Cleanup, ordering and added host variable to client script

MinecraftDiscordBot/Commands/CommandHandlerAttribute.cs

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+namespace MinecraftDiscordBot.Commands;
+
+[AttributeUsage(AttributeTargets.Method, Inherited = true, AllowMultiple = false)]
+public sealed class CommandHandlerAttribute : Attribute {
+    public CommandHandlerAttribute(string commandName) => CommandName = commandName;
+    public string CommandName { get; }
+    public string? HelpText { get; init; }
+}

MinecraftDiscordBot/Commands/CommandRouter.cs

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+using Discord.WebSocket;
+using MinecraftDiscordBot.Services;
+using System.Reflection;
+using System.Text;
+
+namespace MinecraftDiscordBot.Commands;
+
+public abstract class CommandRouter : ICommandHandler<ResponseType> {
+    public record struct HandlerStruct(HandleCommandDelegate<ResponseType> Delegate, CommandHandlerAttribute Attribute);
+    private readonly Dictionary<string, HandlerStruct> _handlers = new();
+    public abstract string HelpTextPrefix { get; }
+    public CommandRouter() {
+        foreach (var method in GetType().GetMethods())
+            if (GetHandlerAttribute(method) is CommandHandlerAttribute attribute)
+                try {
+                    _handlers.Add(attribute.CommandName, new(method.CreateDelegate<HandleCommandDelegate<ResponseType>>(this), attribute));
+                } catch (Exception) {
+                    Program.LogWarning("CommandRouter", $"Could not add delegate for method {attribute.CommandName} in function {method.ReturnType} {method.Name}(...)!");
+                    throw;
+                }
+    }
+
+    [CommandHandler("help", HelpText = "Show this help information!")]
+    public virtual Task<ResponseType> GetHelpText(SocketUserMessage message, string[] parameters, CancellationToken ct)
+        => Task.FromResult(ResponseType.AsString(GenerateHelp()));
+    private static CommandHandlerAttribute? GetHandlerAttribute(MethodInfo method)
+        => method.GetCustomAttributes(typeof(CommandHandlerAttribute), true).OfType<CommandHandlerAttribute>().FirstOrDefault();
+    public abstract Task<ResponseType> RootAnswer(SocketUserMessage message, CancellationToken ct);
+    public abstract Task<ResponseType> FallbackHandler(SocketUserMessage message, string method, string[] parameters, CancellationToken ct);
+    public Task<ResponseType> HandleCommand(SocketUserMessage message, string[] parameters, CancellationToken ct)
+        => parameters is { Length: 0 }
+            ? RootAnswer(message, ct)
+            : _handlers.TryGetValue(parameters[0], out var handler)
+                ? handler.Delegate(message, parameters[1..], ct)
+                : FallbackHandler(message, parameters[0], parameters[1..], ct);
+    private string GenerateHelp() {
+        var sb = new StringBuilder();
+        sb.Append("Command usage:");
+        foreach (var (name, handler) in _handlers) {
+            sb.Append($"\n{HelpTextPrefix}{name}");
+            if (handler.Attribute.HelpText is string help)
+                sb.Append($": {help}");
+        }
+        return sb.ToString();
+    }
+}

MinecraftDiscordBot/Commands/ICommandHandler.cs

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+using Discord.WebSocket;
+
+namespace MinecraftDiscordBot.Commands;
+
+public interface ICommandHandler {
+    Task HandleCommand(SocketUserMessage message, string[] parameters, CancellationToken ct);
+}
+
+public interface ICommandHandler<T> {
+    Task<T> HandleCommand(SocketUserMessage message, string[] parameters, CancellationToken ct);
+}