#!/usr/bin/env python3
"""
This script checks whether the CUPS service is listening on TCP port 631.
If not, it restarts the service and verifies again.

 Example manual usage:
    sudo /usr/local/bin/check_cups_working.py --host 127.0.0.1

 Example crontab entry (run every 5 minutes, silent mode):
    */5 * * * * root /usr/local/bin/check_cups_working.py --host 127.0.0.1 --quiet
"""

import socket
import subprocess
import time
import sys
import argparse

PORT = 631
SERVICE = "cups"

def is_port_listening(host, port):
    with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
        s.settimeout(1)
        try:
            s.connect((host, port))
            return True
        except (ConnectionRefusedError, socket.timeout, OSError):
            return False

def restart_service(service):
    subprocess.run(["systemctl", "restart", service], check=False)
    time.sleep(3)

def main():
    parser = argparse.ArgumentParser(
        description="Checks if CUPS is listening on TCP port 631 and restarts the service if not."
    )
    parser.add_argument("--host", default="127.0.0.1", help="IP address to check (default: 127.0.0.1)")
    parser.add_argument("--quiet", action="store_true", help="Suppress all output (for use in cron jobs)")
    args = parser.parse_args()

    def log(msg):
        if not args.quiet:
            print(msg)

    if is_port_listening(args.host, PORT):
        log(f"CUPS OK: listening on {args.host}:{PORT}")
        sys.exit(0)
    else:
        log(f"CUPS not listening on {args.host}:{PORT}. Restarting service...")
        restart_service(SERVICE)

        if is_port_listening(args.host, PORT):
            log("CUPS restarted and is now listening.")
            sys.exit(0)
        else:
            log("ERROR: CUPS still not listening after restart!")
            sys.exit(2)

if __name__ == "__main__":
    main()