* Added new method for filters report inspection

* Added ArgumentCount filter
* Fixed AddHandler method throwing exception on handler without parameterless constructors

Telegrator/Annotations/CommandArgumentAttributes.cs

@@ -3,6 +3,10 @@ using Telegrator.Filters;
 
 namespace Telegrator.Annotations
 {
+    public class ArgumentCountAttribute(int count)
+        : MessageFilterAttribute(new ArgumentCountFilter(count))
+    { }
+
     /// <summary>
     /// Attribute for filtering messages where a command argument starts with the specified content.
     /// </summary>
@@ -50,7 +54,7 @@ namespace Telegrator.Annotations
     /// <param name="options">The regex options to use for the pattern matching.</param>
     /// <param name="matchTimeout">The timeout for the regex match operation.</param>
     /// <param name="index">The index of the argument to check (0-based).</param>
-    public class ArgumentRegexAttribute(string pattern, RegexOptions options = RegexOptions.None, TimeSpan matchTimeout = default, int index = 0)
-        : MessageFilterAttribute(new ArgumentRegexFilter(pattern, options, matchTimeout, index))
+    public class ArgumentRegexAttribute(string pattern, RegexOptions options = RegexOptions.None, int index = 0)
+        : MessageFilterAttribute(new ArgumentRegexFilter(pattern, options, index: index))
     { }
 }

Telegrator/Filters/CommandArgumentFilter.cs

@@ -42,6 +42,18 @@ namespace Telegrator.Filters
         protected abstract bool CanPassNext(FilterExecutionContext<Message> context);
     }
 
+    public class ArgumentCountFilter(int count) : Filter<Message>
+    {
+        private readonly int Count = count;
+
+        public override bool CanPass(FilterExecutionContext<Message> context)
+        {
+            CommandHandlerAttribute attr = context.CompletedFilters.Get<CommandHandlerAttribute>(0);
+            string[] args = attr.Arguments ??= context.Input.SplitArgs();
+            return args.Length >= Count;
+        }
+    }
+
     /// <summary>
     /// Filter that checks if a command argument starts with a specified content.
     /// </summary>

Telegrator/Handlers/Components/FiltersFallbackReport.cs

@@ -38,27 +38,53 @@ namespace Telegrator.Handlers.Components
         /// </summary>
         public List<FilterFallbackInfo> UpdateFilters { get; } = [];
 
+        public bool Only(string name, int index = 0)
+        {
+            FilterFallbackInfo? info = UpdateFilters.SingleSafe(info => info.Failed);
+            if (info != null && info.Name != name)
+                return false;
+
+            FilterFallbackInfo? target = UpdateFilters.ElementAtOrDefault(index);
+            return ReferenceEquals(target, info);
+        }
+
+        public bool Only(string[] names)
+        {
+            return UpdateFilters
+                .Where(info => info.Failed)
+                .Select(info => info.Name)
+                .SequenceEqual(names);
+        }
+
+        public bool Except(string name, int index = 0)
+        {
+            FilterFallbackInfo? info = UpdateFilters.SingleSafe(info => !info.Failed);
+            if (info != null && info.Name != name)
+                return false;
+
+            FilterFallbackInfo? target = UpdateFilters.ElementAtOrDefault(index);
+            return ReferenceEquals(target, info);
+        }
+
+        public bool Except(string[] names)
+        {
+            return UpdateFilters
+                .Where(info => !info.Failed)
+                .Select(info => info.Name)
+                .SequenceEqual(names);
+        }
+
+        public bool ExceptAttribute<T>(int index = 0) where T : UpdateFilterAttributeBase
+            => Except(nameof(T), index);
+
         /// <summary>
         /// Checks if the failure is due to a specific attribute type, excluding other failures.
         /// </summary>
         /// <typeparam name="T">The attribute type to check for.</typeparam>
         /// <param name="index">The index of the filter to check (default: 0).</param>
         /// <returns>True if the failure is exclusively due to the specified attribute type; otherwise, false.</returns>
-        public bool ExceptAttribute<T>(int index = 0) where T : UpdateFilterAttributeBase
-        {
-            string name = typeof(T).Name;
-            
-            IEnumerable<FilterFallbackInfo> failed = UpdateFilters.Where(info => info.Failed);
-            if (failed.Count() != 1)
-                return false;
-
-            FilterFallbackInfo info = failed.ElementAt(0);
-            if (info.Name != name)
-                return false;
-
-            FilterFallbackInfo? target = UpdateFilters.ElementAtOrDefault(index);
-            return target == info;
-        }
+        public bool OnlyAttribute<T>(int index = 0) where T : UpdateFilterAttributeBase
+            => Only(nameof(T), index);
     }
 
     /// <summary>

Telegrator/Providers/HandlersCollection.cs

@@ -3,7 +3,6 @@ using Telegram.Bot.Types.Enums;
 using Telegrator.Annotations;
 using Telegrator.Attributes;
 using Telegrator.Configuration;
-using Telegrator.Handlers.Components;
 using Telegrator.MadiatorCore;
 using Telegrator.MadiatorCore.Descriptors;
 

Telegrator/TypesExtensions.cs

@@ -1,4 +1,5 @@
-using System.Collections.ObjectModel;
+using System;
+using System.Collections.ObjectModel;
 using System.Reflection;
 using Telegram.Bot;
 using Telegram.Bot.Types;
@@ -643,9 +644,6 @@ namespace Telegrator
 
             if (handlerType.IsCustomDescriptorsProvider())
             {
-                if (!handlerType.HasParameterlessCtor())
-                    throw new Exception();
-
                 ICustomDescriptorsProvider provider = (ICustomDescriptorsProvider)Activator.CreateInstance(handlerType);
                 foreach (HandlerDescriptor handlerDescriptor in provider.DescribeHandlers())
                     handlers.AddDescriptor(handlerDescriptor);
@@ -944,23 +942,6 @@ namespace Telegrator
             return source;
         }
 
-        /* Found built in method :_(
-        /// <summary>
-        /// Creates a new <see cref="IEnumerable{T}"/> with the elements of the <paramref name="source"/> that were successfully cast to the <typeparamref name="TResult"/>
-        /// </summary>
-        /// <typeparam name="TResult"></typeparam>
-        /// <param name="source"></param>
-        /// <returns></returns>
-        public static IEnumerable<TResult> WhereCast<TResult>(this IEnumerable source)
-        {
-            foreach (object value in source)
-            {
-                if (value is TResult result)
-                    yield return result;
-            }
-        }
-        */
-
         /// <summary>
         /// Sets the value of a key in a dictionary, or if the key does not exist, adds it
         /// </summary>
@@ -1027,6 +1008,32 @@ namespace Telegrator
                     list.Add(item);
             }
         }
+
+        public static int IndexOf<T>(this IEnumerable<T> source, Func<T, bool> predicate)
+        {
+            int index = 0;
+            foreach (T item in source)
+            {
+                if (predicate.Invoke(item))
+                    return index;
+
+                index++;
+            }
+
+            return -1;
+        }
+
+        public static IEnumerable<T> Repeat<T>(this T item, int times)
+            => Enumerable.Range(0, times).Select(_ => item);
+
+        public static T? SingleSafe<T>(this IEnumerable<T> source)
+            => source.Count() == 1 ? source.ElementAt(0) : default;
+
+        public static T? SingleSafe<T>(this IEnumerable<T> source, Func<T, bool> predicate)
+        {
+            source = source.Where(predicate);
+            return source.Count() == 1 ? source.ElementAt(0) : default;
+        }
     }
 
     /// <summary>
@@ -1190,6 +1197,22 @@ namespace Telegrator
                 yield return chunk.ToString();
             }
         }
+
+        public static string FirstLetterToUpper(this string target)
+        {
+            char[] chars = target.ToCharArray();
+            int index = chars.IndexOf(char.IsLetter);
+            chars[index] = char.ToUpper(chars[index]);
+            return new string(chars);
+        }
+
+        public static string FirstLetterToLower(this string target)
+        {
+            char[] chars = target.ToCharArray();
+            int index = chars.IndexOf(char.IsLetter);
+            chars[index] = char.ToLower(chars[index]);
+            return new string(chars);
+        }
     }
 
     /// <summary>