using SharpChat.Events;
using SharpChat.Misuzu;
using SharpChat.SockChat.PacketsS2C;
using System;
using System.Linq;
using System.Threading.Tasks;

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

        public KickBanCommand(MisuzuClient msz) {
            Misuzu = msz;
        }

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

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

            if(!ctx.User.Permissions.HasFlag(isBanning ? UserPermissions.BanUser : UserPermissions.KickUser)) {
                ctx.Chat.SendTo(ctx.User, new CommandNotAllowedErrorS2CPacket(ctx.Name));
                return;
            }

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

            (string name, UsersContext.NameTarget target) = SockChatUtility.ExplodeUserName(banUserTarget);
            if(string.IsNullOrEmpty(name) || (banUser = ctx.Chat.Users.Get(name: name, nameTarget: target)) == null) {
                ctx.Chat.SendTo(ctx.User, new UserNotFoundErrorS2CPacket(banUserTarget));
                return;
            }

            if(!ctx.User.IsSuper && banUser.Rank >= ctx.User.Rank && banUser != ctx.User) {
                ctx.Chat.SendTo(ctx.User, new KickBanNotAllowedErrorS2CPacket(SockChatUtility.GetUserName(banUser)));
                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 CommandFormatErrorS2CPacket());
                    return;
                }

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

            if(duration <= TimeSpan.Zero) {
                ctx.Chat.Events.Dispatch("user:kickban", banUser, UserKickBanEventData.OfDuration(UserDisconnectReason.Kicked, TimeSpan.Zero));
                return;
            }

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

            Task.Run(async () => {
                string userId = banUser.UserId.ToString();

                MisuzuBanInfo? fbi = await Misuzu.CheckBanAsync(userId);
                if(fbi != null && fbi.IsBanned && !fbi.HasExpired) {
                    ctx.Chat.SendTo(ctx.User, new KickBanNotAllowedErrorS2CPacket(SockChatUtility.GetUserName(banUser)));
                    return;
                }

                string[] userRemoteAddrs = ctx.Chat.Connections.GetUserRemoteAddresses(banUser);
                string userRemoteAddr = string.Format(", ", userRemoteAddrs);

                // Misuzu only stores the IP address in private comment and doesn't do any checking, so this is fine.
                await Misuzu.CreateBanAsync(
                    userId, userRemoteAddr,
                    ctx.User.UserId.ToString(), ctx.Connection.RemoteAddress,
                    duration, banReason
                );

                ctx.Chat.Events.Dispatch("user:kickban", banUser, UserKickBanEventData.OfDuration(UserDisconnectReason.Kicked, duration));
            }).Wait();
        }
    }
}