from __future__ import annotations

from collections.abc import Callable

from PySide6.QtCore import QObject
from PySide6.QtMultimedia import QVideoFrame


class FrameDispatcher(QObject):
    def __init__(self, parent: QObject | None = None) -> None:
        super().__init__(parent)
        self._subscribers: list[Callable[[QVideoFrame], None]] = []

    def subscribe(self, callback: Callable[[QVideoFrame], None]) -> None:
        self._subscribers.append(callback)

    def unsubscribe(self, callback: Callable[[QVideoFrame], None]) -> None:
        self._subscribers.remove(callback)

    def on_frame(self, frame: QVideoFrame) -> None:
        for cb in self._subscribers:
            cb(frame)