/*
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 "boxes/background_preview_box.h"

#include "lang/lang_keys.h"
#include "mainwidget.h"
#include "window/themes/window_theme.h"
#include "ui/boxes/confirm_box.h"
#include "ui/controls/chat_service_checkbox.h"
#include "ui/chat/chat_theme.h"
#include "ui/chat/chat_style.h"
#include "ui/toast/toast.h"
#include "ui/image/image.h"
#include "ui/widgets/checkbox.h"
#include "ui/ui_utility.h"
#include "history/history.h"
#include "history/history_message.h"
#include "history/view/history_view_message.h"
#include "main/main_session.h"
#include "apiwrap.h"
#include "data/data_session.h"
#include "data/data_user.h"
#include "data/data_document.h"
#include "data/data_document_media.h"
#include "data/data_document_resolver.h"
#include "data/data_file_origin.h"
#include "base/unixtime.h"
#include "boxes/background_preview_box.h"
#include "window/window_session_controller.h"
#include "settings/settings_common.h"
#include "styles/style_chat.h"
#include "styles/style_layers.h"
#include "styles/style_boxes.h"

#include <QtGui/QClipboard>
#include <QtGui/QGuiApplication>

namespace {

constexpr auto kMaxWallPaperSlugLength = 255;

[[nodiscard]] bool IsValidWallPaperSlug(const QString &slug) {
	if (slug.isEmpty() || slug.size() > kMaxWallPaperSlugLength) {
		return false;
	}
	return ranges::none_of(slug, [](QChar ch) {
		return (ch != '.')
			&& (ch != '_')
			&& (ch != '-')
			&& (ch < '0' || ch > '9')
			&& (ch < 'a' || ch > 'z')
			&& (ch < 'A' || ch > 'Z');
	});
}

[[nodiscard]] AdminLog::OwnedItem GenerateTextItem(
		not_null<HistoryView::ElementDelegate*> delegate,
		not_null<History*> history,
		const QString &text,
		bool out) {
	Expects(history->peer->isUser());

	const auto flags = MessageFlag::FakeHistoryItem
		| MessageFlag::HasFromId
		| (out ? MessageFlag::Outgoing : MessageFlag(0));
	const auto replyTo = MsgId();
	const auto viaBotId = UserId();
	const auto groupedId = uint64();
	const auto item = history->makeMessage(
		history->nextNonHistoryEntryId(),
		flags,
		replyTo,
		viaBotId,
		base::unixtime::now(),
		out ? history->session().userId() : peerToUser(history->peer->id),
		QString(),
		TextWithEntities{ text },
		MTP_messageMediaEmpty(),
		HistoryMessageMarkupData(),
		groupedId);
	return AdminLog::OwnedItem(delegate, item);
}

[[nodiscard]] QImage PrepareScaledNonPattern(
		const QImage &image,
		Images::Option blur) {
	const auto size = st::boxWideWidth;
	const auto width = std::max(image.width(), 1);
	const auto height = std::max(image.height(), 1);
	const auto takeWidth = (width > height)
		? (width * size / height)
		: size;
	const auto takeHeight = (width > height)
		? size
		: (height * size / width);
	const auto ratio = style::DevicePixelRatio();
	return Images::Prepare(image, QSize(takeWidth, takeHeight) * ratio, {
		.options = Images::Option::TransparentBackground | blur,
		.outer = { size, size },
	});
}

[[nodiscard]] QImage PrepareScaledFromFull(
		const QImage &image,
		bool isPattern,
		const std::vector<QColor> &background,
		int gradientRotation,
		float64 patternOpacity,
		Images::Option blur = Images::Option(0)) {
	auto result = PrepareScaledNonPattern(image, blur);
	if (isPattern) {
		result = Ui::PreparePatternImage(
			std::move(result),
			background,
			gradientRotation,
			patternOpacity);
	}
	return std::move(result).convertToFormat(
		QImage::Format_ARGB32_Premultiplied);
}

[[nodiscard]] QImage BlackImage(QSize size) {
	auto result = QImage(size, QImage::Format_ARGB32_Premultiplied);
	result.fill(Qt::black);
	return result;
}

} // namespace

BackgroundPreviewBox::BackgroundPreviewBox(
	QWidget*,
	not_null<Window::SessionController*> controller,
	const Data::WallPaper &paper)
: SimpleElementDelegate(controller, [=] { update(); })
, _controller(controller)
, _chatStyle(std::make_unique<Ui::ChatStyle>())
, _text1(GenerateTextItem(
	delegate(),
	_controller->session().data().history(PeerData::kServiceNotificationsId),
	tr::lng_background_text1(tr::now),
	false))
, _text2(GenerateTextItem(
	delegate(),
	_controller->session().data().history(PeerData::kServiceNotificationsId),
	tr::lng_background_text2(tr::now),
	true))
, _paper(paper)
, _media(_paper.document() ? _paper.document()->createMediaView() : nullptr)
, _radial([=](crl::time now) { radialAnimationCallback(now); }) {
	_chatStyle->apply(controller->defaultChatTheme().get());

	if (_media) {
		_media->thumbnailWanted(_paper.fileOrigin());
	}
	generateBackground();
	_controller->session().downloaderTaskFinished(
	) | rpl::start_with_next([=] {
		update();
	}, lifetime());
}

void BackgroundPreviewBox::generateBackground() {
	if (_paper.backgroundColors().empty()) {
		return;
	}
	const auto size = QSize(st::boxWideWidth, st::boxWideWidth)
		* cIntRetinaFactor();
	_generated = Ui::PixmapFromImage((_paper.patternOpacity() >= 0.)
		? Ui::GenerateBackgroundImage(
			size,
			_paper.backgroundColors(),
			_paper.gradientRotation())
		: BlackImage(size));
	_generated.setDevicePixelRatio(cRetinaFactor());
}

not_null<HistoryView::ElementDelegate*> BackgroundPreviewBox::delegate() {
	return static_cast<HistoryView::ElementDelegate*>(this);
}

void BackgroundPreviewBox::prepare() {
	setTitle(tr::lng_background_header());

	addButton(tr::lng_background_apply(), [=] { apply(); });
	addButton(tr::lng_cancel(), [=] { closeBox(); });
	if (_paper.hasShareUrl()) {
		addLeftButton(tr::lng_background_share(), [=] { share(); });
	}
	updateServiceBg(_paper.backgroundColors());

	_paper.loadDocument();
	const auto document = _paper.document();
	if (document && document->loading()) {
		_radial.start(_media->progress());
	}
	if (!_paper.isPattern()
		&& (_paper.localThumbnail()
			|| (document && document->hasThumbnail()))) {
		createBlurCheckbox();
	}
	setScaledFromThumb();
	checkLoadedDocument();

	_text1->setDisplayDate(true);
	_text1->initDimensions();
	_text1->resizeGetHeight(st::boxWideWidth);
	_text2->initDimensions();
	_text2->resizeGetHeight(st::boxWideWidth);

	setDimensions(st::boxWideWidth, st::boxWideWidth);
}

void BackgroundPreviewBox::createBlurCheckbox() {
	_blur = Ui::MakeChatServiceCheckbox(
		this,
		tr::lng_background_blur(tr::now),
		st::backgroundCheckbox,
		st::backgroundCheck,
		_paper.isBlurred(),
		[=] { return _serviceBg.value_or(QColor(255, 255, 255, 0)); });

	rpl::combine(
		sizeValue(),
		_blur->sizeValue()
	) | rpl::start_with_next([=](QSize outer, QSize inner) {
		_blur->move(
			(outer.width() - inner.width()) / 2,
			outer.height() - st::historyPaddingBottom - inner.height());
	}, _blur->lifetime());

	_blur->checkedChanges(
	) | rpl::start_with_next([=](bool checked) {
		checkBlurAnimationStart();
		update();
	}, lifetime());

	_blur->setDisabled(true);
}

void BackgroundPreviewBox::apply() {
	const auto install = (_paper.id() != Window::Theme::Background()->id())
		&& Data::IsCloudWallPaper(_paper);
	_controller->content()->setChatBackground(_paper, std::move(_full));
	if (install) {
		_controller->session().api().request(MTPaccount_InstallWallPaper(
			_paper.mtpInput(&_controller->session()),
			_paper.mtpSettings()
		)).send();
	}
	closeBox();
}

void BackgroundPreviewBox::share() {
	QGuiApplication::clipboard()->setText(
		_paper.shareUrl(&_controller->session()));
	Ui::Toast::Show(
		Ui::BoxShow(this).toastParent(),
		tr::lng_background_link_copied(tr::now));
}

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

	const auto ms = crl::now();
	if (_scaled.isNull()) {
		setScaledFromThumb();
	}
	if (!_generated.isNull()
		&& (_scaled.isNull()
			|| (_fadeOutThumbnail.isNull() && _fadeIn.animating()))) {
		p.drawPixmap(0, 0, _generated);
	}
	if (!_scaled.isNull()) {
		paintImage(p);
		paintRadial(p);
	} else if (_generated.isNull()) {
		p.fillRect(e->rect(), st::boxBg);
		return;
	} else {
		// Progress of pattern loading.
		paintRadial(p);
	}
	paintTexts(p, ms);
}

void BackgroundPreviewBox::paintImage(Painter &p) {
	Expects(!_scaled.isNull());

	const auto factor = cIntRetinaFactor();
	const auto size = st::boxWideWidth;
	const auto from = QRect(
		0,
		(size - height()) / 2 * factor,
		size * factor,
		height() * factor);
	const auto guard = gsl::finally([&] { p.setOpacity(1.); });

	const auto fade = _fadeIn.value(1.);
	if (fade < 1. && !_fadeOutThumbnail.isNull()) {
		p.drawPixmap(rect(), _fadeOutThumbnail, from);
	}
	const auto &pixmap = (!_blurred.isNull() && _paper.isBlurred())
		? _blurred
		: _scaled;
	p.setOpacity(fade);
	p.drawPixmap(rect(), pixmap, from);
	checkBlurAnimationStart();
}

void BackgroundPreviewBox::paintRadial(Painter &p) {
	const auto radial = _radial.animating();
	const auto radialOpacity = radial ? _radial.opacity() : 0.;
	if (!radial) {
		return;
	}
	auto inner = radialRect();

	p.setPen(Qt::NoPen);
	p.setOpacity(radialOpacity);
	p.setBrush(st::radialBg);

	{
		PainterHighQualityEnabler hq(p);
		p.drawEllipse(inner);
	}

	p.setOpacity(1);
	QRect arc(inner.marginsRemoved(QMargins(st::radialLine, st::radialLine, st::radialLine, st::radialLine)));
	_radial.draw(p, arc, st::radialLine, st::radialFg);
}

int BackgroundPreviewBox::textsTop() const {
	const auto bottom = _blur ? _blur->y() : height();
	return bottom
		- st::historyPaddingBottom
		- _text1->height()
		- _text2->height();
}

QRect BackgroundPreviewBox::radialRect() const {
	const auto available = textsTop() - st::historyPaddingBottom;
	return QRect(
		QPoint(
			(width() - st::radialSize.width()) / 2,
			(available - st::radialSize.height()) / 2),
		st::radialSize);
}

void BackgroundPreviewBox::paintTexts(Painter &p, crl::time ms) {
	const auto height1 = _text1->height();
	const auto height2 = _text2->height();
	auto context = _controller->defaultChatTheme()->preparePaintContext(
		_chatStyle.get(),
		rect(),
		rect());
	p.translate(0, textsTop());
	paintDate(p);

	context.outbg = _text1->hasOutLayout();
	_text1->draw(p, context);
	p.translate(0, height1);

	context.outbg = _text2->hasOutLayout();
	_text2->draw(p, context);
	p.translate(0, height2);
}

void BackgroundPreviewBox::paintDate(Painter &p) {
	const auto date = _text1->Get<HistoryView::DateBadge>();
	if (!date || !_serviceBg) {
		return;
	}
	auto hq = PainterHighQualityEnabler(p);
	const auto text = date->text;
	const auto bubbleHeight = st::msgServicePadding.top() + st::msgServiceFont->height + st::msgServicePadding.bottom();
	const auto bubbleTop = st::msgServiceMargin.top();
	const auto textWidth = st::msgServiceFont->width(text);
	const auto bubbleWidth = st::msgServicePadding.left() + textWidth + st::msgServicePadding.right();
	const auto bubbleLeft = (width() - bubbleWidth) / 2;
	const auto radius = bubbleHeight / 2;
	p.setPen(Qt::NoPen);
	p.setBrush(*_serviceBg);
	p.drawRoundedRect(bubbleLeft, bubbleTop, bubbleWidth, bubbleHeight, radius, radius);
	p.setPen(st::msgServiceFg);
	p.setFont(st::msgServiceFont);
	p.drawText(bubbleLeft + st::msgServicePadding.left(), bubbleTop + st::msgServicePadding.top() + st::msgServiceFont->ascent, text);
}

void BackgroundPreviewBox::radialAnimationCallback(crl::time now) {
	Expects(_paper.document() != nullptr);

	const auto document = _paper.document();
	const auto wasAnimating = _radial.animating();
	const auto updated = _radial.update(
		_media->progress(),
		!document->loading(),
		now);
	if ((wasAnimating || _radial.animating())
		&& (!anim::Disabled() || updated)) {
		update(radialRect());
	}
	checkLoadedDocument();
}

void BackgroundPreviewBox::setScaledFromThumb() {
	if (!_scaled.isNull()) {
		return;
	}
	const auto localThumbnail = _paper.localThumbnail();
	const auto thumbnail = localThumbnail
		? localThumbnail
		: _media
		? _media->thumbnail()
		: nullptr;
	if (!thumbnail) {
		return;
	} else if (_paper.isPattern() && _paper.document() != nullptr) {
		return;
	}
	auto scaled = PrepareScaledFromFull(
		thumbnail->original(),
		_paper.isPattern(),
		_paper.backgroundColors(),
		_paper.gradientRotation(),
		_paper.patternOpacity(),
		_paper.document() ? Images::Option::Blur : Images::Option());
	auto blurred = (_paper.document() || _paper.isPattern())
		? QImage()
		: PrepareScaledNonPattern(
			Ui::PrepareBlurredBackground(thumbnail->original()),
			Images::Option(0));
	setScaledFromImage(std::move(scaled), std::move(blurred));
}

void BackgroundPreviewBox::setScaledFromImage(
		QImage &&image,
		QImage &&blurred) {
	updateServiceBg({ Ui::CountAverageColor(image) });
	if (!_full.isNull()) {
		startFadeInFrom(std::move(_scaled));
	}
	_scaled = Ui::PixmapFromImage(std::move(image));
	_blurred = Ui::PixmapFromImage(std::move(blurred));
	if (_blur && (!_paper.document() || !_full.isNull())) {
		_blur->setDisabled(false);
	}
}

void BackgroundPreviewBox::startFadeInFrom(QPixmap previous) {
	_fadeOutThumbnail = std::move(previous);
	_fadeIn.start([=] { update(); }, 0., 1., st::backgroundCheck.duration);
}

void BackgroundPreviewBox::checkBlurAnimationStart() {
	if (_fadeIn.animating()
		|| _blurred.isNull()
		|| !_blur
		|| _paper.isBlurred() == _blur->checked()) {
		return;
	}
	_paper = _paper.withBlurred(_blur->checked());
	startFadeInFrom(_paper.isBlurred() ? _scaled : _blurred);
}

void BackgroundPreviewBox::updateServiceBg(const std::vector<QColor> &bg) {
	const auto count = int(bg.size());
	if (!count) {
		return;
	}
	auto red = 0, green = 0, blue = 0;
	for (const auto &color : bg) {
		red += color.red();
		green += color.green();
		blue += color.blue();
	}
	_serviceBg = Ui::ThemeAdjustedColor(
		st::msgServiceBg->c,
		QColor(red / count, green / count, blue / count));
}

void BackgroundPreviewBox::checkLoadedDocument() {
	const auto document = _paper.document();
	if (!_full.isNull()
		|| !document
		|| !_media->loaded(true)
		|| _generating) {
		return;
	}
	const auto generateCallback = [=](QImage &&image) {
		if (image.isNull()) {
			return;
		}
		crl::async([
			this,
			image = std::move(image),
			isPattern = _paper.isPattern(),
			background = _paper.backgroundColors(),
			gradientRotation = _paper.gradientRotation(),
			patternOpacity = _paper.patternOpacity(),
			guard = _generating.make_guard()
		]() mutable {
			auto scaled = PrepareScaledFromFull(
				image,
				isPattern,
				background,
				gradientRotation,
				patternOpacity);
			auto blurred = !isPattern
				? PrepareScaledNonPattern(
					Ui::PrepareBlurredBackground(image),
					Images::Option(0))
				: QImage();
			crl::on_main(std::move(guard), [
				this,
				image = std::move(image),
				scaled = std::move(scaled),
				blurred = std::move(blurred)
			]() mutable {
				_full = std::move(image);
				setScaledFromImage(std::move(scaled), std::move(blurred));
				update();
			});
		});
	};
	_generating = Data::ReadBackgroundImageAsync(
		_media.get(),
		Ui::PreprocessBackgroundImage,
		generateCallback);
}

bool BackgroundPreviewBox::Start(
		not_null<Window::SessionController*> controller,
		const QString &slug,
		const QMap<QString, QString> &params) {
	if (const auto paper = Data::WallPaper::FromColorsSlug(slug)) {
		controller->show(Box<BackgroundPreviewBox>(
			controller,
			paper->withUrlParams(params)));
		return true;
	}
	if (!IsValidWallPaperSlug(slug)) {
		controller->show(Ui::MakeInformBox(tr::lng_background_bad_link()));
		return false;
	}
	controller->session().api().requestWallPaper(slug, crl::guard(controller, [=](
			const Data::WallPaper &result) {
		controller->show(Box<BackgroundPreviewBox>(
			controller,
			result.withUrlParams(params)));
	}), crl::guard(controller, [=](const MTP::Error &error) {
		controller->show(Ui::MakeInformBox(tr::lng_background_bad_link()));
	}));
	return true;
}

HistoryView::Context BackgroundPreviewBox::elementContext() {
	return HistoryView::Context::ContactPreview;
}