/*
    TikZiT - a GUI diagram editor for TikZ
    Copyright (C) 2018 Aleks Kissinger

    This program 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.

    This program 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.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <https://www.gnu.org/licenses/>.
*/

#include "tikzit.h"
#include "nodeitem.h"
#include "tikzscene.h"
#include "util.h"
#include <cmath>

#include <QPen>
#include <QApplication>
#include <QBrush>
#include <QDebug>
#include <QFont>
#include <QFontMetrics>
#include <QPainterPathStroker>

NodeItem::NodeItem(Node *node)
{
    _node = node;
    setFlag(QGraphicsItem::ItemIsSelectable);
    //setFlag(QGraphicsItem::ItemIsMovable);
    //setFlag(QGraphicsItem::ItemSendsGeometryChanges);
    readPos();
	updateBounds();
}

void NodeItem::readPos()
{
    setPos(toScreen(_node->point()));
}

void NodeItem::writePos()
{
    _node->setPoint(fromScreen(pos()));
}

QRectF NodeItem::labelRect() const {
    QString label = replaceTexConstants(_node->label());
    QFontMetrics fm(Tikzit::LABEL_FONT);
    QRectF rect = fm.boundingRect(label);
    rect.moveCenter(QPointF(0,0));
    return rect;
}

QRectF NodeItem::outerLabelRect() const {
    QString label = replaceTexConstants(_node->data()->property("label"));
    label.replace(QRegularExpression("^[^:]*:"), "");
    QFontMetrics fm(Tikzit::LABEL_FONT);
    QRectF rect = fm.boundingRect(label);
    rect.moveCenter(QPointF(0, -0.5 * GLOBAL_SCALEF));
    return rect;
}

void NodeItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *, QWidget *)
{
    if (_node->style()->isNone()) {
        QColor c(180,180,200);
        painter->setPen(QPen(c));
        painter->setBrush(QBrush(c));
        painter->drawEllipse(QPointF(0,0), 1,1);

        QPen pen(QColor(180,180,220));
        QVector<qreal> p;
        p << 1.0 << 2.0;
        pen.setDashPattern(p);
		pen.setWidthF(2.0);
        painter->setPen(pen);
        painter->setBrush(Qt::NoBrush);
        painter->drawPath(shape());
    } else {
        QPen pen(_node->style()->strokeColor());
        pen.setWidth(_node->style()->strokeThickness());
        painter->setPen(pen);
        painter->setBrush(QBrush(_node->style()->fillColor()));
        painter->drawPath(shape());
    }

    if (_node->label() != "") {
        QRectF rect = labelRect();
        QPen pen(QColor(200,0,0,120));
        QVector<qreal> d;
        d << 2.0 << 2.0;
        pen.setDashPattern(d);
        painter->setPen(pen);
        painter->setBrush(QBrush(QColor(255,255,100,120)));
        painter->drawRect(rect);

        painter->setPen(QPen(Qt::black));
        painter->setFont(Tikzit::LABEL_FONT);
        painter->drawText(rect, Qt::AlignCenter, replaceTexConstants(_node->label()));
    }

    if (_node->data()->hasProperty("label")) {
        QString label = replaceTexConstants(_node->data()->property("label"));
        label.replace(QRegularExpression("^[^:]*:"), "");

        QRectF rect = outerLabelRect();
        QPen pen(QColor(0,0,200,120));
        QVector<qreal> d;
        d << 2.0 << 2.0;
        pen.setDashPattern(d);
        painter->setPen(pen);
        painter->setBrush(QBrush(QColor(100,255,255,120)));
        painter->drawRect(rect);

        painter->setPen(QPen(Qt::black));
        painter->setFont(Tikzit::LABEL_FONT);
        painter->drawText(rect, Qt::AlignCenter, label);
    }

    if (isSelected()) {
        QPainterPath sh = shape();
        QPainterPathStroker stroker;
        stroker.setWidth(4);
        QPainterPath outline = (stroker.createStroke(sh) + sh).simplified();
        painter->setPen(Qt::NoPen);
        painter->setBrush(QBrush(QColor(150,200,255,100)));
        painter->drawPath(outline);
    }

}

QPainterPath NodeItem::shape() const
{
    QPainterPath path;

	if (_node->style()->shape() == "rectangle") {
        path.addRect(-0.2 * GLOBAL_SCALEF, -0.2 * GLOBAL_SCALEF, 0.4 * GLOBAL_SCALEF, 0.4 * GLOBAL_SCALEF);
	} else {
        path.addEllipse(QPointF(0, 0), GLOBAL_SCALEF * 0.2, GLOBAL_SCALEF * 0.2);
	}
    return path;
}

// TODO: nodeitem should sync boundingRect()-relevant stuff (label etc) explicitly,
// to allow prepareGeometryChange()
QRectF NodeItem::boundingRect() const
{
	return _boundingRect;
}

void NodeItem::updateBounds()
{
	prepareGeometryChange();
	QString label = _node->label();
    QString outerLabel = _node->data()->property("label");
    QRectF rect = shape().boundingRect();
	if (label != "") rect = rect.united(labelRect());
    if (outerLabel != "") rect = rect.united(outerLabelRect());
    _boundingRect = rect.adjusted(-4, -4, 4, 4);
}

Node *NodeItem::node() const
{
    return _node;
}

//QVariant NodeItem::itemChange(GraphicsItemChange change, const QVariant &value)
//{
//    if (change == ItemPositionChange) {
//        QPointF newPos = value.toPointF();
//        int gridSize = GLOBAL_SCALE / 8;
//        QPointF gridPos(round(newPos.x()/gridSize)*gridSize, round(newPos.y()/gridSize)*gridSize);
//        _node->setPoint(fromScreen(gridPos));
//
//        return gridPos;
//    } else {
//        return QGraphicsItem::itemChange(change, value);
//    }
//}