"""Resolves directus_product_id -> slug, with periodic refresh.

Uses Directus REST API. Slug map is small (~75 entries) so we keep it
fully in-memory and refresh on a schedule (or on cache invalidation).
"""
import asyncio
import logging
import time

import httpx

from app.config import settings

log = logging.getLogger(__name__)

_slug_map: dict[int, str] = {}
_last_refresh: float = 0.0
_lock = asyncio.Lock()


async def refresh() -> int:
    """Pull product_id -> slug from Directus. Returns count."""
    global _slug_map, _last_refresh
    url = f"{settings.directus_url}/items/products"
    params = {
        "fields": "id,slug",
        "limit": -1,
        "filter[status][_eq]": "published",
    }
    try:
        async with httpx.AsyncClient(timeout=10) as client:
            resp = await client.get(url, params=params)
            resp.raise_for_status()
            data = resp.json().get("data", [])
        new_map = {
            int(item["id"]): item["slug"]
            for item in data
            if item.get("id") is not None and item.get("slug")
        }
        async with _lock:
            _slug_map = new_map
            _last_refresh = time.time()
        log.info("Slug map refreshed: %d entries", len(new_map))
        return len(new_map)
    except Exception as e:
        log.warning("Slug refresh failed: %s", e)
        return 0


async def get_slug(directus_product_id: int | None) -> str | None:
    if directus_product_id is None:
        return None
    # Lazy refresh if stale
    if time.time() - _last_refresh > settings.directus_slug_refresh_seconds:
        await refresh()
    return _slug_map.get(int(directus_product_id))


async def background_refresher():
    """Periodic background task — refresh slug map every N seconds."""
    while True:
        await asyncio.sleep(settings.directus_slug_refresh_seconds)
        try:
            await refresh()
        except Exception as e:
            log.warning("Background slug refresh error: %s", e)