"""Daily joke generation job with retry/backoff and stale-fallback semantics."""
import logging
from datetime import date, datetime, timedelta, timezone
from zoneinfo import ZoneInfo

from . import db
from .config import settings
from .llm_client import generate_jokes
from .wiki_client import get_featured_article

log = logging.getLogger("jokes.generator")

# In-process retry bookkeeping (resets on container restart; cold-start
# generation covers the restart case anyway).
_attempts_today: dict[str, int] = {}
_last_failure: dict[str, datetime] = {}


def today_local() -> date:
    return datetime.now(ZoneInfo(settings.timezone)).date()


def _attempt_key(day: date) -> str:
    return day.isoformat()


def generation_exhausted(day: date) -> bool:
    """True while in cooldown: max attempts hit and the last failure is
    younger than SLOW_RETRY_MINUTES. After the cooldown passes, the daily
    retry loop resumes at the slow interval — so a cold/down LLM endpoint
    at 06:00 no longer kills the whole day."""
    if _attempts_today.get(_attempt_key(day), 0) < settings.max_attempts:
        return False
    last = _last_failure.get(_attempt_key(day))
    if last is None:
        return True
    age = datetime.now(timezone.utc) - last
    return age < timedelta(minutes=settings.slow_retry_minutes)


def run_generation() -> bool:
    """Try to generate today's jokes. Returns True on success."""
    day = today_local()
    if db.get_day(day) is not None:
        log.info("Jokes for %s already exist, skipping", day)
        return True

    if generation_exhausted(day):
        # In cooldown after max attempts; will resume after slow_retry_minutes.
        return False

    _attempts_today[_attempt_key(day)] = _attempts_today.get(_attempt_key(day), 0) + 1
    try:
        article = get_featured_article(day)
        log.info("Fetched featured article: %s", article.title)
        jokes = generate_jokes(article.title, article.extract)
        db.save_batch(day, article.title, article.url, jokes)
        log.info("Saved %d jokes for %s", len(jokes), day)
        return True
    except Exception as exc:  # noqa: BLE001 — job must never crash the scheduler
        used = _attempts_today[_attempt_key(day)]
        _last_failure[_attempt_key(day)] = datetime.now(timezone.utc)
        log.error(
            "Generation attempt %d for %s failed: %s (cooldown %d min before next try)",
            used, day, exc, settings.slow_retry_minutes,
        )
        return False


def next_retry_delay() -> timedelta:
    return timedelta(minutes=settings.retry_minutes)