"""
Entrypoint worker arq – PecFlow IMAP Sync Engine.

Avvio: python -m app.main

Cosa fa:
  1. Connette a Redis tramite arq
  2. on_startup → avvia MailboxPool (N task IMAP asincroni)
  3. on_shutdown → ferma MailboxPool
  4. Registra job arq (sync_mailbox, future: send_pec, archive_batch, ecc.)
  5. Loop arq per processare job dalla coda Redis

L'event loop è condiviso tra arq e MailboxPool (asyncio task).
"""

import asyncio
import logging
import sys
from typing import Any

import redis.asyncio as aioredis
from arq import run_worker
from arq.connections import RedisSettings

from app.config import get_settings
from app.imap.pool import MailboxPool
from app.jobs.sync_mailbox import sync_mailbox
from app.storage.minio_client import ensure_bucket_exists

settings = get_settings()

# Logging
logging.basicConfig(
    level=getattr(logging, settings.log_level.upper(), logging.INFO),
    format="%(asctime)s [%(levelname)s] %(name)s: %(message)s",
    stream=sys.stdout,
)
logger = logging.getLogger(__name__)

# Pool globale (accessibile dalle callback)
_mailbox_pool: MailboxPool | None = None


# ─── Lifecycle callbacks arq ──────────────────────────────────────────────────

async def on_startup(ctx: dict[str, Any]) -> None:
    """
    Inizializzazione worker all'avvio.
    Avvia il MailboxPool con tutte le caselle attive.
    """
    global _mailbox_pool

    logger.info("🚀 PecFlow Worker avviato")
    logger.info(f"  DB:    {settings.database_url.split('@')[-1]}")
    logger.info(f"  Redis: {settings.redis_url}")
    logger.info(f"  MinIO: {settings.minio_endpoint}")

    # Verifica/crea bucket MinIO
    try:
        await ensure_bucket_exists()
    except Exception as e:
        logger.warning(f"MinIO non disponibile al startup: {e}")

    # Crea client Redis condiviso
    redis_client = aioredis.from_url(settings.redis_url, decode_responses=True)
    ctx["redis"] = redis_client

    # Avvia MailboxPool
    _mailbox_pool = MailboxPool(redis_client=redis_client)
    ctx["mailbox_pool"] = _mailbox_pool
    await _mailbox_pool.start()

    logger.info(
        f"✅ Worker pronto: {_mailbox_pool.active_count} caselle IMAP attive"
    )


async def on_shutdown(ctx: dict[str, Any]) -> None:
    """Cleanup all'arresto del worker."""
    global _mailbox_pool

    logger.info("🛑 PecFlow Worker in arresto...")

    pool = ctx.get("mailbox_pool") or _mailbox_pool
    if pool:
        await pool.stop()

    redis_client = ctx.get("redis")
    if redis_client:
        await redis_client.aclose()

    logger.info("🛑 Worker fermato")


# ─── Worker health check ──────────────────────────────────────────────────────

async def health_check(ctx: dict[str, Any]) -> dict:
    """
    Job speciale per health check del worker.
    Può essere chiamato da monitoring esterno.
    """
    pool: MailboxPool | None = ctx.get("mailbox_pool")
    return {
        "status": "ok",
        "active_imap_connections": pool.active_count if pool else 0,
    }


# ─── WorkerSettings arq ───────────────────────────────────────────────────────

def _parse_redis_settings() -> RedisSettings:
    """Parsa REDIS_URL in RedisSettings arq."""
    url = settings.redis_url
    # Supporta redis://host:port/db e redis://user:pass@host:port/db
    import urllib.parse
    parsed = urllib.parse.urlparse(url)

    host = parsed.hostname or "localhost"
    port = parsed.port or 6379
    db = int(parsed.path.lstrip("/") or "0")
    password = parsed.password or None

    return RedisSettings(host=host, port=port, database=db, password=password)


class WorkerSettings:
    """Configurazione del worker arq."""

    # Funzioni/job registrati
    functions = [sync_mailbox, health_check]

    # Callbacks lifecycle
    on_startup = on_startup
    on_shutdown = on_shutdown

    # Redis
    redis_settings = _parse_redis_settings()

    # Concorrenza
    max_jobs = 20

    # Timeout per ogni job (secondi)
    job_timeout = 300

    # Retry automatico in caso di errore
    max_tries = 3

    # Polling interval (arq controlla la coda ogni N ms)
    poll_delay = 0.5

    # Keep job results per N secondi
    keep_result = 3600


# ─── Entrypoint ───────────────────────────────────────────────────────────────

if __name__ == "__main__":
    logger.info("Avvio PecFlow Worker (arq)...")
    run_worker(WorkerSettings)