import pyudev
import signal
import logging
import sys
import os


def on_usb_attached(device):
    print(f"USB device attached: {device.device_node or device.sys_name}")

def on_usb_detached(device):
    print(f"USB device detached: {device.device_node or device.sys_name}")

def list_current_usb_devices():
    print("Currently attached USB devices:")
    context = pyudev.Context()
    for device in context.list_devices(subsystem='usb', DEVTYPE='usb_device'):
        print(f"- {device.device_node or device.sys_name} ({device.get('ID_MODEL', 'Unknown Device')})")
    print()

def monitor_usb():
    context = pyudev.Context()
    monitor = pyudev.Monitor.from_netlink(context)
    monitor.filter_by(subsystem='usb')  # Only USB devices

    for device in iter(monitor.poll, None):
        if device.action == 'add':
            on_usb_attached(device)
        elif device.action == 'remove':
            on_usb_detached(device)

def signal_handler(sig, frame):
    print("\nStopping USB monitor...")
    sys.exit(0)

if __name__ == "__main__":
    logging.basicConfig(format='%(asctime)s %(message)s', level=logging.INFO)
    try:
        CURRENT_NODE_NAME=os.environ['CURRENT_NODE_NAME']
        logging.info(f"Starging USB-watch on {CURRENT_NODE_NAME}")
    except KeyError:
        logging.error('Environment variabel CURRENT_NODE_NAME is not set')
        sys.exit(1)
    signal.signal(signal.SIGINT, signal_handler)

    list_current_usb_devices()
    logging.info("Monitoring USB device changes......")

    monitor_usb()