sharp-chat/SharpChat/Packet/UserChannelJoinPacket.cs

using System;
using System.Collections.Generic;
using System.Text;

namespace SharpChat.Packet {
    public class UserChannelJoinPacket : ServerPacket {
        public ChatUser User { get; private set; }

        public UserChannelJoinPacket(ChatUser user) {
            User = user ?? throw new ArgumentNullException(nameof(user));
        }

        public override IEnumerable<string> Pack() {
            StringBuilder sb = new();

            sb.Append('5');
            sb.Append('\t');
            sb.Append('0');
            sb.Append('\t');
            sb.Append(User.Pack());
            sb.Append('\t');
            sb.Append(SequenceId);

            return new[] { sb.ToString() };
        }
    }
}