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

from __future__ import annotations

import asyncio
import shlex
import sys
from collections.abc import AsyncIterator
from pathlib import Path

import pytest

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) -> tuple[ScreenService, asyncio.Task[None]]:
    service = ScreenService(bus, config)
    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