sharp-chat/SharpChat/Commands/KickBanCommand.cs

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

namespace SharpChat.Commands {
    public class KickBanCommand : IChatCommand {
        private readonly MisuzuClient Misuzu;

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

        public bool IsMatch(ChatCommandContext ctx) {
            return ctx.NameEquals("kick")
                || ctx.NameEquals("ban");
        }

        public void Dispatch(ChatCommandContext ctx) {
            bool isBanning = ctx.NameEquals("ban");

            if(!ctx.User.Permissions.HasFlag(isBanning ? ChatUserPermissions.BanUser : ChatUserPermissions.KickUser)) {
                ctx.Chat.SendTo(ctx.User, new CommandNotAllowedErrorPacket(ctx.Name));
                return;
            }

            string banUserTarget = ctx.Args.ElementAtOrDefault(0) ?? string.Empty;
            string? banDurationStr = ctx.Args.ElementAtOrDefault(1);
            int banReasonIndex = 1;
            ChatUser? banUser = null;

            if(string.IsNullOrEmpty(banUserTarget) || (banUser = ctx.Chat.Users.FirstOrDefault(u => u.NameEquals(banUserTarget))) == null) {
                ctx.Chat.SendTo(ctx.User, new UserNotFoundErrorPacket(banUserTarget));
                return;
            }

            if(!ctx.User.IsSuper && banUser.Rank >= ctx.User.Rank && banUser != ctx.User) {
                ctx.Chat.SendTo(ctx.User, new KickBanNotAllowedErrorPacket(banUser.LegacyName));
                return;
            }

            TimeSpan duration = isBanning ? TimeSpan.MaxValue : TimeSpan.Zero;
            if(!string.IsNullOrWhiteSpace(banDurationStr) && double.TryParse(banDurationStr, out double durationSeconds)) {
                if(durationSeconds < 0) {
                    ctx.Chat.SendTo(ctx.User, new CommandFormatErrorPacket());
                    return;
                }

                duration = TimeSpan.FromSeconds(durationSeconds);
                ++banReasonIndex;
            }

            if(duration <= TimeSpan.Zero) {
                ctx.Chat.BanUser(banUser, duration);
                return;
            }

            string banReason = string.Join(' ', ctx.Args.Skip(banReasonIndex));

            Task.Run(async () => {
                string userId = banUser.UserId.ToString();
                string userIp = ctx.Chat.GetRemoteAddresses(banUser).FirstOrDefault()?.ToString() ?? string.Empty;

                // obviously it makes no sense to only check for one ip address but that's current misuzu limitations
                MisuzuBanInfo? fbi = await Misuzu.CheckBanAsync(userId, userIp);

                if(fbi != null && fbi.IsBanned && !fbi.HasExpired) {
                    ctx.Chat.SendTo(ctx.User, new KickBanNotAllowedErrorPacket(banUser.LegacyName));
                    return;
                }

                await Misuzu.CreateBanAsync(
                    userId, userIp,
                    ctx.User.UserId.ToString(), ctx.Connection.RemoteAddress.ToString(),
                    duration, banReason
                );

                ctx.Chat.BanUser(banUser, duration);
            }).Wait();
        }
    }
}