"""Wait up to three minutes for the flashed device to answer ICMP."""
import argparse
import ipaddress
import json
import subprocess
import sys


def test_device(interface, host_ip, device_ip):
    host = str(ipaddress.IPv4Address(host_ip))
    device = str(ipaddress.IPv4Address(device_ip))
    if host == device:
        raise ValueError('Device IP must differ from the test host IP')
    if not interface or interface.startswith('-'):
        raise ValueError('Invalid network interface')
    result = subprocess.run(
        ['ip', '-j', '-4', 'addr', 'show', 'dev', interface],
        check=True, capture_output=True, text=True, timeout=5,
    )
    addresses = json.loads(result.stdout)
    if not any(info.get('local') == host for entry in addresses for info in entry.get('addr_info', [])):
        raise ValueError(f'Host IP {host} is not configured on {interface}')
    result = subprocess.run(
        ['ip', '-j', '-4', 'route', 'get', device, 'from', host],
        check=True, capture_output=True, text=True, timeout=5,
    )
    routes = json.loads(result.stdout)
    if not routes or any(route.get('dev') != interface for route in routes):
        raise ValueError(f'Route to {device} does not use {interface}')
    print(f'Waiting up to 180 seconds: {host} ({interface}) -> {device}', flush=True)
    # -c 1 exits on the first reply; -w bounds the entire ping run.
    result = subprocess.run(
        ['ping', '-4', '-n', '-B', '-I', host, '-c', '1', '-i', '1', '-W', '1', '-w', '180', device],
        timeout=180,
    )
    if result.returncode:
        raise RuntimeError(f'FAIL: {device} did not pass the ping test (exit {result.returncode})')
    print(f'PASS: device {device} answered ping', flush=True)


def main():
    parser = argparse.ArgumentParser()
    parser.add_argument('--interface', default='eno1')
    parser.add_argument('--host-ip', default='192.168.75.15')
    parser.add_argument('--device-ip', required=True)
    args = parser.parse_args()
    test_device(args.interface, args.host_ip, args.device_ip)


if __name__ == '__main__':
    try:
        main()
    except (ValueError, RuntimeError, OSError, subprocess.SubprocessError) as exc:
        print(f'FAIL: {exc}', file=sys.stderr)
        sys.exit(1)