sharp-chat/SharpChat/Packet/UserUpdateNotificationPacket.cs

using System;
using System.Text;

namespace SharpChat.Packet {
    public class UserUpdateNotificationPacket : ServerPacket {
        public string PreviousName { get; private set; }
        public string NewName { get; private set; }
        public DateTimeOffset Timestamp { get; }

        public UserUpdateNotificationPacket(string previousName, string newName) {
            PreviousName = previousName ?? throw new ArgumentNullException(nameof(previousName));
            NewName = newName ?? throw new ArgumentNullException(nameof(newName));
            Timestamp = DateTimeOffset.Now;
        }

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

            sb.Append('2');
            sb.Append('\t');
            sb.Append(Timestamp.ToUnixTimeSeconds());
            sb.Append("\t-1\t0\fnick\f");
            sb.Append(PreviousName);
            sb.Append('\f');
            sb.Append(NewName);
            sb.Append('\t');
            sb.Append(SequenceId);
            sb.Append("\t10010");

            return sb.ToString();
        }
    }
}