sharp-chat/SharpChat/PacketHandlers/PingHandler.cs

using SharpChat.Misuzu;
using SharpChat.Packet;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace SharpChat.PacketHandlers {
    public class PingHandler : IChatPacketHandler {
        private readonly MisuzuClient Misuzu;

        private readonly object BumpAccess = new();
        private readonly TimeSpan BumpInterval = TimeSpan.FromMinutes(1);
        private DateTimeOffset LastBump = DateTimeOffset.MinValue;

        public PingHandler(MisuzuClient msz) {
            Misuzu = msz ?? throw new ArgumentNullException(nameof(msz));
        }

        public bool IsMatch(ChatPacketHandlerContext ctx) {
            return ctx.CheckPacketId("0");
        }

        public void Handle(ChatPacketHandlerContext ctx) {
            string[] parts = ctx.SplitText(2);

            if(!int.TryParse(parts.FirstOrDefault(), out int pTime))
                return;

            ctx.Connection.BumpPing();
            ctx.Connection.Send(new PongPacket(ctx.Connection.LastPing));

            lock(BumpAccess) {
                if(LastBump < DateTimeOffset.UtcNow - BumpInterval) {
                    (string, string)[] bumpList;
                    lock(ctx.Chat.UsersAccess) {
                        IEnumerable<ChatUser> filtered = ctx.Chat.Users.Where(u => u.Status == ChatUserStatus.Online);

                        lock(ctx.Chat.ConnectionsAccess)
                            filtered = filtered.Where(u => ctx.Chat.Connections.Any(c => c.User == u));

                        bumpList = filtered
                            .Select(u => (u.UserId.ToString(), ctx.Chat.GetRemoteAddresses(u).FirstOrDefault()?.ToString() ?? string.Empty))
                            .ToArray();
                    }

                    if(bumpList.Any())
                        Task.Run(async () => {
                            await Misuzu.BumpUsersOnlineAsync(bumpList);
                        }).Wait();

                    LastBump = DateTimeOffset.UtcNow;
                }
            }
        }
    }
}