feat: enhance product detail loading and initialization logic

- Introduced an `_initialized` flag to manage product loading state more effectively.
- Updated `OnParametersSetAsync` to conditionally load product details based on the initialization state and valid product ID.
- Refactored product retrieval logic in `ProductService` to handle invalid IDs and improve fallback mechanisms for fetching product details.

These changes improve the reliability and performance of the product detail component, ensuring that product information is loaded correctly and efficiently.

src/FrontOffice.Main/Pages/Store/ProductDetail.razor.cs

@@ -21,6 +21,7 @@ public partial class ProductDetail : ComponentBase, IDisposable
 
     private Product? _product;
     private bool _loading;
+    private bool _initialized;
     private int _qty = 1;
     private const int MinQty = 1;
     
@@ -48,29 +49,35 @@ public partial class ProductDetail : ComponentBase, IDisposable
     private bool IsInCart => CurrentCartItem is not null;
     private int CurrentCartQuantity => CurrentCartItem?.Quantity ?? 0;
 
-    protected override async Task OnParametersSetAsync()
-    {
-      
-    }
-
     protected override async Task OnInitializedAsync()
     {
         _isAuthenticated = await AuthService.IsAuthenticatedAsync();
         await Cart.EnsureInitializedAsync();
         Cart.OnChange += HandleCartChanged;
+        _initialized = true;
+    }
 
+    protected override async Task OnParametersSetAsync()
+    {
+        if (!_initialized || id <= 0)
+            return;
 
+        await LoadProductAsync();
+    }
 
+    private async Task LoadProductAsync()
+    {
         _loading = true;
         _product = await ProductService.GetByIdAsync(id);
         _loading = false;
+
         if (_product is not null)
         {
             _galleryItems = BuildGalleryItems(_product);
             _selectedGalleryImage = _galleryItems.FirstOrDefault();
             _categoryPaths = _product.Categories;
             UpdateBreadcrumb();
-            _qty = Math.Clamp(CurrentCartItem?.Quantity ?? _qty, MinQty, MaxQty);
+            _qty = Math.Clamp(CurrentCartItem?.Quantity ?? MinQty, MinQty, Math.Max(MinQty, MaxQty));
         }
         else
         {
@@ -78,19 +85,16 @@ public partial class ProductDetail : ComponentBase, IDisposable
             _categoryPaths = Array.Empty<ProductCategoryPathInfo>();
             _breadcrumbItems.Clear();
         }
-
-        StateHasChanged();
-        await base.OnInitializedAsync();
     }
 
     protected override async Task OnAfterRenderAsync(bool firstRender)
     {
-       await base.OnAfterRenderAsync(firstRender);
         if (firstRender)
         {
-            // بارگذاری نرخ VAT
             await VAT.LoadAsync();
         }
+
+        await base.OnAfterRenderAsync(firstRender);
     }
 
     private async Task AddToCart()

src/FrontOffice.Main/Utilities/ProductService.cs

@@ -137,30 +137,66 @@ public class ProductService
 
     public async Task<Product?> GetByIdAsync(long id)
     {
-        if (TryGetCachedProduct(id, out var cached) && HasDetailedData(cached))
-        {
+        if (id <= 0)
+            return null;
+
+        TryGetCachedProduct(id, out var cached);
+
+        if (cached is not null && HasDetailedData(cached))
+            return cached;
+
+        // جزئیات کامل (گالری + دسته‌بندی)
+        var detailed = await TryFetchDetailAsync(id);
+        if (detailed is not null)
+            return detailed;
+
+        // fallback: همان API لیست محصولات — ناموجودها را هم برمی‌گرداند
+        var fromFilter = await TryFetchByFilterIdAsync(id);
+        if (fromFilter is not null)
+            return fromFilter;
+
         return cached;
     }
 
+    private async Task<Product?> TryFetchDetailAsync(long id)
+    {
         try
         {
             var resp = await _client.GetProductsAsync(new GetProductsRequest { Id = id });
-            if (resp == null)
-            {
+            if (resp is null || resp.Id <= 0)
                 return null;
-            }
 
             return MapAndCache(resp);
         }
         catch
         {
-            if (cached is not null)
-            {
-                return cached;
+            return null;
+        }
     }
 
-            TryGetCachedProduct(id, out var result);
-            return result;
+    private async Task<Product?> TryFetchByFilterIdAsync(long id)
+    {
+        try
+        {
+            var resp = await _client.GetAllProductsByFilterAsync(new GetAllProductsByFilterRequest
+            {
+                PaginationState = new CMSMicroservice.Protobuf.Protos.PaginationState
+                {
+                    PageNumber = 1,
+                    PageSize = 1
+                },
+                Filter = new GetAllProductsByFilterFilter { Id = id }
+            });
+
+            var model = resp.Models.FirstOrDefault(m => m.Id == id);
+            if (model is null)
+                return null;
+
+            return MapAndCache(resp.Models).FirstOrDefault(p => p.Id == id);
+        }
+        catch
+        {
+            return null;
         }
     }