using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Net;
using System.Net.NetworkInformation;
using System.Net.Sockets;
using System.Runtime.InteropServices;
using NewLife.Collections;
using NewLife.IP;
using NewLife.Log;
using NewLife.Net;

namespace System
{
    /// <summary>网络工具类</summary>
    public static class NetHelper
    {
        #region 辅助函数
        /// <summary>设置超时检测时间和检测间隔</summary>
        /// <param name="socket">要设置的Socket对象</param>
        /// <param name="iskeepalive">是否启用Keep-Alive</param>
        /// <param name="starttime">多长时间后开始第一次探测（单位：毫秒）</param>
        /// <param name="interval">探测时间间隔（单位：毫秒）</param>
        public static void SetTcpKeepAlive(this Socket socket, Boolean iskeepalive, Int32 starttime = 10000, Int32 interval = 10000)
        {
            if (socket == null || !socket.Connected) return;
            UInt32 dummy = 0;
            var inOptionValues = new Byte[Marshal.SizeOf(dummy) * 3];
            BitConverter.GetBytes((UInt32)(iskeepalive ? 1 : 0)).CopyTo(inOptionValues, 0);
            BitConverter.GetBytes((UInt32)starttime).CopyTo(inOptionValues, Marshal.SizeOf(dummy));
            BitConverter.GetBytes((UInt32)interval).CopyTo(inOptionValues, Marshal.SizeOf(dummy) * 2);
            socket.IOControl(IOControlCode.KeepAliveValues, inOptionValues, null);
        }

        private static readonly DictionaryCache<String, IPAddress> _dnsCache = new DictionaryCache<String, IPAddress>(StringComparer.OrdinalIgnoreCase) { Expire = 60 };
        /// <summary>分析地址，根据IP或者域名得到IP地址，缓存60秒，异步更新</summary>
        /// <param name="hostname"></param>
        /// <returns></returns>
        public static IPAddress ParseAddress(this String hostname)
        {
            if (hostname.IsNullOrEmpty()) return null;

            if (_dnsCache.FindMethod == null) _dnsCache.FindMethod = s => NetUri.ParseAddress(s)?.FirstOrDefault();

            //return _dnsCache.GetItem(hostname, NetUri.ParseAddress);
            return _dnsCache[hostname];
        }

        /// <summary>分析网络终结点</summary>
        /// <param name="address">地址，可以不带端口</param>
        /// <param name="defaultPort">地址不带端口时指定的默认端口</param>
        /// <returns></returns>
        public static IPEndPoint ParseEndPoint(String address, Int32 defaultPort = 0)
        {
            if (String.IsNullOrEmpty(address)) return null;

            var p = address.IndexOf("://");
            if (p >= 0) address = address.Substring(p + 3);

            p = address.LastIndexOf(':');
            if (p > 0)
                return new IPEndPoint(ParseAddress(address.Substring(0, p)), Int32.Parse(address.Substring(p + 1)));
            else
                return new IPEndPoint(ParseAddress(address), defaultPort);
        }

        /// <summary>针对IPv4和IPv6获取合适的Any地址</summary>
        /// <remarks>除了Any地址以为，其它地址不具备等效性</remarks>
        /// <param name="address"></param>
        /// <param name="family"></param>
        /// <returns></returns>
        public static IPAddress GetRightAny(this IPAddress address, AddressFamily family)
        {
            if (address.AddressFamily == family) return address;

            switch (family)
            {
                case AddressFamily.InterNetwork:
                    if (address == IPAddress.IPv6Any) return IPAddress.Any;
                    break;
                case AddressFamily.InterNetworkV6:
                    if (address == IPAddress.Any) return IPAddress.IPv6Any;
                    break;
                default:
                    break;
            }
            return null;
        }

        /// <summary>是否Any地址，同时处理IPv4和IPv6</summary>
        /// <param name="address"></param>
        /// <returns></returns>
        public static Boolean IsAny(this IPAddress address) => IPAddress.Any.Equals(address) || IPAddress.IPv6Any.Equals(address);

        /// <summary>是否Any结点</summary>
        /// <param name="endpoint"></param>
        /// <returns></returns>
        public static Boolean IsAny(this EndPoint endpoint) => (endpoint as IPEndPoint).Address.IsAny() || (endpoint as IPEndPoint).Port == 0;

        /// <summary>是否IPv4地址</summary>
        /// <param name="address"></param>
        /// <returns></returns>
        public static Boolean IsIPv4(this IPAddress address) => address.AddressFamily == AddressFamily.InterNetwork;

        /// <summary>是否本地地址</summary>
        /// <param name="address"></param>
        /// <returns></returns>
        public static Boolean IsLocal(this IPAddress address) => IPAddress.IsLoopback(address) || GetIPsWithCache().Any(ip => ip.Equals(address));

        /// <summary>获取相对于指定远程地址的本地地址</summary>
        /// <param name="address"></param>
        /// <param name="remote"></param>
        /// <returns></returns>
        public static IPAddress GetRelativeAddress(this IPAddress address, IPAddress remote)
        {
            // 如果不是任意地址，直接返回
            var addr = address;
            if (addr == null || !addr.IsAny()) return addr;

            // 如果是本地环回地址，返回环回地址
            if (IPAddress.IsLoopback(remote)) return addr.IsIPv4() ? IPAddress.Loopback : IPAddress.IPv6Loopback;

            // 否则返回本地第一个IP地址
            foreach (var item in NetHelper.GetIPsWithCache())
            {
                if (item.AddressFamily == addr.AddressFamily) return item;
            }
            return null;
        }

        /// <summary>获取相对于指定远程地址的本地地址</summary>
        /// <param name="local"></param>
        /// <param name="remote"></param>
        /// <returns></returns>
        public static IPEndPoint GetRelativeEndPoint(this IPEndPoint local, IPAddress remote)
        {
            if (local == null || remote == null) return local;

            var addr = GetRelativeAddress(local.Address, remote);
            return addr == null ? local : new IPEndPoint(addr, local.Port);
        }

        /// <summary>指定地址的指定端口是否已被使用，似乎没办法判断IPv6地址</summary>
        /// <param name="protocol"></param>
        /// <param name="address"></param>
        /// <param name="port"></param>
        /// <returns></returns>
        public static Boolean CheckPort(this IPAddress address, NetType protocol, Int32 port)
        {
            //if (NewLife.Runtime.Mono) return false;
            if (!NewLife.Runtime.Windows) return false;

            try
            {
                // 某些情况下检查端口占用会抛出异常，原因未知
                var gp = IPGlobalProperties.GetIPGlobalProperties();

                IPEndPoint[] eps = null;
                switch (protocol)
                {
                    case NetType.Tcp:
                        eps = gp.GetActiveTcpListeners();
                        break;
                    case NetType.Udp:
                        eps = gp.GetActiveUdpListeners();
                        break;
                    default:
                        return false;
                }

                foreach (var item in eps)
                {
                    // 先比较端口，性能更好
                    if (item.Port == port && item.Address.Equals(address)) return true;
                }
            }
            catch (Exception ex)
            {
                XTrace.WriteException(ex);
            }

            return false;
        }

        /// <summary>检查该协议的地址端口是否已经呗使用</summary>
        /// <param name="uri"></param>
        /// <returns></returns>
        public static Boolean CheckPort(this NetUri uri) => CheckPort(uri.Address, uri.Type, uri.Port);
        #endregion

        #region 本机信息
        /// <summary>获取活动的接口信息</summary>
        /// <returns></returns>
        public static IEnumerable<IPInterfaceProperties> GetActiveInterfaces()
        {
            foreach (var item in NetworkInterface.GetAllNetworkInterfaces())
            {
                if (item.OperationalStatus != OperationalStatus.Up) continue;

                var ip = item.GetIPProperties();
                if (ip != null) yield return ip;
            }
        }

        /// <summary>获取可用的DHCP地址</summary>
        /// <returns></returns>
        public static IEnumerable<IPAddress> GetDhcps()
        {
            var list = new List<IPAddress>();
            foreach (var item in GetActiveInterfaces())
            {
                if (item != null && item.DhcpServerAddresses.Count > 0)
                {
                    foreach (var elm in item.DhcpServerAddresses)
                    {
                        if (list.Contains(elm)) continue;
                        list.Add(elm);

                        yield return elm;
                    }
                }
            }
        }

        /// <summary>获取可用的DNS地址</summary>
        /// <returns></returns>
        public static IEnumerable<IPAddress> GetDns()
        {
            var list = new List<IPAddress>();
            foreach (var item in GetActiveInterfaces())
            {
                if (item != null && item.DnsAddresses.Count > 0)
                {
                    foreach (var elm in item.DnsAddresses)
                    {
                        if (list.Contains(elm)) continue;
                        list.Add(elm);

                        yield return elm;
                    }
                }
            }
        }

        /// <summary>获取可用的网关地址</summary>
        /// <returns></returns>
        public static IEnumerable<IPAddress> GetGateways()
        {
            var list = new List<IPAddress>();
            foreach (var item in GetActiveInterfaces())
            {
                if (item != null && item.GatewayAddresses.Count > 0)
                {
                    foreach (var elm in item.GatewayAddresses)
                    {
                        if (list.Contains(elm.Address)) continue;
                        list.Add(elm.Address);

                        yield return elm.Address;
                    }
                }
            }
        }

        /// <summary>获取可用的IP地址</summary>
        /// <returns></returns>
        public static IEnumerable<IPAddress> GetIPs()
        {
            var dic = new Dictionary<UnicastIPAddressInformation, Int32>();
            foreach (var item in GetActiveInterfaces())
            {
                if (item != null && item.UnicastAddresses.Count > 0)
                {
                    var gw = item.GatewayAddresses.Count;
                    foreach (var elm in item.UnicastAddresses)
                    {
                        try
                        {
                            if (elm.DuplicateAddressDetectionState != DuplicateAddressDetectionState.Preferred) continue;
                        }
                        catch { }

                        dic.Add(elm, gw);
                    }
                }
            }

            // 带网关的接口地址很重要，优先返回
            // Linux下不支持PrefixOrigin
            var ips = dic.OrderByDescending(e => e.Value)
                //.ThenByDescending(e => e.Key.PrefixOrigin == PrefixOrigin.Dhcp || e.Key.PrefixOrigin == PrefixOrigin.Manual)
                .Select(e => e.Key.Address).ToList();

            return ips;
        }

        private static readonly DictionaryCache<Int32, IPAddress[]> _ips = new DictionaryCache<Int32, IPAddress[]> { Expire = 60/*, Asynchronous = true*/ };
        /// <summary>获取本机可用IP地址，缓存60秒，异步更新</summary>
        /// <returns></returns>
        public static IPAddress[] GetIPsWithCache()
        {
            //return _ips.GetItem(1, k => GetIPs().ToArray());
            if (_ips.FindMethod == null) _ips.FindMethod = k => GetIPs().ToArray();
            return _ips[1];
        }

        /// <summary>获取可用的多播地址</summary>
        /// <returns></returns>
        public static IEnumerable<IPAddress> GetMulticasts()
        {
            var list = new List<IPAddress>();
            foreach (var item in GetActiveInterfaces())
            {
                if (item != null && item.MulticastAddresses.Count > 0)
                {
                    foreach (var elm in item.MulticastAddresses)
                    {
                        if (list.Contains(elm.Address)) continue;
                        list.Add(elm.Address);

                        yield return elm.Address;
                    }
                }
            }
        }

        private static readonly String[] _Excludes = new[] { "Loopback", "VMware", "VBox", "Virtual", "Teredo", "Microsoft", "VPN", "VNIC", "IEEE" };
        /// <summary>获取所有物理网卡MAC地址</summary>
        /// <returns></returns>
        public static IEnumerable<Byte[]> GetMacs()
        {
            foreach (var item in NetworkInterface.GetAllNetworkInterfaces())
            {
                if (_Excludes.Any(e => item.Description.Contains(e))) continue;
                if (NewLife.Runtime.Windows && item.Speed < 1_000_000) continue;

                var ips = item.GetIPProperties();
                var addrs = ips.UnicastAddresses
                    .Where(e => e.Address.AddressFamily == AddressFamily.InterNetwork)
                    .Select(e => e.Address)
                    .ToArray();
                if (addrs.All(e => IPAddress.IsLoopback(e))) continue;

                var mac = item.GetPhysicalAddress()?.GetAddressBytes();
                if (mac != null && mac.Length == 6) yield return mac;
            }
        }

        /// <summary>获取网卡MAC地址（网关所在网卡）</summary>
        /// <returns></returns>
        public static Byte[] GetMac()
        {
            foreach (var item in NetworkInterface.GetAllNetworkInterfaces())
            {
                if (_Excludes.Any(e => item.Description.Contains(e))) continue;
                if (NewLife.Runtime.Windows && item.Speed < 1_000_000) continue;

                var ips = item.GetIPProperties();
                var addrs = ips.UnicastAddresses
                    .Where(e => e.Address.AddressFamily == AddressFamily.InterNetwork)
                    .Select(e => e.Address)
                    .ToArray();
                if (addrs.All(e => IPAddress.IsLoopback(e))) continue;

                // 网关
                addrs = ips.GatewayAddresses
                    .Where(e => e.Address.AddressFamily == AddressFamily.InterNetwork)
                    .Select(e => e.Address)
                    .ToArray();
                if (addrs.Length == 0) continue;

                var mac = item.GetPhysicalAddress()?.GetAddressBytes();
                if (mac != null && mac.Length == 6) return mac;
            }

            return null;
        }

        /// <summary>获取本地第一个IPv4地址</summary>
        /// <returns></returns>
        public static IPAddress MyIP() => GetIPsWithCache().FirstOrDefault(ip => ip.IsIPv4() && !IPAddress.IsLoopback(ip) && ip.GetAddressBytes()[0] != 169);

        /// <summary>获取本地第一个IPv6地址</summary>
        /// <returns></returns>
        public static IPAddress MyIPv6() => GetIPsWithCache().FirstOrDefault(ip => !ip.IsIPv4() && !IPAddress.IsLoopback(ip));
        #endregion

        #region 远程开机
        /// <summary>唤醒指定MAC地址的计算机</summary>
        /// <param name="macs"></param>
        public static void Wake(params String[] macs)
        {
            if (macs == null || macs.Length < 1) return;

            foreach (var item in macs)
            {
                Wake(item);
            }
        }

        private static void Wake(String mac)
        {
            mac = mac.Replace("-", null).Replace(":", null);
            var buffer = new Byte[mac.Length / 2];
            for (var i = 0; i < buffer.Length; i++)
            {
                buffer[i] = Byte.Parse(mac.Substring(i * 2, 2), NumberStyles.HexNumber);
            }

            var bts = new Byte[6 + 16 * buffer.Length];
            for (var i = 0; i < 6; i++)
            {
                bts[i] = 0xFF;
            }
            for (Int32 i = 6, k = 0; i < bts.Length; i++, k++)
            {
                if (k >= buffer.Length) k = 0;

                bts[i] = buffer[k];
            }

            var client = new UdpClient
            {
                EnableBroadcast = true
            };
            client.Send(bts, bts.Length, new IPEndPoint(IPAddress.Broadcast, 7));
            client.Close();
            //client.SendAsync(bts, bts.Length, new IPEndPoint(IPAddress.Broadcast, 7));
        }
        #endregion

        #region MAC获取/ARP协议
        [DllImport("Iphlpapi.dll")]
        private static extern Int32 SendARP(UInt32 destip, UInt32 srcip, Byte[] mac, ref Int32 length);

        /// <summary>根据IP地址获取MAC地址</summary>
        /// <param name="ip"></param>
        /// <returns></returns>
        public static Byte[] GetMac(this IPAddress ip)
        {
            // 考虑到IPv6是16字节，不确定SendARP是否支持IPv6
            var len = 16;
            var buf = new Byte[16];
            var rs = SendARP(ip.GetAddressBytes().ToUInt32(), 0, buf, ref len);
            if (rs != 0 || len <= 0) return null;

            if (len != buf.Length) buf = buf.ReadBytes(0, len);
            return buf;
        }
        #endregion

        #region IP地理位置
        /// <summary>IP地址提供者</summary>
        public static IPProvider IpProvider;

        /// <summary>获取IP地址的物理地址位置</summary>
        /// <param name="addr"></param>
        /// <returns></returns>
        public static String GetAddress(this IPAddress addr)
        {
            if (addr.IsAny()) return "任意地址";
            if (IPAddress.IsLoopback(addr)) return "本地环回";
            if (addr.IsLocal()) return "本机地址";

            if (IpProvider == null) IpProvider = new MyIpProvider();

            return IpProvider.GetAddress(addr);
        }

        /// <summary>根据字符串形式IP地址转为物理地址</summary>
        /// <param name="addr"></param>
        /// <returns></returns>
        public static String IPToAddress(this String addr)
        {
            if (addr.IsNullOrEmpty()) return String.Empty;

            // 有可能是NetUri
            var p = addr.IndexOf("://");
            if (p >= 0) addr = addr.Substring(p + 3);

            // 有可能是多个IP地址
            p = addr.IndexOf(",");
            if (p >= 0) addr = addr.Split(",").FirstOrDefault();

            // 过滤IPv4/IPv6端口
            if (addr.Replace("::", "").Contains(":")) addr = addr.Substring(0, addr.LastIndexOf(":"));

            if (!IPAddress.TryParse(addr, out var ip)) return String.Empty;

            return ip.GetAddress();
        }

        /// <summary>IP地址提供者</summary>
        public class IPProvider
        {
            /// <summary>获取IP地址的物理地址位置</summary>
            /// <param name="addr"></param>
            /// <returns></returns>
            public virtual String GetAddress(IPAddress addr)
            {
                // 判断局域网地址
                var ip = addr.ToString();
                var myip = MyIP().ToString();
                if (ip.CutEnd(".") == myip.CutEnd(".")) return "本地局域网";

                var f = addr.GetAddressBytes()[0];
                if ((f & 0x7F) == 0) return "A类地址";
                if ((f & 0xC0) == 0x80) return "B类地址";
                if ((f & 0xE0) == 0xC0) return "C类地址";
                if ((f & 0xF0) == 0xE0) return "D类地址";
                if ((f & 0xF8) == 0xF0) return "E类地址";

                return "";
            }
        }
        #endregion

        #region 创建客户端和会话
        /// <summary>根据本地网络标识创建客户端</summary>
        /// <param name="local"></param>
        /// <returns></returns>
        public static ISocketClient CreateClient(this NetUri local)
        {
            if (local == null) throw new ArgumentNullException(nameof(local));

            return local.Type switch
            {
                NetType.Tcp => new TcpSession { Local = local },
                NetType.Udp => new UdpServer { Local = local },
                _ => throw new NotSupportedException("不支持{0}协议".F(local.Type)),
            };
        }

        /// <summary>根据远程网络标识创建客户端</summary>
        /// <param name="remote"></param>
        /// <returns></returns>
        public static ISocketClient CreateRemote(this NetUri remote)
        {
            if (remote == null) throw new ArgumentNullException(nameof(remote));

            return remote.Type switch
            {
                NetType.Tcp => new TcpSession { Remote = remote },
                NetType.Udp => new UdpServer { Remote = remote },
                //case NetType.Http:
                //    var http = new HttpClient { Remote = remote };
                //    //http.IsSSL = remote.Protocol.EqualIgnoreCase("https");
                //    return http;
                //case NetType.WebSocket:
                //    var ws = new HttpClient { Remote = remote };
                //    //ws.IsSSL = remote.Protocol.EqualIgnoreCase("https");
                //    ws.IsWebSocket = true;
                //    return ws;
                _ => throw new NotSupportedException("不支持{0}协议".F(remote.Type)),
            };
        }

        ///// <summary>根据远程网络标识创建客户端</summary>
        ///// <param name="uri"></param>
        ///// <returns></returns>
        //public static ISocketClient CreateRemote(this Uri uri)
        //{
        //    var http = new HttpClient();
        //    http.Request.Url = uri ?? throw new ArgumentNullException(nameof(uri));
        //    http.Remote = new NetUri(uri + "");

        //    switch (uri.Scheme.ToLower())
        //    {
        //        case "https":
        //            http.IsSSL = true;
        //            break;
        //        case "wss":
        //            http.IsWebSocket = true;
        //            http.IsSSL = true;
        //            break;
        //        case "ws":
        //            http.IsWebSocket = true;
        //            break;
        //        default:
        //            break;
        //    }

        //    return http;
        //}

        internal static Socket CreateTcp(Boolean ipv4 = true) => new Socket(ipv4 ? AddressFamily.InterNetwork : AddressFamily.InterNetworkV6, SocketType.Stream, ProtocolType.Tcp);

        internal static Socket CreateUdp(Boolean ipv4 = true) => new Socket(ipv4 ? AddressFamily.InterNetwork : AddressFamily.InterNetworkV6, SocketType.Dgram, ProtocolType.Udp);
        #endregion
    }
}