* Added protection from NotImplementedException to HandlerBuilderBase

* Moved AddHandler<T> and AddHandler(Type) methods from IHandlersCollection to extension methods
* Added public constructor to IHost types form extensibility
* Code cleanup

Telegrator.Hosting/Providers/Components/IHostHandlersCollection.cs

@@ -0,0 +1,16 @@
+using Telegrator.MadiatorCore;
+
+namespace Telegrator.Hosting.Providers.Components
+{
+    /// <summary>
+    /// Collection class for managing handler descriptors organized by update type for host apps.
+    /// Provides functionality for collecting, adding, scanning, and organizing handlers.
+    /// </summary>
+    public interface IHostHandlersCollection : IHandlersCollection
+    {
+        /// <summary>
+        /// List of tasks that should be completed right before building the bot
+        /// </summary>
+        public List<PreBuildingRoutine> PreBuilderRoutines { get; }
+    }
+}

Telegrator.Hosting/Providers/HostHandlersCollection.cs

@@ -2,6 +2,7 @@
 using System.Reflection;
 using Telegrator.Configuration;
 using Telegrator.Hosting.Components;
+using Telegrator.Hosting.Providers.Components;
 using Telegrator.MadiatorCore;
 using Telegrator.MadiatorCore.Descriptors;
 using Telegrator.Providers;
@@ -15,7 +16,7 @@ namespace Telegrator.Hosting.Providers
     public delegate void PreBuildingRoutine(ITelegramBotHostBuilder builder);
 
     /// <inheritdoc/>
-    public class HostHandlersCollection(IServiceCollection hostServiceColletion, ITelegratorOptions options) : HandlersCollection(options)
+    public class HostHandlersCollection(IServiceCollection hostServiceColletion, ITelegratorOptions options) : HandlersCollection(options), IHostHandlersCollection
     {
         private readonly IServiceCollection Services = hostServiceColletion;
 
@@ -25,20 +26,14 @@ namespace Telegrator.Hosting.Providers
         /// <summary>
         /// List of tasks that should be completed right before building the bot
         /// </summary>
-        public readonly List<PreBuildingRoutine> PreBuilderRoutines = [];
-
-        /// <inheritdoc/>
-        public override IHandlersCollection AddHandler(Type handlerType)
-        {
-            if (handlerType.IsPreBuildingRoutine(out MethodInfo? routineMethod))
-                PreBuilderRoutines.Add(routineMethod.CreateDelegate<PreBuildingRoutine>(null));
-
-            return base.AddHandler(handlerType);
-        }
+        public List<PreBuildingRoutine> PreBuilderRoutines { get; } = [];
 
         /// <inheritdoc/>
         public override IHandlersCollection AddDescriptor(HandlerDescriptor descriptor)
         {
+            if (descriptor.HandlerType.IsPreBuildingRoutine(out MethodInfo? routineMethod))
+                PreBuilderRoutines.Add(routineMethod.CreateDelegate<PreBuildingRoutine>(null));
+
             switch (descriptor.Type)
             {
                 case DescriptorType.General:

Telegrator.Hosting/TelegramBotHost.cs

@@ -5,9 +5,6 @@ using System.Text;
 using Telegram.Bot.Types.Enums;
 using Telegrator.Configuration;
 using Telegrator.Hosting.Components;
-using Telegrator.Hosting.Logging;
-using Telegrator.Logging;
-using Telegrator.Hosting.Providers;
 using Telegrator.MadiatorCore;
 using Telegrator.MadiatorCore.Descriptors;
 
@@ -19,13 +16,14 @@ namespace Telegrator.Hosting
     public class TelegramBotHost : ITelegramBotHost
     {
         private readonly IHost _innerHost;
+        private readonly IServiceProvider _serviceProvider;
         private readonly IUpdateRouter _updateRouter;
         private readonly ILogger<TelegramBotHost> _logger;
 
         private bool _disposed;
 
         /// <inheritdoc/>
-        public IServiceProvider Services => _innerHost.Services;
+        public IServiceProvider Services => _serviceProvider;
 
         /// <inheritdoc/>
         public IUpdateRouter UpdateRouter => _updateRouter;
@@ -38,15 +36,16 @@ namespace Telegrator.Hosting
         /// <summary>
         /// Initializes a new instance of the <see cref="TelegramBotHost"/> class.
         /// </summary>
-        /// <param name="hostApplicationBuilder">The service provider.</param>
+        /// <param name="hostApplicationBuilder">The proxied instance of host builder.</param>
         /// <param name="handlers"></param>
-        internal TelegramBotHost(HostApplicationBuilder hostApplicationBuilder, HostHandlersCollection handlers)
+        public TelegramBotHost(HostApplicationBuilder hostApplicationBuilder, IHandlersCollection handlers)
         {
             // Registering this host in services for easy access
-            RegisterHostServices(hostApplicationBuilder, handlers);
+            RegisterHostServices(hostApplicationBuilder.Services, handlers);
 
             // Building proxy hoster
             _innerHost = hostApplicationBuilder.Build();
+            _serviceProvider = _innerHost.Services;
 
             // Initializing bot info, as it requires to make a request via tg bot
             Services.GetRequiredService<ITelegramBotInfo>();
@@ -131,7 +130,7 @@ namespace Telegrator.Hosting
             _disposed = true;
         }
 
-        private void LogHandlers(HostHandlersCollection handlers)
+        private void LogHandlers(IHandlersCollection handlers)
         {
             StringBuilder logBuilder = new StringBuilder("Registered handlers : ");
             if (!handlers.Keys.Any())
@@ -153,14 +152,14 @@ namespace Telegrator.Hosting
             Logger.LogInformation(logBuilder.ToString());
         }
 
-        private void RegisterHostServices(HostApplicationBuilder hostApplicationBuilder, HostHandlersCollection handlers)
+        private void RegisterHostServices(IServiceCollection services, IHandlersCollection handlers)
         {
-            //hostApplicationBuilder.Services.RemoveAll<IHost>();
-            //hostApplicationBuilder.Services.AddSingleton<IHost>(this);
+            //services.RemoveAll<IHost>();
+            //services.AddSingleton<IHost>(this);
 
-            hostApplicationBuilder.Services.AddSingleton<ITelegramBotHost>(this);
-            hostApplicationBuilder.Services.AddSingleton<ITelegratorBot>(this);
-            hostApplicationBuilder.Services.AddSingleton<IHandlersCollection>(handlers);
+            services.AddSingleton<ITelegramBotHost>(this);
+            services.AddSingleton<ITelegratorBot>(this);
+            services.AddSingleton<IHandlersCollection>(handlers);
         }
     }
 }

Telegrator.Hosting/TelegramBotHostBuilder.cs

@@ -9,6 +9,7 @@ using Telegrator.Hosting;
 using Telegrator.Hosting.Components;
 using Telegrator.Hosting.Configuration;
 using Telegrator.Hosting.Providers;
+using Telegrator.Hosting.Providers.Components;
 using Telegrator.MadiatorCore;
 
 #pragma warning disable IDE0001
@@ -21,7 +22,7 @@ namespace Telegrator.Hosting
     {
         private readonly HostApplicationBuilder _innerBuilder;
         private readonly TelegramBotHostBuilderSettings _settings;
-        private readonly HostHandlersCollection _handlers;
+        private readonly IHandlersCollection _handlers;
 
         /// <inheritdoc/>
         public IHandlersCollection Handlers => _handlers;
@@ -43,30 +44,48 @@ namespace Telegrator.Hosting
         /// </summary>
         /// <param name="hostApplicationBuilder"></param>
         /// <param name="settings"></param>
-        internal TelegramBotHostBuilder(HostApplicationBuilder hostApplicationBuilder, TelegramBotHostBuilderSettings? settings = null)
+        public TelegramBotHostBuilder(HostApplicationBuilder hostApplicationBuilder, TelegramBotHostBuilderSettings? settings = null)
         {
-            _innerBuilder = hostApplicationBuilder;
+            _innerBuilder = hostApplicationBuilder ?? throw new ArgumentNullException(nameof(hostApplicationBuilder));
             _settings = settings ?? new TelegramBotHostBuilderSettings();
             _handlers = new HostHandlersCollection(Services, _settings);
 
             _innerBuilder.Logging.ClearProviders();
         }
 
+        /// <summary>
+        /// Initializes a new instance of the <see cref="TelegramBotHostBuilder"/> class.
+        /// </summary>
+        /// <param name="hostApplicationBuilder"></param>
+        /// <param name="handlers"></param>
+        /// <param name="settings"></param>
+        public TelegramBotHostBuilder(HostApplicationBuilder hostApplicationBuilder, IHandlersCollection handlers, TelegramBotHostBuilderSettings? settings = null)
+        {
+            _innerBuilder = hostApplicationBuilder ?? throw new ArgumentNullException(nameof(hostApplicationBuilder));
+            _settings = settings ?? new TelegramBotHostBuilderSettings();
+            _handlers = handlers ?? throw new ArgumentNullException(nameof(handlers));
+
+            _innerBuilder.Logging.ClearProviders();
+        }
+
         /// <summary>
         /// Builds the host.
         /// </summary>
         /// <returns></returns>
         public TelegramBotHost Build()
         {
-            foreach (PreBuildingRoutine preBuildRoutine in _handlers.PreBuilderRoutines)
+            if (_handlers is IHostHandlersCollection hostHandlers)
             {
-                try
+                foreach (PreBuildingRoutine preBuildRoutine in hostHandlers.PreBuilderRoutines)
                 {
-                    preBuildRoutine.Invoke(this);
-                }
-                catch (NotImplementedException)
-                {
-                    _ = 0xBAD + 0xC0DE;
+                    try
+                    {
+                        preBuildRoutine.Invoke(this);
+                    }
+                    catch (NotImplementedException)
+                    {
+                        _ = 0xBAD + 0xC0DE;
+                    }
                 }
             }