using System;
using System.Collections.Generic;
using System.Text;
using System.Linq;
using System.Net;
using System.Net.NetworkInformation;
using System.Net.Sockets;

namespace SunlightAggregationManager.UserClass
{
    public class GetLocalIP
    {
        public static string GetLocalIPv4Address()
        {
            // 获取所有网络接口
            var networkInterfaces = NetworkInterface.GetAllNetworkInterfaces();

            foreach (var ni in networkInterfaces)
            {
                // 筛选条件：
                // 1. 网卡状态为 Up (已连接)
                // 2. 排除虚拟网卡、回环网卡、隧道网卡
                // 3. 支持 IPv4
                if (ni.OperationalStatus == OperationalStatus.Up &&
                    ni.NetworkInterfaceType != NetworkInterfaceType.Loopback &&
                    ni.NetworkInterfaceType != NetworkInterfaceType.Tunnel &&
                    !ni.Description.Contains("Virtual") && // 排除常见的虚拟网卡描述
                    ni.Supports(NetworkInterfaceComponent.IPv4))
                {
                    var ipProperties = ni.GetIPProperties();
                    // 获取单播地址（即分配的 IP 地址）
                    var unicastAddresses = ipProperties.UnicastAddresses;

                    foreach (var ua in unicastAddresses)
                    {
                        // 筛选出 IPv4 地址，且排除 127.0.0.1 回环地址
                        if (ua.Address.AddressFamily == AddressFamily.InterNetwork && !IPAddress.IsLoopback(ua.Address))
                        {
                            // 优先返回有默认网关的地址（通常是当前正在上网的主网卡）
                            if (ipProperties.GatewayAddresses.Any(g => g.Address.AddressFamily == AddressFamily.InterNetwork))
                            {
                                return ua.Address.ToString();
                            }
                        }
                    }
                }
            }
            return "未找到有效的局域网IPv4地址";
        }

    }
}