sharp-chat/SharpChat/C2SPacketHandlers/SendMessageC2SPacketHandler.cs

89 lines
3.2 KiB
C#

using SharpChat.Configuration;
using SharpChat.Events;
using SharpChat.Snowflake;
using System.Globalization;
using System.Text;
namespace SharpChat.C2SPacketHandlers;
public class SendMessageC2SPacketHandler(
RandomSnowflake randomSnowflake,
CachedValue<int> maxMsgLength
) : C2SPacketHandler {
private readonly CachedValue<int> MaxMessageLength = maxMsgLength ?? throw new ArgumentNullException(nameof(maxMsgLength));
private List<ClientCommand> Commands { get; } = [];
public void AddCommand(ClientCommand command) {
Commands.Add(command ?? throw new ArgumentNullException(nameof(command)));
}
public void AddCommands(IEnumerable<ClientCommand> commands) {
Commands.AddRange(commands ?? throw new ArgumentNullException(nameof(commands)));
}
public bool IsMatch(C2SPacketHandlerContext ctx) {
return ctx.CheckPacketId("2");
}
public async Task Handle(C2SPacketHandlerContext ctx) {
string[] args = ctx.SplitText(3);
User? user = ctx.Connection.User;
string? messageText = args.ElementAtOrDefault(2);
if(user == null || !user.Can(UserPermissions.SendMessage) || string.IsNullOrWhiteSpace(messageText))
return;
// Extra validation step, not necessary at all but enforces proper formatting in SCv1.
if(!long.TryParse(args[1], out long mUserId) || user.UserId != mUserId.ToString())
return;
ctx.Chat.ContextAccess.Wait();
try {
if(!ctx.Chat.UserLastChannel.TryGetValue(user.UserId, out Channel? channel)
&& (channel is null || !ctx.Chat.IsInChannel(user, channel)))
return;
if(user.Status != UserStatus.Online)
await ctx.Chat.UpdateUser(user, status: UserStatus.Online);
int maxMsgLength = MaxMessageLength;
StringInfo messageTextInfo = new(messageText);
if(Encoding.UTF8.GetByteCount(messageText) > (maxMsgLength * 10)
|| messageTextInfo.LengthInTextElements > maxMsgLength)
messageText = messageTextInfo.SubstringByTextElements(0, Math.Min(messageTextInfo.LengthInTextElements, maxMsgLength));
messageText = messageText.Trim();
#if DEBUG
Logger.Write($"<{ctx.Connection.Id} {user.UserName}> {messageText}");
#endif
if(messageText.StartsWith('/')) {
ClientCommandContext context = new(messageText, ctx.Chat, user, ctx.Connection, channel);
foreach(ClientCommand cmd in Commands)
if(cmd.IsMatch(context)) {
await cmd.Dispatch(context);
return;
}
}
await ctx.Chat.DispatchEvent(new MessageCreateEvent(
randomSnowflake.Next(),
channel.Name,
user.UserId,
user.UserName,
user.Colour,
user.Rank,
user.NickName,
user.Permissions,
DateTimeOffset.Now,
messageText,
false, false, false
));
} finally {
ctx.Chat.ContextAccess.Release();
}
}
}