sharp-chat/SharpChat/Packet/ChatMessageAddPacket.cs

using System;

namespace SharpChat.Packet {
    public class ChatMessageAddPacket : ServerPacket {
        private readonly DateTimeOffset Created;
        private readonly long UserId;
        private readonly string Body;
        private readonly bool IsAction;
        private readonly bool IsPrivate;

        public ChatMessageAddPacket(
            long msgId,
            DateTimeOffset created,
            long userId,
            string body,
            bool isAction,
            bool isPrivate
        ) : base(msgId) {
            Created = created;
            UserId = userId < 0 ? -1 : userId;
            Body = body ?? throw new ArgumentNullException(nameof(body));
            IsAction = isAction;
            IsPrivate = isPrivate;
        }

        public override string Pack() {
            string body = Body.Replace("<", "&lt;").Replace(">", "&gt;").Replace("\n", " <br/> ").Replace("\t", "    ");
            if(IsAction)
                body = string.Format("<i>{0}</i>", body);

            return string.Format(
                "2\t{0}\t{1}\t{2}\t{3}\t{4}{5}{6}{7}{8}",
                Created.ToUnixTimeSeconds(),
                UserId,
                body,
                SequenceId,
                1,
                IsAction ? 1 : 0,
                0,
                IsAction ? 0 : 1,
                IsPrivate ? 1 : 0
            );
        }
    }
}