using System;
using System.Net;
using System.Net.NetworkInformation;
using System.Net.Sockets;
using System.Text;
using System.Threading;
using UnityEngine;

public class BroadcastServer : MonoBehaviour
{
    private UdpClient udpClient; // 用于发送广播的UDP客户端
    private Thread broadcastThread; // 广播线程
    private volatile bool isRunning = true; // 线程安全的运行标志

    [Header("网络配置")]
    [SerializeField] private int broadcastPort = 9999; // UDP广播端口
    [SerializeField] private float broadcastInterval = 1f; // 广播间隔（秒）
    [SerializeField] private string preferredNetworkInterface = ""; // 优先网络接口（可选）

    [Header("日志级别")]
    [SerializeField] private LogLevel logLevel = LogLevel.Verbose; // 日志级别控制
    public enum LogLevel { None, Minimal, Verbose }

    // 脚本启动时调用
    void Start()
    {
        try
        {
            udpClient = new UdpClient();
            udpClient.EnableBroadcast = true;
            broadcastThread = new Thread(BroadcastIP);
            broadcastThread.Start();
            if (logLevel != LogLevel.None)
            {
                Debug.Log($"广播服务器已启动，端口: {broadcastPort}");
            }
        }
        catch (Exception ex)
        {
            Debug.LogError($"初始化UDP客户端失败: {ex.Message}");
        }
    }

    // 广播显示端服务器的IP地址
    private void BroadcastIP()
    {
        string localIP = GetLocalIPAddress();
        if (string.IsNullOrEmpty(localIP))
        {
            Debug.LogError("无法获取本地IP地址，广播停止");
            return;
        }

        string message = $"ServerIP:{localIP}";
        byte[] data = Encoding.UTF8.GetBytes(message);
        IPEndPoint endPoint = new IPEndPoint(IPAddress.Broadcast, broadcastPort);

        while (isRunning)
        {
            try
            {
                udpClient.Send(data, data.Length, endPoint);
                if (logLevel == LogLevel.Verbose)
                {
                    Debug.Log($"广播IP: {message}");
                }
                Thread.Sleep((int)(broadcastInterval * 1000));
            }
            catch (Exception ex)
            {
                if (logLevel != LogLevel.None)
                {
                    Debug.LogError($"广播错误: {ex.Message}");
                }
                Thread.Sleep(5000);
            }
        }
    }

    // 获取本地IP地址，排除回环地址
    private string GetLocalIPAddress()
    {
        try
        {
            foreach (var networkInterface in NetworkInterface.GetAllNetworkInterfaces())
            {
                if (networkInterface.OperationalStatus != OperationalStatus.Up ||
                    networkInterface.NetworkInterfaceType == NetworkInterfaceType.Loopback)
                    continue;

                if (!string.IsNullOrEmpty(preferredNetworkInterface) && networkInterface.Name != preferredNetworkInterface)
                    continue;

                foreach (var unicastIPAddress in networkInterface.GetIPProperties().UnicastAddresses)
                {
                    if (unicastIPAddress.Address.AddressFamily == AddressFamily.InterNetwork)
                    {
                        string ip = unicastIPAddress.Address.ToString();
                        if (!ip.StartsWith("127."))
                        {
                            if (logLevel == LogLevel.Verbose)
                            {
                                Debug.Log($"选择IP: {ip} (接口: {networkInterface.Name})");
                            }
                            return ip;
                        }
                    }
                }
            }
            Debug.LogError("未找到有效的IPv4地址");
            return "";
        }
        catch (Exception ex)
        {
            Debug.LogError($"获取IP地址错误: {ex.Message}");
            return "";
        }
    }

    // 应用程序退出时清理资源
    private void OnApplicationQuit()
    {
        isRunning = false;
        udpClient?.Close();
        if (broadcastThread != null && broadcastThread.IsAlive)
        {
            broadcastThread.Join(1000);
        }
        if (logLevel != LogLevel.None)
        {
            Debug.Log("广播服务器已停止");
        }
    }

    // 确保资源在销毁时清理
    private void OnDestroy()
    {
        OnApplicationQuit();
    }
}