from __future__ import annotations

import argparse
import os
import signal
import time

import libtorrent as lt

from common import touch_ready


def settings_for(mode: str, port: int) -> dict:
    tcp = mode in ("plain", "mse")
    utp = mode in ("utp", "utp-mse")
    encrypted = mode in ("mse", "utp-mse")
    settings = {
        "listen_interfaces": f"0.0.0.0:{port}",
        "enable_dht": False,
        "enable_lsd": False,
        "enable_upnp": False,
        "enable_natpmp": False,
        "enable_outgoing_tcp": tcp,
        "enable_incoming_tcp": tcp,
        "enable_outgoing_utp": utp,
        "enable_incoming_utp": utp,
        "announce_to_all_trackers": False,
        "announce_to_all_tiers": False,
        "alert_mask": 0,
    }
    if encrypted:
        settings.update({
            "in_enc_policy": int(lt.enc_policy.forced),
            "out_enc_policy": int(lt.enc_policy.forced),
            "allowed_enc_level": int(lt.enc_level.rc4),
            "prefer_rc4": True,
        })
    else:
        settings.update({
            "in_enc_policy": int(lt.enc_policy.disabled),
            "out_enc_policy": int(lt.enc_policy.disabled),
        })
    return settings


def main() -> int:
    ap = argparse.ArgumentParser(description="Seed a fixture with libtorrent.")
    ap.add_argument("--torrent", required=True)
    ap.add_argument("--data", required=True)
    ap.add_argument("--port", required=True, type=int)
    ap.add_argument("--mode", required=True, choices=["plain", "mse", "utp", "utp-mse"])
    args = ap.parse_args()

    stop = False

    def _stop(signum, frame):
        nonlocal stop
        stop = True

    signal.signal(signal.SIGTERM, _stop)
    signal.signal(signal.SIGINT, _stop)

    ses = lt.session(settings_for(args.mode, args.port))
    h = ses.add_torrent({
        "ti": lt.torrent_info(args.torrent),
        "save_path": args.data,
        "flags": lt.torrent_flags.seed_mode,
    })
    deadline = time.time() + 60
    while time.time() < deadline and not h.status().is_seeding:
        time.sleep(0.25)
    if not h.status().is_seeding:
        raise TimeoutError(f"libtorrent {args.mode} did not enter seed mode")
    touch_ready()
    print(f"libtorrent {args.mode} seeding on {args.port}", flush=True)
    while not stop:
        time.sleep(1)
    ses.remove_torrent(h)
    return 0


if __name__ == "__main__":
    raise SystemExit(main())