"Fix-BUTTON_DATA_INVALID-and-add-multi-buy-buttons"

TeleBot/TeleBot/Handlers/CallbackHandler.cs

@@ -29,6 +29,8 @@ namespace TeleBot.Handlers
         private readonly IBotActivityTracker _activityTracker;
         private readonly IConfiguration _configuration;
         private readonly ILogger<CallbackHandler> _logger;
+        private readonly MenuBuilder _menuBuilder;
+        private readonly CallbackDataMapper _mapper;
 
         public CallbackHandler(
             ISessionManager sessionManager,
@@ -37,7 +39,9 @@ namespace TeleBot.Handlers
             IProductCarouselService carouselService,
             IBotActivityTracker activityTracker,
             IConfiguration configuration,
-            ILogger<CallbackHandler> logger)
+            ILogger<CallbackHandler> logger,
+            MenuBuilder menuBuilder,
+            CallbackDataMapper mapper)
         {
             _sessionManager = sessionManager;
             _shopService = shopService;
@@ -46,6 +50,8 @@ namespace TeleBot.Handlers
             _activityTracker = activityTracker;
             _configuration = configuration;
             _logger = logger;
+            _menuBuilder = menuBuilder;
+            _mapper = mapper;
         }
         
         public async Task HandleCallbackAsync(ITelegramBotClient bot, CallbackQuery callbackQuery)
@@ -115,7 +121,11 @@ namespace TeleBot.Handlers
                         break;
                         
                     case "remove":
-                        await HandleRemoveFromCart(bot, callbackQuery, session, Guid.Parse(data[1]));
+                        {
+                            var (_, productId, _, _) = _mapper.ParseCallback(callbackQuery.Data);
+                            if (productId.HasValue)
+                                await HandleRemoveFromCart(bot, callbackQuery, session, productId.Value);
+                        }
                         break;
                         
                     case "clear_cart":
@@ -372,32 +382,40 @@ namespace TeleBot.Handlers
         
         private async Task HandleQuantityChange(ITelegramBotClient bot, Message message, UserSession session, string[] data)
         {
-            // Format: qty:productId:newQuantity
+            // Parse callback data using mapper
-            var productId = Guid.Parse(data[1]);
+            var (_, productId, quantity, _) = _mapper.ParseCallback(string.Join(":", data));
-            var quantity = int.Parse(data[2]);
 
-            var product = await _shopService.GetProductAsync(productId);
+            if (!productId.HasValue || !quantity.HasValue)
+                return;
+
+            var product = await _shopService.GetProductAsync(productId.Value);
             if (product == null)
                 return;
 
-            session.TempData["current_quantity"] = quantity;
+            session.TempData["current_quantity"] = quantity.Value;
 
             await bot.EditMessageReplyMarkupAsync(
                 message.Chat.Id,
                 message.MessageId,
-                MenuBuilder.ProductDetailMenu(product, quantity)
+                _menuBuilder.ProductDetailMenu(product, quantity.Value)
             );
         }
         
         private async Task HandleAddToCart(ITelegramBotClient bot, CallbackQuery callbackQuery, UserSession session, string[] data)
         {
-            // Format: add:productId:quantity or add:productId:quantity:multiBuyId or add:productId:quantity:multiBuyId:variant
+            // Parse callback data using mapper
-            var productId = Guid.Parse(data[1]);
+            var (_, productId, quantity, multiBuyId) = _mapper.ParseCallback(string.Join(":", data));
-            var quantity = int.Parse(data[2]);
-            Guid? multiBuyId = data.Length > 3 && !data[3].Contains(":") ? Guid.Parse(data[3]) : null;
-            string? selectedVariant = data.Length > 4 ? data[4] : (data.Length > 3 && data[3].Contains(":") ? data[3] : null);
 
-            var product = await _shopService.GetProductAsync(productId);
+            if (!productId.HasValue || !quantity.HasValue)
+            {
+                await bot.AnswerCallbackQueryAsync(callbackQuery.Id, "Invalid product data", showAlert: true);
+                return;
+            }
+
+            // Check for variant in data (old format compatibility)
+            string? selectedVariant = data.Length > 4 ? data[4] : null;
+
+            var product = await _shopService.GetProductAsync(productId.Value);
             if (product == null)
             {
                 await bot.AnswerCallbackQueryAsync(callbackQuery.Id, "Product not found", showAlert: true);
@@ -407,13 +425,15 @@ namespace TeleBot.Handlers
             // If product has variants but none selected, show variant selection
             if (selectedVariant == null && product.Variants?.Any() == true)
             {
-                await ShowVariantSelection(bot, callbackQuery.Message!, session, product, quantity, multiBuyId);
+                await ShowVariantSelection(bot, callbackQuery.Message!, session, product, quantity.Value, multiBuyId);
                 return;
             }
 
             // Get price based on multi-buy or base product
             decimal price = product.Price;
             string itemName = product.Name;
+            int finalQuantity = quantity.Value;
+
             if (multiBuyId.HasValue && product.MultiBuys != null)
             {
                 var multiBuy = product.MultiBuys.FirstOrDefault(mb => mb.Id == multiBuyId);
@@ -421,7 +441,7 @@ namespace TeleBot.Handlers
                 {
                     price = multiBuy.Price;
                     itemName = $"{product.Name} ({multiBuy.Name})";
-                    quantity = multiBuy.Quantity; // Use multi-buy quantity
+                    finalQuantity = multiBuy.Quantity; // Use multi-buy quantity
                 }
             }
 
@@ -431,7 +451,7 @@ namespace TeleBot.Handlers
                 itemName += $" - {selectedVariant}";
             }
 
-            session.Cart.AddItem(productId, itemName, price, quantity, multiBuyId, selectedVariant);
+            session.Cart.AddItem(productId.Value, itemName, price, finalQuantity, multiBuyId, selectedVariant);
 
             // Track add to cart action
             await _activityTracker.TrackActivityAsync(
@@ -439,13 +459,13 @@ namespace TeleBot.Handlers
                 ActivityTypes.AddToCart,
                 $"Added to cart: {itemName}",
                 product,
-                price * quantity,
+                price * finalQuantity,
-                quantity
+                finalQuantity
             );
 
             await bot.AnswerCallbackQueryAsync(
                 callbackQuery.Id,
-                $"✅ Added {quantity}x {itemName} to cart",
+                $"✅ Added {finalQuantity}x {itemName} to cart",
                 showAlert: false
             );
 
@@ -469,7 +489,7 @@ namespace TeleBot.Handlers
                 message.MessageId,
                 MessageFormatter.FormatCart(session.Cart),
                 parseMode: Telegram.Bot.Types.Enums.ParseMode.Markdown,
-                replyMarkup: MenuBuilder.CartMenu(session.Cart)
+                replyMarkup: _menuBuilder.CartMenu(session.Cart)
             );
             session.State = SessionState.ViewingCart;
         }
@@ -480,7 +500,7 @@ namespace TeleBot.Handlers
                 chatId,
                 MessageFormatter.FormatCart(session.Cart),
                 parseMode: Telegram.Bot.Types.Enums.ParseMode.Markdown,
-                replyMarkup: MenuBuilder.CartMenu(session.Cart)
+                replyMarkup: _menuBuilder.CartMenu(session.Cart)
             );
             session.State = SessionState.ViewingCart;
         }
@@ -565,7 +585,7 @@ namespace TeleBot.Handlers
                 callbackQuery.Message!.Chat.Id,
                 MessageFormatter.FormatCart(session.Cart),
                 parseMode: Telegram.Bot.Types.Enums.ParseMode.Markdown,
-                replyMarkup: MenuBuilder.CartMenu(session.Cart)
+                replyMarkup: _menuBuilder.CartMenu(session.Cart)
             );
 
             // Immediately proceed to checkout
@@ -634,7 +654,7 @@ namespace TeleBot.Handlers
                 callbackQuery.Message!.Chat.Id,
                 MessageFormatter.FormatCart(session.Cart),
                 parseMode: Telegram.Bot.Types.Enums.ParseMode.Markdown,
-                replyMarkup: MenuBuilder.CartMenu(session.Cart)
+                replyMarkup: _menuBuilder.CartMenu(session.Cart)
             );
 
             // Immediately proceed to checkout
@@ -738,7 +758,7 @@ namespace TeleBot.Handlers
                     message.Chat.Id,
                     message.MessageId,
                     "❌ Failed to create order. Please try again.",
-                    replyMarkup: MenuBuilder.CartMenu(session.Cart)
+                    replyMarkup: _menuBuilder.CartMenu(session.Cart)
                 );
                 return;
             }
@@ -823,7 +843,7 @@ namespace TeleBot.Handlers
                         $"• Network connectivity issues\n\n" +
                         $"Your cart has been restored. Please try again.",
                         Telegram.Bot.Types.Enums.ParseMode.Markdown,
-                        MenuBuilder.CartMenu(session.Cart)
+                        _menuBuilder.CartMenu(session.Cart)
                     );
                     return;
                 }
@@ -863,7 +883,7 @@ namespace TeleBot.Handlers
                     $"Our payment system may be undergoing maintenance.\n" +
                     $"Your cart has been restored. Please try again later.",
                     Telegram.Bot.Types.Enums.ParseMode.Markdown,
-                    MenuBuilder.CartMenu(session.Cart)
+                    _menuBuilder.CartMenu(session.Cart)
                 );
                 return;
             }

TeleBot/TeleBot/Handlers/CommandHandler.cs

@@ -20,19 +20,22 @@ namespace TeleBot.Handlers
         private readonly IPrivacyService _privacyService;
         private readonly IProductCarouselService _carouselService;
         private readonly ILogger<CommandHandler> _logger;
+        private readonly MenuBuilder _menuBuilder;
 
         public CommandHandler(
             ISessionManager sessionManager,
             ILittleShopService shopService,
             IPrivacyService privacyService,
             IProductCarouselService carouselService,
-            ILogger<CommandHandler> logger)
+            ILogger<CommandHandler> logger,
+            MenuBuilder menuBuilder)
         {
             _sessionManager = sessionManager;
             _shopService = shopService;
             _privacyService = privacyService;
             _carouselService = carouselService;
             _logger = logger;
+            _menuBuilder = menuBuilder;
         }
         
         public async Task HandleCommandAsync(ITelegramBotClient bot, Message message, string command, string? args)
@@ -202,7 +205,7 @@ namespace TeleBot.Handlers
                 message.Chat.Id,
                 text,
                 parseMode: Telegram.Bot.Types.Enums.ParseMode.Markdown,
-                replyMarkup: MenuBuilder.CartMenu(session.Cart)
+                replyMarkup: _menuBuilder.CartMenu(session.Cart)
             );
             
             session.State = Models.SessionState.ViewingCart;

TeleBot/TeleBot/Program.cs

@@ -16,6 +16,7 @@ using TeleBot;
 using TeleBot.Handlers;
 using TeleBot.Services;
 using TeleBot.Http;
+using TeleBot.UI;
 
 var builder = WebApplication.CreateBuilder(args);
 var BrandName = "Little Shop";
@@ -90,6 +91,10 @@ builder.Services.AddSingleton<ICommandHandler, CommandHandler>();
 builder.Services.AddSingleton<ICallbackHandler, CallbackHandler>();
 builder.Services.AddSingleton<IMessageHandler, MessageHandler>();
 
+// Callback Data Mapper (for short IDs to avoid Telegram's 64-byte limit)
+builder.Services.AddSingleton<CallbackDataMapper>();
+builder.Services.AddSingleton<MenuBuilder>();
+
 // Bot Manager Service (for registration and metrics) - Single instance with direct connection (internal API)
 builder.Services.AddHttpClient<BotManagerService>()
     .ConfigurePrimaryHttpMessageHandler(sp =>

TeleBot/TeleBot/Services/CallbackDataMapper.cs

@@ -0,0 +1,100 @@
+using System.Collections.Concurrent;
+
+namespace TeleBot.Services;
+
+/// <summary>
+/// Maps long GUIDs to short IDs for Telegram callback data (64-byte limit)
+/// </summary>
+public class CallbackDataMapper
+{
+    private readonly ConcurrentDictionary<string, Guid> _shortToGuid = new();
+    private readonly ConcurrentDictionary<Guid, string> _guidToShort = new();
+    private int _nextId = 1;
+    private readonly object _lock = new();
+
+    /// <summary>
+    /// Get or create a short ID for a GUID
+    /// </summary>
+    public string GetShortId(Guid guid, string prefix = "id")
+    {
+        if (_guidToShort.TryGetValue(guid, out var existing))
+            return existing;
+
+        lock (_lock)
+        {
+            // Double-check after acquiring lock
+            if (_guidToShort.TryGetValue(guid, out existing))
+                return existing;
+
+            var shortId = $"{prefix}{_nextId++}";
+            _shortToGuid[shortId] = guid;
+            _guidToShort[guid] = shortId;
+            return shortId;
+        }
+    }
+
+    /// <summary>
+    /// Decode a short ID back to GUID
+    /// </summary>
+    public Guid? DecodeShortId(string shortId)
+    {
+        return _shortToGuid.TryGetValue(shortId, out var guid) ? guid : null;
+    }
+
+    /// <summary>
+    /// Build callback data with short IDs
+    /// Format: action:shortProductId[:quantity[:shortMultiBuyId]]
+    /// </summary>
+    public string BuildCallback(string action, Guid productId, int? quantity = null, Guid? multiBuyId = null)
+    {
+        var parts = new List<string> { action, GetShortId(productId, "p") };
+
+        if (quantity.HasValue)
+            parts.Add(quantity.Value.ToString());
+
+        if (multiBuyId.HasValue)
+            parts.Add(GetShortId(multiBuyId.Value, "mb"));
+
+        var result = string.Join(":", parts);
+
+        // Ensure we don't exceed Telegram's 64-byte limit
+        if (result.Length > 63)
+            throw new InvalidOperationException($"Callback data too long ({result.Length} bytes): {result}");
+
+        return result;
+    }
+
+    /// <summary>
+    /// Parse callback data with short IDs
+    /// </summary>
+    public (string action, Guid? productId, int? quantity, Guid? multiBuyId) ParseCallback(string callbackData)
+    {
+        var parts = callbackData.Split(':');
+        var action = parts[0];
+
+        Guid? productId = null;
+        int? quantity = null;
+        Guid? multiBuyId = null;
+
+        if (parts.Length > 1)
+            productId = DecodeShortId(parts[1]);
+
+        if (parts.Length > 2 && int.TryParse(parts[2], out var qty))
+            quantity = qty;
+
+        if (parts.Length > 3)
+            multiBuyId = DecodeShortId(parts[3]);
+
+        return (action, productId, quantity, multiBuyId);
+    }
+
+    /// <summary>
+    /// Clear old mappings (call periodically to prevent memory buildup)
+    /// </summary>
+    public void ClearMappings()
+    {
+        _shortToGuid.Clear();
+        _guidToShort.Clear();
+        _nextId = 1;
+    }
+}

TeleBot/TeleBot/Services/ProductCarouselService.cs

@@ -29,15 +29,18 @@ namespace TeleBot.Services
         private readonly IConfiguration _configuration;
         private readonly ILogger<ProductCarouselService> _logger;
         private readonly HttpClient _httpClient;
+        private readonly MenuBuilder _menuBuilder;
         private readonly string _imageCachePath;
 
         public ProductCarouselService(
             IConfiguration configuration,
             ILogger<ProductCarouselService> logger,
-            HttpClient httpClient)
+            HttpClient httpClient,
+            MenuBuilder menuBuilder)
         {
             _configuration = configuration;
             _logger = logger;
+            _menuBuilder = menuBuilder;
             _httpClient = httpClient;
             _imageCachePath = Path.Combine(Environment.CurrentDirectory, "image_cache");
             
@@ -208,7 +211,7 @@ namespace TeleBot.Services
                         image,
                         caption: FormatProductCaption(product),
                         parseMode: Telegram.Bot.Types.Enums.ParseMode.Markdown,
-                        replyMarkup: MenuBuilder.ProductDetailMenu(product)
+                        replyMarkup: _menuBuilder.ProductDetailMenu(product)
                     );
                 }
                 else
@@ -218,7 +221,7 @@ namespace TeleBot.Services
                         chatId,
                         MessageFormatter.FormatProductDetail(product),
                         parseMode: Telegram.Bot.Types.Enums.ParseMode.Markdown,
-                        replyMarkup: MenuBuilder.ProductDetailMenu(product)
+                        replyMarkup: _menuBuilder.ProductDetailMenu(product)
                     );
                 }
             }
@@ -231,7 +234,7 @@ namespace TeleBot.Services
                     chatId,
                     MessageFormatter.FormatProductDetail(product),
                     parseMode: Telegram.Bot.Types.Enums.ParseMode.Markdown,
-                    replyMarkup: MenuBuilder.ProductDetailMenu(product)
+                    replyMarkup: _menuBuilder.ProductDetailMenu(product)
                 );
             }
         }

TeleBot/TeleBot/TestCarousel.cs

@@ -20,8 +20,10 @@ namespace TeleBot
             var config = new ConfigurationBuilder().Build();
             var logger = NullLogger<ProductCarouselService>.Instance;
             var httpClient = new System.Net.Http.HttpClient();
+            var mapper = new TeleBot.Services.CallbackDataMapper();
+            var menuBuilder = new TeleBot.UI.MenuBuilder(mapper);
 
-            var carouselService = new ProductCarouselService(config, logger, httpClient);
+            var carouselService = new ProductCarouselService(config, logger, httpClient, menuBuilder);
             
             // Test image URL validation
             var validUrls = new[]
@@ -43,8 +45,10 @@ namespace TeleBot
             var config = new ConfigurationBuilder().Build();
             var logger = NullLogger<ProductCarouselService>.Instance;
             var httpClient = new System.Net.Http.HttpClient();
+            var mapper = new TeleBot.Services.CallbackDataMapper();
+            var menuBuilder = new TeleBot.UI.MenuBuilder(mapper);
 
-            var carouselService = new ProductCarouselService(config, logger, httpClient);
+            var carouselService = new ProductCarouselService(config, logger, httpClient, menuBuilder);
             
             // Create a test product with image
             var testProduct = new Product

TeleBot/TeleBot/UI/MenuBuilder.cs

@@ -4,11 +4,18 @@ using System.Linq;
 using LittleShop.Client.Models;
 using Telegram.Bot.Types.ReplyMarkups;
 using TeleBot.Models;
+using TeleBot.Services;
 
 namespace TeleBot.UI
 {
-    public static class MenuBuilder
+    public class MenuBuilder
     {
+        private readonly CallbackDataMapper _mapper;
+
+        public MenuBuilder(CallbackDataMapper mapper)
+        {
+            _mapper = mapper;
+        }
         public static InlineKeyboardMarkup MainMenu()
         {
             return new InlineKeyboardMarkup(new[]
@@ -90,7 +97,7 @@ namespace TeleBot.UI
             return new InlineKeyboardMarkup(buttons);
         }
         
-        public static InlineKeyboardMarkup ProductDetailMenu(Product product, int quantity = 1)
+        public InlineKeyboardMarkup ProductDetailMenu(Product product, int quantity = 1)
         {
             var buttons = new List<InlineKeyboardButton[]>();
 
@@ -106,14 +113,14 @@ namespace TeleBot.UI
 
                 foreach (var multiBuy in product.MultiBuys.Where(mb => mb.IsActive).OrderBy(mb => mb.Quantity))
                 {
-                    var label = $"{multiBuy.Name} - ${multiBuy.Price:F2}";
+                    var label = $"{multiBuy.Name} - £{multiBuy.Price:F2}";
                     if (multiBuy.Quantity > 1)
-                        label += $" (${multiBuy.PricePerUnit:F2}/each)";
+                        label += $" (£{multiBuy.PricePerUnit:F2}/each)";
 
-                    // If has variants, need variant selection first
+                    // Use short callback data
                     var callbackData = hasVariants
-                        ? $"selectvar:{product.Id}:{multiBuy.Quantity}:{multiBuy.Id}"
+                        ? _mapper.BuildCallback("selectvar", product.Id, multiBuy.Quantity, multiBuy.Id)
-                        : $"add:{product.Id}:{multiBuy.Quantity}:{multiBuy.Id}";
+                        : _mapper.BuildCallback("add", product.Id, multiBuy.Quantity, multiBuy.Id);
 
                     buttons.Add(new[]
                     {
@@ -123,12 +130,12 @@ namespace TeleBot.UI
 
                 // Add regular single item option
                 var singleCallbackData = hasVariants
-                    ? $"selectvar:{product.Id}:1"
+                    ? _mapper.BuildCallback("selectvar", product.Id, 1)
-                    : $"add:{product.Id}:1";
+                    : _mapper.BuildCallback("add", product.Id, 1);
 
                 buttons.Add(new[] {
                     InlineKeyboardButton.WithCallbackData(
-                        $"🛒 Single Item - ${product.Price:F2}",
+                        $"🛒 Single Item - £{product.Price:F2}",
                         singleCallbackData
                     )
                 });
@@ -138,21 +145,21 @@ namespace TeleBot.UI
                 // No multi-buys, show quantity selector
                 var quantityButtons = new List<InlineKeyboardButton>();
                 if (quantity > 1)
-                    quantityButtons.Add(InlineKeyboardButton.WithCallbackData("➖", $"qty:{product.Id}:{quantity - 1}"));
+                    quantityButtons.Add(InlineKeyboardButton.WithCallbackData("➖", _mapper.BuildCallback("qty", product.Id, quantity - 1)));
                 quantityButtons.Add(InlineKeyboardButton.WithCallbackData($"Qty: {quantity}", "noop"));
                 if (quantity < 10)
-                    quantityButtons.Add(InlineKeyboardButton.WithCallbackData("➕", $"qty:{product.Id}:{quantity + 1}"));
+                    quantityButtons.Add(InlineKeyboardButton.WithCallbackData("➕", _mapper.BuildCallback("qty", product.Id, quantity + 1)));
 
                 buttons.Add(quantityButtons.ToArray());
 
                 // Add to cart button
                 var addCallbackData = hasVariants
-                    ? $"selectvar:{product.Id}:{quantity}"
+                    ? _mapper.BuildCallback("selectvar", product.Id, quantity)
-                    : $"add:{product.Id}:{quantity}";
+                    : _mapper.BuildCallback("add", product.Id, quantity);
 
                 buttons.Add(new[] {
                     InlineKeyboardButton.WithCallbackData(
-                        $"🛒 Add to Cart - ${product.Price * quantity:F2}",
+                        $"🛒 Add to Cart - £{product.Price * quantity:F2}",
                         addCallbackData
                     )
                 });
@@ -184,7 +191,7 @@ namespace TeleBot.UI
             return new InlineKeyboardMarkup(buttons);
         }
         
-        public static InlineKeyboardMarkup CartMenu(ShoppingCart cart)
+        public InlineKeyboardMarkup CartMenu(ShoppingCart cart)
         {
             var buttons = new List<InlineKeyboardButton[]>();
 
@@ -196,7 +203,7 @@ namespace TeleBot.UI
                     buttons.Add(new[] {
                         InlineKeyboardButton.WithCallbackData(
                             $"❌ Remove {item.ProductName}",
-                            $"remove:{item.ProductId}"
+                            _mapper.BuildCallback("remove", item.ProductId)
                         )
                     });
                 }