hermes-server/Socket/Handlers/EmoteDetailsHandler.cs

using HermesSocketLibrary.Requests.Messages;
using HermesSocketLibrary.Socket.Data;
using HermesSocketServer.Services;
using ILogger = Serilog.ILogger;

namespace HermesSocketServer.Socket.Handlers
{
    public class EmoteDetailsHandler : ISocketHandler
    {
        private const int EMOTE_BUFFER_SIZE = 5000;

        public int OperationCode { get; } = 7;
        private readonly ChannelManager _manager;
        private readonly HashSet<string> _emotes;
        private readonly string[] _array;
        private readonly ILogger _logger;
        private readonly Mutex _mutex;

        private int _index;

        public EmoteDetailsHandler(ChannelManager manager, ILogger logger)
        {
            _manager = manager;
            _emotes = new HashSet<string>(EMOTE_BUFFER_SIZE);
            _array = new string[EMOTE_BUFFER_SIZE];
            _logger = logger;
            _mutex = new Mutex();
            _index = -1;
        }

        public async Task Execute<T>(WebSocketUser sender, T message, HermesSocketManager sockets)
        {
            if (message is not EmoteDetailsMessage data || sender.Id == null)
                return;
            if (data.Emotes == null || !data.Emotes.Any())
                return;
            if (sender.Slave && !sender.WebLogin)
            {
                _logger.Warning($"Received message from a slave client [message type: emote details][sender id: {sender.Id}][sender session: {sender.SessionId}]");
                return;
            }

            try
            {
                _mutex.WaitOne();
                foreach (var entry in data.Emotes)
                {
                    if (_emotes.Contains(entry.Key))
                    {
                        data.Emotes.Remove(entry.Key);
                        continue;
                    }

                    _emotes.Add(entry.Key);

                    if (_index == _array.Length - 1)
                        _index = -1;

                    var previous = _array[++_index];
                    if (previous != null)
                    {
                        _emotes.Remove(previous);
                    }
                    _array[_index] = entry.Key;
                }
            }
            finally
            {
                _mutex.ReleaseMutex();
            }

            if (!data.Emotes.Any())
                return;

            var channel = _manager.Get(sender.Id);
            if (channel == null)
                return;
            
            foreach (var entry in data.Emotes)
                channel.Emotes.Set(entry.Key, new EmoteInfo() { Id = entry.Key, Name = entry.Value, UserId = channel.Id });
        }
    }
}