#!/usr/bin/env python3
"""Register this PID as anchor, then exec the real `mosaic yolo` launcher."""

from __future__ import annotations

import argparse
import json
import os
import socket
import sys


def request(socket_path: str, payload: dict[str, object]) -> dict[str, object]:
    conn = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
    conn.connect(socket_path)
    conn.sendall((json.dumps(payload) + "\n").encode())
    response = json.loads(conn.makefile("r", encoding="utf-8").readline())
    conn.close()
    return response


def main() -> None:
    parser = argparse.ArgumentParser()
    parser.add_argument("--socket", required=True)
    parser.add_argument("runtime", choices=["pi", "claude"])
    parser.add_argument("args", nargs=argparse.REMAINDER)
    ns = parser.parse_args()

    response = request(ns.socket, {"action": "register-anchor", "runtime": ns.runtime})
    if response.get("decision") != "ACCEPT":
        raise SystemExit("anchor registration refused")
    os.environ["GATE0_SESSION_ID"] = str(response["session_id"])
    argv = ["mosaic", "yolo", ns.runtime, *ns.args]
    print(
        json.dumps(
            {
                "event": "anchor-exec",
                "pid": os.getpid(),
                "argv": ["mosaic", "yolo", ns.runtime, f"<{len(ns.args)} runtime args>"],
                "note": "os.execvpe retains pid and /proc starttime",
            },
            sort_keys=True,
        ),
        file=sys.stderr,
        flush=True,
    )
    os.execvpe("mosaic", argv, os.environ)


if __name__ == "__main__":
    main()