"""Remplit servers.domain_ltd via resolution DNS.

Pour chaque serveur sans domain_ltd, essaye de resoudre hostname.<suffix>
en testant les domaines SANEF. Le 1er qui resout gagne.

Ordre de test: sanef.groupe, sanef-rec.fr, serveur.est.sanef.fr, serveur.ouest.sanef.fr

Usage:
    python tools/fill_domain_ltd_by_dns.py [--dry-run] [--timeout 2]
"""
import os
import socket
import threading
import argparse
from sqlalchemy import create_engine, text

DATABASE_URL = os.getenv("DATABASE_URL_DEMO") or os.getenv("DATABASE_URL") \
    or "postgresql://patchcenter:PatchCenter2026!@localhost:5432/patchcenter_demo"

SUFFIXES = [
    "sanef.groupe",
    "sanef-rec.fr",
    "serveur.est.sanef.fr",
    "serveur.ouest.sanef.fr",
    "sanef.fr",
]


def resolve(hostname, suffix, timeout):
    """Retourne True si hostname.suffix resout en DNS, timeout via thread."""
    fqdn = f"{hostname}.{suffix}"
    result = [False]

    def _do():
        try:
            socket.gethostbyname(fqdn)
            result[0] = True
        except Exception:
            result[0] = False

    t = threading.Thread(target=_do, daemon=True)
    t.start()
    t.join(timeout)
    return result[0]


def main():
    parser = argparse.ArgumentParser()
    parser.add_argument("--dry-run", action="store_true")
    parser.add_argument("--timeout", type=float, default=2.0)
    args = parser.parse_args()

    engine = create_engine(DATABASE_URL)
    print(f"[INFO] DB: {DATABASE_URL.split('@')[-1]}")
    conn = engine.connect().execution_options(isolation_level="AUTOCOMMIT")

    rows = conn.execute(text("""
        SELECT id, hostname FROM servers
        WHERE (domain_ltd IS NULL OR domain_ltd = '')
        ORDER BY hostname
    """)).fetchall()
    print(f"[INFO] {len(rows)} serveurs sans domain_ltd")

    updated = skipped = 0
    for i, r in enumerate(rows, 1):
        h = (r.hostname or "").strip()
        if not h:
            skipped += 1
            continue
        print(f"  [{i}/{len(rows)}] Resolve {h}...", flush=True)
        found = None
        for suffix in SUFFIXES:
            if resolve(h, suffix, args.timeout):
                found = suffix
                break
        if not found:
            print(f"  [NO-DNS] {h}")
            skipped += 1
            continue
        if args.dry_run:
            print(f"  DRY: {h:25s} -> {found}")
        else:
            conn.execute(text("UPDATE servers SET domain_ltd=:d WHERE id=:sid"),
                         {"d": found, "sid": r.id})
        updated += 1

    conn.close()
    print(f"\n[DONE] Maj: {updated} | Skip (DNS KO): {skipped}")


if __name__ == "__main__":
    main()