using System;
using System.Diagnostics;
using System.IO;
using Server.Gumps;
using Server.Mobiles;
using Server.Network;

namespace Server.Misc
{
  public class ClientVerification
  {
    private static readonly bool m_DetectClientRequirement = true;
    private static readonly OldClientResponse m_OldClientResponse = OldClientResponse.LenientKick;

    private static readonly TimeSpan m_AgeLeniency = TimeSpan.FromDays(10);
    private static readonly TimeSpan m_GameTimeLeniency = TimeSpan.FromHours(25);

    public static ClientVersion Required { get; set; }

    public static bool AllowRegular { get; set; } = true;

    public static bool AllowUOTD { get; set; } = true;

    public static bool AllowGod { get; set; } = true;

    public static TimeSpan KickDelay { get; set; } = TimeSpan.FromSeconds(20.0);

    public static void Initialize()
    {
      EventSink.ClientVersionReceived += EventSink_ClientVersionReceived;

      // ClientVersion.Required = null;
      // Required = new ClientVersion( "6.0.0.0" );

      if (m_DetectClientRequirement)
      {
        string path = Core.FindDataFile("client.exe");

        if (File.Exists(path))
        {
          FileVersionInfo info = FileVersionInfo.GetVersionInfo(path);

          if (info.FileMajorPart != 0 || info.FileMinorPart != 0 || info.FileBuildPart != 0 ||
              info.FilePrivatePart != 0)
            Required = new ClientVersion(info.FileMajorPart, info.FileMinorPart, info.FileBuildPart,
              info.FilePrivatePart);
        }
      }

      if (Required != null)
      {
        Utility.PushColor(ConsoleColor.White);
        Console.WriteLine("Restricting client version to {0}. Action to be taken: {1}", Required,
          m_OldClientResponse);
        Utility.PopColor();
      }
    }

    private static void EventSink_ClientVersionReceived(NetState state, ClientVersion version)
    {
      string kickMessage = null;

      if (state.Mobile?.AccessLevel != AccessLevel.Player)
        return;

      if (Required != null && version < Required && (m_OldClientResponse == OldClientResponse.Kick ||
                                                     (m_OldClientResponse == OldClientResponse.LenientKick &&
                                                     DateTime.UtcNow - state.Mobile.CreationTime > m_AgeLeniency &&
                                                     state.Mobile is PlayerMobile mobile &&
                                                     mobile.GameTime > m_GameTimeLeniency)))
      {
        kickMessage = $"This server requires your client version be at least {Required}.";
      }
      else if (!AllowGod || !AllowRegular || !AllowUOTD)
      {
        if (!AllowGod && version.Type == ClientType.God)
          kickMessage = "This server does not allow god clients to connect.";
        else if (!AllowRegular && version.Type == ClientType.Regular)
          kickMessage = "This server does not allow regular clients to connect.";
        else if (!AllowUOTD && state.IsUOTDClient)
          kickMessage = "This server does not allow UO:TD clients to connect.";

        if (!AllowGod && !AllowRegular && !AllowUOTD)
        {
          kickMessage = "This server does not allow any clients to connect.";
        }
        else if (AllowGod && !AllowRegular && !AllowUOTD && version.Type != ClientType.God)
        {
          kickMessage = "This server requires you to use the god client.";
        }
        else if (kickMessage != null)
        {
          if (AllowRegular && AllowUOTD)
            kickMessage += " You can use regular or UO:TD clients.";
          else if (AllowRegular)
            kickMessage += " You can use regular clients.";
          else if (AllowUOTD)
            kickMessage += " You can use UO:TD clients.";
        }
      }

      if (kickMessage != null)
      {
        state.Mobile.SendMessage(0x22, kickMessage);
        state.Mobile.SendMessage(0x22, "You will be disconnected in {0} seconds.", KickDelay.TotalSeconds);

        Timer.DelayCall(KickDelay, () =>
        {
          if (state.Connection != null)
          {
            Console.WriteLine("Client: {0}: Disconnecting, bad version", state);
            state.Dispose();
          }
        });
      }
      else if (Required != null && version < Required)
      {
        switch (m_OldClientResponse)
        {
          case OldClientResponse.Warn:
            {
              state.Mobile.SendMessage(0x22, "Your client is out of date. Please update your client.", Required);
              state.Mobile.SendMessage(0x22, "This server recommends that your client version be at least {0}.",
                Required);
              break;
            }
          case OldClientResponse.LenientKick:
          case OldClientResponse.Annoy:
            {
              SendAnnoyGump(state.Mobile);
              break;
            }
        }
      }
    }

    private static void KickMessage(Mobile from, bool okay)
    {
      from.SendMessage("You will be reminded of this again.");

      if (m_OldClientResponse == OldClientResponse.LenientKick)
        from.SendMessage(
          "Old clients will be kicked after {0} days of character age and {1} hours of play time",
          m_AgeLeniency, m_GameTimeLeniency);

      Timer.DelayCall(TimeSpan.FromMinutes(Utility.Random(5, 15)), () => SendAnnoyGump(from));
    }

    private static void SendAnnoyGump(Mobile m)
    {
      if (m.NetState != null && m.NetState.Version < Required)
      {
        Gump g = new WarningGump(1060637, 30720,
          $"Your client is out of date. Please update your client.<br>This server recommends that your client version be at least {Required}.<br> <br>You are currently using version {m.NetState.Version}.<br> <br>To patch, run UOPatch.exe inside your Ultima Online folder.",
          0xFFC000, 480, 360, okay => KickMessage(m, okay), false);

        g.Draggable = false;
        g.Closable = false;
        g.Resizable = false;

        m.SendGump(g);
      }
    }

    private enum OldClientResponse
    {
      Ignore,
      Warn,
      Annoy,
      LenientKick,
      Kick
    }
  }
}