musicmouse/python-backend/tests/test_screen.py

"""The screen service: runs the configured command per toggle, and never takes the bus down."""

from __future__ import annotations

import asyncio
import io
import os
import shlex
import sys
import wave
from collections.abc import AsyncIterator
from pathlib import Path

import pytest

from musicmouse.blubb import RATE, blubb_wav
from musicmouse.bus import EventBus
from musicmouse.config import ScreenConfig
from musicmouse.events import ToggleScreenRequested
from musicmouse.services.screen import ScreenService


def _python(code: str) -> str:
    return f"{shlex.quote(sys.executable)} -c {shlex.quote(code)}"


def _appending(log: Path, *, then: str = "") -> str:
    """A command that appends a line to ``log`` each time it runs."""
    return _python(f"open({str(log)!r}, 'a').write('ran\\n'); {then}")


@pytest.fixture
async def bus() -> AsyncIterator[EventBus]:
    async with EventBus() as bus:
        yield bus


async def _settle(service: ScreenService) -> None:
    while service._running is not None and not service._running.done():
        await asyncio.sleep(0.01)


async def _started(
    bus: EventBus,
    config: ScreenConfig,
    *,
    alsa_device: str | None = None,
    volume: float = 0.5,
) -> tuple[ScreenService, asyncio.Task[None]]:
    service = ScreenService(bus, config, alsa_device=alsa_device, volume=lambda: volume)
    task = asyncio.create_task(service.run())
    await asyncio.sleep(0)  # let it subscribe
    return service, task


async def test_each_press_runs_the_command(bus: EventBus, tmp_path: Path) -> None:
    log = tmp_path / "ran"
    service, task = await _started(bus, ScreenConfig(toggle_command=_appending(log)))
    try:
        for _ in range(2):
            await bus.emit_and_wait(ToggleScreenRequested(source="lirc"))
            await _settle(service)
    finally:
        task.cancel()

    assert log.read_text() == "ran\nran\n"


async def test_a_press_while_the_command_runs_is_ignored(bus: EventBus, tmp_path: Path) -> None:
    log = tmp_path / "ran"
    command = _appending(log, then="import time; time.sleep(0.3)")
    service, task = await _started(bus, ScreenConfig(toggle_command=command))
    try:
        await bus.emit_and_wait(ToggleScreenRequested(source="lirc"))
        await bus.emit_and_wait(ToggleScreenRequested(source="lirc"))
        await _settle(service)
    finally:
        task.cancel()

    assert log.read_text() == "ran\n"


async def test_a_failing_command_is_logged(bus: EventBus, caplog: pytest.LogCaptureFixture) -> None:
    command = _python("import sys; print('no display'); sys.exit(3)")
    service, task = await _started(bus, ScreenConfig(toggle_command=command))
    try:
        await bus.emit_and_wait(ToggleScreenRequested(source="lirc"))
        await _settle(service)
    finally:
        task.cancel()

    assert "exit 3" in caplog.text
    assert "no display" in caplog.text


async def test_a_missing_command_is_logged(
    bus: EventBus, caplog: pytest.LogCaptureFixture, tmp_path: Path
) -> None:
    service, task = await _started(
        bus, ScreenConfig(toggle_command=str(tmp_path / "no-such-command"))
    )
    try:
        await bus.emit_and_wait(ToggleScreenRequested(source="lirc"))
        await _settle(service)
    finally:
        task.cancel()

    assert "could not start" in caplog.text


async def test_a_hung_command_is_killed(bus: EventBus, caplog: pytest.LogCaptureFixture) -> None:
    command = _python("import time; time.sleep(30)")
    service, task = await _started(bus, ScreenConfig(toggle_command=command, timeout=0.2))
    try:
        await bus.emit_and_wait(ToggleScreenRequested(source="lirc"))
        await asyncio.wait_for(_settle(service), 5)
    finally:
        task.cancel()

    assert "killed" in caplog.text


# ------------------------------------------------------------------------ the blubb


def test_the_blubb_is_a_short_mono_wav() -> None:
    with wave.open(io.BytesIO(blubb_wav(on=True, gain=0.5))) as wav:
        assert (wav.getnchannels(), wav.getsampwidth(), wav.getframerate()) == (1, 2, RATE)
        assert 0.1 < wav.getnframes() / RATE < 0.5


def test_on_and_off_sound_different() -> None:
    assert blubb_wav(on=True, gain=0.5) != blubb_wav(on=False, gain=0.5)


@pytest.fixture
def fake_aplay(tmp_path: Path, monkeypatch: pytest.MonkeyPatch) -> Path:
    """An ``aplay`` on PATH that records its arguments and what it was fed."""
    bin_dir = tmp_path / "bin"
    bin_dir.mkdir()
    record = tmp_path / "aplay"
    script = bin_dir / "aplay"
    script.write_text(
        f'#!/bin/sh\necho "$@" > {shlex.quote(str(record))}.args\n'
        f"cat > {shlex.quote(str(record))}.wav\n"
    )
    script.chmod(0o755)
    monkeypatch.setenv("PATH", f"{bin_dir}:{os.environ['PATH']}")
    return record


async def test_a_switch_plays_the_blubb_its_way(bus: EventBus, fake_aplay: Path) -> None:
    service, task = await _started(
        bus, ScreenConfig(toggle_command=_python("print('off')")), alsa_device="softvol_effects"
    )
    try:
        await bus.emit_and_wait(ToggleScreenRequested(source="lirc"))
        await _settle(service)
    finally:
        task.cancel()

    assert Path(f"{fake_aplay}.args").read_text().split() == ["-q", "-D", "softvol_effects", "-"]
    assert Path(f"{fake_aplay}.wav").read_bytes() == blubb_wav(on=False, gain=0.35 * 0.5)


@pytest.mark.parametrize(
    ("output", "alsa_device", "volume"),
    [
        ("print('on')", None, 0.5),  # simulated audio
        ("print('on')", "softvol_effects", 0.0),  # muted
        ("print('done')", "softvol_effects", 0.5),  # no direction to go by
    ],
)
async def test_no_blubb(
    bus: EventBus, fake_aplay: Path, output: str, alsa_device: str | None, volume: float
) -> None:
    service, task = await _started(
        bus, ScreenConfig(toggle_command=_python(output)), alsa_device=alsa_device, volume=volume
    )
    try:
        await bus.emit_and_wait(ToggleScreenRequested(source="lirc"))
        await _settle(service)
    finally:
        task.cancel()

    assert not Path(f"{fake_aplay}.wav").exists()