control.py

"""Thread-safe bridge between the HomeKit accessory and the display loop.

The pyhap driver runs in its own thread and mutates this object from setter
callbacks; the main loop reads it every tick. Keep it tiny and lock-guarded so
neither side can see a half-updated value. No third-party deps, so the app
imports cleanly whether or not HomeKit is installed.
"""

from __future__ import annotations

import threading


class DisplayControl:
    """Shared on/off + brightness state for the display.

    ``enabled`` is whether the time is shown at all (False blanks the 7-seg to
    extend its life). ``brightness`` is the HT16K33 dimming level (0-15), the
    same scale as Config.brightness.
    """

    def __init__(self, *, enabled: bool = True, brightness: int = 3) -> None:
        self._lock = threading.Lock()
        self._enabled = bool(enabled)
        self._brightness = self._clamp(brightness)

    @staticmethod
    def _clamp(level: int) -> int:
        return max(0, min(15, int(level)))

    @property
    def enabled(self) -> bool:
        with self._lock:
            return self._enabled

    @enabled.setter
    def enabled(self, value: bool) -> None:
        with self._lock:
            self._enabled = bool(value)

    @property
    def brightness(self) -> int:
        with self._lock:
            return self._brightness

    @brightness.setter
    def brightness(self, level: int) -> None:
        with self._lock:
            self._brightness = self._clamp(level)