using Microsoft.Win32;
using System;
using System.Collections.Generic;
using System.IO.Ports;
using System.Linq;
using System.Text.RegularExpressions;

namespace DeviceCenter
{
    class PortUtil
    {
        public static List<string> FindComPortNames(String VID, String PID)
        {
            String pattern = String.Format("^VID_{0}.PID_{1}", VID, PID);
            Regex _rx = new Regex(pattern, RegexOptions.IgnoreCase);
            List<string> comports = new List<string>();

            RegistryKey rk1 = Registry.LocalMachine;
            RegistryKey rk2 = rk1.OpenSubKey("SYSTEM\\CurrentControlSet\\Enum");

            foreach (String s3 in rk2.GetSubKeyNames())
            {
                RegistryKey rk3 = rk2.OpenSubKey(s3);
                foreach (String s in rk3.GetSubKeyNames())
                {
                    if (_rx.Match(s).Success)
                    {
                        RegistryKey rk4 = rk3.OpenSubKey(s);
                        foreach (String s2 in rk4.GetSubKeyNames())
                        {
                            RegistryKey rk5 = rk4.OpenSubKey(s2);
                            string location = (string)rk5.GetValue("LocationInformation");
                            RegistryKey rk6 = rk5.OpenSubKey("Device Parameters");
                            string portName = (string)rk6.GetValue("PortName");
                            if (!String.IsNullOrEmpty(portName) && SerialPort.GetPortNames().Contains(portName))
                                comports.Add((string)rk6.GetValue("PortName"));
                        }
                    }
                }
            }
            return comports;
        }
    }
}