Исправления (но нужно проверить)

FurnitureAssembly/FurnitureAssembly/FormMain.cs

@@ -195,18 +195,12 @@ namespace FurnitureAssembly
 
                     var modelShop = new ShopBindingModel
                     {
-                        Id = form.Id,
-                        ShopName = form.ShopModel.ShopName,
-                        Address = form.ShopModel.Address,
-                        DateOpening = form.ShopModel.DateOpening,                      
+                        Id = form.Id                                          
                     };
 
                     var modelFurn = new FurnitureBindingModel
                     {
-                        Id = form.FurnitureId,
-                        FurnitureName = form.FurnitureModel.FurnitureName,
-                        Price = form.FurnitureModel.Price,
-                        FurnitureComponents = form.FurnitureModel.FurnitureComponents
+                        Id = form.FurnitureId                       
                     };
 
                     var operationResult = _shopLogic.AddFurniture(modelShop, modelFurn, form.Count);

FurnitureAssembly/FurnitureAssembly/FormShop.cs

@@ -96,7 +96,6 @@ namespace FurnitureAssembly
                         dateTimePicker.Value = view.DateOpening;
                         _shopFurnitures = view.Furnitures ?? new
                         Dictionary<int, (IFurnitureModel, int)>();
-                        dta
                         LoadData();
                     }
                 }

FurnitureAssembly/FurnitureAssemblyBusinessLogic/ShopLogic.cs

@@ -16,11 +16,13 @@ namespace FurnitureAssemblyBusinessLogic
     {
         private readonly ILogger _logger;
         private readonly IShopStorage _shopStorage;
+        private readonly IFurnitureStorage _furnitureStorage;
 
-        public ShopLogic(ILogger<ShopLogic> logger, IShopStorage shopStorage)
+        public ShopLogic(ILogger<ShopLogic> logger, IShopStorage shopStorage, IFurnitureStorage furnitureStorage)
         {
             _logger = logger;
             _shopStorage = shopStorage;
+            _furnitureStorage = furnitureStorage;
         }
         public ShopViewModel? ReadElement(ShopSearchModel model)
         {
@@ -117,9 +119,27 @@ namespace FurnitureAssemblyBusinessLogic
 
         public bool AddFurniture(ShopBindingModel model, FurnitureBindingModel furnitureModel, int count)
         {
-            CheckModel(model);
-            
-            if (_shopStorage.AddFurniture(model, furnitureModel, count) == null)
+            var shop = _shopStorage.GetElement(new ShopSearchModel { Id = model.Id });
+            var furniture = _furnitureStorage.GetElement(new FurnitureSearchModel { Id = furnitureModel.Id });
+
+            if (shop == null || furniture == null)
+            {
+                return false;
+            }
+            if (shop.Furnitures.ContainsKey(furniture.Id))
+            {
+                int prev_count = shop.Furnitures[furniture.Id].Item2;
+                shop.Furnitures[furniture.Id] = (furniture, prev_count + count);
+            }
+            else
+            {
+                shop.Furnitures[furniture.Id] = (furniture, count);
+            }
+            model.Furnitures = shop.Furnitures;
+            model.DateOpening = shop.DateOpening;
+            model.Address = shop.Address;
+            model.ShopName = shop.ShopName;          
+            if (_shopStorage.Update(model) == null)
             {
                 _logger.LogWarning("Replenishment operation failed");
                 return false;

FurnitureAssembly/FurnitureAssemblyContracts/StoragesContracts/IShopStorage.cs

@@ -12,7 +12,6 @@ namespace FurnitureAssemblyContracts.StoragesContracts
         ShopViewModel? GetElement(ShopSearchModel model);
         ShopViewModel? Insert(ShopBindingModel model);
         ShopViewModel? Update(ShopBindingModel model);
-        ShopViewModel? Delete(ShopBindingModel model);
-        ShopViewModel? AddFurniture(ShopBindingModel model, FurnitureBindingModel furniture, int count);
+        ShopViewModel? Delete(ShopBindingModel model);      
     }
 }

FurnitureAssembly/FurnitureAssemblyListImplement/Implements/ShopStorage.cs

@@ -109,18 +109,5 @@ namespace FurnitureAssemblyListImplement.Implements
             }
             return null;
         }
-
-        public ShopViewModel? AddFurniture(ShopBindingModel model, FurnitureBindingModel furniture, int count)
-        {
-            foreach (var shop in _source.Shops)
-            {
-                if (shop.Id == model.Id)
-                {
-                    shop.AddFurniture(model, furniture, count);
-                    return shop.GetViewModel;
-                }
-            }
-            return null;
-        }
     }
 }

FurnitureAssembly/FurnitureAssemblyListImplement/Models/Shop.cs

@@ -48,22 +48,7 @@ namespace FurnitureAssemblyListImplement.Models
             DateOpening = model.DateOpening;
             Furnitures = model.Furnitures;
         }
-
-        public void AddFurniture(ShopBindingModel? model, FurnitureBindingModel furniture, int count)
-        {
-            if (model == null)
-            {
-                return;
-            }
-            if (Furnitures.ContainsKey(furniture.Id))
-            {
-                int prev_count = Furnitures[furniture.Id].Item2;
-                Furnitures[furniture.Id] = (furniture, prev_count + count);
-            } else
-            {
-                Furnitures[furniture.Id] = (furniture, count);
-            }
-        }
+     
         public ShopViewModel GetViewModel => new()
         {
             Id = Id,