// Self-termination for the e2e fake binaries: no fixture should be able to
// outlive the run that spawned it, whatever happens to the server above it.
//
// The app-side fixes (cancelling live jobs before the registry is wiped, and on
// graceful shutdown) cover every case where something is still alive to send a
// signal. This covers the case where nothing is: a SIGKILLed dev server can't
// run shutdown code, so its children reparent and keep spinning. A full suite
// once left 27 of these alive at ~29% of a core each — enough to saturate the
// box, push load to 46, and turn a 30-minute suite with 1 failure into a
// 1.3-hour suite with 13 failures that all looked like real regressions.
//
// Two independent triggers, because neither alone is sufficient:
//
//   1. Reparenting — our parent died. Checked as "ppid changed since startup",
//      NOT "ppid === 1": on a systemd-user box (this one) a child subreaper
//      adopts orphans, so the pid-1 test would silently never fire.
//   2. A max-lifetime backstop, for the case where the parent is alive but
//      wedged. The longest legitimate fixture life is 30s
//      (fake-parakeet-stitch's completion backstop, and fake-ytdlp --test-slow,
//      which jobs-retry/jobs-reorder/queues specs rely on), so the default 120s
//      leaves 4x margin. Override with E2E_FIXTURE_MAX_LIFETIME_MS if a future
//      fixture legitimately needs longer.
//
// BOTH timers are unref'd. That is the load-bearing detail: a ref'd timer would
// hold the event loop open and keep an otherwise-finished fixture alive — this
// module would then create exactly the leak it exists to prevent.

const POLL_MS = 1_000;
const DEFAULT_MAX_LIFETIME_MS = 120_000;

export function installFixtureWatchdog() {
  const label = process.argv[1]?.split("/").pop() ?? "fixture";
  const initialPpid = process.ppid;

  const poll = setInterval(() => {
    // process.ppid is re-read from the OS on each access, so this observes the
    // reparent rather than a value cached at startup.
    if (process.ppid !== initialPpid) {
      process.stderr.write(
        `[watchdog] ${label}: parent ${initialPpid} died (now ${process.ppid}) — exiting rather than orphaning\n`,
      );
      process.exit(1);
    }
  }, POLL_MS);
  poll.unref();

  const maxLifetimeMs =
    Number(process.env.E2E_FIXTURE_MAX_LIFETIME_MS) || DEFAULT_MAX_LIFETIME_MS;
  const backstop = setTimeout(() => {
    process.stderr.write(
      `[watchdog] ${label}: exceeded ${maxLifetimeMs}ms lifetime — exiting\n`,
    );
    process.exit(1);
  }, maxLifetimeMs);
  backstop.unref();
}