"""
Melde-Briefkasten der Box (Lucy-Proaktivität, Faden A3).

Alles, was die Box dem Commander aktiv sagen will (Health-Wächter, Auto-Updates,
Radar, Hermes-cron via notify.sh), landet als Eintrag hier. Die Lucy-Desktop-App
pollt `/api/voice/announcements` und SPRICHT neue Einträge von sich aus.

Persistenz als JSON neben den Modellen (übersteht Deploys/Neustarts, wie der
Discover-Cache). Bewusst klein: fortlaufende IDs als Cursor, Ring der letzten
MAX_ITEMS Einträge, ein Lock für die FastAPI-Threadpool-Worker.
"""

import json
import logging
import os
import threading
import time
from pathlib import Path

from config import MODELS_DIR

log = logging.getLogger(__name__)

STORE_PATH = Path(os.environ.get("MC_ANNOUNCE_STORE", str(MODELS_DIR / "mc2-announce.json")))
MAX_ITEMS = int(os.environ.get("MC_ANNOUNCE_MAX", "200"))

_lock = threading.Lock()
_state: dict | None = None   # {"next_id": int, "items": [...]}


def _load() -> dict:
    global _state
    if _state is None:
        try:
            _state = json.loads(STORE_PATH.read_text(encoding="utf-8"))
            assert isinstance(_state.get("next_id"), int) and isinstance(_state.get("items"), list)
        except Exception:
            _state = {"next_id": 1, "items": []}
    return _state


def _save(state: dict) -> None:
    try:
        tmp = STORE_PATH.with_suffix(".tmp")
        tmp.write_text(json.dumps(state, ensure_ascii=False), encoding="utf-8")
        tmp.replace(STORE_PATH)
    except OSError:
        # Briefkasten darf den Absender nie blockieren — dann eben nur in-memory.
        log.warning("announce: Store %s nicht schreibbar", STORE_PATH, exc_info=True)


def add(text: str, subject: str = "", source: str = "", priority: str = "normal") -> dict:
    """Eintrag anhängen. priority: 'normal' (sprechen) | 'silent' (nur Verlauf/Panel)."""
    text = (text or "").strip()
    if not text:
        raise ValueError("Leere Meldung.")
    with _lock:
        state = _load()
        item = {
            "id": state["next_id"],
            "ts": time.time(),
            "subject": (subject or "").strip()[:120],
            "text": text[:4000],
            "source": (source or "").strip()[:60],
            "priority": priority if priority in ("normal", "silent") else "normal",
        }
        state["next_id"] += 1
        state["items"].append(item)
        del state["items"][:-MAX_ITEMS]
        _save(state)
    log.info("announce #%s [%s] %s: %.80s", item["id"], item["source"] or "-", item["subject"] or "-", text)
    return item


def list_after(after: int | None, limit: int = 20) -> dict:
    """Einträge NACH Cursor `after` (aufsteigend). Ohne Cursor nur den aktuellen
    Stand liefern (latest) — so initialisiert Lucy ihren Cursor, ohne Altes nachzuplappern."""
    with _lock:
        state = _load()
        latest = state["next_id"] - 1
        items = [] if after is None else [i for i in state["items"] if i["id"] > after][: max(1, min(limit, 100))]
    return {"latest": latest, "items": items}