"""Ends a spawned Chrome whose kernel died without closing it.

`spawn()` starts one of these beside each owned Chrome, reading a pipe the
kernel holds the only write end of. A kernel that closes its browser writes a
byte first, and this exits leaving everything alone. End of input without that
byte means the kernel died, SIGKILL included, where its atexit cleanup never
ran: Chrome's process group is ended, and its lock and temporary profile are
removed, so no headless Chrome outlives the kernel that started it.
"""

from __future__ import annotations

import asyncio
import os
from pathlib import Path
import select
import shutil
import sys

sys.path.insert(0, str(Path(__file__).resolve().parents[2]))

import albedo_proc  # noqa: E402

# How often a quiet pipe checks whether Chrome ended on its own.
POLL_SECONDS = 5


def main(pgid: int, leader: str, profile: Path, lock: Path, temporary: bool) -> None:
    group = albedo_proc.Group(pgid, leader or None)
    while True:
        ready, _, _ = select.select([0], [], [], POLL_SECONDS)
        if ready:
            if os.read(0, 1):
                return  # the kernel closed the browser itself
            break
        if not albedo_proc.alive(group):
            return  # Chrome ended; the kernel releases what it owned
    asyncio.run(albedo_proc.terminate([group], term=2.0))
    if temporary:
        shutil.rmtree(profile, ignore_errors=True)
    else:
        lock.unlink(missing_ok=True)


if __name__ == "__main__":
    main(
        int(sys.argv[1]),
        sys.argv[2],
        Path(sys.argv[3]),
        Path(sys.argv[4]),
        sys.argv[5] == "temporary",
    )