"""Read-only local connection check. Python 3.10+; asyncua 2.0.1.

Install in a virtual environment: python -m pip install asyncua==2.0.1
Run: python read_iqunet_local.py opc.tcp://GATEWAY:4840
Optional: add --sensor YOUR_SENSOR_MAC to read its boardTemperature.
Use the endpoint and access policy approved for your installation.
"""
import argparse
import asyncio
from asyncua import Client, ua


async def read(endpoint, sensor=None):
    async with Client(endpoint, timeout=10) as client:
        # Standard OPC UA ServerStatus.CurrentTime node.
        clock = await client.get_node('i=2258').read_data_value()
        print('Connected. Server status:', clock.StatusCode.name)
        print('Server UTC:', clock.Value.Value.isoformat())
        if sensor:
            namespace = await client.get_namespace_index('http://www.iqunet.com')
            temperature = await client.nodes.objects.get_child([
                ua.QualifiedName(sensor, namespace),
                ua.QualifiedName('boardTemperature', namespace),
            ])
            value = await temperature.read_data_value()
            print('Temperature (deg C):', value.Value.Value)
            print('Status:', value.StatusCode.name)
            print('Source UTC:', value.SourceTimestamp)


if __name__ == '__main__':
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument('endpoint', help='Approved local opc.tcp endpoint')
    parser.add_argument('--sensor', help='Sensor macId shown in Sensor Manager')
    args = parser.parse_args()
    try:
        asyncio.run(read(args.endpoint, args.sensor))
    except (OSError, TimeoutError, ua.UaError, ValueError) as error:
        parser.exit(1, f'Read failed: {type(error).__name__}: {error}\n')