using linker.libs;
using linker.libs.extends;
using linker.messenger.relay.messenger;
using System.Buffers;
using System.Collections.Concurrent;
using System.Net;
using System.Net.Sockets;

namespace linker.messenger.relay.server
{
    /// <summary>
    /// 中继节点操作
    /// </summary>
    public class RelayServerNodeTransfer
    {
        private uint connectionNum = 0;
        private IConnection localConnection;
        private IConnection remoteConnection;

        private long bytes = 0;
        private long lastBytes = 0;
        private RelaySpeedLimit limitTotal = new RelaySpeedLimit();
        private readonly ConcurrentDictionary<ulong, RelayTrafficCacheInfo> trafficDict = new ConcurrentDictionary<ulong, RelayTrafficCacheInfo>();
        private readonly ConcurrentDictionary<long, long> cdkeyLastBytes = new ConcurrentDictionary<long, long>();

        private readonly ISerializer serializer;
        private readonly IRelayServerNodeStore relayServerNodeStore;
        private readonly IRelayServerMasterStore relayServerMasterStore;
        private readonly IMessengerResolver messengerResolver;
        private readonly IMessengerSender messengerSender;

        public RelayServerNodeTransfer(ISerializer serializer, IRelayServerNodeStore relayServerNodeStore, IRelayServerMasterStore relayServerMasterStore, IMessengerResolver messengerResolver, IMessengerSender messengerSender)
        {
            this.serializer = serializer;
            this.relayServerNodeStore = relayServerNodeStore;
            this.relayServerMasterStore = relayServerMasterStore;
            this.messengerResolver = messengerResolver;
            this.messengerSender = messengerSender;

            limitTotal.SetLimit((uint)Math.Ceiling((relayServerNodeStore.Node.MaxBandwidthTotal * 1024 * 1024) / 8.0));

            TrafficTask();
            ReportTask();
            SignInTask();

        }

        public async ValueTask<RelayCacheInfo> TryGetRelayCache(string key, string nodeid)
        {
            try
            {
                IConnection connection = relayServerNodeStore.Node.Id == RelayServerNodeInfo.MASTER_NODE_ID ? localConnection : remoteConnection;

                MessageResponeInfo resp = await messengerSender.SendReply(new MessageRequestWrap
                {
                    Connection = connection,
                    MessengerId = (ushort)RelayMessengerIds.NodeGetCache,
                    Payload = serializer.Serialize(key)
                });
                if (resp.Code == MessageResponeCodes.OK && resp.Data.Length > 0)
                {
                    return serializer.Deserialize<RelayCacheInfo>(resp.Data.Span);
                }
            }
            catch (Exception ex)
            {
                if (LoggerHelper.Instance.LoggerLevel <= LoggerTypes.DEBUG)
                    LoggerHelper.Instance.Error($"{ex}");
            }
            return null;
        }

        /// <summary>
        /// 无效请求
        /// </summary>
        /// <returns></returns>
        public bool Validate(RelayCacheInfo relayCache)
        {
            //已认证的没有流量限制
            if (relayCache.Validated) return true;
            //流量卡有的，就能继续用
            if (relayCache.Cdkey.Any(c => c.LastBytes > 0)) return true;

            return ValidateConnection(relayCache) && ValidateBytes(relayCache);
        }
        /// <summary>
        /// 连接数是否够
        /// </summary>
        /// <returns></returns>
        private bool ValidateConnection(RelayCacheInfo relayCache)
        {
            bool res = relayServerNodeStore.Node.MaxConnection == 0 || relayServerNodeStore.Node.MaxConnection * 2 > connectionNum;
            if (res == false && LoggerHelper.Instance.LoggerLevel <= LoggerTypes.DEBUG)
                LoggerHelper.Instance.Debug($"relay  ValidateConnection false,{connectionNum}/{relayServerNodeStore.Node.MaxConnection * 2}");

            return res;
        }
        /// <summary>
        /// 流量是否够
        /// </summary>
        /// <returns></returns>
        private bool ValidateBytes(RelayCacheInfo relayCache)
        {
            bool res = relayServerNodeStore.Node.MaxGbTotal == 0
                || (relayServerNodeStore.Node.MaxGbTotal > 0 && relayServerNodeStore.Node.MaxGbTotalLastBytes > 0);

            if (res == false && LoggerHelper.Instance.LoggerLevel <= LoggerTypes.DEBUG)
                LoggerHelper.Instance.Debug($"relay  ValidateBytes false,{relayServerNodeStore.Node.MaxGbTotalLastBytes}bytes/{relayServerNodeStore.Node.MaxGbTotal}gb");

            return res;
        }

        /// <summary>
        /// 增加连接数
        /// </summary>
        public void IncrementConnectionNum()
        {
            Interlocked.Increment(ref connectionNum);
        }
        /// <summary>
        /// 减少连接数
        /// </summary>
        public void DecrementConnectionNum()
        {
            Interlocked.Decrement(ref connectionNum);
        }

        /// <summary>
        /// 是否需要总限速
        /// </summary>
        /// <returns></returns>
        public bool NeedLimit(RelayTrafficCacheInfo relayCache)
        {
            if (relayCache.Cache.Validated) return false;
            //if (relayCache.CurrentCdkey != null) return false;
            return limitTotal.NeedLimit();
        }
        /// <summary>
        /// 总限速
        /// </summary>
        /// <param name="length"></param>
        /// <returns></returns>
        public bool TryLimit(ref int length)
        {
            return limitTotal.TryLimit(ref length);
        }


        /// <summary>
        /// 开始计算流量
        /// </summary>
        /// <param name="relayCache"></param>
        public void AddTrafficCache(RelayTrafficCacheInfo relayCache)
        {
            SetLimit(relayCache);
            trafficDict.TryAdd(relayCache.Cache.FlowId, relayCache);
        }
        /// <summary>
        /// 取消计算流量
        /// </summary>
        /// <param name="relayCache"></param>
        public void RemoveTrafficCache(RelayTrafficCacheInfo relayCache)
        {
            trafficDict.TryRemove(relayCache.Cache.FlowId, out _);
            foreach (var item in relayCache.Cache.Cdkey)
            {
                cdkeyLastBytes.TryRemove(item.CdkeyId, out _);
            }
        }
        /// <summary>
        /// 消耗流量
        /// </summary>
        /// <param name="length"></param>
        /// <returns></returns>
        public bool AddBytes(RelayTrafficCacheInfo cache, long length)
        {
            Interlocked.Add(ref bytes, length);

            //验证过的，不消耗流量
            if (cache.Cache.Validated) return true;
            //节点无流量限制的，不消耗流量
            if (relayServerNodeStore.Node.MaxGbTotal == 0) return true;

            Interlocked.Add(ref cache.Sendt, length);

            var current = cache.CurrentCdkey;
            if (current != null) return current.LastBytes > 0;

            return relayServerNodeStore.Node.MaxGbTotalLastBytes > 0;
        }

        /// <summary>
        /// 设置限速
        /// </summary>
        /// <param name="relayCache"></param>
        private void SetLimit(RelayTrafficCacheInfo relayCache)
        {
            //无限制
            if (relayCache.Cache.Validated || relayServerNodeStore.Node.MaxBandwidth == 0)
            {
                relayCache.Limit.SetLimit(0);
                return;
            }

            RelayServerCdkeyInfo currentCdkey = relayCache.Cache.Cdkey.Where(c => c.LastBytes > 0).OrderByDescending(c => c.Bandwidth).FirstOrDefault();
            //有cdkey，且带宽大于节点带宽，就用cdkey的带宽
            if (currentCdkey != null && (currentCdkey.Bandwidth == 0 || currentCdkey.Bandwidth > relayServerNodeStore.Node.MaxBandwidth))
            {
                relayCache.CurrentCdkey = currentCdkey;
                relayCache.Limit.SetLimit((uint)Math.Ceiling((relayCache.CurrentCdkey.Bandwidth * 1024 * 1024) / 8.0));
                return;
            }

            relayCache.CurrentCdkey = null;
            relayCache.Limit.SetLimit((uint)Math.Ceiling((relayServerNodeStore.Node.MaxBandwidth * 1024 * 1024) / 8.0));
        }

        private void ResetNodeBytes()
        {
            foreach (var cache in trafficDict.Values.Where(c => c.CurrentCdkey == null))
            {
                long length = cache.Sendt;
                Interlocked.Exchange(ref cache.Sendt, 0);
                if (relayServerNodeStore.Node.MaxGbTotalLastBytes >= length)
                    relayServerNodeStore.SetMaxGbTotalLastBytes(relayServerNodeStore.Node.MaxGbTotalLastBytes - length);
                else relayServerNodeStore.SetMaxGbTotalLastBytes(0);
            }
            if (relayServerNodeStore.Node.MaxGbTotalMonth != DateTime.Now.Month)
            {
                relayServerNodeStore.SetMaxGbTotalMonth(DateTime.Now.Month);
                relayServerNodeStore.SetMaxGbTotalLastBytes((long)(relayServerNodeStore.Node.MaxGbTotal * 1024 * 1024 * 1024));
            }
            relayServerNodeStore.Confirm();
        }
        private void DownloadBytes()
        {
            TimerHelper.Async(async () =>
            {
                List<long> ids = trafficDict.Values.SelectMany(c => c.Cache.Cdkey).Select(c => c.CdkeyId).Distinct().ToList();
                while (ids.Count > 0)
                {
                    //分批更新，可能数量很大
                    List<long> id = ids.Take(100).ToList();
                    ids.RemoveRange(0, id.Count);

                    MessageResponeInfo resp = await messengerSender.SendReply(new MessageRequestWrap
                    {
                        Connection = relayServerNodeStore.Node.Id == RelayServerNodeInfo.MASTER_NODE_ID ? localConnection : remoteConnection,
                        MessengerId = (ushort)RelayMessengerIds.TrafficReport,
                        Payload = serializer.Serialize(new RelayTrafficUpdateInfo
                        {
                            Dic = [],
                            Ids = id,
                            SecretKey = relayServerNodeStore.Node.Id == RelayServerNodeInfo.MASTER_NODE_ID
                             ? relayServerMasterStore.Master.SecretKey
                             : relayServerNodeStore.Node.MasterSecretKey
                        }),
                        Timeout = 4000
                    });

                    if (resp.Code == MessageResponeCodes.OK && resp.Data.Length > 0)
                    {
                        Dictionary<long, long> dic = serializer.Deserialize<Dictionary<long, long>>(resp.Data.Span);
                        //更新剩余流量
                        foreach (KeyValuePair<long, long> item in dic)
                        {
                            cdkeyLastBytes.AddOrUpdate(item.Key, item.Value, (a, b) => item.Value);
                        }
                        //查不到的，归零
                        foreach (long item in id.Except(dic.Keys))
                        {
                            cdkeyLastBytes.AddOrUpdate(item, 0, (a, b) => 0);
                        }
                    }
                }
            });
        }
        private void UploadBytes()
        {
            TimerHelper.Async(async () =>
            {
                MessageResponeInfo resp = await messengerSender.SendReply(new MessageRequestWrap
                {
                    Connection = relayServerNodeStore.Node.Id == RelayServerNodeInfo.MASTER_NODE_ID ? localConnection : remoteConnection,
                    MessengerId = (ushort)RelayMessengerIds.TrafficReport,
                    Payload = serializer.Serialize(new RelayTrafficUpdateInfo
                    {
                        Dic = trafficDict.Values.Where(c => c.CurrentCdkey != null && c.Sendt > 0).GroupBy(c => c.CurrentCdkey.CdkeyId).ToDictionary(c => c.Key, d => d.Sum(d => d.Sendt)),
                        Ids = [],
                        SecretKey = relayServerNodeStore.Node.Id == RelayServerNodeInfo.MASTER_NODE_ID
                             ? relayServerMasterStore.Master.SecretKey
                             : relayServerNodeStore.Node.MasterSecretKey
                    }),
                    Timeout = 4000
                });

                if (resp.Code == MessageResponeCodes.OK)
                {
                    try
                    {
                        serializer.Deserialize<Dictionary<string, ulong>>(resp.Data.Span);
                        //成功报告了流量，就重新计数
                        foreach (var cache in trafficDict.Values.Where(c => c.CurrentCdkey != null))
                        {
                            Interlocked.Exchange(ref cache.Sendt, 0);
                            //检查一下是不是需要更新剩余流量
                            if (cdkeyLastBytes.TryGetValue(cache.CurrentCdkey.CdkeyId, out long value))
                            {
                                cache.CurrentCdkey.LastBytes = value;
                            }
                            //当前cdkey流量用完了，就重新找找新的cdkey
                            if (cache.CurrentCdkey.LastBytes <= 0)
                            {
                                SetLimit(cache);
                            }
                        }
                    }
                    catch (Exception)
                    {
                    }
                }
            });
        }
        private void TrafficTask()
        {
            TimerHelper.SetIntervalLong(() =>
            {
                UploadBytes();
                DownloadBytes();

                ResetNodeBytes();

                return true;
            }, 5000);
        }

        private void ReportTask()
        {
            TimerHelper.SetIntervalLong(async () =>
            {
                IEnumerable<RelayServerNodeInfo> nodes = new List<RelayServerNodeInfo>
                {
                    //默认报告给自己，作为本服务器的一个默认中继节点
                    new RelayServerNodeInfo{
                        Id = RelayServerNodeInfo.MASTER_NODE_ID,
                        Host = new IPEndPoint(IPAddress.Any, relayServerNodeStore.ServicePort).ToString(),
                        MasterHost =  new IPEndPoint(IPAddress.Loopback, relayServerNodeStore.ServicePort).ToString(),
                        MasterSecretKey = relayServerMasterStore.Master.SecretKey,
                        MaxBandwidth = 0,
                        MaxConnection = 0,
                        MaxBandwidthTotal=0,
                        MaxGbTotal=0,
                        MaxGbTotalLastBytes=0,
                        MaxGbTotalMonth=0,
                        Name = "default",
                        Public = false
                    },
                    //配置的中继节点
                    relayServerNodeStore.Node
                }.Where(c => string.IsNullOrWhiteSpace(c.MasterHost) == false && string.IsNullOrWhiteSpace(c.MasterSecretKey) == false)
                .Where(c => string.IsNullOrWhiteSpace(c.Name) == false && string.IsNullOrWhiteSpace(c.Id) == false);

                double diff = (bytes - lastBytes) * 8 / 1024.0 / 1024.0;
                lastBytes = bytes;

                foreach (var node in nodes)
                {
                    try
                    {
                        IConnection connection = node.Id == RelayServerNodeInfo.MASTER_NODE_ID ? localConnection : remoteConnection;
                        IPEndPoint endPoint = await NetworkHelper.GetEndPointAsync(node.Host, relayServerNodeStore.ServicePort) ?? new IPEndPoint(IPAddress.Any, relayServerNodeStore.ServicePort);

                        RelayServerNodeReportInfo relayNodeReportInfo = new RelayServerNodeReportInfo
                        {
                            Id = node.Id,
                            Name = node.Name,
                            Public = node.Public,
                            MaxBandwidth = node.MaxBandwidth,
                            BandwidthRatio = Math.Round(node.MaxBandwidthTotal == 0 ? 0 : diff / 5 / node.MaxBandwidthTotal, 2),
                            MaxBandwidthTotal = node.MaxBandwidthTotal,
                            MaxGbTotal = node.MaxGbTotal,
                            MaxGbTotalLastBytes = node.MaxGbTotalLastBytes,
                            MaxConnection = node.MaxConnection,
                            ConnectionRatio = Math.Round(node.MaxConnection == 0 ? 0 : connectionNum / 2.0 / node.MaxConnection, 2),
                            EndPoint = endPoint
                        };

                        await messengerSender.SendOnly(new MessageRequestWrap
                        {
                            Connection = connection,
                            MessengerId = (ushort)RelayMessengerIds.NodeReport,
                            Payload = serializer.Serialize(relayNodeReportInfo)
                        });
                    }
                    catch (Exception ex)
                    {
                        if (LoggerHelper.Instance.LoggerLevel <= LoggerTypes.DEBUG)
                        {
                            LoggerHelper.Instance.Error($"relay report : {ex}");
                        }
                    }
                }
                return true;
            }, 5000);
        }

        private void SignInTask()
        {
            TimerHelper.SetIntervalLong(async () =>
            {
                if ((remoteConnection == null || remoteConnection.Connected == false) && string.IsNullOrWhiteSpace(relayServerNodeStore.Node.MasterHost) == false)
                {
                    remoteConnection = await SignIn(relayServerNodeStore.Node.MasterHost, relayServerNodeStore.Node.MasterSecretKey).ConfigureAwait(false);
                }
                if (localConnection == null || localConnection.Connected == false)
                {
                    localConnection = await SignIn(new IPEndPoint(IPAddress.Loopback, relayServerNodeStore.ServicePort).ToString(), relayServerMasterStore.Master.SecretKey).ConfigureAwait(false);
                }
                return true;
            }, 3000);
        }
        private async Task<IConnection> SignIn(string host, string secretKey)
        {
            byte[] bytes = ArrayPool<byte>.Shared.Rent(1024);
            try
            {
                byte[] secretKeyBytes = secretKey.Md5().ToBytes();

                bytes[0] = (byte)secretKeyBytes.Length;
                secretKeyBytes.AsSpan().CopyTo(bytes.AsSpan(1));


                IPEndPoint remote = await NetworkHelper.GetEndPointAsync(host, 1802);

                Socket socket = new Socket(remote.Address.AddressFamily, SocketType.Stream, ProtocolType.Tcp);
                socket.KeepAlive();
                await socket.ConnectAsync(remote).WaitAsync(TimeSpan.FromMilliseconds(5000)).ConfigureAwait(false);
                return await messengerResolver.BeginReceiveClient(socket, true, (byte)ResolverType.RelayReport, bytes.AsMemory(0, secretKeyBytes.Length + 1)).ConfigureAwait(false);
            }
            catch (Exception ex)
            {
                if (LoggerHelper.Instance.LoggerLevel <= LoggerTypes.DEBUG)
                {
                    LoggerHelper.Instance.Error(ex);
                }
            }
            finally
            {
                ArrayPool<byte>.Shared.Return(bytes);
            }
            return null;
        }
    }

    public sealed partial class RelayTrafficUpdateInfo
    {
        /// <summary>
        /// cdkey id  和 流量
        /// </summary>
        public Dictionary<long, long> Dic { get; set; }
        /// <summary>
        /// 需要知道哪些cdkey的剩余流量
        /// </summary>
        public List<long> Ids { get; set; }
        public string SecretKey { get; set; }
    }

}