using System;
using System.Collections.Generic;
using System.IO;
using Server.Json;

namespace Server.Network;

public static class PacketThrottles
{
    // Delay in milliseconds
    private static readonly int[] Delays = new int[0x100];
    private const string ThrottlesConfiguration = "Configuration/throttles.json";

    public static void Configure()
    {
        CommandSystem.Register("GetThrottle", AccessLevel.Administrator, GetThrottle);
        CommandSystem.Register("SetThrottle", AccessLevel.Administrator, SetThrottle);
    }

    public static unsafe void Initialize()
    {
        var path = Path.Join(Core.BaseDirectory, ThrottlesConfiguration);

        if (File.Exists(path))
        {
            var throttles = JsonConfig.Deserialize<SortedDictionary<string, int>>(path);
            foreach (var (k, v) in throttles)
            {
                if (!Utility.ToInt32(k, out var packetId))
                {
                    Utility.PushColor(ConsoleColor.DarkYellow);
                    Console.WriteLine("Packet Throttles: Error deserializing {0} from {1}", k, ThrottlesConfiguration);
                    Utility.PopColor();
                    continue;
                }

                Delays[packetId] = v;
            }
        }
        else
        {
            Delays[0x03] = 25;  // Speech
            Delays[0xAD] = 25;  // Speech
            Delays[0x12] = 25;  // Text Commands
            Delays[0x75] = 500; // Rename request
        }

        for (int i = 0; i < 0x100; i++)
        {
            if (Delays[i] > 0)
            {
                IncomingPackets.RegisterThrottler(i, &Throttle);
            }
        }

        SaveDelays();
    }

    [Usage("GetThrottle <packetID>")]
    [Description("Gets throttle for the given packet.")]
    public static void GetThrottle(CommandEventArgs e)
    {
        if (e.Length != 1)
        {
            e.Mobile.SendMessage("Invalid Command Format. Should be [GetThrottle <packetID>");
            return;
        }

        int packetID = e.GetInt32(0);

        if (packetID is < 0 or > 0x100)
        {
            e.Mobile.SendMessage("Invalid Command Format. PacketID must be between 0 and 0x100.");
            return;
        }

        e.Mobile.SendMessage($"Packet 0x{packetID:X} throttle is currently {Delays[packetID]}ms.");
    }

    [Usage("SetThrottle <packetID> <timeInMilliseconds>")]
    [Description("Sets a throttle for the given packet.")]
    public static unsafe void SetThrottle(CommandEventArgs e)
    {
        if (e.Length != 2)
        {
            e.Mobile.SendMessage("Invalid Command Format. Should be [SetThrottle <packetID> <timeInMilliseconds>");
            return;
        }

        int packetID = e.GetInt32(0);
        int delay = e.GetInt32(1);

        if (packetID is < 0 or > 0x100)
        {
            e.Mobile.SendMessage("Invalid Command Format. PacketID must be between 0 and 0x100.");
            return;
        }

        if (delay > 5000)
        {
            e.Mobile.SendMessage("Invalid Command Format. Delay cannot exceed 5000 milliseconds.");
            return;
        }

        long oldDelay = Delays[packetID];

        if (oldDelay == 0 && delay > 0)
        {
            IncomingPackets.RegisterThrottler(packetID, &Throttle);
            e.Mobile.SendMessage($"Set throttle for packet 0x{packetID:X2} to {delay}ms.");
        }
        else if (oldDelay > 0 && delay == 0)
        {
            IncomingPackets.RegisterThrottler(packetID, null);
            e.Mobile.SendMessage($"Removed throttle for packet 0x{packetID:X2}");
        }

        Delays[packetID] = delay;
        SaveDelays();
    }

    private static void SaveDelays()
    {
        SortedDictionary<string, int> table = new();
        for (var i = 0; i < Delays.Length; i++)
        {
            var delay = Delays[i];

            if (delay != 0)
            {
                table[$"0x{i:X2}"] = delay;
            }
        }

        var path = Path.Join(Core.BaseDirectory, ThrottlesConfiguration);
        JsonConfig.Serialize(path, table);
    }

    public static bool Throttle(int packetId, NetState ns) =>
        ns.Mobile is { AccessLevel: AccessLevel.Player } && Core.TickCount - ns.GetPacketTime(packetId) < Delays[packetId];
}