#include "mainwindow.h"
#include "ui_mainwindow.h"

#include <QDrag>
#include <QMimeData>
#include <QMetaObject>
#include <QGraphicsSceneDragDropEvent>
#include <QAbstractGraphicsShapeItem>
#include <QFileDialog>
#include <QApplication>

/* ---------------------------------------------------------------------- */

void dragEnter (QGraphicsSceneDragDropEvent *event)
{
    const QMimeData * data = event->mimeData();
    if (data->hasText() || data->hasColor())
        event->setAccepted(true);
}

void drop (QGraphicsSceneDragDropEvent *event, QAbstractGraphicsShapeItem * target)
{
    const QMimeData * data = event->mimeData();
    if (data->hasColor())
    {
       QColor c = qvariant_cast <QColor> ( data->colorData() );
       Qt::DropAction action = event->proposedAction();
       if (action == Qt::MoveAction)
          target->setPen (c);
       else
          target->setBrush (c);
    }
    if (data->hasText())
    {
        QString s = data->text ();
        QGraphicsTextItem * item = new QGraphicsTextItem;
        item->setDefaultTextColor(QColor ("lime"));
        item->setFont (QFont ("Sans Serif", 20));
        item->setPlainText (s);
        item->setFlags (QGraphicsItem::ItemIsMovable | QGraphicsItem::ItemIsSelectable);
        item->setParentItem (target);
    }

}

/* ---------------------------------------------------------------------- */

void Ellipse::dragEnterEvent (QGraphicsSceneDragDropEvent *event)
{
    dragEnter (event);
}

void Ellipse::dropEvent (QGraphicsSceneDragDropEvent *event)
{
    drop (event, this);
}

void Ellipse::readXmlShape (QXmlStreamReader & r)
{
    int x = 0;
    int y = 0;
    int w = 40;
    int h = 40;
    QColor p = QColor ("blue");
    QColor b = QColor ("orange");

    QXmlStreamAttributes a = r.attributes();

    if (a.hasAttribute("x")) x = a.value("x").toInt();
    if (a.hasAttribute("y")) y = a.value("y").toInt();
    if (a.hasAttribute("w")) w = a.value("w").toInt();
    if (a.hasAttribute("h")) h = a.value("h").toInt();
    if (a.hasAttribute("pen")) p = QColor (a.value("pen").toString());
    if (a.hasAttribute("brush")) b = QColor (a.value("brush").toString());

    setRect (x, y, w, h);
    setPen (p);
    setBrush (b);
}

void Ellipse::writeXmlShape (QXmlStreamWriter & w)
{
    w.writeAttribute ("x", QString::number (this->x()));
    w.writeAttribute ("y", QString::number (this->y()));
    w.writeAttribute ("tooltip", this->toolTip());

    w.writeAttribute("w", QString::number (this->boundingRect().width()));
    w.writeAttribute("h", QString::number (this->boundingRect().height()));
    w.writeAttribute("pen", this->pen().color().name());
    w.writeAttribute("brush", this->brush().color().name());
}


Ellipse::Ellipse ()
{
    setAcceptDrops (true);

    /*
    // QLinearGradient d (0, 0, 200, 100);
    QRadialGradient d (100, 100, 100, 100, 50);
    d.setColorAt(0.0, QColor ("yellow"));
    d.setColorAt (1.0, QColor ("blue"));
    QBrush b (d);
    setBrush (b);
    */

    setBrush (QColor ("yellow"));
    setRect (0, 0, 200, 100);
    setFlags (QGraphicsItem::ItemIsMovable | QGraphicsItem::ItemIsSelectable);
}

/* ---------------------------------------------------------------------- */

void Rectangle::dragEnterEvent (QGraphicsSceneDragDropEvent *event)
{
    dragEnter (event);
}

void Rectangle::dropEvent (QGraphicsSceneDragDropEvent *event)
{
    drop (event, this);
}

void Rectangle::readXmlShape (QXmlStreamReader & r)
{
    int x = 0;
    int y = 0;
    int w = 40;
    int h = 40;
    QColor p = QColor ("blue");
    QColor b = QColor ("orange");

    QXmlStreamAttributes a = r.attributes();

    if (a.hasAttribute("x")) x = a.value("x").toInt();
    if (a.hasAttribute("y")) y = a.value("y").toInt();
    if (a.hasAttribute("w")) w = a.value("w").toInt();
    if (a.hasAttribute("h")) h = a.value("h").toInt();
    if (a.hasAttribute("pen")) p = QColor (a.value("pen").toString());
    if (a.hasAttribute("brush")) b = QColor (a.value("brush").toString());

    setRect (x, y, w, h);
    setPen (p);
    setBrush (b);
}

void Rectangle::writeXmlShape (QXmlStreamWriter & w)
{
    w.writeAttribute ("x", QString::number (this->x()));
    w.writeAttribute ("y", QString::number (this->y()));
    w.writeAttribute ("tooltip", this->toolTip());

    w.writeAttribute("w", QString::number (this->boundingRect().width()));
    w.writeAttribute("h", QString::number (this->boundingRect().height()));
    w.writeAttribute("pen", this->pen().color().name());
    w.writeAttribute("brush", this->brush().color().name());
}

Rectangle::Rectangle ()
{
    setAcceptDrops (true);
    setBrush (QColor ("yellow"));
    setRect (0, 0, 100, 100);
    setFlags (QGraphicsItem::ItemIsMovable | QGraphicsItem::ItemIsSelectable);
}

/* ---------------------------------------------------------------------- */

QPixmap image (int size, QColor color)
{
   QPixmap p (size, size);
   p.fill (Qt::transparent);
   QPainter t (&p);
   t.setPen (color);
   t.setBrush (color);
   t.drawEllipse (1, 1, size-2, size-2);
   return p;
}

QIcon mark (QColor color)
{
    return QIcon (image (32, color));
}

ColorButton::ColorButton (QColor c)
   : color (c)
{
   setIcon (mark (color));
}

void ColorButton::mousePressEvent(QMouseEvent *event)
{
    QMimeData * data = new QMimeData;
    data->setColorData (color);
    QDrag * drag = new QDrag (this);
    drag->setPixmap (image (16, color));
    drag->setHotSpot (QPoint (10, 10));
    drag->setMimeData(data);
    drag->start (Qt::CopyAction | Qt::MoveAction | Qt::LinkAction);
}

/* ---------------------------------------------------------------------- */

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    QStringList names;
    names << "red" << "green" << "blue" << "yellow" << "orange";
    int x = 0;
    for (QString name : names)
    {
        QColor color (name);
        ColorButton * b = new ColorButton (color);
        b->setToolTip (name);
        b->setParent (ui->colorTab);
        b->move (x, 0);
        x += 36;
    }

    QGraphicsScene * scene = new QGraphicsScene;
    ui->graphicsView->setScene (scene);
    scene->addLine (0, 0, 100, 100, QColor ("red"));

    scene->addItem (new Ellipse);

    for (int i = 1; i <= 3; i++)
    {
        QGraphicsRectItem * r = new QGraphicsRectItem;
        r->setRect (0, 0, 40, 40);
        r->setPos (40 + 10*i, 40+10*i);
        r->setPen (QColor ("blue"));
        r->setBrush(QColor::fromHsv (60*i, 255, 255));
        r->setToolTip ("Muj obdelnik " + QString::number (i));
        r->setFlags (QGraphicsItem::ItemIsMovable | QGraphicsItem::ItemIsSelectable);
        scene->addItem (r);
    }
}

MainWindow::~MainWindow()
{
    delete ui;
}

void MainWindow::on_action_Quit_triggered()
{
    close ();
}

/* ---------------------------------------------------------------------- */

void MainWindow::on_action_Run_triggered()
{
    QGraphicsScene * scene = ui->graphicsView->scene();

    ui->treeWidget->clear();
    for (QGraphicsItem * item : scene->items ())
    {
        QString s = QString::number (item->x()) + "," +
                    QString::number (item->y()) + ": " +
                    item->toolTip();

        TreeItem * node = new TreeItem;
        node->obj = item;
        node->setText (0, s);
        ui->treeWidget->addTopLevelItem (node);
    }
}

void MainWindow::showText (int line, QString name, QString value)
{
    QTableWidgetItem * a = new QTableWidgetItem;
    a->setText (name);
    ui->tableWidget->setItem (line, 0, a);

    QTableWidgetItem * b = new QTableWidgetItem;
    b->setText (value);
    ui->tableWidget->setItem (line, 1, b);
}

void MainWindow::showNumber (int line, QString name, int value)
{
    QTableWidgetItem * a = new QTableWidgetItem;
    a->setText (name);
    ui->tableWidget->setItem (line, 0, a);

    QTableWidgetItem * b = new QTableWidgetItem;
    b->setData (Qt::EditRole, value);
    ui->tableWidget->setItem (line, 1, b);
}

void MainWindow::showColor (int line, QString name, QColor value)
{
    QTableWidgetItem * a = new QTableWidgetItem;
    a->setText (name);
    ui->tableWidget->setItem (line, 0, a);

    QTableWidgetItem * b = new QTableWidgetItem;
    b->setText (value.name());
    b->setData (Qt::DecorationRole, value);
    ui->tableWidget->setItem (line, 1, b);
}

void MainWindow::on_treeWidget_itemClicked(QTreeWidgetItem *item, int column)
{
    TreeItem * node = dynamic_cast <TreeItem*> (item);
    if (node != nullptr)
    {
        ui->graphicsView->scene()->clearSelection();
        node->obj->setSelected (true);
        ui->statusBar->showMessage ("item selected: " + node->obj->toolTip());

        ui->tableWidget->clearContents();
        ui->tableWidget->setColumnCount(2);
        ui->tableWidget->setRowCount(5);

        int x = node->obj->x();
        int y = node->obj->y();

        showNumber (0, "x", x);
        showNumber (1, "y", y);
        showText (2, "tooltip", node->obj->toolTip());

        QAbstractGraphicsShapeItem * p = dynamic_cast <QAbstractGraphicsShapeItem *> (node->obj);
        if (p != nullptr)
        {
            showColor (3, "pen", p->pen().color());
            showColor (4, "brush", p->brush().color());
        }
    }

}

/* ---------------------------------------------------------------------- */

void MainWindow::readXml (QXmlStreamReader & r)
{
    QGraphicsItem * target = nullptr;
    while (!r.atEnd())
    {
        r.readNext ();
        if (r.isStartElement())
        {
            QString name = r.name().toString();
            QGraphicsItem * item = nullptr;

            if (name == "image") { }
            else if (name == "ellipse")
            {
                Ellipse * e = new Ellipse;
                e->readXmlShape (r);
                item = e;
            }
            else if (name == "rectangle")
            {
                Rectangle * e = new Rectangle;
                e->readXmlShape (r);
                item = e;
            }

            if (item != nullptr)
            {
                if (target == NULL)
                    ui->graphicsView->scene()->addItem (item);
                else
                   item->setParentItem(target);
                target = item;
            }
        }
        else if (r.isStartElement())
        {
            if (target != nullptr)
                target = target->parentItem();
        }
    }
}

void MainWindow::writeXml (QXmlStreamWriter & w)
{
    w.setAutoFormatting(true);
    w.writeStartDocument();
    w.writeStartElement("image");

    QGraphicsScene * scene = ui->graphicsView->scene();
    for (QGraphicsItem * item : scene->items ())
    {
        QString name = "item";

        Ellipse * e = dynamic_cast <Ellipse*> (item);
        Rectangle * f = dynamic_cast <Rectangle*> (item);

        QGraphicsRectItem * r = dynamic_cast <QGraphicsRectItem*> (item);
        QGraphicsLineItem * c = dynamic_cast <QGraphicsLineItem*> (item);
        QGraphicsTextItem * t = dynamic_cast <QGraphicsTextItem*> (item);
        if (e != nullptr) name = "ellipse";
        if (f != nullptr) name = "rectangle";
        if (r != nullptr) name = "rectangle";
        if (c != nullptr) name = "line";
        if (t != nullptr) name = "text";
        QAbstractGraphicsShapeItem * s = dynamic_cast <QAbstractGraphicsShapeItem*> (item);

        w.writeStartElement(name);

        if (e != nullptr)
            e->writeXmlShape(w);
        else if (f != nullptr)
            f->writeXmlShape(w);
        else
        {

            w.writeAttribute("x", QString::number (item->x()));
            w.writeAttribute("y", QString::number (item->y()));
            w.writeAttribute("tooltip", item->toolTip());

            if (s != nullptr)
            {
                w.writeAttribute("w", QString::number (s->boundingRect().width()));
                w.writeAttribute("h", QString::number (s->boundingRect().height()));
                w.writeAttribute("pen", s->pen().color().name());
                w.writeAttribute("brush", s->brush().color().name());
            }

            if (c != nullptr)
            {
                w.writeAttribute("x2", QString::number (c->line().x2()));
                w.writeAttribute("y2", QString::number (c->line().y2()));
                w.writeAttribute("pen", c->pen().color().name());
            }

            if (t != nullptr)
            {
                w.writeAttribute("text", t->toPlainText());
                w.writeAttribute("color", t->defaultTextColor().name());
            }
        }

        w.writeEndElement();
    }

    w.writeEndElement();
    w.writeEndDocument();
}

void MainWindow::on_actionOpen_triggered()
{
    QString fileName = QFileDialog::getOpenFileName (this, "Open image data");
    if (fileName != "")
    {
        QFile f (fileName);
        if (f.open (QFile::ReadOnly | QFile::Text))
        {
           QXmlStreamReader r (&f);
           readXml (r);
           f.close ();
        }
    }
}

void MainWindow::on_actionSave_triggered()
{
    QString fileName = QFileDialog::getSaveFileName(this, "Save image data");
    if (fileName != "")
    {
        ui->statusBar->showMessage ("Save to " + fileName);
        QFile f (fileName);
        if (f.open (QFile::WriteOnly | QFile::Text))
        {
           QXmlStreamWriter w (&f);
           writeXml (w);
           f.close ();
        }
    }
}

/* ---------------------------------------------------------------------- */

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;
    w.show();

    return a.exec();
}