#!/usr/bin/env python3
"""
identify_port.py
Tool to identify a specific physical device's port name.
1. Lists all connected USB Serial devices.
2. Asks you to power down or unplug ONE device.
3. Tells you exactly which /dev/ttyUSBx port disappeared.
"""

import time
import sys
from serial.tools import list_ports

class Colors:
    GREEN = '\033[92m'
    RED = '\033[91m'
    YELLOW = '\033[93m'
    BLUE = '\033[94m'
    RESET = '\033[0m'

def get_current_ports():
    """
    Returns a set of all detected USB/ACM serial ports.
    We look for standard USB-to-Serial drivers.
    """
    # Grab all ports that look like USB serial adapters
    ports = list(list_ports.grep("USB|ACM|CP210|FT232"))
    # Return a set of device paths (e.g. {'/dev/ttyUSB0', '/dev/ttyUSB1'})
    return set(p.device for p in ports)

def main():
    print(f"{Colors.BLUE}{'='*60}{Colors.RESET}")
    print(f"  USB Port Identifier")
    print(f"{Colors.BLUE}{'='*60}{Colors.RESET}")

    # 1. Initial Scan
    print("Scanning for connected devices...", end='', flush=True)
    initial_ports = get_current_ports()
    print(f" Found {len(initial_ports)} devices.")

    if not initial_ports:
        print(f"{Colors.RED}No USB serial devices found!{Colors.RESET}")
        sys.exit(1)

    # Print current list nicely
    sorted_ports = sorted(list(initial_ports))
    print(f"\n{Colors.GREEN}Active Ports:{Colors.RESET}")
    for p in sorted_ports:
        print(f"  - {p}")

    # 2. Prompt User
    print(f"\n{Colors.YELLOW}>>> ACTION REQUIRED: Power down (or unplug) the device you want to identify.{Colors.RESET}")
    input(f"{Colors.YELLOW}>>> Press ENTER once the device is off...{Colors.RESET}")

    # 3. Final Scan
    print("Rescanning...", end='', flush=True)
    # Give the OS a moment to deregister the device if it was just pulled
    time.sleep(1.0)
    final_ports = get_current_ports()
    print(" Done.")

    # 4. Calculate Difference
    removed_ports = initial_ports - final_ports
    added_ports = final_ports - initial_ports

    print(f"\n{Colors.BLUE}{'='*60}{Colors.RESET}")
    print(f"  Result")
    print(f"{Colors.BLUE}{'='*60}{Colors.RESET}")

    if len(removed_ports) == 1:
        target = list(removed_ports)[0]
        print(f"The device you powered down was: {Colors.RED}{target}{Colors.RESET}")
    elif len(removed_ports) > 1:
        print(f"{Colors.RED}Multiple ports disappeared!{Colors.RESET}")
        for p in removed_ports:
            print(f"  - {p}")
    elif len(added_ports) > 0:
        print(f"{Colors.YELLOW}No ports removed, but new ones appeared?{Colors.RESET}")
        for p in added_ports:
            print(f"  + {p}")
    else:
        print(f"{Colors.YELLOW}No changes detected. Did you power it down?{Colors.RESET}")

if __name__ == '__main__':
    main()