// This file is part of Desktop App Toolkit,
// a set of libraries for developing nice desktop applications.
//
// For license and copyright information please follow this link:
// https://github.com/desktop-app/legal/blob/master/LEGAL
//
#include "ui/widgets/buttons.h"

#include "ui/widgets/checkbox.h"
#include "ui/effects/ripple_animation.h"
#include "ui/effects/cross_animation.h"
#include "ui/effects/numbers_animation.h"
#include "ui/image/image_prepare.h"
#include "ui/painter.h"

#include <QtGui/QtEvents>

namespace Ui {

LinkButton::LinkButton(
	QWidget *parent,
	const QString &text,
	const style::LinkButton &st)
: AbstractButton(parent)
, _st(st)
, _text(text)
, _textWidth(st.font->width(_text)) {
	resize(
		naturalWidth(),
		_st.padding.top() + _st.font->height + _st.padding.bottom());
	setCursor(style::cur_pointer);
}

int LinkButton::naturalWidth() const {
	return _st.padding.left() + _textWidth + _st.padding.right();
}

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

	const auto &font = (isOver() ? _st.overFont : _st.font);
	const auto pen = _textFgOverride.has_value()
		? QPen(*_textFgOverride)
		: isOver()
		? _st.overColor
		: _st.color;
	p.setFont(font);
	p.setPen(pen);
	const auto left = _st.padding.left();
	const auto top = _st.padding.top() + font->ascent;
	if (width() < naturalWidth()) {
		const auto available = width() - left - _st.padding.right();
		p.drawText(left, top, font->elided(_text, available));
	} else {
		p.drawText(left, top, _text);
	}
}

void LinkButton::setText(const QString &text) {
	_text = text;
	_textWidth = _st.font->width(_text);
	resize(naturalWidth(), _st.font->height);
	update();
}

void LinkButton::setColorOverride(std::optional<QColor> textFg) {
	_textFgOverride = textFg;
	update();
}

void LinkButton::onStateChanged(State was, StateChangeSource source) {
	update();
}

RippleButton::RippleButton(QWidget *parent, const style::RippleAnimation &st)
: AbstractButton(parent)
, _st(st) {
}

void RippleButton::clearState() {
	AbstractButton::clearState();
	finishAnimating();
}

void RippleButton::finishAnimating() {
	if (_ripple) {
		_ripple.reset();
		update();
	}
}

void RippleButton::setForceRippled(
		bool rippled,
		anim::type animated) {
	if (_forceRippled != rippled) {
		_forceRippled = rippled;
		if (_forceRippled) {
			_forceRippledSubscription = style::PaletteChanged(
			) | rpl::filter([=] {
				return _ripple != nullptr;
			}) | rpl::start_with_next([=] {
				_ripple->forceRepaint();
			});
			ensureRipple();
			if (_ripple->empty()) {
				_ripple->addFading();
			} else {
				_ripple->lastUnstop();
			}
		} else {
			if (_ripple) {
				_ripple->lastStop();
			}
			_forceRippledSubscription.destroy();
		}
	}
	if (animated == anim::type::instant && _ripple) {
		_ripple->lastFinish();
	}
	update();
}

void RippleButton::paintRipple(
		QPainter &p,
		const QPoint &point,
		const QColor *colorOverride) {
	paintRipple(p, point.x(), point.y(), colorOverride);
}

void RippleButton::paintRipple(QPainter &p, int x, int y, const QColor *colorOverride) {
	if (_ripple) {
		_ripple->paint(p, x, y, width(), colorOverride);
		if (_ripple->empty()) {
			_ripple.reset();
		}
	}
}

void RippleButton::onStateChanged(State was, StateChangeSource source) {
	update();

	auto wasDown = static_cast<bool>(was & StateFlag::Down);
	auto down = isDown();
	if (!_st.showDuration || down == wasDown || _forceRippled) {
		return;
	}

	if (down && (source == StateChangeSource::ByPress)) {
		// Start a ripple only from mouse press.
		auto position = prepareRippleStartPosition();
		if (position != DisabledRippleStartPosition()) {
			ensureRipple();
			_ripple->add(position);
		}
	} else if (!down && _ripple) {
		// Finish ripple anyway.
		_ripple->lastStop();
	}
}

void RippleButton::ensureRipple() {
	if (!_ripple) {
		_ripple = std::make_unique<RippleAnimation>(_st, prepareRippleMask(), [this] { update(); });
	}
}

QImage RippleButton::prepareRippleMask() const {
	return RippleAnimation::rectMask(size());
}

QPoint RippleButton::prepareRippleStartPosition() const {
	return mapFromGlobal(QCursor::pos());
}

RippleButton::~RippleButton() = default;

FlatButton::FlatButton(
	QWidget *parent,
	const QString &text,
	const style::FlatButton &st)
: RippleButton(parent, st.ripple)
, _text(text)
, _st(st) {
	if (_st.width < 0) {
		_width = textWidth() - _st.width;
	} else if (!_st.width) {
		_width = textWidth() + _st.height - _st.font->height;
	} else {
		_width = _st.width;
	}
	resize(_width, _st.height);
}

void FlatButton::setText(const QString &text) {
	_text = text;
	update();
}

void FlatButton::setWidth(int w) {
	_width = w;
	if (_width < 0) {
		_width = textWidth() - _st.width;
	} else if (!_width) {
		_width = textWidth() + _st.height - _st.font->height;
	}
	resize(_width, height());
}

void FlatButton::setColorOverride(std::optional<QColor> color) {
	_colorOverride = color;
	update();
}

int32 FlatButton::textWidth() const {
	return _st.font->width(_text);
}

void FlatButton::onStateChanged(State was, StateChangeSource source) {
	RippleButton::onStateChanged(was, source);
	update();
}

void FlatButton::paintEvent(QPaintEvent *e) {
	QPainter p(this);

	const auto inner = QRect(0, height() - _st.height, width(), _st.height);
	p.fillRect(inner, isOver() ? _st.overBgColor : _st.bgColor);

	paintRipple(p, 0, 0);

	p.setFont(isOver() ? _st.overFont : _st.font);
	p.setRenderHint(QPainter::TextAntialiasing);
	if (_colorOverride) {
		p.setPen(*_colorOverride);
	} else {
		p.setPen(isOver() ? _st.overColor : _st.color);
	}

	const auto textRect = inner.marginsRemoved(
		_textMargins
	).marginsRemoved(
		{ 0, _st.textTop, 0, 0 }
	);
	p.drawText(textRect, _text, style::al_top);
}

void FlatButton::setTextMargins(QMargins margins) {
	_textMargins = margins;
	update();
}

RoundButton::RoundButton(
	QWidget *parent,
	rpl::producer<QString> text,
	const style::RoundButton &st)
: RippleButton(parent, st.ripple)
, _textFull(std::move(text))
, _st(st)
, _roundRect(st::buttonRadius, _st.textBg)
, _roundRectOver(st::buttonRadius, _st.textBgOver) {
	_textFull.value(
	) | rpl::start_with_next([=](const QString &text) {
		resizeToText(text);
	}, lifetime());
}

void RoundButton::setTextTransform(TextTransform transform) {
	_transform = transform;
	resizeToText(_textFull.current());
}

void RoundButton::setText(rpl::producer<QString> text) {
	_textFull = std::move(text);
}

void RoundButton::setNumbersText(const QString &numbersText, int numbers) {
	if (numbersText.isEmpty()) {
		_numbers.reset();
	} else {
		if (!_numbers) {
			_numbers = std::make_unique<NumbersAnimation>(_st.font, [this] {
				numbersAnimationCallback();
			});
		}
		_numbers->setText(numbersText, numbers);
	}
	resizeToText(_textFull.current());
}

void RoundButton::setWidthChangedCallback(Fn<void()> callback) {
	if (!_numbers) {
		_numbers = std::make_unique<NumbersAnimation>(_st.font, [this] {
			numbersAnimationCallback();
		});
	}
	_numbers->setWidthChangedCallback(std::move(callback));
}

void RoundButton::finishNumbersAnimation() {
	if (_numbers) {
		_numbers->finishAnimating();
	}
}

void RoundButton::numbersAnimationCallback() {
	resizeToText(_textFull.current());
}

void RoundButton::setFullWidth(int newFullWidth) {
	_fullWidthOverride = newFullWidth;
	resizeToText(_textFull.current());
}

void RoundButton::setFullRadius(bool enabled) {
	_fullRadius = enabled;
	update();
}

void RoundButton::resizeToText(const QString &text) {
	_text = (_transform == TextTransform::ToUpper) ? text.toUpper() : text;
	_textWidth = _st.font->width(_text);

	int innerWidth = contentWidth();
	if (_fullWidthOverride > 0) {
		if (_fullWidthOverride < innerWidth + (_st.height - _st.font->height)) {
			_text = _st.font->elided(text, qMax(_fullWidthOverride - (_st.height - _st.font->height), 1));
			_textWidth = _st.font->width(_text);
		}
		resize(_fullWidthOverride, _st.height + _st.padding.top() + _st.padding.bottom());
	} else if (_fullWidthOverride < 0) {
		resize(innerWidth - _fullWidthOverride, _st.height + _st.padding.top() + _st.padding.bottom());
	} else if (_st.width <= 0) {
		resize(innerWidth - _st.width + _st.padding.left() + _st.padding.right(), _st.height + _st.padding.top() + _st.padding.bottom());
	} else {
		if (_st.width < innerWidth + (_st.height - _st.font->height)) {
			_text = _st.font->elided(_text, qMax(_st.width - (_st.height - _st.font->height), 1));
			_textWidth = _st.font->width(_text);
		}
		resize(_st.width + _st.padding.left() + _st.padding.right(), _st.height + _st.padding.top() + _st.padding.bottom());
	}

	update();
}

int RoundButton::contentWidth() const {
	auto result = _textWidth;
	if (_numbers) {
		result += (result ? _st.numbersSkip : 0) + _numbers->countWidth();
	}
	if (!_st.icon.empty() && _st.iconPosition.x() < 0) {
		result += _st.icon.width() - _st.iconPosition.x();
	}
	return result;
}

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

	auto innerWidth = contentWidth();
	auto rounded = rect().marginsRemoved(_st.padding);
	if (_fullWidthOverride < 0) {
		rounded = QRect(0, rounded.top(), innerWidth - _fullWidthOverride, rounded.height());
	}
	const auto drawRect = [&](const RoundRect &rect) {
		const auto fill = myrtlrect(rounded);
		if (_fullRadius) {
			const auto radius = rounded.height() / 2;
			PainterHighQualityEnabler hq(p);
			p.setPen(Qt::NoPen);
			p.setBrush(rect.color());
			p.drawRoundedRect(fill, radius, radius);
		} else {
			rect.paint(p, fill);
		}
	};
	drawRect(_roundRect);

	auto over = isOver();
	auto down = isDown();
	if (over || down) {
		drawRect(_roundRectOver);
	}

	paintRipple(p, rounded.topLeft());

	p.setFont(_st.font);
	const auto textTop = _st.padding.top() + _st.textTop;
	auto textLeft = _st.padding.left()
		+ ((width()
			- innerWidth
			- _st.padding.left()
			- _st.padding.right()) / 2);
	if (_fullWidthOverride < 0) {
		textLeft = -_fullWidthOverride / 2;
	}
	if (!_st.icon.empty() && _st.iconPosition.x() < 0) {
		textLeft += _st.icon.width() - _st.iconPosition.x();
	}
	const auto iconLeft = (_st.iconPosition.x() >= 0)
		? _st.iconPosition.x()
		: (textLeft + _st.iconPosition.x() - _st.icon.width());
	const auto iconTop = (_st.iconPosition.y() >= 0)
		? _st.iconPosition.y()
		: (textTop + _st.iconPosition.y());
	if (!_text.isEmpty()) {
		p.setPen((over || down) ? _st.textFgOver : _st.textFg);
		p.drawTextLeft(textLeft, textTop, width(), _text);
	}
	if (_numbers) {
		textLeft += _textWidth + (_textWidth ? _st.numbersSkip : 0);
		p.setPen((over || down) ? _st.numbersTextFgOver : _st.numbersTextFg);
		_numbers->paint(p, textLeft, textTop, width());
	}
	if (!_st.icon.empty()) {
		const auto &current = ((over || down) && !_st.iconOver.empty())
			? _st.iconOver
			: _st.icon;
		current.paint(p, QPoint(iconLeft, iconTop), width());
	}
}

QImage RoundButton::prepareRippleMask() const {
	auto innerWidth = contentWidth();
	auto rounded = style::rtlrect(rect().marginsRemoved(_st.padding), width());
	if (_fullWidthOverride < 0) {
		rounded = QRect(0, rounded.top(), innerWidth - _fullWidthOverride, rounded.height());
	}
	return RippleAnimation::roundRectMask(
		rounded.size(),
		_fullRadius ? (rounded.height() / 2) : st::buttonRadius);
}

QPoint RoundButton::prepareRippleStartPosition() const {
	return mapFromGlobal(QCursor::pos()) - QPoint(_st.padding.left(), _st.padding.top());
}

RoundButton::~RoundButton() = default;

IconButton::IconButton(QWidget *parent, const style::IconButton &st) : RippleButton(parent, st.ripple)
, _st(st) {
	resize(_st.width, _st.height);
}

void IconButton::setIconOverride(const style::icon *iconOverride, const style::icon *iconOverOverride) {
	_iconOverride = iconOverride;
	_iconOverrideOver = iconOverOverride;
	update();
}

void IconButton::setRippleColorOverride(const style::color *colorOverride) {
	_rippleColorOverride = colorOverride;
}

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

	paintRipple(p, _st.rippleAreaPosition, _rippleColorOverride ? &(*_rippleColorOverride)->c : nullptr);

	auto down = isDown();
	auto overIconOpacity = (down || forceRippled()) ? 1. : _a_over.value(isOver() ? 1. : 0.);
	auto overIcon = [this] {
		if (_iconOverrideOver) {
			return _iconOverrideOver;
		} else if (!_st.iconOver.empty()) {
			return &_st.iconOver;
		} else if (_iconOverride) {
			return _iconOverride;
		}
		return &_st.icon;
	};
	auto justIcon = [this] {
		if (_iconOverride) {
			return _iconOverride;
		}
		return &_st.icon;
	};
	auto icon = (overIconOpacity == 1.) ? overIcon() : justIcon();
	auto position = _st.iconPosition;
	if (position.x() < 0) {
		position.setX((width() - icon->width()) / 2);
	}
	if (position.y() < 0) {
		position.setY((height() - icon->height()) / 2);
	}
	icon->paint(p, position, width());
	if (overIconOpacity > 0. && overIconOpacity < 1.) {
		auto iconOver = overIcon();
		if (iconOver != icon) {
			p.setOpacity(overIconOpacity);
			iconOver->paint(p, position, width());
		}
	}
}

void IconButton::onStateChanged(State was, StateChangeSource source) {
	RippleButton::onStateChanged(was, source);

	auto over = isOver();
	auto wasOver = static_cast<bool>(was & StateFlag::Over);
	if (over != wasOver) {
		if (_st.duration) {
			auto from = over ? 0. : 1.;
			auto to = over ? 1. : 0.;
			_a_over.start([this] { update(); }, from, to, _st.duration);
		} else {
			update();
		}
	}
}

QPoint IconButton::prepareRippleStartPosition() const {
	auto result = mapFromGlobal(QCursor::pos())
		- _st.rippleAreaPosition;
	auto rect = QRect(0, 0, _st.rippleAreaSize, _st.rippleAreaSize);
	return rect.contains(result)
		? result
		: DisabledRippleStartPosition();
}

QImage IconButton::prepareRippleMask() const {
	return RippleAnimation::ellipseMask(QSize(_st.rippleAreaSize, _st.rippleAreaSize));
}

CrossButton::CrossButton(QWidget *parent, const style::CrossButton &st) : RippleButton(parent, st.ripple)
, _st(st)
, _loadingAnimation([=](crl::time now) { return loadingCallback(now); }) {
	resize(_st.width, _st.height);
	setCursor(style::cur_pointer);
	setVisible(false);
}

bool CrossButton::loadingCallback(crl::time now) {
	const auto result = !stopLoadingAnimation(now);
	if (!result || !anim::Disabled()) {
		update();
	}
	return result;
}

void CrossButton::toggle(bool visible, anim::type animated) {
	if (_shown != visible) {
		_shown = visible;
		if (animated == anim::type::normal) {
			if (isHidden()) {
				setVisible(true);
			}
			_showAnimation.start(
				[=] { animationCallback(); },
				_shown ? 0. : 1.,
				_shown ? 1. : 0.,
				_st.duration);
		}
	}
	if (animated == anim::type::instant) {
		finishAnimating();
	}
}

void CrossButton::animationCallback() {
	update();
	if (!_showAnimation.animating()) {
		setVisible(_shown);
	}
}

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

	auto over = isOver();
	auto shown = _showAnimation.value(_shown ? 1. : 0.);
	p.setOpacity(shown);

	paintRipple(p, _st.crossPosition);

	auto loading = 0.;
	if (_loadingAnimation.animating()) {
		const auto now = crl::now();
		if (stopLoadingAnimation(now)) {
			_loadingAnimation.stop();
		} else if (anim::Disabled()) {
			CrossAnimation::paintStaticLoading(
				p,
				_st.cross,
				over ? _st.crossFgOver : _st.crossFg,
				_st.crossPosition.x(),
				_st.crossPosition.y(),
				width(),
				shown);
			return;
		} else {
			loading = ((now - _loadingAnimation.started())
				% _st.loadingPeriod) / float64(_st.loadingPeriod);
		}
	}
	CrossAnimation::paint(
		p,
		_st.cross,
		over ? _st.crossFgOver : _st.crossFg,
		_st.crossPosition.x(),
		_st.crossPosition.y(),
		width(),
		shown,
		loading);
}

bool CrossButton::stopLoadingAnimation(crl::time now) {
	if (!_loadingStopMs) {
		return false;
	}
	const auto stopPeriod = (_loadingStopMs - _loadingAnimation.started())
		/ _st.loadingPeriod;
	const auto currentPeriod = (now - _loadingAnimation.started())
		/ _st.loadingPeriod;
	if (currentPeriod != stopPeriod) {
		Assert(currentPeriod > stopPeriod);
		return true;
	}
	return false;
}

void CrossButton::setLoadingAnimation(bool enabled) {
	if (enabled) {
		_loadingStopMs = 0;
		if (!_loadingAnimation.animating()) {
			_loadingAnimation.start();
		}
	} else if (_loadingAnimation.animating()) {
		_loadingStopMs = crl::now();
		if (!((_loadingStopMs - _loadingAnimation.started())
			% _st.loadingPeriod)) {
			_loadingAnimation.stop();
		}
	}
	if (anim::Disabled()) {
		update();
	}
}

void CrossButton::onStateChanged(State was, StateChangeSource source) {
	RippleButton::onStateChanged(was, source);

	auto over = isOver();
	auto wasOver = static_cast<bool>(was & StateFlag::Over);
	if (over != wasOver) {
		update();
	}
}

QPoint CrossButton::prepareRippleStartPosition() const {
	return mapFromGlobal(QCursor::pos()) - _st.crossPosition;
}

QImage CrossButton::prepareRippleMask() const {
	return RippleAnimation::ellipseMask(QSize(_st.cross.size, _st.cross.size));
}

SettingsButton::SettingsButton(
	QWidget *parent,
	rpl::producer<QString> &&text)
: SettingsButton(parent, std::move(text), st::defaultSettingsButton) {
}

SettingsButton::SettingsButton(
	QWidget *parent,
	rpl::producer<QString> &&text,
	const style::SettingsButton &st)
: RippleButton(parent, st.ripple)
, _st(st) {
	std::move(
		text
	) | rpl::start_with_next([this](QString &&value) {
		setText(std::move(value));
	}, lifetime());
}

SettingsButton *SettingsButton::toggleOn(rpl::producer<bool> &&toggled) {
	Expects(_toggle == nullptr);
	_toggle = std::make_unique<Ui::ToggleView>(
		isOver() ? _st.toggleOver : _st.toggle,
		false,
		[this] { rtlupdate(toggleRect()); });
	addClickHandler([this] {
		_toggle->setChecked(!_toggle->checked(), anim::type::normal);
	});
	std::move(
		toggled
	) | rpl::start_with_next([this](bool toggled) {
		_toggle->setChecked(toggled, anim::type::normal);
	}, lifetime());
	_toggle->finishAnimating();
	return this;
}

bool SettingsButton::toggled() const {
	return _toggle ? _toggle->checked() : false;
}

rpl::producer<bool> SettingsButton::toggledChanges() const {
	if (_toggle) {
		return _toggle->checkedChanges();
	}
	return nullptr;
}

rpl::producer<bool> SettingsButton::toggledValue() const {
	if (_toggle) {
		return _toggle->checkedValue();
	}
	return nullptr;
}

void SettingsButton::setColorOverride(std::optional<QColor> textColorOverride) {
	_textColorOverride = textColorOverride;
	update();
}

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

	auto paintOver = (isOver() || isDown()) && !isDisabled();
	p.fillRect(e->rect(), paintOver ? _st.textBgOver : _st.textBg);

	paintRipple(p, 0, 0);

	auto outerw = width();
	p.setFont(_st.font);
	p.setPen(_textColorOverride
		? QPen(*_textColorOverride)
		: paintOver
		? _st.textFgOver
		: _st.textFg);
	p.drawTextLeft(
		_st.padding.left(),
		_st.padding.top(),
		outerw,
		_text,
		_textWidth);

	if (_toggle) {
		auto rect = toggleRect();
		_toggle->paint(p, rect.left(), rect.top(), outerw);
	}
}

QRect SettingsButton::toggleRect() const {
	Expects(_toggle != nullptr);

	auto size = _toggle->getSize();
	auto left = width() - _st.toggleSkip - size.width();
	auto top = (height() - size.height()) / 2;
	return { QPoint(left, top), size };
}

int SettingsButton::resizeGetHeight(int newWidth) {
	updateVisibleText(newWidth);
	return _st.padding.top() + _st.height + _st.padding.bottom();
}

void SettingsButton::onStateChanged(
		State was,
		StateChangeSource source) {
	if (!isDisabled() || !isDown()) {
		RippleButton::onStateChanged(was, source);
	}
	if (_toggle) {
		_toggle->setStyle(isOver() ? _st.toggleOver : _st.toggle);
	}
	setPointerCursor(!isDisabled());
}

void SettingsButton::setText(QString &&text) {
	_original = std::move(text);
	_originalWidth = _st.font->width(_original);
	updateVisibleText(width());
}

void SettingsButton::updateVisibleText(int newWidth) {
	auto availableWidth = newWidth
		- _st.padding.left()
		- _st.padding.right();
	if (_toggle) {
		availableWidth -= (width() - toggleRect().x());
	}
	accumulate_max(availableWidth, 0);
	if (availableWidth < _originalWidth) {
		_text = _st.font->elided(_original, availableWidth);
		_textWidth = _st.font->width(_text);
	} else {
		_text = _original;
		_textWidth = _originalWidth;
	}
	update();
}

} // namespace Ui
