"""Keep outbound Celery work paused during a verified cold-data migration.

The operator creates the hold file in the candidate data clone before startup
and removes it only after committing the verified deployment. Normal startups
without a hold file behave unchanged. This does not pause an existing worker.
"""

import os
import stat
import sys
import time
from pathlib import Path

HOLD_FILE = Path("/app/local/.migration-worker-hold")
COMMANDS = {
    "worker": [
        "/app/.venv/bin/celery",
        "-A",
        "config",
        "worker",
        "-l",
        "INFO",
        "-Q",
        "high,default,low",
        "--concurrency=2",
    ],
    "scheduler": [
        "/app/.venv/bin/celery",
        "-A",
        "config",
        "beat",
        "-l",
        "INFO",
        "--schedule",
        "/tmp/celerybeat-schedule",  # noqa: S108 - existing supervised container-local schedule path
    ],
}


def hold_active(path=HOLD_FILE):
    try:
        mode = path.lstat().st_mode
    except FileNotFoundError:
        return False
    if not stat.S_ISREG(mode):
        raise RuntimeError("Migration hold must be a regular file")
    return True


def start(role, *, check=hold_active, sleep=time.sleep, execute=os.execv):
    if role not in COMMANDS:
        raise ValueError("Unsupported supervised process")
    while check():
        sleep(1)
    command = COMMANDS[role]
    execute(command[0], command)


if __name__ == "__main__":
    start(sys.argv[1] if len(sys.argv) == 2 else "")