from PySide6.QtCore import Qt, QObject, Signal
from PySide6.QtGui import QPen, QBrush, QColor
from PySide6.QtWidgets import QApplication, QGraphicsScene, QGraphicsView, QGraphicsEllipseItem, QGraphicsLineItem


class CustomEllipseItem(QGraphicsEllipseItem, QObject):
  clicked = Signal()

  def __init__(self, x, y, width, height, pen_circle, brush_circle, parent=None):
    super().__init__(0, 0, width, height, parent)
    QObject.__init__(self)

    self.setPen(pen_circle)
    self.setBrush(brush_circle)
    self.setPos(x - 50, y - 50)
    self.setFlag(QGraphicsEllipseItem.ItemIsMovable, True)
    self.setFlag(QGraphicsEllipseItem.ItemIsSelectable, True)

  def mousePressEvent(self, event):
    super().mousePressEvent(event)
    self.clicked.emit()


class GraphicsDrawer(QGraphicsView):
  def __init__(self, graphics_view):
    super().__init__()

    self.graphics_view = graphics_view
    self.scene = QGraphicsScene()
    self.graphics_view.setScene(self.scene)

    pen_circle = QPen(Qt.red)
    pen_circle.setWidth(2)
    brush_circle = QBrush(QColor(255, 0, 0, 100))

    circle_item1 = CustomEllipseItem(0, 0, 100, 100, pen_circle, brush_circle)
    circle_item2 = CustomEllipseItem(150, 0, 100, 100, pen_circle, brush_circle)

    self.scene.addItem(circle_item1)
    self.scene.addItem(circle_item2)

    circle_item1.clicked.connect(lambda: self.handle_click(circle_item1, circle_item2))
    circle_item2.clicked.connect(lambda: self.handle_release(circle_item1, circle_item2))

  def handle_click(self, item_pressed, item_released):
    print(f"{item_pressed} pressed")

  def handle_release(self, item_pressed, item_released):
    print(f"{item_released} released")
    self.create_connection(item_pressed, item_released)

  def create_connection(self, item_pressed, item_released):
    pen_line = QPen(Qt.green)
    pen_line.setWidth(2)
    line_item = QGraphicsLineItem(item_pressed.pos().x() + 50, item_pressed.pos().y() + 50,
                                  item_released.pos().x() + 50, item_released.pos().y() + 50)
    line_item.setPen(pen_line)
    self.scene.addItem(line_item)


if __name__ == "__main__":
  app = QApplication([])

  view = QGraphicsView()
  drawer = GraphicsDrawer(view)
  view.show()

  app.exec()