#!/usr/bin/env python3
"""Send management commands to ESP32 CSI devices over UDP."""

import socket
import sys

DEFAULT_PORT = 5501
TIMEOUT = 2.0

USAGE = """\
Usage: esp-cmd <ip> <command> [args...]

Commands:
  STATUS              Query device state (uptime, heap, RSSI, tx_power, rate)
  REBOOT              Restart the ESP32
  IDENTIFY            Blink LED solid for 5 seconds
  RATE <10-100>       Set ping frequency in Hz (saved to NVS)
  POWER <2-20>        Set TX power in dBm (saved to NVS)

Examples:
  esp-cmd 192.168.1.50 STATUS
  esp-cmd 192.168.1.50 RATE 50
  esp-cmd 192.168.1.50 POWER 10
  esp-cmd 192.168.1.50 REBOOT
  esp-cmd 192.168.1.50 IDENTIFY"""


def main():
    if len(sys.argv) < 3 or sys.argv[1] in ("-h", "--help"):
        print(USAGE)
        sys.exit(0 if sys.argv[1:] and sys.argv[1] in ("-h", "--help") else 2)

    ip = sys.argv[1]
    cmd = " ".join(sys.argv[2:]).strip()

    sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    sock.settimeout(TIMEOUT)

    try:
        sock.sendto(cmd.encode(), (ip, DEFAULT_PORT))
        data, _ = sock.recvfrom(512)
        print(data.decode().strip())
    except socket.timeout:
        print(f"ERR: no reply from {ip}:{DEFAULT_PORT} (timeout {TIMEOUT}s)", file=sys.stderr)
        sys.exit(1)
    except OSError as e:
        print(f"ERR: {e}", file=sys.stderr)
        sys.exit(1)
    finally:
        sock.close()


if __name__ == "__main__":
    main()