/*
This file is part of Telegram Desktop,
the official desktop version of Telegram messaging app, see https://telegram.org

Telegram Desktop is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

It is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.

In addition, as a special exception, the copyright holders give permission
to link the code of portions of this program with the OpenSSL library.

Full license: https://github.com/telegramdesktop/tdesktop/blob/master/LICENSE
Copyright (c) 2014-2016 John Preston, https://desktop.telegram.org
*/
#include "stdafx.h"
#include "ui/widgets/buttons.h"

namespace Ui {

FlatButton::FlatButton(QWidget *parent, const QString &text, const style::FlatButton &st) : AbstractButton(parent)
, _text(text)
, _st(st)
, a_over(0)
, _a_appearance(animation(this, &FlatButton::step_appearance)) {
	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);
	setCursor(_st.cursor);
}

void FlatButton::setOpacity(float64 o) {
	_opacity = o;
	update();
}

float64 FlatButton::opacity() const {
	return _opacity;
}

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

void FlatButton::setWidth(int32 w) {
	_width = w;
	if (_width < 0) {
		_width = textWidth() - _st.width;
	} else if (!_width) {
		_width = textWidth() + _st.height - _st.font->height;
	}
	resize(_width, height());
}

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

void FlatButton::step_appearance(float64 ms, bool timer) {
	float64 dt = ms / _st.duration;
	if (dt >= 1) {
		_a_appearance.stop();
		a_over.finish();
	} else {
		a_over.update(dt, anim::linear);
	}
	if (timer) update();
}

void FlatButton::onStateChanged(int oldState, StateChangeSource source) {
	a_over.start((_state & StateOver) ? 1. : 0.);
	if (source == StateChangeSource::ByUser || source == StateChangeSource::ByPress) {
		_a_appearance.stop();
		a_over.finish();
		update();
	} else {
		_a_appearance.start();
	}
}

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

	QRect r(0, height() - _st.height, width(), _st.height);

	p.setOpacity(_opacity);
	p.fillRect(r, anim::brush(_st.bgColor, _st.overBgColor, a_over.current()));

	p.setFont((_state & StateOver) ? _st.overFont : _st.font);
	p.setRenderHint(QPainter::TextAntialiasing);
	p.setPen(anim::pen(_st.color, _st.overColor, a_over.current()));

	int32 top = (_state & StateOver) ? ((_state & StateDown) ? _st.downTextTop : _st.overTextTop) : _st.textTop;
	r.setTop(top);

	p.drawText(r, _text, style::al_top);
}

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

int LinkButton::naturalWidth() const {
	return _textWidth;
}

void LinkButton::paintEvent(QPaintEvent *e) {
	Painter p(this);
	auto &font = ((_state & StateOver) ? _st.overFont : _st.font);
	auto &pen = ((_state & StateDown) ? _st.downColor : ((_state & StateOver) ? _st.overColor : _st.color));
	p.setFont(font);
	p.setPen(pen);
	if (_textWidth > width()) {
		p.drawText(0, font->ascent, font->elided(_text, width()));
	} else {
		p.drawText(0, font->ascent, _text);
	}
}

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

void LinkButton::onStateChanged(int oldState, StateChangeSource source) {
	update();
}

RoundButton::RoundButton(QWidget *parent, const QString &text, const style::RoundButton &st) : AbstractButton(parent)
, _fullText(text)
, _st(st) {
	setCursor(style::cur_pointer);
	updateText();
}

void RoundButton::setTextTransform(TextTransform transform) {
	_transform = transform;
	updateText();
}

void RoundButton::setText(const QString &text) {
	_fullText = text;
	updateText();
}

void RoundButton::setSecondaryText(const QString &secondaryText) {
	_fullSecondaryText = secondaryText;
	updateText();
}

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

void RoundButton::updateText() {
	if (_transform == TextTransform::ToUpper) {
		_text = _fullText.toUpper();
		_secondaryText = _fullSecondaryText.toUpper();
	} else {
		_text = _fullText;
		_secondaryText = _fullSecondaryText;
	}
	_textWidth = _text.isEmpty() ? 0 : _st.font->width(_text);
	_secondaryTextWidth = _secondaryText.isEmpty() ? 0 : _st.font->width(_secondaryText);

	resizeToText();
}

void RoundButton::resizeToText() {
	int innerWidth = contentWidth();
	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(_fullText, qMax(_st.width - (_st.height - _st.font->height), 1));
			innerWidth = _st.font->width(_text);
		}
		resize(_st.width + _st.padding.left() + _st.padding.right(), _st.height + _st.padding.top() + _st.padding.bottom());
	}
}

int RoundButton::contentWidth() const {
	int result = _textWidth + _secondaryTextWidth;
	if (_textWidth > 0 && _secondaryTextWidth > 0) {
		result += _st.secondarySkip;
	}
	return result;
}

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

	int innerWidth = contentWidth();
	auto rounded = rtlrect(rect().marginsRemoved(_st.padding), width());
	if (_fullWidthOverride < 0) {
		rounded = QRect(0, rounded.top(), innerWidth - _fullWidthOverride, rounded.height());
	}
	App::roundRect(p, rounded, _st.textBg, ImageRoundRadius::Small);

	auto over = (_state & StateOver);
	if (over) {
		App::roundRect(p, rounded, _st.textBgOver, ImageRoundRadius::Small);
	}

	p.setFont(_st.font);
	int textLeft = _st.padding.left() + ((width() - innerWidth - _st.padding.left() - _st.padding.right()) / 2);
	if (_fullWidthOverride < 0) {
		textLeft = -_fullWidthOverride / 2;
	}
	int textTopDelta = (_state & StateDown) ? (_st.downTextTop - _st.textTop) : 0;
	int textTop = _st.padding.top() + _st.textTop + textTopDelta;
	if (!_text.isEmpty()) {
		p.setPen(over ? _st.textFgOver : _st.textFg);
		p.drawTextLeft(textLeft, textTop, width(), _text);
	}
	if (!_secondaryText.isEmpty()) {
		textLeft += _textWidth + (_textWidth ? _st.secondarySkip : 0);
		p.setPen(over ? _st.secondaryTextFgOver : _st.secondaryTextFg);
		p.drawTextLeft(textLeft, textTop, width(), _secondaryText);
	}
	_st.icon.paint(p, QPoint(_st.padding.left(), _st.padding.right() + textTopDelta), width());
}

void RoundButton::onStateChanged(int oldState, StateChangeSource source) {
	update();
}

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

void IconButton::setIcon(const style::icon *icon, const style::icon *iconOver) {
	_iconOverride = icon;
	_iconOverrideOver = iconOver;
	update();
}

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

	auto over = _a_over.current(getms(), (_state & StateOver) ? 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 = (over == 1.) ? overIcon() : justIcon();
	auto position = (_state & StateDown) ? _st.iconPositionDown : _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 (over > 0. && over < 1.) {
		auto iconOver = overIcon();
		if (iconOver != icon) {
			p.setOpacity(over);
			iconOver->paint(p, position, width());
		}
	}
}

void IconButton::onStateChanged(int oldState, StateChangeSource source) {
	auto over = (_state & StateOver);
	if (over != (oldState & StateOver)) {
		if (_st.duration) {
			auto from = over ? 0. : 1.;
			auto to = over ? 1. : 0.;
			_a_over.start([this] { update(); }, from, to, _st.duration);
		} else {
			update();
		}
	}
}

} // namespace Ui