Name adjustments and moved some things to the common lib.

SharpChat/ClientCommands/AFKClientCommand.cs

@@ -0,0 +1,34 @@
+using System.Globalization;
+using System.Text;
+
+namespace SharpChat.ClientCommands {
+    public class AFKClientCommand : ClientCommand {
+        private const string DEFAULT = "AFK";
+        public const int MAX_GRAPHEMES = 5;
+        public const int MAX_BYTES = MAX_GRAPHEMES * 10;
+
+        public bool IsMatch(ClientCommandContext ctx) {
+            return ctx.NameEquals("afk");
+        }
+
+        public void Dispatch(ClientCommandContext ctx) {
+            string? statusText = ctx.Args.FirstOrDefault();
+            if(string.IsNullOrWhiteSpace(statusText))
+                statusText = DEFAULT;
+            else {
+                statusText = statusText.Trim();
+
+                StringInfo sti = new(statusText);
+                if(Encoding.UTF8.GetByteCount(statusText) > MAX_BYTES
+                    || sti.LengthInTextElements > MAX_GRAPHEMES)
+                    statusText = sti.SubstringByTextElements(0, Math.Min(sti.LengthInTextElements, MAX_GRAPHEMES)).Trim();
+            }
+
+            ctx.Chat.UpdateUser(
+                ctx.User,
+                status: UserStatus.Away,
+                statusText: statusText
+            );
+        }
+    }
+}