Enhance command handling and add namespace imports

- Added `using` directives for essential namespaces in `Plugin.cs`.
- Implemented a "set" subcommand for configuring activity options, including color and prefix/suffix settings.
- Added error handling for duplicate and invalid inputs, with user feedback via chat.
- Updated the configuration for the first activity based on user input.

SpotifyHonorific/Plugin.cs

@@ -6,6 +6,12 @@ using Dalamud.Plugin.Services;
 using SpotifyHonorific.Windows;
 using SpotifyHonorific.Activities;
 using SpotifyHonorific.Updaters;
+using System;
+using System.Diagnostics;
+using System.Globalization;
+using System.Linq;
+using System.Xml.Linq;
+using System.Numerics;
 
 namespace SpotifyHonorific;
 
@@ -70,6 +76,87 @@ public sealed class Plugin : IDalamudPlugin
             Config.Save();
             Updater.Stop();
         }
+        else if (subcommand == "set")
+        {
+            var splitArgs = args.Trim().Split(' ', 2, StringSplitOptions.TrimEntries | StringSplitOptions.RemoveEmptyEntries);
+            if (splitArgs.Length != 2)
+            {
+                return;
+            }
+            var setArgs = splitArgs[1].Split('|', StringSplitOptions.TrimEntries | StringSplitOptions.RemoveEmptyEntries);
+            bool? prefix = null;
+            Vector3? color = null;
+            Vector3? glow = null;
+
+            foreach (var a in setArgs)
+            {
+
+                var arg = a.ToLower();
+
+                var colorArg = arg.Skip(arg.StartsWith('#') ? 1 : 0).ToArray();
+
+                if (colorArg.Length == 6 && colorArg.All(chr => chr is >= '0' and <= '9' or >= 'a' and <= 'f'))
+                {
+
+                    if (color != null && glow != null)
+                    {
+                        ChatGui.PrintError($"Duplicate Option in Set: '{a}'", "SpotifyHonorific");
+                        return;
+                    }
+
+                    var rHex = string.Join(null, colorArg.Skip(0).Take(2));
+                    var gHex = string.Join(null, colorArg.Skip(2).Take(2));
+                    var bHex = string.Join(null, colorArg.Skip(4).Take(2));
+
+
+                    if (byte.TryParse(rHex, NumberStyles.HexNumber, NumberFormatInfo.InvariantInfo, out var r) &&
+                        byte.TryParse(gHex, NumberStyles.HexNumber, NumberFormatInfo.InvariantInfo, out var g) &&
+                        byte.TryParse(bHex, NumberStyles.HexNumber, NumberFormatInfo.InvariantInfo, out var b))
+                    {
+
+                        var c = new Vector3(r / 255f, g / 255f, b / 255f);
+                        if (color == null)
+                        {
+                            color = c;
+                            continue;
+                        }
+
+                        glow = c;
+                        continue;
+                    }
+                }
+
+                if (arg is "p" or "prefix" or "pre")
+                {
+                    if (prefix != null)
+                    {
+                        ChatGui.PrintError($"Duplicate Option in Set: '{a}'", "SpotifyHonorific");
+                        return;
+                    }
+
+                    prefix = true;
+                    continue;
+                }
+
+                if (arg is "s" or "suffix")
+                {
+                    if (prefix != null)
+                    {
+                        ChatGui.PrintError($"Duplicate Option in Set: '{a}'", "SpotifyHonorific");
+                        return;
+                    }
+                    prefix = false;
+                    continue;
+                }
+                ChatGui.PrintError($"Invalid Option in Set: '{a}'", "SpotifyHonorific");
+                return;
+            }
+
+            Config.ActivityConfigs.First().Color = color;
+            Config.ActivityConfigs.First().Glow = glow;
+            Config.ActivityConfigs.First().IsPrefix = prefix ?? false;
+            ChatGui.Print("Updated Title", "SpotifyHonorific");
+        }
         else
         {
             ChatGui.Print(CommandHelpMessage);