using System;
using System.Collections.Generic;
using System.Linq;
using System.Net.NetworkInformation;
using System.Text;
using System.Threading.Tasks;

namespace AIK.Common.SysCommon
{
    public static class MacAddressHelper
    {
        /// <summary>
        /// 获取主物理网卡的 MAC 地址（格式：00-1A-2B-3C-4D-5E）
        /// </summary>
        public static string GetPrimaryMacAddress()
        {
            try
            {
                var activeAdapters = NetworkInterface
                    .GetAllNetworkInterfaces()
                    .Where(nic =>
                        nic.OperationalStatus == OperationalStatus.Up &&
                        nic.NetworkInterfaceType is NetworkInterfaceType.Ethernet or NetworkInterfaceType.Wireless80211 &&
                        !IsVirtualOrLoopback(nic))
                    .OrderByDescending(nic => nic.Speed) // 优先有线 > 无线
                    .ToList();

                var primary = activeAdapters.FirstOrDefault()
                           ?? NetworkInterface.GetAllNetworkInterfaces()
                               .FirstOrDefault(nic => !IsVirtualOrLoopback(nic));

                if (primary?.GetPhysicalAddress().GetAddressBytes().Length > 0 is true)
                {
                    return FormatMacAddress(primary.GetPhysicalAddress().GetAddressBytes());
                }

                return "未检测到有效物理网卡";
            }
            catch (Exception ex)
            {
                return $"获取失败: {ex.Message}";
            }
        }

        private static bool IsVirtualOrLoopback(NetworkInterface nic)
        {
            if (nic.NetworkInterfaceType == NetworkInterfaceType.Loopback)
                return true;

            string desc = nic.Description.ToLowerInvariant();
            return desc.Contains("virtual") ||
                   desc.Contains("vmware") ||
                   desc.Contains("vbox") ||
                   desc.Contains("hyper-v") ||
                   desc.Contains("bluetooth") ||
                   desc.Contains("tunnel") ||
                   desc.Contains("isatap") ||
                   desc.Contains("6to4") ||
                   desc.Contains("teredo");
        }

        private static string FormatMacAddress(ReadOnlySpan<byte> macBytes)
        {
            // 使用 Span 高效构建格式化字符串（.NET 8 推荐）
            var result = new StringBuilder(macBytes.Length * 3 - 1);
            for (int i = 0; i < macBytes.Length; i++)
            {
                if (i > 0) result.Append('-');
                result.Append($"{macBytes[i]:X2}");
            }
            return result.ToString();
        }
    }
}