#include "TextField.h"

#include <QApplication>
#include <QEventTransition>
#include <QFontDatabase>
#include <QPaintEvent>
#include <QPainter>
#include <QPropertyAnimation>

TextField::TextField(QWidget *parent)
    : QLineEdit(parent)
{
	state_machine_ = new TextFieldStateMachine(this);
	label_ = 0;
	label_font_size_ = 9.5;
	show_label_ = false;
	background_color_ = QColor("white");

	setFrame(false);
	setAttribute(Qt::WA_Hover);
	setMouseTracking(true);
	setTextMargins(0, 2, 0, 4);

	QFontDatabase db;
	QFont font(db.font("Open Sans", "Regular", 11));
	setFont(font);

	state_machine_->start();
	QCoreApplication::processEvents();
}

TextField::~TextField()
{
}

void TextField::setBackgroundColor(const QColor &color)
{
	background_color_ = color;
}

QColor TextField::backgroundColor() const
{
	return background_color_;
}

void TextField::setShowLabel(bool value)
{
	if (show_label_ == value) {
		return;
	}

	show_label_ = value;

	if (!label_ && value) {
		label_ = new TextFieldLabel(this);
		state_machine_->setLabel(label_);
	}

	if (value) {
		setContentsMargins(0, 23, 0, 0);
	} else {
		setContentsMargins(0, 0, 0, 0);
	}
}

bool TextField::hasLabel() const
{
	return show_label_;
}

void TextField::setLabelFontSize(qreal size)
{
	label_font_size_ = size;

	if (label_) {
		QFont font(label_->font());
		font.setPointSizeF(size);
		label_->setFont(font);
		label_->update();
	}
}

qreal TextField::labelFontSize() const
{
	return label_font_size_;
}

void TextField::setLabel(const QString &label)
{
	label_text_ = label;
	setShowLabel(true);
	label_->update();
}

QString TextField::label() const
{
	return label_text_;
}

void TextField::setTextColor(const QColor &color)
{
	text_color_ = color;
	setStyleSheet(QString("QLineEdit { color: %1; }").arg(color.name()));
}

QColor TextField::textColor() const
{
	if (!text_color_.isValid()) {
		return QColor("black");
	}

	return text_color_;
}

void TextField::setLabelColor(const QColor &color)
{
	label_color_ = color;
}

QColor TextField::labelColor() const
{
	if (!label_color_.isValid()) {
		return QColor("#abb");  // TODO: Move this into Theme.h
	}

	return label_color_;
}

void TextField::setInkColor(const QColor &color)
{
	ink_color_ = color;
}

QColor TextField::inkColor() const
{
	if (!ink_color_.isValid()) {
		return QColor("black");
	}

	return ink_color_;
}

void TextField::setUnderlineColor(const QColor &color)
{
	underline_color_ = color;
}

QColor TextField::underlineColor() const
{
	if (!underline_color_.isValid()) {
		return QColor("black");
	}

	return underline_color_;
}

bool TextField::event(QEvent *event)
{
	switch (event->type()) {
	case QEvent::Resize:
	case QEvent::Move: {
		if (label_)
			label_->setGeometry(rect());
		break;
	}
	default:
		break;
	}

	return QLineEdit::event(event);
}

void TextField::paintEvent(QPaintEvent *event)
{
	QLineEdit::paintEvent(event);

	QPainter painter(this);

	if (text().isEmpty()) {
		painter.setOpacity(1 - state_machine_->progress());
		//painter.fillRect(rect(), parentWidget()->palette().color(backgroundRole()));
		painter.fillRect(rect(), backgroundColor());
	}

	const int y = height() - 1;
	const int wd = width() - 5;

	QPen pen;
	pen.setWidth(1);
	pen.setColor(underlineColor());
	painter.setPen(pen);
	painter.setOpacity(1);
	painter.drawLine(2, y, wd, y);

	QBrush brush;
	brush.setStyle(Qt::SolidPattern);
	brush.setColor(inkColor());

	const qreal progress = state_machine_->progress();

	if (progress > 0) {
		painter.setPen(Qt::NoPen);
		painter.setBrush(brush);
		const int w = (1 - progress) * static_cast<qreal>(wd / 2);
		painter.drawRect(w + 2.5, height() - 2, wd - 2 * w, 2);
	}
}

TextFieldStateMachine::TextFieldStateMachine(TextField *parent)
    : QStateMachine(parent), text_field_(parent)
{
	normal_state_ = new QState;
	focused_state_ = new QState;

	label_ = 0;
	offset_anim_ = 0;
	color_anim_ = 0;
	progress_ = 0.0;

	addState(normal_state_);
	addState(focused_state_);

	setInitialState(normal_state_);

	QEventTransition *transition;
	QPropertyAnimation *animation;

	transition = new QEventTransition(parent, QEvent::FocusIn);
	transition->setTargetState(focused_state_);
	normal_state_->addTransition(transition);

	animation = new QPropertyAnimation(this, "progress", this);
	animation->setEasingCurve(QEasingCurve::InCubic);
	animation->setDuration(310);
	transition->addAnimation(animation);

	transition = new QEventTransition(parent, QEvent::FocusOut);
	transition->setTargetState(normal_state_);
	focused_state_->addTransition(transition);

	animation = new QPropertyAnimation(this, "progress", this);
	animation->setEasingCurve(QEasingCurve::OutCubic);
	animation->setDuration(310);
	transition->addAnimation(animation);

	normal_state_->assignProperty(this, "progress", 0);
	focused_state_->assignProperty(this, "progress", 1);

	setupProperties();

	connect(text_field_, SIGNAL(textChanged(QString)), this, SLOT(setupProperties()));
}

TextFieldStateMachine::~TextFieldStateMachine()
{
}

void TextFieldStateMachine::setLabel(TextFieldLabel *label)
{
	if (label_) {
		delete label_;
	}

	if (offset_anim_) {
		removeDefaultAnimation(offset_anim_);
		delete offset_anim_;
	}

	if (color_anim_) {
		removeDefaultAnimation(color_anim_);
		delete color_anim_;
	}

	label_ = label;

	if (label_) {
		offset_anim_ = new QPropertyAnimation(label_, "offset", this);
		offset_anim_->setDuration(210);
		offset_anim_->setEasingCurve(QEasingCurve::OutCubic);
		addDefaultAnimation(offset_anim_);

		color_anim_ = new QPropertyAnimation(label_, "color", this);
		color_anim_->setDuration(210);
		addDefaultAnimation(color_anim_);
	}

	setupProperties();
}

void TextFieldStateMachine::setupProperties()
{
	if (label_) {
		const int m = text_field_->textMargins().top();

		if (text_field_->text().isEmpty()) {
			normal_state_->assignProperty(label_, "offset", QPointF(0, 26));
		} else {
			normal_state_->assignProperty(label_, "offset", QPointF(0, 0 - m));
		}

		focused_state_->assignProperty(label_, "offset", QPointF(0, 0 - m));
		focused_state_->assignProperty(label_, "color", text_field_->inkColor());
		normal_state_->assignProperty(label_, "color", text_field_->labelColor());

		if (0 != label_->offset().y() && !text_field_->text().isEmpty()) {
			label_->setOffset(QPointF(0, 0 - m));
		} else if (!text_field_->hasFocus() && label_->offset().y() <= 0 && text_field_->text().isEmpty()) {
			label_->setOffset(QPointF(0, 26));
		}
	}

	text_field_->update();
}

TextFieldLabel::TextFieldLabel(TextField *parent)
    : QWidget(parent), text_field_(parent)
{
	x_ = 0;
	y_ = 26;
	scale_ = 1;
	color_ = parent->labelColor();

	QFontDatabase db;
	QFont font(db.font("Open Sans", "Medium", parent->labelFontSize()));
	font.setLetterSpacing(QFont::PercentageSpacing, 102);
	setFont(font);
}

TextFieldLabel::~TextFieldLabel()
{
}

void TextFieldLabel::paintEvent(QPaintEvent *)
{
	if (!text_field_->hasLabel())
		return;

	QPainter painter(this);
	painter.setRenderHint(QPainter::Antialiasing);
	painter.scale(scale_, scale_);
	painter.setPen(color_);
	painter.setOpacity(1);

	QPointF pos(2 + x_, height() - 36 + y_);
	painter.drawText(pos.x(), pos.y(), text_field_->label());
}