import sys

from PyQt6.QtWidgets import (
    QApplication,
    QWidget,
    QHBoxLayout,
    QSpinBox,
    QLabel,
    QLineEdit,
)
from PyQt6.QtGui import QFont


class Window(QWidget):
    def __init__(self) -> None:
        super().__init__()
        self.setGeometry(*(500,) * 4)
        self.setWindowTitle("Окно")
        self.price = 300
        self.amount = 0

        hbox = QHBoxLayout()

        self.line_edit = QLineEdit(str(self.price))
        self.line_edit.setFont(QFont("Times", 14))

        self.spin_box = QSpinBox()
        self.spin_box.valueChanged.connect(self.handle_spin_box)
        self.result = QLabel(str(self.total))

        hbox.addWidget(self.line_edit)
        hbox.addWidget(self.spin_box)
        hbox.addWidget(self.result)

        self.setLayout(hbox)

    def handle_spin_box(self) -> None:
        try:
            self.price = int(self.line_edit.text())
        except ValueError:
            return
        self.amount = self.spin_box.value()
        self.result.setText(str(self.total))

    @property
    def total(self) -> int:
        return self.amount * self.price

    def handle_line_edit(self) -> None:
        pass


def main() -> None:
    app = QApplication(sys.argv)
    window = Window()
    window.show()
    sys.exit(app.exec())


if __name__ == "__main__":
    main()