Screen: switch off by itself when nothing is going on

With `general.screen.off_command` set, the monitor switches off once nothing has
played and nobody has done anything for `auto_off_minutes` (15 by default, 0 for
never, editable in parent mode). "Doing anything" is any intent a person could
have caused: a remote key, a web command, or a key press or tap in the kiosk,
which the page reports at most every 30s via POST /api/screen/activity. The first
such intent after an auto-off runs `on_command`, so the remote wakes the screen
too. The auto-off itself is silent; switches a person asks for still blubb.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

python-backend/tests/test_screen.py

@@ -15,8 +15,18 @@ import pytest
 
 from musicmouse.blubb import RATE, blubb_wav
 from musicmouse.bus import EventBus
+from musicmouse.clock import FakeClock
+from musicmouse.color import ColorRGBW
 from musicmouse.config import ScreenConfig
-from musicmouse.events import ToggleScreenRequested
+from musicmouse.effects import EffectStaticConfig
+from musicmouse.events import (
+    LedEffectRequested,
+    PlaybackChanged,
+    PlayRemoteSlotRequested,
+    ToggleScreenRequested,
+    UserActivity,
+)
+from musicmouse.hardware import LedZone
 from musicmouse.services.screen import ScreenService
 
 
@@ -184,3 +194,157 @@ async def test_no_blubb(
         task.cancel()
 
     assert not Path(f"{fake_aplay}.wav").exists()
+
+
+# ------------------------------------------------------------------- idle auto-off
+
+
+class _Idle:
+    """A started service with a fake clock and an ``off`` and ``on`` command that log."""
+
+    def __init__(self, bus: EventBus, tmp_path: Path, **config: object) -> None:
+        self.bus = bus
+        self.off_log = tmp_path / "off"
+        self.on_log = tmp_path / "on"
+        self.playing = False
+        self.clock = FakeClock(idle=bus.drain)
+        settings: dict[str, object] = {
+            "toggle_command": _python("print('toggled')"),
+            "off_command": _appending(self.off_log, then="print('off')"),
+            "on_command": _appending(self.on_log, then="print('on')"),
+            "auto_off_minutes": 15,
+        }
+        settings.update(config)
+        self.service = ScreenService(
+            bus,
+            ScreenConfig.model_validate(settings),
+            alsa_device=None,
+            volume=lambda: 0.5,
+            is_playing=lambda: self.playing,
+            clock=self.clock,
+        )
+        self.task: asyncio.Task[None] | None = None
+
+    async def __aenter__(self) -> _Idle:
+        self.task = asyncio.create_task(self.service.run())
+        await asyncio.sleep(0)
+        return self
+
+    async def __aexit__(self, *_: object) -> None:
+        assert self.task is not None
+        self.task.cancel()
+
+    async def wait(self, minutes: float) -> None:
+        await self.clock.advance(minutes * 60)
+        await _settle(self.service)
+
+    def offs(self) -> int:
+        return len(self.off_log.read_text().splitlines()) if self.off_log.exists() else 0
+
+    def ons(self) -> int:
+        return len(self.on_log.read_text().splitlines()) if self.on_log.exists() else 0
+
+
+async def test_the_screen_goes_off_after_the_idle_time(bus: EventBus, tmp_path: Path) -> None:
+    async with _Idle(bus, tmp_path) as idle:
+        await idle.wait(14)
+        assert idle.offs() == 0
+        await idle.wait(1)
+        assert idle.offs() == 1
+        await idle.wait(60)
+        assert idle.offs() == 1  # once, not every half minute after
+
+
+async def test_not_while_music_plays(bus: EventBus, tmp_path: Path) -> None:
+    async with _Idle(bus, tmp_path) as idle:
+        idle.playing = True
+        await idle.wait(60)
+        assert idle.offs() == 0
+
+        # The countdown starts when the music stops.
+        idle.playing = False
+        await bus.emit_and_wait(PlaybackChanged(playing=False, source="player"))
+        await idle.wait(14)
+        assert idle.offs() == 0
+        await idle.wait(1)
+        assert idle.offs() == 1
+
+
+@pytest.mark.parametrize(
+    "event",
+    [UserActivity(source="web"), PlayRemoteSlotRequested(digit="3", source="lirc")],
+)
+async def test_activity_restarts_the_countdown(
+    bus: EventBus, tmp_path: Path, event: UserActivity | PlayRemoteSlotRequested
+) -> None:
+    async with _Idle(bus, tmp_path) as idle:
+        await idle.wait(10)
+        await bus.emit_and_wait(event)
+        await idle.wait(10)
+        assert idle.offs() == 0
+        await idle.wait(5)
+        assert idle.offs() == 1
+
+
+async def test_automations_do_not_count_as_activity(bus: EventBus, tmp_path: Path) -> None:
+    async with _Idle(bus, tmp_path) as idle:
+        await idle.wait(10)
+        effect = EffectStaticConfig(ColorRGBW(0, 0, 0, 0))
+        automation = LedEffectRequested(zone=LedZone.MOUSE, effect=effect, source="mqtt")
+        await bus.emit_and_wait(automation)
+        await idle.wait(5)
+        assert idle.offs() == 1
+
+
+async def test_someone_coming_back_switches_it_on(bus: EventBus, tmp_path: Path) -> None:
+    async with _Idle(bus, tmp_path) as idle:
+        await idle.wait(15)
+        assert idle.offs() == 1
+
+        await bus.emit_and_wait(UserActivity(source="web"))
+        await _settle(idle.service)
+        await bus.emit_and_wait(UserActivity(source="web"))
+        await _settle(idle.service)
+        assert idle.ons() == 1  # only the first wakes it
+
+        await idle.wait(15)
+        assert idle.offs() == 2  # and the countdown runs again
+
+
+async def test_the_power_key_after_an_auto_off_is_left_to_the_toggle(
+    bus: EventBus, tmp_path: Path
+) -> None:
+    async with _Idle(bus, tmp_path) as idle:
+        await idle.wait(15)
+        await bus.emit_and_wait(ToggleScreenRequested(source="lirc"))
+        await _settle(idle.service)
+        await bus.emit_and_wait(UserActivity(source="web"))
+        await _settle(idle.service)
+        assert idle.ons() == 0
+
+
+async def test_zero_minutes_means_never(bus: EventBus, tmp_path: Path) -> None:
+    async with _Idle(bus, tmp_path, auto_off_minutes=0) as idle:
+        await idle.wait(600)
+        assert idle.offs() == 0
+
+
+async def test_no_off_command_means_never(bus: EventBus, tmp_path: Path) -> None:
+    async with _Idle(bus, tmp_path, off_command=None) as idle:
+        await idle.wait(600)
+        assert idle.offs() == 0
+
+
+async def test_a_new_idle_time_applies_at_once(bus: EventBus, tmp_path: Path) -> None:
+    async with _Idle(bus, tmp_path) as idle:
+        idle.service.config.auto_off_minutes = 5  # what parent mode does
+        await idle.wait(5)
+        assert idle.offs() == 1
+
+
+async def test_the_auto_off_is_silent(bus: EventBus, tmp_path: Path, fake_aplay: Path) -> None:
+    async with _Idle(bus, tmp_path) as idle:
+        idle.service.alsa_device = "softvol_effects"
+        await idle.wait(15)
+        assert idle.offs() == 1
+    assert not Path(f"{fake_aplay}.wav").exists()