using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Net;
using System.Net.NetworkInformation;
using System.Net.Sockets;
using System.Runtime.CompilerServices;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;

namespace TeamAAS.Feeder.Network
{
    /// <summary>
    /// 网卡接口信息（IPv4）。
    /// </summary>
    public class NetworkInterfaceInfo
    {
        public string Name { get; set; }
        public IPAddress IPv4Address { get; set; }
        public IPAddress IPv4Mask { get; set; }
    }

    /// <summary>
    /// UDP 扫描发现的 Feeder 网络信息。
    /// </summary>
    public class FeederNetworkInfo : INotifyPropertyChanged
    {
        public string FeederType { get; set; }
        public string Version { get; set; }
        public string IP { get; set; }
        public int Port { get; set; }
        public string Subnet { get; set; }
        public string Gateway { get; set; }
        public string MAC { get; set; }

        private bool _isAccessible;
        /// <summary>是否与本机某网卡处于同一网段（前三段相同）。</summary>
        public bool IsAccessible
        {
            get { return _isAccessible; }
            set { SetProperty(ref _isAccessible, value); }
        }

        /// <summary>发现该 Feeder 所使用的本机网卡。</summary>
        public NetworkInterfaceInfo Network { get; set; }

        public override string ToString() => $"{FeederType} {IP}:{Port} ({MAC})";

        public event PropertyChangedEventHandler PropertyChanged;
        private void SetProperty<T>(ref T storage, T value, [CallerMemberName] string propertyName = null)
        {
            if (EqualityComparer<T>.Default.Equals(storage, value)) return;
            storage = value;
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
        }
    }

    /// <summary>
    /// Feeder IP 自动搜索/设置（UDP 广播扫描）。
    /// 纯 System.Net.Sockets.UdpClient 实现，无第三方依赖。
    /// 协议：向 255.255.255.255:1234 广播 {udpscan}，Feeder 回应
    /// { FF0Ver2.6.5 / ip:192.168.31.200:5000 / sub:255.255.255.0 / gw:... / mac:...}。
    /// </summary>
    public class FeederIpScanner
    {
        private const int BroadcastPort = 1234;
        private const int LocalBindPort = 8000;
        private const string LogSource = "Feeder.Scan";

        private UdpClient _udpClient = new UdpClient();

        /// <summary>扫描所有网卡，返回发现的 Feeder 列表。</summary>
        public async Task<List<FeederNetworkInfo>> ScanAsync()
        {
            return await Task.Run(() =>
            {
                var result = new List<FeederNetworkInfo>();
                try
                {
                    var netList = GetAllNetworkInterface();
                    foreach (var nic in netList)
                    {
                        Bind(nic.IPv4Address.ToString());
                        var feeders = GetFeederList(nic);
                        result.AddRange(feeders);
                    }
                    AppLogger.Info($"UDP 扫描完成，发现 {result.Count} 个 Feeder", LogSource);
                }
                catch (Exception ex)
                {
                    AppLogger.Error("UDP 扫描 Feeder 失败", ex, LogSource);
                }
                return result;
            });
        }

        /// <summary>绑定到指定本机网卡 IP 与固定本地端口。</summary>
        public void Bind(string ip)
        {
            var localIpAddress = IPAddress.Parse(ip);
            try { _udpClient.Client.Close(); } catch { }
            try { _udpClient.Client.Dispose(); } catch { }
            _udpClient = new UdpClient();
            _udpClient.Client.Bind(new IPEndPoint(localIpAddress, LocalBindPort));
        }

        /// <summary>获取所有已启用、非回环/隧道网口的 IPv4 信息。</summary>
        public NetworkInterfaceInfo[] GetAllNetworkInterface()
        {
            var networks = new List<NetworkInterfaceInfo>();
            foreach (var ni in NetworkInterface.GetAllNetworkInterfaces())
            {
                if (ni.OperationalStatus != OperationalStatus.Up ||
                    ni.NetworkInterfaceType == NetworkInterfaceType.Loopback ||
                    ni.NetworkInterfaceType == NetworkInterfaceType.Tunnel ||
                    ni.NetworkInterfaceType == NetworkInterfaceType.Unknown)
                    continue;

                foreach (var ua in ni.GetIPProperties().UnicastAddresses)
                {
                    if (ua.Address.AddressFamily == AddressFamily.InterNetwork)
                    {
                        networks.Add(new NetworkInterfaceInfo
                        {
                            Name = ni.Name,
                            IPv4Address = ua.Address,
                            IPv4Mask = ua.IPv4Mask
                        });
                    }
                }
            }
            return networks.ToArray();
        }

        /// <summary>在指定网卡上广播扫描并收集回应。</summary>
        public FeederNetworkInfo[] GetFeederList(NetworkInterfaceInfo network)
        {
            var feeders = new List<FeederNetworkInfo>();
            var ep = new IPEndPoint(IPAddress.Broadcast, BroadcastPort);
            var data = Encoding.UTF8.GetBytes("{udpscan}");
            try
            {
                _udpClient.Send(data, data.Length, ep);
                _udpClient.Client.ReceiveTimeout = 500;
                for (int i = 0; i < 10; i++)
                {
                    try
                    {
                        var da = _udpClient.Receive(ref ep);
                        string config = Encoding.UTF8.GetString(da, 0, da.Length).TrimEnd('\n').TrimEnd('\r');
                        var info = AnalysisIP(config);
                        if (info != null)
                        {
                            info.IsAccessible = AreFirstThreeOctetsEqual(IPAddress.Parse(info.IP), network.IPv4Address);
                            info.Network = network;
                            feeders.Add(info);
                        }
                        ep = new IPEndPoint(IPAddress.Broadcast, BroadcastPort);
                    }
                    catch (Exception)
                    {
                        break;
                    }
                }
            }
            catch (Exception ex)
            {
                AppLogger.Warning($"网卡 {network.Name} 扫描异常: {ex.Message}", LogSource);
            }
            return feeders.ToArray();
        }

        /// <summary>解析 Feeder 回应串为网络信息；不匹配返回 null。</summary>
        public FeederNetworkInfo AnalysisIP(string input)
        {
            const string pattern = @"{(?<Name>[^V]+)Ver(?<Version>[^\/]+)\/ip:(?<IP>[^:]+):(?<Port>\d+)\/sub:(?<Subnet>[^\/]+)\/gw:(?<Gateway>[^\/]+)\/mac:(?<MAC>[^}]+)}";
            var match = Regex.Match(input, pattern);
            if (!match.Success) return null;

            int.TryParse(match.Groups["Port"].Value.Trim(), out var port);
            return new FeederNetworkInfo
            {
                FeederType = match.Groups["Name"].Value.Trim(),
                Version = match.Groups["Version"].Value.Trim(),
                IP = match.Groups["IP"].Value.Trim(),
                Port = port,
                Subnet = match.Groups["Subnet"].Value.Trim(),
                Gateway = match.Groups["Gateway"].Value.Trim(),
                MAC = match.Groups["MAC"].Value.Trim()
            };
        }

        /// <summary>通过 MAC 重置 Feeder 参数。</summary>
        public bool ResetFeeder(string feederMac, NetworkInterfaceInfo network = null)
        {
            try
            {
                if (network != null) Bind(network.IPv4Address.ToString());
                var ep = new IPEndPoint(IPAddress.Broadcast, BroadcastPort);
                string cmd = "{ParReset/mac:" + feederMac + "}";
                var data = Encoding.UTF8.GetBytes(cmd);
                _udpClient.Send(data, data.Length, ep);
                _udpClient.Client.ReceiveTimeout = 5000;
                var da = _udpClient.Receive(ref ep);
                string rev = Encoding.UTF8.GetString(da, 0, da.Length).TrimEnd('\n').TrimEnd('\r');
                bool ok = string.Equals(rev, cmd);
                AppLogger.Info($"重置 Feeder {feederMac} {(ok ? "成功" : "失败")}", LogSource);
                return ok;
            }
            catch (Exception ex)
            {
                AppLogger.Error($"重置 Feeder {feederMac} 异常", ex, LogSource);
                return false;
            }
        }

        /// <summary>通过 MAC 设置 Feeder 的 IP/端口/掩码。</summary>
        public async Task<bool> SetFeederIpAsync(string feederMac, string targetIp, int targetPort, string targetSub, NetworkInterfaceInfo network = null)
        {
            try
            {
                if (network != null) Bind(network.IPv4Address.ToString());
                var ep = new IPEndPoint(IPAddress.Broadcast, BroadcastPort);
                string cmd = "{ipset/mac:" + $"{feederMac}/ip:{targetIp}:{targetPort}/sub:{targetSub}" + "}";
                var data = Encoding.UTF8.GetBytes(cmd);
                await _udpClient.SendAsync(data, data.Length, ep);
                _udpClient.Client.ReceiveTimeout = 5000;
                var received = await _udpClient.ReceiveAsync();
                string rev = Encoding.UTF8.GetString(received.Buffer, 0, received.Buffer.Length).TrimEnd('\n').TrimEnd('\r');
                bool ok = string.Equals(rev, cmd);
                AppLogger.Info($"设置 Feeder {feederMac} -> {targetIp}:{targetPort}/{targetSub} {(ok ? "成功" : "失败")}", LogSource);
                return ok;
            }
            catch (Exception ex)
            {
                AppLogger.Error($"设置 Feeder {feederMac} IP 异常", ex, LogSource);
                return false;
            }
        }

        /// <summary>判断两个 IP 前三段是否相同（是否同网段）。</summary>
        public bool AreFirstThreeOctetsEqual(IPAddress ip1, IPAddress ip2)
        {
            var b1 = ip1.GetAddressBytes();
            var b2 = ip2.GetAddressBytes();
            for (int i = 0; i < 3; i++)
                if (b1[i] != b2[i]) return false;
            return true;
        }

        public void Dispose()
        {
            try { _udpClient?.Client?.Close(); } catch { }
            try { _udpClient?.Client?.Dispose(); } catch { }
            try { _udpClient?.Dispose(); } catch { }
        }
    }
}