != Data::Stickers::FavedSetId)) {
		return;
	}

	clearSelection();
	const auto &sticker = _mySets[section].stickers[index];
	const auto document = sticker.document;
	session().data().stickers().setFaved(document, false);
	Api::ToggleFavedSticker(
		document,
		Data::FileOriginStickerSet(Data::Stickers::FavedSetId, 0),
		false);
}

void StickersListWidget::setColumnCount(int count) {
	Expects(count > 0);

	if (_columnCount != count) {
		_columnCount = count;
		refreshFooterIcons();
	}
}

void StickersListWidget::mouseMoveEvent(QMouseEvent *e) {
	_lastMousePosition = e->globalPos();
	updateSelected();
}

void StickersListWidget::resizeEvent(QResizeEvent *e) {
	_settings->moveToLeft(
		(width() - _settings->width()) / 2,
		height() / 3);
	if (!_megagroupSetAbout.isEmpty()) {
		refreshMegagroupSetGeometry();
	}
}

void StickersListWidget::leaveEventHook(QEvent *e) {
	clearSelection();
}

void StickersListWidget::leaveToChildEvent(QEvent *e, QWidget *child) {
	clearSelection();
}

void StickersListWidget::enterFromChildEvent(QEvent *e, QWidget *child) {
	_lastMousePosition = QCursor::pos();
	updateSelected();
}

void StickersListWidget::clearSelection() {
	setPressed(v::null);
	setSelected(v::null);
	update();
}

TabbedSelector::InnerFooter *StickersListWidget::getFooter() const {
	return _footer;
}

void StickersListWidget::processHideFinished() {
	clearSelection();
	clearHeavyData();
	if (_footer) {
		_footer->clearHeavyData();
	}
}

void StickersListWidget::processPanelHideFinished() {
	clearInstalledLocally();
	clearHeavyData();
	if (_footer) {
		_footer->clearHeavyData();
	}
	// Preserve panel state through visibility toggles.
	//// Reset to the recent stickers section.
	//if (_section == Section::Featured && (!_footer || !_footer->hasOnlyFeaturedSets())) {
	//	setSection(Section::Stickers);
	//	validateSelectedIcon(ValidateIconAnimations::None);
	//}
}

void StickersListWidget::setSection(Section section) {
	if (_section == section) {
		return;
	}
	clearHeavyData();
	_section = section;
}

void StickersListWidget::clearHeavyData() {
	for (auto &set : shownSets()) {
		clearHeavyIn(set, false);
	}
}

void StickersListWidget::refreshStickers() {
	clearSelection();

	refreshMySets();
	refreshFeaturedSets();
	refreshSearchSets();

	resizeToWidth(width());

	if (_footer) {
		refreshFooterIcons();
	}
	refreshSettingsVisibility();

	_lastMousePosition = QCursor::pos();
	updateSelected();
	update();
}

void StickersListWidget::refreshMySets() {
	auto wasSets = base::take(_mySets);
	_favedStickersMap.clear();
	_mySets.reserve(session().data().stickers().setsOrder().size() + 3);

	refreshFavedStickers();
	refreshRecentStickers(false);
	refreshMegagroupStickers(GroupStickersPlace::Visible);
	for (const auto setId : session().data().stickers().setsOrder()) {
		const auto externalLayout = false;
		appendSet(_mySets, setId, externalLayout, AppendSkip::Archived);
	}
	refreshMegagroupStickers(GroupStickersPlace::Hidden);

	takeHeavyData(_mySets, wasSets);
}

void StickersListWidget::refreshFeaturedSets() {
	auto wasFeaturedSetsCount = base::take(_featuredSetsCount);
	auto wereOfficial = base::take(_officialSets);
	_officialSets.reserve(
		session().data().stickers().featuredSetsOrder().size()
		+ wereOfficial.size()
		- wasFeaturedSetsCount);
	for (const auto setId : session().data().stickers().featuredSetsOrder()) {
		const auto externalLayout = true;
		appendSet(_officialSets, setId, externalLayout, AppendSkip::Installed);
	}
	_featuredSetsCount = _officialSets.size();
	if (wereOfficial.size() > wasFeaturedSetsCount) {
		const auto &sets = session().data().stickers().sets();
		const auto from = begin(wereOfficial) + wasFeaturedSetsCount;
		const auto till = end(wereOfficial);
		for (auto i = from; i != till; ++i) {
			auto &set = *i;
			auto it = sets.find(set.id);
			if (it == sets.cend()
				|| ((it->second->flags & MTPDstickerSet::Flag::f_installed_date)
					&& !(it->second->flags & MTPDstickerSet::Flag::f_archived)
					&& !_installedLocallySets.contains(set.id))) {
				continue;
			}
			set.flags = it->second->flags;
			_officialSets.push_back(std::move(set));
		}
	}
}

void StickersListWidget::refreshSearchSets() {
	refreshSearchIndex();

	const auto &sets = session().data().stickers().sets();
	for (auto &entry : _searchSets) {
		if (const auto it = sets.find(entry.id); it != sets.end()) {
			const auto set = it->second.get();
			entry.flags = set->flags;
			if (!set->stickers.empty()) {
				entry.lottiePlayer = nullptr;
				entry.stickers = PrepareStickers(set->stickers);
			}
			if (!SetInMyList(entry.flags)) {
				_installedLocallySets.remove(entry.id);
				entry.externalLayout = true;
			}
		}
	}
}

void StickersListWidget::refreshSearchIndex() {
	_searchIndex.clear();
	for (const auto &set : _mySets) {
		if (set.flags & MTPDstickerSet_ClientFlag::f_special) {
			continue;
		}
		const auto string = set.title + ' ' + set.shortName;
		const auto list = TextUtilities::PrepareSearchWords(string);
		_searchIndex.emplace_back(set.id, list);
	}
}

void StickersListWidget::refreshSettingsVisibility() {
	const auto visible = (_section == Section::Stickers) && _mySets.empty();
	_settings->setVisible(visible);
}

void StickersListWidget::refreshFooterIcons() {
	_footer->refreshIcons(ValidateIconAnimations::None);
	if (_footer->hasOnlyFeaturedSets() && _section != Section::Featured) {
		showStickerSet(Data::Stickers::FeaturedSetId);
	}
}

void StickersListWidget::preloadImages() {
	if (_footer) {
		_footer->preloadImages();
	}
}

uint64 StickersListWidget::currentSet(int yOffset) const {
	if (_section == Section::Featured) {
		return Data::Stickers::FeaturedSetId;
	}
	const auto &sets = shownSets();
	return sets.empty()
		? Data::Stickers::RecentSetId
		: sets[sectionInfoByOffset(yOffset).section].id;
}

bool StickersListWidget::appendSet(
		std::vector<Set> &to,
		uint64 setId,
		bool externalLayout,
		AppendSkip skip) {
	const auto &sets = session().data().stickers().sets();
	auto it = sets.find(setId);
	if (it == sets.cend()
		|| (!externalLayout && it->second->stickers.isEmpty())) {
		return false;
	}
	const auto set = it->second.get();
	if ((skip == AppendSkip::Archived)
		&& (set->flags & MTPDstickerSet::Flag::f_archived)) {
		return false;
	}
	if ((skip == AppendSkip::Installed)
		&& (set->flags & MTPDstickerSet::Flag::f_installed_date)
		&& !(set->flags & MTPDstickerSet::Flag::f_archived)) {
		if (!_installedLocallySets.contains(setId)) {
			return false;
		}
	}
	to.emplace_back(
		set->id,
		set,
		set->flags,
		set->title,
		set->shortName,
		set->count,
		externalLayout,
		PrepareStickers((set->stickers.empty() && externalLayout)
			? set->covers
			: set->stickers));
	return true;
}

void StickersListWidget::refreshRecent() {
	if (_section == Section::Stickers) {
		refreshRecentStickers();
	}
	if (_footer && _footer->hasOnlyFeaturedSets() && _section != Section::Featured) {
		showStickerSet(Data::Stickers::FeaturedSetId);
	}
}

auto StickersListWidget::collectRecentStickers() -> std::vector<Sticker> {
	_custom.clear();
	auto result = std::vector<Sticker>();

	const auto &sets = session().data().stickers().sets();
	const auto &recent = session().data().stickers().getRecentPack();
	const auto customIt = sets.find(Data::Stickers::CustomSetId);
	const auto cloudIt = sets.find(Data::Stickers::CloudRecentSetId);
	const auto customCount = (customIt != sets.cend())
		? customIt->second->stickers.size()
		: 0;
	const auto cloudCount = (cloudIt != sets.cend())
		? cloudIt->second->stickers.size()
		: 0;
	result.reserve(cloudCount + recent.size() + customCount);
	_custom.reserve(cloudCount + recent.size() + customCount);

	auto add = [&](not_null<DocumentData*> document, bool custom) {
		if (result.size() >= kRecentDisplayLimit) {
			return;
		}
		const auto i = ranges::find(result, document, &Sticker::document);
		if (i != end(result)) {
			const auto index = (i - begin(result));
			if (index >= cloudCount && custom) {
				// Mark stickers from local recent as custom.
				_custom[index] = true;
			}
		} else if (!_favedStickersMap.contains(document)) {
			result.push_back(Sticker{
				document
			});
			_custom.push_back(custom);
		}
	};

	if (cloudCount > 0) {
		for (const auto document : std::as_const(cloudIt->second->stickers)) {
			add(document, false);
		}
	}
	for (const auto &recentSticker : recent) {
		add(recentSticker.first, false);
	}
	if (customCount > 0) {
		for (const auto document : std::as_const(customIt->second->stickers)) {
			add(document, true);
		}
	}
	return result;
}

void StickersListWidget::refreshRecentStickers(bool performResize) {
	clearSelection();

	auto recentPack = collectRecentStickers();
	auto recentIt = std::find_if(_mySets.begin(), _mySets.end(), [](auto &set) {
		return set.id == Data::Stickers::RecentSetId;
	});
	if (!recentPack.empty()) {
		const auto shortName = QString();
		const auto externalLayout = false;
		auto set = Set(
			Data::Stickers::RecentSetId,
			nullptr,
			(MTPDstickerSet::Flag::f_official
				| MTPDstickerSet_ClientFlag::f_special),
			tr::lng_recent_stickers(tr::now),
			shortName,
			recentPack.size(),
			externalLayout,
			std::move(recentPack));
		if (recentIt == _mySets.end()) {
			const auto where = (_mySets.empty()
				|| _mySets.begin()->id != Data::Stickers::FavedSetId)
				? _mySets.begin()
				: (_mySets.begin() + 1);
			_mySets.insert(where, std::move(set));
		} else {
			std::swap(*recentIt, set);
			takeHeavyData(*recentIt, set);
		}
	} else if (recentIt != _mySets.end()) {
		_mySets.erase(recentIt);
	}

	if (performResize && (_section == Section::Stickers || _section == Section::Featured)) {
		resizeToWidth(width());
		updateSelected();
	}
}

void StickersListWidget::refreshFavedStickers() {
	clearSelection();
	const auto &sets = session().data().stickers().sets();
	const auto it = sets.find(Data::Stickers::FavedSetId);
	if (it == sets.cend() || it->second->stickers.isEmpty()) {
		return;
	}
	const auto set = it->second.get();
	const auto externalLayout = false;
	const auto shortName = QString();
	_mySets.insert(_mySets.begin(), Set{
		Data::Stickers::FavedSetId,
		nullptr,
		(MTPDstickerSet::Flag::f_official
			| MTPDstickerSet_ClientFlag::f_special),
		Lang::Hard::FavedSetTitle(),
		shortName,
		set->count,
		externalLayout,
		PrepareStickers(set->stickers)
	});
	_favedStickersMap = base::flat_set<not_null<DocumentData*>> {
		set->stickers.begin(),
		set->stickers.end()
	};
}

void StickersListWidget::refreshMegagroupStickers(GroupStickersPlace place) {
	if (!_megagroupSet) {
		return;
	}
	auto canEdit = _megagroupSet->canEditStickers();
	auto isShownHere = [place](bool hidden) {
		return (hidden == (place == GroupStickersPlace::Hidden));
	};
	if (_megagroupSet->mgInfo->stickerSet.type() == mtpc_inputStickerSetEmpty) {
		if (canEdit) {
			auto hidden = session().settings().isGroupStickersSectionHidden(
				_megagroupSet->id);
			if (isShownHere(hidden)) {
				const auto shortName = QString();
				const auto externalLayout = false;
				const auto count = 0;
				_mySets.emplace_back(
					Data::Stickers::MegagroupSetId,
					nullptr,
					MTPDstickerSet_ClientFlag::f_special | 0,
					tr::lng_group_stickers(tr::now),
					shortName,
					count,
					externalLayout);
			}
		}
		return;
	}
	auto hidden = session().settings().isGroupStickersSectionHidden(_megagroupSet->id);
	auto removeHiddenForGroup = [this, &hidden] {
		if (hidden) {
			session().settings().removeGroupStickersSectionHidden(_megagroupSet->id);
			session().saveSettings();
			hidden = false;
		}
	};
	if (canEdit && hidden) {
		removeHiddenForGroup();
	}
	if (_megagroupSet->mgInfo->stickerSet.type() != mtpc_inputStickerSetID) {
		return;
	}
	auto &set = _megagroupSet->mgInfo->stickerSet.c_inputStickerSetID();
	const auto &sets = session().data().stickers().sets();
	const auto it = sets.find(set.vid().v);
	if (it != sets.cend()) {
		const auto set = it->second.get();
		auto isInstalled = (set->flags & MTPDstickerSet::Flag::f_installed_date)
			&& !(set->flags & MTPDstickerSet::Flag::f_archived);
		if (isInstalled && !canEdit) {
			removeHiddenForGroup();
		} else if (isShownHere(hidden)) {
			const auto shortName = QString();
			const auto externalLayout = false;
			_mySets.emplace_back(
				Data::Stickers::MegagroupSetId,
				set,
				MTPDstickerSet_ClientFlag::f_special | 0,
				tr::lng_group_stickers(tr::now),
				shortName,
				set->count,
				externalLayout,
				PrepareStickers(set->stickers));
		}
		return;
	} else if (!isShownHere(hidden)
		|| _megagroupSetIdRequested == set.vid().v) {
		return;
	}
	_megagroupSetIdRequested = set.vid().v;
	_api.request(MTPmessages_GetStickerSet(
		_megagroupSet->mgInfo->stickerSet
	)).done([=](const MTPmessages_StickerSet &result) {
		if (const auto set = session().data().stickers().feedSetFull(result)) {
			refreshStickers();
			if (set->id == _megagroupSetIdRequested) {
				_megagroupSetIdRequested = 0;
			} else {
				LOG(("API Error: Got different set."));
			}
		}
	}).send();
}

std::vector<StickerIcon> StickersListWidget::fillIcons() {
	auto result = std::vector<StickerIcon>();
	result.reserve(_mySets.size() + 1);
	if (!_officialSets.empty()) {
		result.emplace_back(Data::Stickers::FeaturedSetId);
	}

	auto i = 0;
	if (i != _mySets.size() && _mySets[i].id == Data::Stickers::FavedSetId) {
		++i;
		result.emplace_back(Data::Stickers::FavedSetId);
	}
	if (i != _mySets.size() && _mySets[i].id == Data::Stickers::RecentSetId) {
		++i;
		if (result.empty() || result.back().setId != Data::Stickers::FavedSetId) {
			result.emplace_back(Data::Stickers::RecentSetId);
		}
	}
	for (auto l = _mySets.size(); i != l; ++i) {
		if (_mySets[i].id == Data::Stickers::MegagroupSetId) {
			result.emplace_back(Data::Stickers::MegagroupSetId);
			result.back().megagroup = _megagroupSet;
			continue;
		}
		const auto set = _mySets[i].set;
		Assert(set != nullptr);
		const auto s = _mySets[i].stickers[0].document;
		const auto availw = st::stickerIconWidth - 2 * st::stickerIconPadding;
		const auto availh = st::emojiFooterHeight - 2 * st::stickerIconPadding;
		const auto size = set->hasThumbnail()
			? QSize(
				set->thumbnailLocation().width(),
				set->thumbnailLocation().height())
			: s->hasThumbnail()
			? QSize(
				s->thumbnailLocation().width(),
				s->thumbnailLocation().height())
			: QSize();
		auto thumbw = size.width(), thumbh = size.height(), pixw = 1, pixh = 1;
		if (availw * thumbh > availh * thumbw) {
			pixh = availh;
			pixw = (pixh * thumbw) / thumbh;
		} else {
			pixw = availw;
			pixh = thumbw ? ((pixw * thumbh) / thumbw) : 1;
		}
		if (pixw < 1) pixw = 1;
		if (pixh < 1) pixh = 1;
		result.emplace_back(set, s, pixw, pixh);
	}
	return result;
}

bool StickersListWidget::preventAutoHide() {
	return _removingSetId != 0 || _displayingSet != 0;
}

void StickersListWidget::updateSelected() {
	if (!v::is_null(_pressed) && !_previewShown) {
		return;
	}

	auto newSelected = OverState { v::null };
	auto p = mapFromGlobal(_lastMousePosition);
	if (!rect().contains(p)
		|| p.y() < getVisibleTop() || p.y() >= getVisibleBottom()
		|| !isVisible()) {
		clearSelection();
		return;
	}
	auto &sets = shownSets();
	auto sx = (rtl() ? width() - p.x() : p.x()) - stickersLeft();
	if (!shownSets().empty()) {
		auto info = sectionInfoByOffset(p.y());
		auto section = info.section;
		if (p.y() >= info.top && p.y() < info.rowsTop) {
			if (hasRemoveButton(section) && myrtlrect(removeButtonRect(section)).contains(p.x(), p.y())) {
				newSelected = OverButton { section };
			} else if (featuredHasAddButton(section) && myrtlrect(featuredAddRect(section)).contains(p.x(), p.y())) {
				newSelected = OverButton{ section };
			} else if (!(sets[section].flags & MTPDstickerSet_ClientFlag::f_special)) {
				newSelected = OverSet { section };
			} else if (sets[section].id == Data::Stickers::MegagroupSetId
					&& (_megagroupSet->canEditStickers() || !sets[section].stickers.empty())) {
				newSelected = OverSet { section };
			}
		} else if (p.y() >= info.rowsTop && p.y() < info.rowsBottom && sx >= 0) {
			auto yOffset = p.y() - info.rowsTop;
			auto &set = sets[section];
			if (set.id == Data::Stickers::MegagroupSetId && set.stickers.empty()) {
				if (_megagroupSetButtonRect.contains(stickersLeft() + sx, yOffset)) {
					newSelected = OverGroupAdd {};
				}
			} else {
				auto special = ((set.flags & MTPDstickerSet::Flag::f_official) != 0);
				auto rowIndex = qFloor(yOffset / _singleSize.height());
				auto columnIndex = qFloor(sx / _singleSize.width());
				auto index = rowIndex * _columnCount + columnIndex;
				if (index >= 0 && index < set.stickers.size()) {
					auto overDelete = false;
					if (stickerHasDeleteButton(set, index)) {
						auto inx = sx - (columnIndex * _singleSize.width());
						auto iny = yOffset - (rowIndex * _singleSize.height());
						if (inx >= _singleSize.width() - st::stickerPanDeleteIconBg.width() && iny < st::stickerPanDeleteIconBg.height()) {
							overDelete = true;
						}
					}
					newSelected = OverSticker { section, index, overDelete };
				}
			}
		}
	}

	setSelected(newSelected);
}

bool StickersListWidget::setHasTitle(const Set &set) const {
	if (set.id == Data::Stickers::FavedSetId) {
		return false;
	} else if (set.id == Data::Stickers::RecentSetId) {
		return !_mySets.empty() && _mySets[0].id == Data::Stickers::FavedSetId;
	}
	return true;
}

bool StickersListWidget::stickerHasDeleteButton(const Set &set, int index) const {
	if (set.id == Data::Stickers::RecentSetId) {
		Assert(index >= 0 && index < _custom.size());
		return _custom[index];
	}
	return (set.id == Data::Stickers::FavedSetId);
}

void StickersListWidget::setSelected(OverState newSelected) {
	if (_selected != newSelected) {
		setCursor(!v::is_null(newSelected)
			? style::cur_pointer
			: style::cur_default);

		auto &sets = shownSets();
		auto updateSelected = [&]() {
			if (auto sticker = std::get_if<OverSticker>(&_selected)) {
				rtlupdate(stickerRect(sticker->section, sticker->index));
			} else if (auto button = std::get_if<OverButton>(&_selected)) {
				if (button->section >= 0
					&& button->section < sets.size()
					&& sets[button->section].externalLayout) {
					rtlupdate(featuredAddRect(button->section));
				} else {
					rtlupdate(removeButtonRect(button->section));
				}
			} else if (std::get_if<OverGroupAdd>(&_selected)) {
				rtlupdate(megagroupSetButtonRectFinal());
			}
		};
		updateSelected();
		_selected = newSelected;
		updateSelected();

		if (_previewShown && _pressed != _selected) {
			if (const auto sticker = std::get_if<OverSticker>(&_selected)) {
				_pressed = _selected;
				Assert(sticker->section >= 0 && sticker->section < sets.size());
				const auto &set = sets[sticker->section];
				Assert(sticker->index >= 0 && sticker->index < set.stickers.size());
				const auto document = set.stickers[sticker->index].document;
				controller()->widget()->showMediaPreview(
					document->stickerSetOrigin(),
					document);
			}
		}
	}
}

void StickersListWidget::showPreview() {
	if (const auto sticker = std::get_if<OverSticker>(&_pressed)) {
		const auto &sets = shownSets();
		Assert(sticker->section >= 0 && sticker->section < sets.size());
		const auto &set = sets[sticker->section];
		Assert(sticker->index >= 0 && sticker->index < set.stickers.size());
		const auto document = set.stickers[sticker->index].document;
		controller()->widget()->showMediaPreview(
			document->stickerSetOrigin(),
			document);
		_previewShown = true;
	}
}

auto StickersListWidget::getLottieRenderer()
-> std::shared_ptr<Lottie::FrameRenderer> {
	if (auto result = _lottieRenderer.lock()) {
		return result;
	}
	auto result = Lottie::MakeFrameRenderer();
	_lottieRenderer = result;
	return result;
}

void StickersListWidget::showStickerSet(uint64 setId) {
	clearSelection();

	if (setId == Data::Stickers::FeaturedSetId) {
		if (_section != Section::Featured) {
			setSection(Section::Featured);
			refreshRecentStickers(true);
			refreshSettingsVisibility();
			if (_footer) {
				_footer->refreshIcons(ValidateIconAnimations::Scroll);
			}
			update();
		}

		scrollTo(0);
		_scrollUpdated.fire({});
		return;
	}

	auto needRefresh = (_section != Section::Stickers);
	if (needRefresh) {
		setSection(Section::Stickers);
		refreshRecentStickers(true);
		refreshSettingsVisibility();
	}

	auto y = 0;
	enumerateSections([this, setId, &y](const SectionInfo &info) {
		if (shownSets()[info.section].id == setId) {
			y = info.top;
			return false;
		}
		return true;
	});
	scrollTo(y);
	_scrollUpdated.fire({});

	if (needRefresh && _footer) {
		_footer->refreshIcons(ValidateIconAnimations::Scroll);
	}

	_lastMousePosition = QCursor::pos();

	update();
}

void StickersListWidget::refreshMegagroupSetGeometry() {
	auto left = megagroupSetInfoLeft();
	auto availableWidth = (width() - left);
	auto top = _megagroupSetAbout.countHeight(availableWidth) + st::stickerGroupCategoryAddMargin.top();
	_megagroupSetButtonTextWidth = st::stickerGroupCategoryAdd.font->width(_megagroupSetButtonText);
	auto buttonWidth = _megagroupSetButtonTextWidth - st::stickerGroupCategoryAdd.width;
	_megagroupSetButtonRect = QRect(left, top, buttonWidth, st::stickerGroupCategoryAdd.height);
}

void StickersListWidget::showMegagroupSet(ChannelData *megagroup) {
	Expects(!megagroup || megagroup->isMegagroup());

	if (_megagroupSet != megagroup) {
		_megagroupSet = megagroup;

		if (_megagroupSetAbout.isEmpty()) {
			_megagroupSetAbout.setText(
				st::stickerGroupCategoryAbout,
				tr::lng_group_stickers_description(tr::now));
			_megagroupSetButtonText = tr::lng_group_stickers_add(tr::now).toUpper();
			refreshMegagroupSetGeometry();
		}
		_megagroupSetButtonRipple.reset();

		refreshStickers();
	}
}

void StickersListWidget::afterShown() {
	if (_footer) {
		_footer->stealFocus();
	}
}

void StickersListWidget::beforeHiding() {
	if (_footer) {
		_footer->returnFocus();
	}
}

void StickersListWidget::displaySet(uint64 setId) {
	if (setId == Data::Stickers::MegagroupSetId) {
		if (_megagroupSet->canEditStickers()) {
			_displayingSet = true;
			checkHideWithBox(Ui::show(
				Box<StickersBox>(controller(), _megagroupSet),
				Ui::LayerOption::KeepOther).data());
			return;
		} else if (_megagroupSet->mgInfo->stickerSet.type() == mtpc_inputStickerSetID) {
			setId = _megagroupSet->mgInfo->stickerSet.c_inputStickerSetID().vid().v;
		} else {
			return;
		}
	}
	const auto &sets = session().data().stickers().sets();
	auto it = sets.find(setId);
	if (it != sets.cend()) {
		_displayingSet = true;
		checkHideWithBox(Ui::show(
			Box<StickerSetBox>(controller(), it->second->mtpInput()),
			Ui::LayerOption::KeepOther).data());
	}
}

void StickersListWidget::checkHideWithBox(QPointer<Ui::BoxContent> box) {
	if (!box) {
		return;
	}
	connect(box, &QObject::destroyed, this, [=] {
		_displayingSet = false;
		_checkForHide.fire({});
	});
}

void StickersListWidget::installSet(uint64 setId) {
	const auto &sets = session().data().stickers().sets();
	const auto it = sets.find(setId);
	if (it != sets.cend()) {
		const auto set = it->second.get();
		const auto input = set->mtpInput();
		if ((set->flags & MTPDstickerSet_ClientFlag::f_not_loaded)
			|| set->stickers.empty()) {
			_api.request(MTPmessages_GetStickerSet(
				input
			)).done([=](const MTPmessages_StickerSet &result) {
				session().data().stickers().feedSetFull(result);
				sendInstallRequest(setId, input);
			}).send();
		} else {
			sendInstallRequest(setId, input);
		}
	}
}

void StickersListWidget::sendInstallRequest(
		uint64 setId,
		const MTPInputStickerSet &input) {
	_api.request(MTPmessages_InstallStickerSet(
		input,
		MTP_bool(false)
	)).done([=](const MTPmessages_StickerSetInstallResult &result) {
		if (result.type() == mtpc_messages_stickerSetInstallResultArchive) {
			session().data().stickers().applyArchivedResult(
				result.c_messages_stickerSetInstallResultArchive());
		}
	}).fail([=](const MTP::Error &error) {
		notInstalledLocally(setId);
		session().data().stickers().undoInstallLocally(setId);
	}).send();

	installedLocally(setId);
	session().data().stickers().installLocally(setId);
}

void StickersListWidget::removeMegagroupSet(bool locally) {
	if (locally) {
		session().settings().setGroupStickersSectionHidden(_megagroupSet->id);
		session().saveSettings();
		refreshStickers();
		return;
	}
	_removingSetId = Data::Stickers::MegagroupSetId;
	Ui::show(Box<ConfirmBox>(tr::lng_stickers_remove_group_set(tr::now), crl::guard(this, [this, group = _megagroupSet] {
		Expects(group->mgInfo != nullptr);

		if (group->mgInfo->stickerSet.type() != mtpc_inputStickerSetEmpty) {
			session().api().setGroupStickerSet(group, MTP_inputStickerSetEmpty());
		}
		Ui::hideLayer();
		_removingSetId = 0;
		_checkForHide.fire({});
	}), crl::guard(this, [this] {
		_removingSetId = 0;
		_checkForHide.fire({});
	})));
}

void StickersListWidget::removeSet(uint64 setId) {
	const auto &sets = session().data().stickers().sets();
	const auto it = sets.find(setId);
	if (it != sets.cend()) {
		const auto set = it->second.get();
		_removingSetId = set->id;
		auto text = tr::lng_stickers_remove_pack(tr::now, lt_sticker_pack, set->title);
		Ui::show(Box<ConfirmBox>(text, tr::lng_stickers_remove_pack_confirm(tr::now), crl::guard(this, [=] {
			Ui::hideLayer();
			const auto &sets = session().data().stickers().sets();
			const auto it = sets.find(_removingSetId);
			if (it != sets.cend()) {
				const auto set = it->second.get();
				if (set->id && set->access) {
					_api.request(MTPmessages_UninstallStickerSet(MTP_inputStickerSetID(MTP_long(set->id), MTP_long(set->access)))).send();
				} else if (!set->shortName.isEmpty()) {
					_api.request(MTPmessages_UninstallStickerSet(MTP_inputStickerSetShortName(MTP_string(set->shortName)))).send();
				}
				auto writeRecent = false;
				auto &recent = session().data().stickers().getRecentPack();
				for (auto i = recent.begin(); i != recent.cend();) {
					if (set->stickers.indexOf(i->first) >= 0) {
						i = recent.erase(i);
						writeRecent = true;
					} else {
						++i;
					}
				}
				set->flags &= ~MTPDstickerSet::Flag::f_installed_date;
				set->installDate = TimeId(0);
				//
				// Set can be in search results.
				//
				//if (!(set->flags & MTPDstickerSet_ClientFlag::f_featured)
				//	&& !(set->flags & MTPDstickerSet_ClientFlag::f_special)) {
				//	sets.erase(it);
				//}
				int removeIndex = session().data().stickers().setsOrder().indexOf(_removingSetId);
				if (removeIndex >= 0) session().data().stickers().setsOrderRef().removeAt(removeIndex);
				refreshStickers();
				session().local().writeInstalledStickers();
				if (writeRecent) session().saveSettings();
			}
			_removingSetId = 0;
			_checkForHide.fire({});
		}), crl::guard(this, [=] {
			_removingSetId = 0;
			_checkForHide.fire({});
		})));
	}
}

StickersListWidget::~StickersListWidget() = default;

} // namespace ChatHelpers
