using System;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Logging;
using QRCoder;
using Telegram.Bot;
using Telegram.Bot.Exceptions;
using Telegram.Bot.Types;
using Telegram.Bot.Types.ReplyMarkups;
using TeleBot.Models;
using TeleBot.Services;
using TeleBot.UI;
using LittleShop.Client.Models;

namespace TeleBot.Handlers
{
    public interface ICallbackHandler
    {
        Task HandleCallbackAsync(ITelegramBotClient bot, CallbackQuery callbackQuery);
    }
    
    public class CallbackHandler : ICallbackHandler
    {
        private readonly ISessionManager _sessionManager;
        private readonly ILittleShopService _shopService;
        private readonly IPrivacyService _privacyService;
        private readonly IProductCarouselService _carouselService;
        private readonly IConfiguration _configuration;
        private readonly ILogger<CallbackHandler> _logger;
        
        public CallbackHandler(
            ISessionManager sessionManager,
            ILittleShopService shopService,
            IPrivacyService privacyService,
            IProductCarouselService carouselService,
            IConfiguration configuration,
            ILogger<CallbackHandler> logger)
        {
            _sessionManager = sessionManager;
            _shopService = shopService;
            _privacyService = privacyService;
            _carouselService = carouselService;
            _configuration = configuration;
            _logger = logger;
        }
        
        public async Task HandleCallbackAsync(ITelegramBotClient bot, CallbackQuery callbackQuery)
        {
            if (callbackQuery.Message == null || callbackQuery.Data == null)
                return;
            
            var session = await _sessionManager.GetOrCreateSessionAsync(callbackQuery.From.Id);
            bool callbackAnswered = false;
            
            try
            {
                // Answer callback immediately to prevent timeout
                await bot.AnswerCallbackQueryAsync(callbackQuery.Id);
                callbackAnswered = true;
                
                var data = callbackQuery.Data.Split(':');
                var action = data[0];
                
                switch (action)
                {
                    case "menu":
                        await HandleMainMenu(bot, callbackQuery.Message, session);
                        break;
                        
                    case "browse":
                        await HandleBrowse(bot, callbackQuery.Message, session);
                        break;
                        
                    case "category":
                        await HandleCategory(bot, callbackQuery.Message, session, Guid.Parse(data[1]));
                        break;
                        
                    case "products":
                        if (data.Length > 1 && data[1] == "page")
                        {
                            await HandleProductsPage(bot, callbackQuery.Message, session, data);
                        }
                        else
                        {
                            await HandleProductList(bot, callbackQuery.Message, session, data);
                        }
                        break;
                        
                    case "product":
                        await HandleProductDetail(bot, callbackQuery.Message, session, Guid.Parse(data[1]));
                        break;
                        
                    case "qty":
                        await HandleQuantityChange(bot, callbackQuery.Message, session, data);
                        break;
                        
                    case "add":
                        await HandleAddToCart(bot, callbackQuery, session, data);
                        break;

                    case "quickbuy":
                        await HandleQuickBuy(bot, callbackQuery, session, data);
                        break;

                    case "quickbuyvar":
                        await HandleQuickBuyWithVariation(bot, callbackQuery, session, data);
                        break;

                    case "cart":
                        await HandleViewCart(bot, callbackQuery.Message, session);
                        break;
                        
                    case "remove":
                        await HandleRemoveFromCart(bot, callbackQuery, session, Guid.Parse(data[1]));
                        break;
                        
                    case "clear_cart":
                        await HandleClearCart(bot, callbackQuery, session);
                        break;
                        
                    case "checkout":
                        await HandleCheckout(bot, callbackQuery.Message, session);
                        break;
                        
                    case "confirm_order":
                        await HandleConfirmOrder(bot, callbackQuery.Message, session, callbackQuery.From);
                        break;
                        
                    case "pay":
                        await HandlePayment(bot, callbackQuery.Message, session, data[1]);
                        break;
                        
                    case "orders":
                        await HandleViewOrders(bot, callbackQuery.Message, session, callbackQuery.From);
                        break;
                        
                    case "order":
                        await HandleViewOrder(bot, callbackQuery.Message, session, Guid.Parse(data[1]), callbackQuery.From);
                        break;
                        
                    case "privacy":
                        await HandlePrivacySettings(bot, callbackQuery.Message, session, data.Length > 1 ? data[1] : null);
                        break;
                        
                    case "help":
                        await HandleHelp(bot, callbackQuery.Message);
                        break;
                        
                    case "support":
                        await HandleSupportCallback(bot, callbackQuery, session);
                        break;
                        
                    case "refresh_conversation":
                        await HandleRefreshConversation(bot, callbackQuery, session);
                        break;
                        
                    case "exit_chat":
                        await HandleExitChat(bot, callbackQuery, session);
                        break;
                        
                    case "noop":
                        // No operation - used for display-only buttons
                        break;
                        
                    case "cancel_support":
                        await HandleCancelSupport(bot, callbackQuery, session);
                        break;
                        
                    default:
                        _logger.LogWarning("Unknown callback action: {Action}", action);
                        break;
                }
                
                await _sessionManager.UpdateSessionAsync(session);
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Error handling callback {Data}", callbackQuery.Data);
                
                // Only try to answer callback if not already answered
                if (!callbackAnswered)
                {
                    try
                    {
                        await bot.AnswerCallbackQueryAsync(
                            callbackQuery.Id,
                            "An error occurred. Please try again.",
                            showAlert: true
                        );
                    }
                    catch (ApiRequestException apiEx) when (apiEx.Message.Contains("query is too old"))
                    {
                        // Callback already expired, ignore
                        _logger.LogDebug("Callback query already expired");
                    }
                }
            }
        }
        
        private async Task HandleMainMenu(ITelegramBotClient bot, Message message, UserSession session)
        {
            await bot.EditMessageTextAsync(
                message.Chat.Id,
                message.MessageId,
                MessageFormatter.FormatWelcome(true),
                parseMode: Telegram.Bot.Types.Enums.ParseMode.Markdown,
                replyMarkup: MenuBuilder.MainMenu()
            );
            session.State = SessionState.MainMenu;
        }
        
        private async Task HandleBrowse(ITelegramBotClient bot, Message message, UserSession session)
        {
            var categories = await _shopService.GetCategoriesAsync();
            
            await bot.EditMessageTextAsync(
                message.Chat.Id,
                message.MessageId,
                MessageFormatter.FormatCategories(categories),
                parseMode: Telegram.Bot.Types.Enums.ParseMode.Markdown,
                replyMarkup: MenuBuilder.CategoryMenu(categories)
            );
            session.State = SessionState.BrowsingCategories;
        }
        
        private async Task HandleCategory(ITelegramBotClient bot, Message message, UserSession session, Guid categoryId)
        {
            var categories = await _shopService.GetCategoriesAsync();
            var category = categories.FirstOrDefault(c => c.Id == categoryId);
            var products = await _shopService.GetProductsAsync(categoryId, 1);
            
            // Edit the original message to show category header (bigger, more prominent)
            var headerText = $"**{category?.Name ?? "Unknown Category"} PRODUCTS**\n\nBrowse individual products below:";
                
            await bot.EditMessageTextAsync(
                message.Chat.Id,
                message.MessageId,
                headerText,
                parseMode: Telegram.Bot.Types.Enums.ParseMode.Markdown,
                replyMarkup: MenuBuilder.CategoryNavigationMenu(categoryId)
            );
            
            // Send individual product bubbles
            if (products.Items.Any())
            {
                foreach (var product in products.Items)
                {
                    await bot.SendTextMessageAsync(
                        message.Chat.Id,
                        MessageFormatter.FormatSingleProduct(product),
                        parseMode: Telegram.Bot.Types.Enums.ParseMode.Markdown,
                        replyMarkup: MenuBuilder.SingleProductMenu(product.Id)
                    );
                }
                
                // Send navigation buttons after all products
                await bot.SendTextMessageAsync(
                    message.Chat.Id,
                    ".",
                    replyMarkup: MenuBuilder.ProductNavigationMenu(categoryId)
                );
            }
            else
            {
                await bot.SendTextMessageAsync(
                    message.Chat.Id,
                    "No products available in this category.",
                    replyMarkup: MenuBuilder.BackToCategoriesMenu()
                );
            }
            
            session.State = SessionState.ViewingProducts;
        }
        
        private async Task HandleProductList(ITelegramBotClient bot, Message message, UserSession session, string[] data)
        {
            // Format: products:categoryId:page or products:all:page
            var page = int.Parse(data[2]);
            Guid? categoryId = data[1] != "all" ? Guid.Parse(data[1]) : null;
            
            var products = await _shopService.GetProductsAsync(categoryId, page);
            string? categoryName = null;
            
            if (categoryId.HasValue)
            {
                var categories = await _shopService.GetCategoriesAsync();
                categoryName = categories.FirstOrDefault(c => c.Id == categoryId)?.Name;
            }
            
            // Use carousel service to send products with images
            await _carouselService.SendProductCarouselAsync(bot, message.Chat.Id, products, categoryName, page);
            session.State = SessionState.ViewingProducts;
        }
        
        private async Task HandleProductsPage(ITelegramBotClient bot, Message message, UserSession session, string[] data)
        {
            // Format: products:page:pageNumber
            var page = int.Parse(data[2]);
            
            // Get products for all categories (no specific category filter)
            var products = await _shopService.GetProductsAsync(null, page);
            
            // Use carousel service to send products with images
            await _carouselService.SendProductCarouselAsync(bot, message.Chat.Id, products, "All Categories", page);
            session.State = SessionState.ViewingProducts;
        }
        
        private async Task HandleProductDetail(ITelegramBotClient bot, Message message, UserSession session, Guid productId)
        {
            var product = await _shopService.GetProductAsync(productId);
            if (product == null)
            {
                await bot.AnswerCallbackQueryAsync("", "Product not found", showAlert: true);
                return;
            }
            
            // Store current product in temp data for quantity selection
            session.TempData["current_product"] = productId;
            session.TempData["current_quantity"] = 1;
            
            // Use carousel service to send product with image
            await _carouselService.SendSingleProductWithImageAsync(bot, message.Chat.Id, product);
            session.State = SessionState.ViewingProduct;
        }
        
        private async Task HandleQuantityChange(ITelegramBotClient bot, Message message, UserSession session, string[] data)
        {
            // Format: qty:productId:newQuantity
            var productId = Guid.Parse(data[1]);
            var quantity = int.Parse(data[2]);
            
            var product = await _shopService.GetProductAsync(productId);
            if (product == null)
                return;
            
            session.TempData["current_quantity"] = quantity;
            
            await bot.EditMessageReplyMarkupAsync(
                message.Chat.Id,
                message.MessageId,
                MenuBuilder.ProductDetailMenu(product, quantity)
            );
        }
        
        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
            var productId = Guid.Parse(data[1]);
            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 (product == null)
            {
                await bot.AnswerCallbackQueryAsync(callbackQuery.Id, "Product not found", showAlert: true);
                return;
            }

            // 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);
                return;
            }

            // Get price based on multi-buy or base product
            decimal price = product.Price;
            string itemName = product.Name;
            if (multiBuyId.HasValue && product.MultiBuys != null)
            {
                var multiBuy = product.MultiBuys.FirstOrDefault(mb => mb.Id == multiBuyId);
                if (multiBuy != null)
                {
                    price = multiBuy.Price;
                    itemName = $"{product.Name} ({multiBuy.Name})";
                    quantity = multiBuy.Quantity; // Use multi-buy quantity
                }
            }

            // Add variant to item name if selected
            if (!string.IsNullOrEmpty(selectedVariant))
            {
                itemName += $" - {selectedVariant}";
            }

            session.Cart.AddItem(productId, itemName, price, quantity, multiBuyId, selectedVariant);

            await bot.AnswerCallbackQueryAsync(
                callbackQuery.Id,
                $"✅ Added {quantity}x {itemName} to cart",
                showAlert: false
            );

            // Send new cart message instead of editing
            await SendNewCartMessage(bot, callbackQuery.Message!.Chat.Id, session);
        }
        
        private async Task HandleViewCart(ITelegramBotClient bot, Message message, UserSession session)
        {
            await bot.EditMessageTextAsync(
                message.Chat.Id,
                message.MessageId,
                MessageFormatter.FormatCart(session.Cart),
                parseMode: Telegram.Bot.Types.Enums.ParseMode.Markdown,
                replyMarkup: MenuBuilder.CartMenu(session.Cart)
            );
            session.State = SessionState.ViewingCart;
        }

        private async Task SendNewCartMessage(ITelegramBotClient bot, long chatId, UserSession session)
        {
            await bot.SendTextMessageAsync(
                chatId,
                MessageFormatter.FormatCart(session.Cart),
                parseMode: Telegram.Bot.Types.Enums.ParseMode.Markdown,
                replyMarkup: MenuBuilder.CartMenu(session.Cart)
            );
            session.State = SessionState.ViewingCart;
        }

        private async Task ShowVariantSelection(ITelegramBotClient bot, Message message, UserSession session, Product product, int quantity, Guid? multiBuyId)
        {
            var text = $"**{product.Name}**\n\n";
            text += "Please select a variant:\n";

            var buttons = new List<InlineKeyboardButton[]>();

            if (product.Variants?.Any() == true)
            {
                foreach (var variant in product.Variants.OrderBy(v => v.SortOrder))
                {
                    var callbackData = multiBuyId.HasValue
                        ? $"add:{product.Id}:{quantity}:{multiBuyId}:{variant.Name}"
                        : $"add:{product.Id}:{quantity}::{variant.Name}";

                    buttons.Add(new[]
                    {
                        InlineKeyboardButton.WithCallbackData(variant.Name, callbackData)
                    });
                }
            }

            buttons.Add(new[]
            {
                InlineKeyboardButton.WithCallbackData("« Back", $"product:{product.Id}")
            });

            await bot.EditMessageTextAsync(
                message.Chat.Id,
                message.MessageId,
                text,
                parseMode: Telegram.Bot.Types.Enums.ParseMode.Markdown,
                replyMarkup: new InlineKeyboardMarkup(buttons)
            );
        }

        private async Task HandleQuickBuy(ITelegramBotClient bot, CallbackQuery callbackQuery, UserSession session, string[] data)
        {
            // Format: quickbuy:productId:quantity
            var productId = Guid.Parse(data[1]);
            var quantity = int.Parse(data[2]);

            var product = await _shopService.GetProductAsync(productId);
            if (product == null)
            {
                await bot.AnswerCallbackQueryAsync(callbackQuery.Id, "Product not found", showAlert: true);
                return;
            }

            // If variants exist, show variant selection with quickbuy flow
            if (product.Variants?.Any() == true)
            {
                await ShowVariantSelectionForQuickBuy(bot, callbackQuery.Message!, session, product, quantity);
                return;
            }

            // Add to cart with base product
            session.Cart.AddItem(productId, product.Name, product.Price, quantity, null, null);

            await bot.AnswerCallbackQueryAsync(
                callbackQuery.Id,
                $"✅ Added {quantity}x {product.Name} to cart",
                showAlert: false
            );

            // Send cart summary in new message
            await bot.SendTextMessageAsync(
                callbackQuery.Message!.Chat.Id,
                MessageFormatter.FormatCart(session.Cart),
                parseMode: Telegram.Bot.Types.Enums.ParseMode.Markdown,
                replyMarkup: MenuBuilder.CartMenu(session.Cart)
            );

            // Immediately proceed to checkout
            await Task.Delay(500); // Small delay for better UX
            await HandleCheckout(bot, callbackQuery.Message, session);
        }

        private async Task ShowVariantSelectionForQuickBuy(ITelegramBotClient bot, Message message, UserSession session, Product product, int quantity)
        {
            var text = $"**Quick Buy: {product.Name}**\n\n";
            text += "Please select a variant:\n";
            var buttons = new List<InlineKeyboardButton[]>();

            if (product.Variants?.Any() == true)
            {
                // Add buttons for each variant with quickbuy flow
                foreach (var variant in product.Variants.OrderBy(v => v.SortOrder))
                {
                    buttons.Add(new[]
                    {
                        InlineKeyboardButton.WithCallbackData(variant.Name, $"quickbuyvar:{product.Id}:{quantity}:{variant.Name}")
                    });
                }
            }

            // Add back button
            buttons.Add(new[]
            {
                InlineKeyboardButton.WithCallbackData("⬅️ Back", "menu")
            });

            await bot.SendTextMessageAsync(
                message.Chat.Id,
                text + "\n\n*Select an option for quick checkout:*",
                parseMode: Telegram.Bot.Types.Enums.ParseMode.Markdown,
                replyMarkup: new InlineKeyboardMarkup(buttons)
            );
        }

        private async Task HandleQuickBuyWithVariation(ITelegramBotClient bot, CallbackQuery callbackQuery, UserSession session, string[] data)
        {
            // Format: quickbuyvar:productId:quantity:variantName
            var productId = Guid.Parse(data[1]);
            var quantity = int.Parse(data[2]);
            var variantName = data[3];

            var product = await _shopService.GetProductAsync(productId);
            if (product == null)
            {
                await bot.AnswerCallbackQueryAsync(callbackQuery.Id, "Product not found", showAlert: true);
                return;
            }

            // Add to cart with variant
            var itemName = $"{product.Name} - {variantName}";
            session.Cart.AddItem(productId, itemName, product.Price, quantity, null, variantName);

            await bot.AnswerCallbackQueryAsync(
                callbackQuery.Id,
                $"✅ Added {quantity}x {itemName} to cart",
                showAlert: false
            );

            // Send cart summary in new message
            await bot.SendTextMessageAsync(
                callbackQuery.Message!.Chat.Id,
                MessageFormatter.FormatCart(session.Cart),
                parseMode: Telegram.Bot.Types.Enums.ParseMode.Markdown,
                replyMarkup: MenuBuilder.CartMenu(session.Cart)
            );

            // Immediately proceed to checkout
            await Task.Delay(500); // Small delay for better UX
            await HandleCheckout(bot, callbackQuery.Message, session);
        }
        
        private async Task HandleRemoveFromCart(ITelegramBotClient bot, CallbackQuery callbackQuery, UserSession session, Guid productId)
        {
            var item = session.Cart.Items.FirstOrDefault(i => i.ProductId == productId);
            if (item != null)
            {
                session.Cart.RemoveItem(productId);
                await bot.AnswerCallbackQueryAsync(
                    callbackQuery.Id,
                    $"❌ Removed {item.ProductName} from cart",
                    showAlert: false
                );
            }
            
            await HandleViewCart(bot, callbackQuery.Message!, session);
        }
        
        private async Task HandleClearCart(ITelegramBotClient bot, CallbackQuery callbackQuery, UserSession session)
        {
            session.Cart.Clear();
            await bot.AnswerCallbackQueryAsync(
                callbackQuery.Id,
                "🗑️ Cart cleared",
                showAlert: false
            );
            
            await HandleViewCart(bot, callbackQuery.Message!, session);
        }
        
        private async Task HandleCheckout(ITelegramBotClient bot, Message message, UserSession session)
        {
            if (session.Cart.IsEmpty())
            {
                await bot.AnswerCallbackQueryAsync("", "Your cart is empty", showAlert: true);
                return;
            }

            // Initialize order flow
            session.OrderFlow = new OrderFlowData
            {
                UsePGPEncryption = session.Privacy.RequirePGP
            };

            session.State = SessionState.CheckoutFlow;

            // Send new message for checkout instead of editing
            await bot.SendTextMessageAsync(
                message.Chat.Id,
                "📦 *Checkout - Step 1/5*\n\n" +
                "Please enter your shipping name:\n\n" +
                "_Reply to this message with your name_",
                parseMode: Telegram.Bot.Types.Enums.ParseMode.Markdown
            );
        }
        
        private async Task HandleConfirmOrder(ITelegramBotClient bot, Message message, UserSession session, User telegramUser)
        {
            if (session.OrderFlow == null || session.Cart.IsEmpty())
            {
                await bot.AnswerCallbackQueryAsync("", "Invalid order state", showAlert: true);
                return;
            }
            
            // Create the order with customer information
            var order = await _shopService.CreateOrderAsync(
                session,
                telegramUser.Id,
                telegramUser.Username ?? "",
                $"{telegramUser.FirstName} {telegramUser.LastName}".Trim(),
                telegramUser.FirstName ?? "",
                telegramUser.LastName ?? "");
            
            if (order == null)
            {
                await bot.EditMessageTextAsync(
                    message.Chat.Id,
                    message.MessageId,
                    "❌ Failed to create order. Please try again.",
                    replyMarkup: MenuBuilder.CartMenu(session.Cart)
                );
                return;
            }
            
            // Backup cart in case payment fails - we'll need to restore it
            var cartBackup = System.Text.Json.JsonSerializer.Serialize(session.Cart);
            session.TempData["cart_backup"] = cartBackup;

            // Clear cart after successful order (will restore if payment fails)
            session.Cart.Clear();

            // Store order ID for payment
            session.TempData["current_order_id"] = order.Id;
            
            // Show payment options - get currencies dynamically from SilverPay support + admin settings
            var currencies = await _shopService.GetAvailableCurrenciesAsync();
            
            await bot.EditMessageTextAsync(
                message.Chat.Id,
                message.MessageId,
                $"✅ *Order Created Successfully!*\n\n" +
                $"Order ID: `{order.Id}`\n" +
                $"Total: ${order.TotalAmount:F2}\n\n" +
                "Select your preferred payment method:",
                parseMode: Telegram.Bot.Types.Enums.ParseMode.Markdown,
                replyMarkup: MenuBuilder.PaymentMethodMenu(currencies)
            );
        }
        
        private async Task HandlePayment(ITelegramBotClient bot, Message message, UserSession session, string currency)
        {
            if (!session.TempData.TryGetValue("current_order_id", out var orderIdObj) || orderIdObj is not Guid orderId)
            {
                await SafeEditMessageAsync(
                    bot,
                    message.Chat.Id,
                    message.MessageId,
                    "❌ Order not found. Please start a new order.",
                    Telegram.Bot.Types.Enums.ParseMode.Markdown,
                    MenuBuilder.MainMenu()
                );
                return;
            }
            
            // Show processing message
            await SafeEditMessageAsync(
                bot,
                message.Chat.Id,
                message.MessageId,
                $"🔄 Creating {currency} payment...\n\nPlease wait...",
                Telegram.Bot.Types.Enums.ParseMode.Markdown
            );
            
            try
            {
                var payment = await _shopService.CreatePaymentAsync(orderId, currency);
                
                if (payment == null)
                {
                    // Restore cart from backup since payment failed
                    if (session.TempData.TryGetValue("cart_backup", out var cartBackupObj) && cartBackupObj is string cartBackupJson)
                    {
                        try
                        {
                            session.Cart = System.Text.Json.JsonSerializer.Deserialize<ShoppingCart>(cartBackupJson) ?? new ShoppingCart();
                            session.TempData.Remove("cart_backup");
                        }
                        catch
                        {
                            // If restoration fails, cart remains empty
                        }
                    }

                    await SafeEditMessageAsync(
                        bot,
                        message.Chat.Id,
                        message.MessageId,
                        $"❌ *Payment Creation Failed*\n\n" +
                        $"Unable to create {currency} payment.\n" +
                        $"This might be due to:\n" +
                        $"• Payment gateway temporarily unavailable\n" +
                        $"• Network connectivity issues\n\n" +
                        $"Your cart has been restored. Please try again.",
                        Telegram.Bot.Types.Enums.ParseMode.Markdown,
                        MenuBuilder.CartMenu(session.Cart)
                    );
                    return;
                }
                
                // Payment created successfully, remove cart backup
                session.TempData.Remove("cart_backup");

                // Continue with display
                var paymentText = MessageFormatter.FormatPayment(payment);

                await DisplayPaymentInfo(bot, message, payment, paymentText);
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Failed to create payment for order {OrderId} with currency {Currency}", orderId, currency);

                // Restore cart from backup since payment failed
                if (session.TempData.TryGetValue("cart_backup", out var cartBackupObj) && cartBackupObj is string cartBackupJson)
                {
                    try
                    {
                        session.Cart = System.Text.Json.JsonSerializer.Deserialize<ShoppingCart>(cartBackupJson) ?? new ShoppingCart();
                        session.TempData.Remove("cart_backup");
                    }
                    catch
                    {
                        // If restoration fails, cart remains empty
                    }
                }

                await SafeEditMessageAsync(
                    bot,
                    message.Chat.Id,
                    message.MessageId,
                    $"❌ *Payment System Error*\n\n" +
                    $"Sorry, there was a technical issue creating your {currency} payment.\n\n" +
                    $"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)
                );
                return;
            }
        }
        
        /// <summary>
        /// Safely edit a message only if the content has changed
        /// </summary>
        private async Task SafeEditMessageAsync(ITelegramBotClient bot, ChatId chatId, int messageId, string newText, 
            Telegram.Bot.Types.Enums.ParseMode parseMode = Telegram.Bot.Types.Enums.ParseMode.Html, 
            InlineKeyboardMarkup? replyMarkup = null)
        {
            try
            {
                await bot.EditMessageTextAsync(chatId, messageId, newText, parseMode: parseMode, replyMarkup: replyMarkup);
            }
            catch (ApiRequestException apiEx) when (apiEx.Message.Contains("message is not modified"))
            {
                // Message content hasn't changed, this is fine
                _logger.LogDebug("Attempted to edit message with identical content");
            }
        }

        private async Task DisplayPaymentInfo(ITelegramBotClient bot, Message message, dynamic payment, string paymentText)
        {
            
            // Generate QR code if enabled
            if (_configuration.GetValue<bool>("Features:EnableQRCodes"))
            {
                try
                {
                    using var qrGenerator = new QRCodeGenerator();
                    var qrCodeData = qrGenerator.CreateQrCode(payment.WalletAddress, QRCodeGenerator.ECCLevel.Q);
                    using var qrCode = new PngByteQRCode(qrCodeData);
                    var qrCodeBytes = qrCode.GetGraphic(10);
                    
                    using var stream = new System.IO.MemoryStream(qrCodeBytes);
                    await bot.SendPhotoAsync(
                        message.Chat.Id,
                        InputFile.FromStream(stream, "payment_qr.png"),
                        caption: paymentText,
                        parseMode: Telegram.Bot.Types.Enums.ParseMode.Markdown
                    );
                    
                    // Delete the original message
                    await bot.DeleteMessageAsync(message.Chat.Id, message.MessageId);
                }
                catch (Exception ex)
                {
                    _logger.LogError(ex, "Failed to generate QR code");
                    // Fall back to text-only
                    await SafeEditMessageAsync(
                        bot,
                        message.Chat.Id,
                        message.MessageId,
                        paymentText,
                        Telegram.Bot.Types.Enums.ParseMode.Markdown,
                        MenuBuilder.MainMenu()
                    );
                }
            }
            else
            {
                await SafeEditMessageAsync(
                    bot,
                    message.Chat.Id,
                    message.MessageId,
                    paymentText,
                    Telegram.Bot.Types.Enums.ParseMode.Markdown,
                    MenuBuilder.MainMenu()
                );
            }
        }
        
        private async Task HandleViewOrders(ITelegramBotClient bot, Message message, UserSession session, User telegramUser)
        {
            // Use new customer-based order lookup
            var orders = await _shopService.GetCustomerOrdersAsync(
                telegramUser.Id,
                telegramUser.Username ?? "",
                $"{telegramUser.FirstName} {telegramUser.LastName}".Trim(),
                telegramUser.FirstName ?? "",
                telegramUser.LastName ?? ""
            );
            
            if (!orders.Any())
            {
                await bot.EditMessageTextAsync(
                    message.Chat.Id,
                    message.MessageId,
                    "📦 *Your Orders*\n\nYou have no orders yet.",
                    parseMode: Telegram.Bot.Types.Enums.ParseMode.Markdown,
                    replyMarkup: MenuBuilder.MainMenu()
                );
            }
            else
            {
                await bot.EditMessageTextAsync(
                    message.Chat.Id,
                    message.MessageId,
                    $"📦 *Your Orders*\n\nFound {orders.Count} order(s):",
                    parseMode: Telegram.Bot.Types.Enums.ParseMode.Markdown,
                    replyMarkup: MenuBuilder.OrderListMenu(orders)
                );
            }
            
            session.State = SessionState.ViewingOrders;
        }
        
        private async Task HandleViewOrder(ITelegramBotClient bot, Message message, UserSession session, Guid orderId, User telegramUser)
        {
            var order = await _shopService.GetCustomerOrderAsync(
                orderId,
                telegramUser.Id,
                telegramUser.Username ?? "",
                $"{telegramUser.FirstName} {telegramUser.LastName}".Trim(),
                telegramUser.FirstName ?? "",
                telegramUser.LastName ?? ""
            );
            
            if (order == null)
            {
                await bot.AnswerCallbackQueryAsync("", "Order not found", showAlert: true);
                return;
            }
            
            await bot.EditMessageTextAsync(
                message.Chat.Id,
                message.MessageId,
                MessageFormatter.FormatOrder(order),
                parseMode: Telegram.Bot.Types.Enums.ParseMode.Markdown,
                replyMarkup: MenuBuilder.MainMenu()
            );
            
            session.State = SessionState.ViewingOrder;
        }
        
        private async Task HandlePrivacySettings(ITelegramBotClient bot, Message message, UserSession session, string? setting)
        {
            if (setting != null)
            {
                switch (setting)
                {
                    case "ephemeral":
                        session.Privacy.UseEphemeralMode = !session.Privacy.UseEphemeralMode;
                        session.IsEphemeral = session.Privacy.UseEphemeralMode;
                        break;
                        
                    case "tor":
                        session.Privacy.UseTorOnly = !session.Privacy.UseTorOnly;
                        break;
                        
                    case "pgp":
                        session.Privacy.RequirePGP = !session.Privacy.RequirePGP;
                        if (session.Privacy.RequirePGP && string.IsNullOrEmpty(session.Privacy.PGPPublicKey))
                        {
                            await bot.SendTextMessageAsync(
                                message.Chat.Id,
                                "Please set your PGP public key using:\n`/pgpkey YOUR_PUBLIC_KEY`",
                                parseMode: Telegram.Bot.Types.Enums.ParseMode.Markdown
                            );
                        }
                        break;
                        
                    case "analytics":
                        session.Privacy.DisableAnalytics = !session.Privacy.DisableAnalytics;
                        break;
                        
                    case "disappearing":
                        session.Privacy.EnableDisappearingMessages = !session.Privacy.EnableDisappearingMessages;
                        break;
                        
                    case "delete":
                        await _sessionManager.DeleteUserDataAsync(message.From!.Id);
                        await bot.EditMessageTextAsync(
                            message.Chat.Id,
                            message.MessageId,
                            "✅ *All your data has been deleted*\n\nYou can start fresh with /start",
                            parseMode: Telegram.Bot.Types.Enums.ParseMode.Markdown
                        );
                        return;
                }
            }
            
            await bot.EditMessageTextAsync(
                message.Chat.Id,
                message.MessageId,
                MessageFormatter.FormatPrivacyPolicy(),
                parseMode: Telegram.Bot.Types.Enums.ParseMode.Markdown,
                replyMarkup: MenuBuilder.PrivacyMenu(session.Privacy)
            );
            
            session.State = SessionState.PrivacySettings;
        }
        
        private async Task HandleHelp(ITelegramBotClient bot, Message message)
        {
            await bot.EditMessageTextAsync(
                message.Chat.Id,
                message.MessageId,
                MessageFormatter.FormatHelp(),
                parseMode: Telegram.Bot.Types.Enums.ParseMode.Markdown,
                replyMarkup: MenuBuilder.MainMenu()
            );
        }
        
        private async Task HandleSupportCallback(ITelegramBotClient bot, CallbackQuery callbackQuery, UserSession session)
        {
            session.State = SessionState.CustomerSupport;
            
            await ShowCustomerConversationInCallback(bot, callbackQuery, session);
            await bot.AnswerCallbackQueryAsync(callbackQuery.Id);
        }
        
        private async Task HandleRefreshConversation(ITelegramBotClient bot, CallbackQuery callbackQuery, UserSession session)
        {
            await ShowCustomerConversationInCallback(bot, callbackQuery, session);
            await bot.AnswerCallbackQueryAsync(callbackQuery.Id, "Messages refreshed");
        }
        
        private async Task HandleExitChat(ITelegramBotClient bot, CallbackQuery callbackQuery, UserSession session)
        {
            session.State = SessionState.MainMenu;
            
            await bot.EditMessageTextAsync(
                callbackQuery.Message!.Chat.Id,
                callbackQuery.Message.MessageId,
                "Chat ended. How can I help you today?",
                replyMarkup: MenuBuilder.MainMenu()
            );
            
            await bot.AnswerCallbackQueryAsync(callbackQuery.Id);
        }
        
        private async Task ShowCustomerConversationInCallback(ITelegramBotClient bot, CallbackQuery callbackQuery, UserSession session)
        {
            try
            {
                var user = callbackQuery.From;
                
                // Get conversation history for this customer
                var messages = await _shopService.GetCustomerConversationAsync(
                    user.Id,
                    user.Username ?? "",
                    $"{user.FirstName} {user.LastName}".Trim(),
                    user.FirstName ?? "",
                    user.LastName ?? ""
                );

                var conversationText = "💬 *Your Messages*\n\n";
                
                if (messages?.Any() == true)
                {
                    conversationText += "Recent conversation:\n\n";
                    
                    foreach (var msg in messages.OrderBy(m => m.CreatedAt).TakeLast(8)) // Show last 8 messages
                    {
                        var isFromBusiness = msg.Direction == 0; // AdminToCustomer
                        var sender = isFromBusiness ? "🏪 Shop" : "👤 You";
                        var time = msg.CreatedAt.ToString("MMM dd, HH:mm");
                        
                        conversationText += $"*{sender}* _{time}_\n{msg.Content}\n\n";
                    }
                }
                else
                {
                    conversationText += "No messages yet. Start a conversation by typing below!\n\n";
                }
                
                conversationText += "_Type your message or use buttons below._";

                await bot.EditMessageTextAsync(
                    callbackQuery.Message!.Chat.Id,
                    callbackQuery.Message.MessageId,
                    conversationText,
                    parseMode: Telegram.Bot.Types.Enums.ParseMode.Markdown,
                    replyMarkup: MenuBuilder.ConversationMenu()
                );
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Error showing customer conversation in callback");
                await bot.EditMessageTextAsync(
                    callbackQuery.Message!.Chat.Id,
                    callbackQuery.Message.MessageId,
                    "💬 *Customer Messages*\n\nReady to chat with our support team!\n\n_Type your message below._",
                    parseMode: Telegram.Bot.Types.Enums.ParseMode.Markdown,
                    replyMarkup: MenuBuilder.ConversationMenu()
                );
            }
        }

        private async Task HandleCancelSupport(ITelegramBotClient bot, CallbackQuery callbackQuery, UserSession session)
        {
            session.State = SessionState.MainMenu;
            
            await bot.EditMessageTextAsync(
                callbackQuery.Message!.Chat.Id,
                callbackQuery.Message.MessageId,
                "Customer support cancelled. How can I help you today?",
                replyMarkup: MenuBuilder.MainMenu()
            );
            
            await bot.AnswerCallbackQueryAsync(callbackQuery.Id);
        }
    }
}