using System;
using System.Reflection;
using UnityEngine;

namespace DanroJump.Hardware.Com
{
    public sealed class ReflectionComPortProvider : IComPortProvider
    {
        private static readonly Type SerialPortType = Type.GetType("System.IO.Ports.SerialPort, System");

        public string[] GetPortNames()
        {
            if (SerialPortType == null)
            {
                Debug.LogWarning("[ComSystem] System.IO.Ports.SerialPort is not available in this Unity profile.");
                return Array.Empty<string>();
            }

            try
            {
                return (string[])SerialPortType.GetMethod("GetPortNames", BindingFlags.Public | BindingFlags.Static)
                    ?.Invoke(null, null) ?? Array.Empty<string>();
            }
            catch (Exception exception)
            {
                Debug.LogWarning($"[ComSystem] Failed to list COM ports: {Unwrap(exception).Message}");
                return Array.Empty<string>();
            }
        }

        private static Exception Unwrap(Exception exception)
        {
            return exception is TargetInvocationException { InnerException: not null }
                ? exception.InnerException
                : exception;
        }
    }
}