using System;
using System.Collections;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading;

using BeWo.Data;
using BeWo.Data.Access;
using BeWo.Data.Entities;

using BS.Shared;
using BS.Shared.Extensions;


namespace BeWoChatServer
{
    public class Server
    {
        // Fehlercodes zwischen 1000 und 1499

        private static readonly object _Lock = string.Empty;

        private static readonly ConcurrentDictionary<Socket, LoginData> clientList = new ConcurrentDictionary<Socket, LoginData>();
        protected static Socket serverSocket;

        private static AsyncCallback asyncCallback;

        private static int clientCount;

        public static void Main(string[] args)
        {
            try
            {
                Console.WriteLine(DateTime.Now + ": Starte Server");

                serverSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);

                var server = new IPEndPoint(IPAddress.Any, 5000);

                serverSocket.Bind(server);
                serverSocket.Listen(4);

                serverSocket.BeginAccept(OnClientConnected, null);

                while (true) { }
            }
            catch (Exception e)
            {
                WriteErrorMessageToConsole(e.Message, e.StackTrace, e);
            }
        }

        public static void OnClientConnected(IAsyncResult asyncResult)
        {
            try
            {
                var workerSocket = serverSocket.EndAccept(asyncResult);

                Interlocked.Increment(ref clientCount);

                var couldAdd = clientList.TryAdd(workerSocket, new LoginData(0, "", DateTime.Now));

                if(!couldAdd)
                {
                    Console.WriteLine("Socket war schon in der clientListe enthalten und konnte nicht hinzugefügt werden");
                }

                Console.WriteLine(DateTime.Now + ": Client hinzugefügt (" + workerSocket.RemoteEndPoint + ")");

                WaitForClientData(workerSocket, "", 0, 0, true);

                serverSocket.BeginAccept(OnClientConnected, null);

                LogAllClients();
            }
            catch (SocketException e)
            {
                WriteErrorMessageToConsole(e.Message, e.StackTrace, e);
            }
        }

        public static void WaitForClientData(Socket socket, string clientName, long oid, long recipientPersonOid, bool isEmployee)
        {
            try
            {
                if (asyncCallback == null)
                {
                    asyncCallback = OnReceiveData;
                }

                var packet = new Packet(socket, clientName, oid, recipientPersonOid, isEmployee);
                
                socket.BeginReceive(packet.DataBuffer, 0, packet.DataBuffer.Length, SocketFlags.None, asyncCallback, packet);
            }
            catch (Exception e)
            {
                WriteErrorMessageToConsole(e.Message, e.StackTrace, e);
            }
        }

        private static void LogAllClients()
        {
            Console.BackgroundColor = ConsoleColor.Black;
            Console.ForegroundColor = ConsoleColor.DarkMagenta;

            Console.WriteLine("Folgende Benutzer sind angemeldet:");
            var abc = "";
            clientList.DoForEach(c =>abc += "\t" + c.Key.RemoteEndPoint.ToString() + "; Angemeldete Person: " + c.Value.PersonOid + "; MAC: " + c.Value.MacAddress + "; Zeitpunkt: " + c.Value.LoginTime.ToString("dd.MM.yyyy HH:mm:ss.ffff") + "\n");

            Console.Write(abc);

            Console.BackgroundColor = ConsoleColor.Black;
            Console.ForegroundColor = ConsoleColor.Gray;
        }

        public static void OnReceiveData(IAsyncResult asyncResult)
        {
            
            var dataPacket = (Packet) asyncResult.AsyncState;

            Console.WriteLine(DateTime.Now + ": Empfange Nachricht (" + dataPacket.DataIdentifier.ToString() + ")");

            LogAllClients();

            try
            {
                var responseByteCount = dataPacket.Socket.EndReceive(asyncResult);

                var chars = new char[responseByteCount];

                var decoder = Encoding.UTF8.GetDecoder();
                decoder.GetChars(dataPacket.DataBuffer, 0, responseByteCount, chars, 0);

                if(chars.Count(f => f.Equals(';')) >= 4)
                {
                    var message = new string(chars);

                    dataPacket.GetData(message);
                }
                else
                {
                    Console.WriteLine("dataPacket ist korrupt: " + dataPacket);
                }

                switch(dataPacket.DataIdentifier) {
                    case DataIdentifier.KeepAlive:

                        //spiele Ping-Pong

                        var keepAlivePacket = new Packet(
                                dataPacket.Socket,
                                dataPacket.ClientName,
                                dataPacket.SenderPersonOid,
                                0,
                                dataPacket.IsEmployee)
                        {
                            DataIdentifier = DataIdentifier.KeepAlive,
                            Tenant = dataPacket.Tenant
                        };

                        dataPacket.Socket.Send(keepAlivePacket.GetDataStream());

                        break;

                    case DataIdentifier.Login:
                        try
                        {
                            Console.WriteLine(DateTime.Now + ": Login von " + dataPacket.ClientName + " mit MAC: " + dataPacket.ChatMessage);
                            Monitor.Enter(_Lock);

                            var endPoint = dataPacket.Socket.RemoteEndPoint;

                            var endPointCollection = clientList.Select(s => s.Key.RemoteEndPoint).ToList();

                            var istEnthalten = endPointCollection.Contains(endPoint);

                            var alteLogins = clientList.Values.Any(a => a.MacAddress.Equals(dataPacket.ChatMessage));

                            if(alteLogins)
                            {
                                var alt = clientList.Where(w => w.Value.MacAddress.Equals(dataPacket.ChatMessage) && !w.Key.Equals(dataPacket.Socket));
                                clientList.RemoveRange(alt);
                            }
                            
                            if(istEnthalten)
                            {
                                clientList[dataPacket.Socket].PersonOid = dataPacket.SenderPersonOid;
                                clientList[dataPacket.Socket].MacAddress = dataPacket.ChatMessage;
                            }

                            var notificationPacket = new Packet(
                                dataPacket.Socket, 
                                dataPacket.ClientName, 
                                dataPacket.SenderPersonOid, 
                                0, 
                                dataPacket.IsEmployee)
                                {
                                    DataIdentifier = DataIdentifier.StatusNotificationLogin, 
                                    Tenant = dataPacket.Tenant
                                };

                            Console.WriteLine(DateTime.Now + ": Benachrichtige die anderen angemeldeten Clients. Alte Logins enthalten: " + alteLogins);
                            foreach (var client in clientList.Where(w => !w.Value.PersonOid.Equals(dataPacket.SenderPersonOid)))
                            {
                                Console.WriteLine("Sende Login-Benachrichtigung an " + client.Value.MacAddress + " mit PersonOid " + client.Value.PersonOid);
                                client.Key.Send(notificationPacket.GetDataStream());
                            }

                            var successfulLoginNotification = new Packet(dataPacket.Socket, dataPacket.ClientName, dataPacket.SenderPersonOid, 0, dataPacket.IsEmployee) { DataIdentifier = DataIdentifier.LoginSuccess, Tenant = dataPacket.Tenant };
                            dataPacket.Socket.Send(successfulLoginNotification.GetDataStream());

                            // Boradcast
                            var abc = clientList.Where(w => w.Value.PersonOid != dataPacket.SenderPersonOid && w.Value.PersonOid > 0).Select(s => s.Value.PersonOid).Distinct().ToList();
                            var msg = "";

                            foreach(var oid in abc)
                            {
                                msg += oid;

                                if(abc.IndexOf(oid) != abc.Count - 1)
                                {
                                    msg += ",";
                                }
                            }

                            if(msg.Length > 0)
                            {
                                var packet = new Packet {ChatMessage = msg, ClientName = dataPacket.ClientName, DataIdentifier = DataIdentifier.StatusNotificationLoginBroadcast, MessageTimeStamp = DateTime.Now, Tenant = dataPacket.Tenant, SenderPersonOid = dataPacket.SenderPersonOid};

                                dataPacket.Socket.Send(packet.GetDataStream());
                            }

                            LogAllClients();
                        }
                        finally
                        {
                            Monitor.Exit(_Lock);
                        }

                        break;
                    case DataIdentifier.Message:
                        if(responseByteCount == 0)
                        {
                            try
                            {
                                Console.WriteLine(DateTime.Now + ": Chat-Nachricht ist leer und sorgt dafür, dass der Client ausgeloggt wird");

                                Monitor.Enter(_Lock);

                                var notificationPacketLogout2 = new Packet(dataPacket.Socket, dataPacket.ClientName, dataPacket.SenderPersonOid, 0, dataPacket.IsEmployee) { DataIdentifier = DataIdentifier.StatusNotificationLogout, Tenant = dataPacket.Tenant};

                                LoginData wtf = null;
                                var wasAbleToRemoveClient = clientList.TryRemove(dataPacket.Socket, out wtf);

                                if(!wasAbleToRemoveClient)
                                {
                                    Console.WriteLine("Konnte den Client nicht aus der Liste entfernen.");
                                }

                                Console.WriteLine(DateTime.Now + ": Leite Logout an die anderen Clients weiter");
                                foreach(var client in clientList)
                                {
                                    client.Key.Send(notificationPacketLogout2.GetDataStream());
                                }

                                dataPacket.Socket.Close();
                            }
                            finally
                            {
                                Monitor.Exit(_Lock);
                            }

                            return;
                        }

                        try
                        {
                            Console.BackgroundColor = ConsoleColor.Black;
                            Console.ForegroundColor = ConsoleColor.DarkYellow;
                            Console.WriteLine(DateTime.Now + ": Chat-Nachricht erhalten: " + dataPacket.MessageTimeStamp.ToString("dd.MM.yyyy HH:mm:ss"));
                            Console.BackgroundColor = ConsoleColor.Black;
                            Console.ForegroundColor = ConsoleColor.Gray;

                            Monitor.Enter(_Lock);

                            DefaultHibernateSessionManager.CurrentTenant = dataPacket.Tenant;

                            var chatMessage = new ChatMessage
                            {
                                SenderPersonOid = dataPacket.SenderPersonOid,
                                ChatText = Encoding.UTF8.GetBytes(dataPacket.ChatMessage),
                                EmpfaengerPersonOid = dataPacket.RecipientPersonOid,
                                Uhrzeit = DateTime.Now,
                                InsUser = dataPacket.ClientName,
                                IsDelivered = true,
                                MessageId = dataPacket.MessageId,
                                MediaTyp = dataPacket.MediaTyp
                            };

                            Console.WriteLine(DateTime.Now + ": Speichere die Chat-Nachricht in der Datenbank");

                            DAOFactory.GenericDAO.Insert(chatMessage);
                            
                            var newestMessage = DAOFactory.SearchDAO.GetNewestChatMessageForConversation(dataPacket.RecipientPersonOid, dataPacket.SenderPersonOid, false);
                            var newestChatMessage = new NewestChatMessage
                            {
                                ChatMessageOid = chatMessage.Oid,
                                IsTeam = false,
                                RecipientPersonOid = dataPacket.RecipientPersonOid,
                                SenderPersonOid = dataPacket.SenderPersonOid
                            };

                            if (newestMessage != null)
                            {
                                DAOFactory.GenericDAO.Delete(newestMessage);
                            }

                            DAOFactory.GenericDAO.Insert(newestChatMessage);

                            //Media Bereich mit Bild und Dok. 
                            if(dataPacket.MediaDatei != null)
                            {
                                byte[] media = dataPacket.MediaDatei;
                                byte[] ThImage = null;

                                if (dataPacket.MediaTyp == 1)
                                {
                                    ThImage = media;
                                }

                                var chatMediaMessage = new ChatMediaMessage
                                {
                                    Media = media,
                                    InsUser = dataPacket.ClientName,
                                    ImageThumpNail = BS.Shared.Core.Utils.ErstelleThumbnail(ThImage, 150, 150),
                                    ChatMessageOid = chatMessage.Oid
                                };

                                 Console.WriteLine(DateTime.Now + ": Speichere die Chat-Media-Nachricht in der Datenbank");

                                DAOFactory.GenericDAO.Insert(chatMediaMessage);

                            }

                            if(chatMessage.Oid != null)
                            {
                                Console.WriteLine(DateTime.Now + ": Chat-Nachricht erfolgreich mit Oid " + chatMessage.Oid.Value + " gespeichert");
                                dataPacket.ServerseitigeOid = chatMessage.Oid.Value;
                            }

                            if(dataPacket.RecipientPersonOid > 0)
                            {
                                if(clientList.Values.Any(a => a.PersonOid.Equals(dataPacket.RecipientPersonOid)))
                                {
                                    var recipients = clientList.Where(w => w.Value.PersonOid.Equals(dataPacket.RecipientPersonOid));

                                    Console.WriteLine(DateTime.Now + ": Leite die Chat-Nachricht an die Empfänger (Derselbe User angemeldet an verschiedenen Clients) weiter");
                                    foreach(var recipient in recipients)
                                    {
                                        recipient.Key.Send(dataPacket.GetDataStream());
                                    }
                                }

                                var packet = new Packet
                                {
                                    ClientseitigeOid = dataPacket.ClientseitigeOid,
                                    ServerseitigeOid = dataPacket.ServerseitigeOid,
                                    DataIdentifier = DataIdentifier.MessageResponse,
                                    MessageTimeStamp = chatMessage.Uhrzeit,
                                    MessageId = dataPacket.MessageId
                                };

                                Console.WriteLine(DateTime.Now + ": Sende Datenbank-Insert-Bestätigung an den Absender, damit die Nachricht später nicht doppelt auf den Client heruntergeladen wird");
                                dataPacket.Socket.Send(packet.GetDataStream());
                            }
                        }
                        finally
                        {
                            Monitor.Exit(_Lock);
                        }

                        break;
                    case DataIdentifier.Logout:
                        LoginData ld;
                        var wasAbleToRemoveClient2 = clientList.TryRemove(dataPacket.Socket, out ld);
                        if(!wasAbleToRemoveClient2)
                        {
                            Console.WriteLine("Konnte den Client nicht aus der Liste entfernen.");
                        }

                        var notificationPacketLogout = new Packet(dataPacket.Socket, dataPacket.ClientName, dataPacket.SenderPersonOid, 0, dataPacket.IsEmployee)
                        {
                            DataIdentifier = DataIdentifier.StatusNotificationLogout,
                            Tenant = dataPacket.Tenant
                        };

                        Console.WriteLine(DateTime.Now + ": Sende Logout von " + dataPacket.ClientName + " an alle anderen Clients");
                        foreach (var client in clientList.Where(w => !w.Value.PersonOid.Equals(dataPacket.SenderPersonOid)))
                        {
                            client.Key.Send(notificationPacketLogout.GetDataStream());
                        }

                        LogAllClients();

                        break;

                    case DataIdentifier.Team:
                        try
                        {
                            Console.WriteLine(DateTime.Now + ": Team-Nachricht erhalten");

                            Monitor.Enter(_Lock);

                            DefaultHibernateSessionManager.CurrentTenant = dataPacket.Tenant;

                            var chatMessage = new ChatMessage
                            {
                                SenderPersonOid = dataPacket.SenderPersonOid,
                                ChatText = Encoding.UTF8.GetBytes(dataPacket.ChatMessage),
                                EmpfaengerPersonOid = dataPacket.RecipientPersonOid,
                                Uhrzeit = dataPacket.MessageTimeStamp,
                                InsUser = dataPacket.ClientName,
                                TeamOid = dataPacket.RecipientPersonOid,
                                IsDelivered = true,
                                MessageId = dataPacket.MessageId,
                                MediaTyp = dataPacket.MediaTyp
                            };

                            var team = DAOFactory.GenericDAO.LoadByID<Team>(dataPacket.RecipientPersonOid);

                            Console.WriteLine(DateTime.Now + ": Speichere Team-Nachricht in der Datenbank");
                            DAOFactory.GenericDAO.Insert(chatMessage);

                            var newestMessage = DAOFactory.SearchDAO.GetNewestChatMessageForConversation(dataPacket.RecipientPersonOid, dataPacket.SenderPersonOid, true);
                            var newestChatMessage = new NewestChatMessage
                            {
                                ChatMessageOid = chatMessage.Oid,
                                IsTeam = true,
                                RecipientPersonOid = dataPacket.RecipientPersonOid,
                                SenderPersonOid = dataPacket.SenderPersonOid
                            };

                            if (newestMessage != null)
                            {
                                DAOFactory.GenericDAO.Delete(newestMessage);
                            }

                            DAOFactory.GenericDAO.Insert(newestChatMessage);

                            //Media Bereich mit Bild und Dok. 
                            if (dataPacket.MediaDatei != null)
                            {
                                byte[] media = dataPacket.MediaDatei;
                                byte[] ThImage = null;

                                if (dataPacket.MediaTyp == 1)
                                {
                                    ThImage = media;
                                }

                                var chatMediaMessage = new ChatMediaMessage
                                {
                                    Media = media,
                                    InsUser = dataPacket.ClientName,
                                    ImageThumpNail = BS.Shared.Core.Utils.ErstelleThumbnail(ThImage, 150, 150),
                                    ChatMessageOid = chatMessage.Oid
                                };

                                Console.WriteLine(DateTime.Now + ": Speichere die Chat-Media-Nachricht in der Datenbank");

                                DAOFactory.GenericDAO.Insert(chatMediaMessage);
                            }

                            var personOids = team.MemberList.Select(s => s.Person.Oid.Value);

                            if (chatMessage.Oid != null)
                            {
                                Console.WriteLine(DateTime.Now + ": Team-Nachricht erfolgreich mit Oid " + chatMessage.Oid.Value + " gespeichert");
                                dataPacket.ServerseitigeOid = chatMessage.Oid.Value;
                            }

                            Console.WriteLine(DateTime.Now + ": Leite die Team-Nachricht an die Empfänger weiter");
                            foreach (var recipient in clientList.Where(w => w.Value.PersonOid != dataPacket.SenderPersonOid && personOids.Contains(w.Value.PersonOid)))
                            {
                                recipient.Key.Send(dataPacket.GetDataStream());
                            }

                            var packet = new Packet
                            {
                                ClientseitigeOid = dataPacket.ClientseitigeOid,
                                ServerseitigeOid = dataPacket.ServerseitigeOid,
                                DataIdentifier = DataIdentifier.MessageResponse,
                                MessageId = dataPacket.MessageId
                            };

                            Console.WriteLine(DateTime.Now + ": Sende Datenbank-Insert-Bestätigung an den Absender, damit die Nachricht später nicht doppelt auf den Client heruntergeladen wird");
                            dataPacket.Socket.Send(packet.GetDataStream());
                        }
                        finally
                        {
                            Monitor.Exit(_Lock);
                        }

                        break;

                    case DataIdentifier.StatusNotificationBeschäftigt:

                        SendNotificationPacket(dataPacket, DataIdentifier.StatusNotificationBeschäftigt);

                        break;

                    case DataIdentifier.StatusNotificationOnline:

                        SendNotificationPacket(dataPacket, DataIdentifier.StatusNotificationOnline);

                        break;

                    case DataIdentifier.StatusNotificationOffline:

                        SendNotificationPacket(dataPacket, DataIdentifier.StatusNotificationOffline);

                        break;

                    case DataIdentifier.Null:

                        var asfdabc = dataPacket.ChatMessage;

                        break;

                    case DataIdentifier.StatusRequest:
                        
                        var onlinePersons = clientList.Where(w => w.Value.PersonOid != dataPacket.SenderPersonOid && w.Value.PersonOid > 0).Select(s => s.Value.PersonOid).Distinct().ToList();
                            var oidCSV = "";

                            foreach (var oid in onlinePersons)
                            {
                                oidCSV += oid;

                                if (onlinePersons.IndexOf(oid) != onlinePersons.Count - 1)
                                {
                                    oidCSV += ",";
                                }
                            }

                            if (oidCSV.Length > 0)
                            {
                                var packet = new Packet { ChatMessage = oidCSV, ClientName = dataPacket.ClientName, DataIdentifier = DataIdentifier.StatusRequest, MessageTimeStamp = DateTime.Now, Tenant = dataPacket.Tenant, SenderPersonOid = dataPacket.SenderPersonOid };

                                dataPacket.Socket.Send(packet.GetDataStream());
                            }

                        break;
                }

                WaitForClientData(dataPacket.Socket, dataPacket.ClientName, dataPacket.SenderPersonOid, dataPacket.RecipientPersonOid, dataPacket.IsEmployee);
            }
            catch (Exception e)
            {
                Console.WriteLine(DateTime.Now + ": Ein Fehler ist aufgetreten oder die App ist abgestürzt. Der Client wird ausgeloggt (" + dataPacket.ClientName + ")");

                var sender = dataPacket.Socket;

                var notificationPacketLogout = new Packet(dataPacket.Socket, dataPacket.ClientName, dataPacket.SenderPersonOid, 0, dataPacket.IsEmployee) { DataIdentifier = DataIdentifier.StatusNotificationLogout, Tenant = dataPacket.Tenant};

                try
                {
                    Monitor.Enter(_Lock);

                    if(clientList.ContainsKey(sender))
                    {
                        LoginData loginData;
                        var wasAbleToRemoveClient3 = clientList.TryRemove(sender, out loginData);
                        if(!wasAbleToRemoveClient3)
                        {
                            Console.WriteLine("Konnte den Client nicht aus der Liste entfernen.");
                        }

                        LogAllClients();

                        Console.WriteLine(DateTime.Now + ": Leite Logout an die anderen Clients weiter");
                        foreach(var client in clientList)
                        {
                            client.Key.Send(notificationPacketLogout.GetDataStream());
                        }

                        sender.Close();
                    }
                }
                catch(SocketException se)
                {
                    WriteErrorMessageToConsole(se.Message, se.StackTrace, se);
                }
                finally
                {
                    Monitor.Exit(_Lock);
                }

                WriteErrorMessageToConsole(e.Message, e.StackTrace, e);
            }
        }

        private static Random random = new Random();
        public static string RandomString(int length)
        {
            const string chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
            return new string(Enumerable.Repeat(chars, length)
              .Select(s => s[random.Next(s.Length)]).ToArray());
        }

        private static void SendNotificationPacket(Packet dataPacket, DataIdentifier dataIdentifier)
        {
            var notificationPacket = new Packet(dataPacket.Socket, dataPacket.ClientName, dataPacket.SenderPersonOid, 0, dataPacket.IsEmployee) { DataIdentifier = DataIdentifier.StatusNotificationLogout, Tenant = dataPacket.Tenant};

            Console.WriteLine(DateTime.Now + ": Sende Statusänderung(" + dataIdentifier + ") an alle anderen Clients");
            foreach (var client in clientList.Where(w => w.Value.PersonOid != dataPacket.SenderPersonOid))
            {
                client.Key.Send(notificationPacket.GetDataStream());
            }
        }

        private static void WriteErrorMessageToConsole(string message, string stackTrace, Exception ex = null)
        {
            Console.BackgroundColor = ConsoleColor.Black;
            Console.ForegroundColor = ConsoleColor.Red;
            Console.WriteLine(DateTime.Now + ": " + message);
            Console.WriteLine(stackTrace);

            if(ex != null)
            {
                var st = new StackTrace(ex, true);
                var frame = st.GetFrame(st.FrameCount - 1);
                var line = frame.GetFileLineNumber();

                Console.WriteLine("Zeile: " + line);
            }

            Console.BackgroundColor = ConsoleColor.Black;
            Console.ForegroundColor = ConsoleColor.Gray;
        }
    }

    public class LoginData
    {
        public long     PersonOid  { get; set; }
        public string   MacAddress { get; set; }
        public DateTime LoginTime  { get; set; }

        public LoginData(long pPersonOid, string pMacAddress, DateTime pLoginTime)
        {
            PersonOid  = pPersonOid;
            MacAddress = pMacAddress;
            LoginTime  = pLoginTime;
        }
    }
}