Restructure

Bot/SlashCommand/Command.cs

@@ -0,0 +1,24 @@
+namespace Lunaris2.SlashCommand;
+
+public static class Command
+{
+    public static class Hello
+    {
+        public const string Name = "hello";
+        public const string Description = "Say hello to the bot!";
+    }
+
+    public static class Goodbye
+    {
+        public const string Name = "goodbye";
+        public const string Description = "Say goodbye to the bot!";
+    }
+    
+    public static string[] GetAllCommands()
+    {
+        return typeof(Command)
+            .GetNestedTypes()
+            .Select(command => command.GetField("Name")?.GetValue(null)?.ToString())
+            .ToArray()!;
+    }
+}

Bot/SlashCommand/SlashCommandBuilder.cs

@@ -0,0 +1,57 @@
+using Discord.Net;
+using Discord.WebSocket;
+using Newtonsoft.Json;
+
+namespace Lunaris2.SlashCommand;
+
+public class SlashCommandBuilder(string commandName, string commandDescription)
+{
+    private string CommandName { get; set; } = commandName;
+    private string CommandDescription { get; set; } = commandDescription;
+
+    public async Task CreateSlashCommand(DiscordSocketClient client)
+    {
+        var registeredCommands = await client.GetGlobalApplicationCommandsAsync();
+        await RemoveUnusedCommands(Command.GetAllCommands(), registeredCommands);
+        
+        if (await CommandExists(registeredCommands))
+            return;
+
+        var globalCommand = new Discord.SlashCommandBuilder();
+        globalCommand.WithName(CommandName);
+        globalCommand.WithDescription(CommandDescription);
+
+        try
+        {
+            await client.CreateGlobalApplicationCommandAsync(globalCommand.Build());
+            Console.WriteLine($"Command {CommandName} has been registered.");
+        }
+        catch(HttpException exception)
+        {
+            var json = JsonConvert.SerializeObject(exception.Errors, Formatting.Indented);
+            Console.WriteLine(json);
+        }
+    }
+
+    private static async Task RemoveUnusedCommands(string[] commands, IEnumerable<SocketApplicationCommand> registeredCommands)
+    {
+        // Remove commands from Discord(registeredCommands) that are not in the list of commands
+        foreach(var command in registeredCommands)
+        {
+            if (commands.Contains(command.Name)) 
+                continue;
+            
+            await command.DeleteAsync();
+            Console.WriteLine($"Command {command.Name} has been removed.");
+        }
+    }
+    
+    private async Task<bool> CommandExists(IEnumerable<SocketApplicationCommand> registeredCommands)
+    {
+        if (!registeredCommands.Any(command => command.Name == CommandName && command.Description == CommandDescription))
+            return false;
+        
+        Console.WriteLine($"Command {CommandName} already exists.");
+        return true;
+    }
+}

Bot/SlashCommand/SlashCommandRegistration.cs

@@ -0,0 +1,18 @@
+using Discord.WebSocket;
+
+namespace Lunaris2.SlashCommand;
+
+public static class SlashCommandRegistration
+{
+    public static void RegisterCommands(this DiscordSocketClient client)
+    {
+        RegisterCommand(client, Command.Hello.Name, Command.Hello.Description);
+        RegisterCommand(client, Command.Goodbye.Name, Command.Goodbye.Description);
+    }
+
+    private static void RegisterCommand(DiscordSocketClient client, string commandName, string commandDescription)
+    {
+        var command = new SlashCommandBuilder(commandName, commandDescription);
+        _ = command.CreateSlashCommand(client);
+    }
+}