"""Recurring worker-tier jobs: keep the curated city set warm and ping IndexNow
on a schedule, so neither needs a human to run it after every deploy anymore.

Only the process that already won leader election for the notifier runs this
too (gated by the same check in web/app.py's _lifespan) — APScheduler has no
cross-host coordination of its own, so running it unguarded on every worker
replica would repeat every job once per replica, same reason the notifier
itself needs a leader.

APScheduler, not a Postgres-native queue: there is exactly one process that
ever runs this, no fan-out/backpressure/dead-letter need, and it needs no new
infrastructure. procrastinate/pgqueuer are the documented upgrade path if that
changes — see docs/architecture/repo-topology-and-infrastructure.md §7.
"""
import os

from apscheduler.schedulers.background import BackgroundScheduler

# How often the curated city set is (re-)warmed. warm_cities.py's own docstring
# frames it as a deploy-time script ("Run at/after deploy") because a warm cache
# mostly just stays warm; scheduling it periodically instead catches a newly
# added city, or one that fell out of cache, without waiting for the next
# deploy. Daily is plenty — every already-cached city is a cheap skip.
WARM_CITIES_INTERVAL_HOURS = int(os.environ.get("THERMOGRAPH_WARM_CITIES_INTERVAL_HOURS", "24") or 24)

# How often to check whether the indexable URL set changed and, if so, ping
# IndexNow. submit_if_changed() is a cheap no-op when nothing changed, so this
# can run more often than warm_cities without spending anything on most ticks.
INDEXNOW_INTERVAL_HOURS = int(os.environ.get("THERMOGRAPH_INDEXNOW_INTERVAL_HOURS", "6") or 6)

_scheduler: "BackgroundScheduler | None" = None


def _warm_cities_job() -> None:
    import warm_cities   # local import: a script-style top-level module — only
                          # pay its import cost on the process that runs the job
    warm_cities.main()


def _indexnow_job() -> None:
    import indexnow
    indexnow.submit_if_changed()


def start() -> None:
    """Start the scheduler (idempotent, mirroring notify.start()). The caller is
    responsible for the leader-election gate — see web/app.py's _lifespan."""
    global _scheduler
    if _scheduler is not None:
        return
    sched = BackgroundScheduler(daemon=True)
    # No next_run_time override: the default first run is one interval from now,
    # not immediately — warm_cities already runs at deploy time (warm_cities.py /
    # the deploy hook), so an immediate duplicate run on every worker boot/restart
    # would just be wasted work.
    sched.add_job(_warm_cities_job, "interval", hours=WARM_CITIES_INTERVAL_HOURS,
                 id="warm_cities")
    sched.add_job(_indexnow_job, "interval", hours=INDEXNOW_INTERVAL_HOURS,
                 id="indexnow")
    sched.start()
    _scheduler = sched


def stop() -> None:
    global _scheduler
    if _scheduler is not None:
        _scheduler.shutdown(wait=False)
        _scheduler = None