Product purchasable check feature, close #18

modules/EasyAbp.EShop.Products/src/EasyAbp.EShop.Products.Application.Contracts/EasyAbp/EShop/Products/Products/IProductAppService.cs

@@ -23,5 +23,7 @@ namespace EasyAbp.EShop.Products.Products
         Task<ProductDto> GetAsync(Guid id, Guid storeId);
 
         Task<ProductDto> DeleteSkuAsync(Guid productId, Guid productSkuId, Guid storeId);
+
+        Task<GetProductPurchasableStatusResult> GetPurchasableStatusAsync(Guid productId, Guid productSkuId, Guid storeId);
     }
 }
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modules/EasyAbp.EShop.Products/src/EasyAbp.EShop.Products.Application/EasyAbp/EShop/Products/Products/ProductAppService.cs

@@ -24,17 +24,20 @@ namespace EasyAbp.EShop.Products.Products
         protected override string GetPolicyName { get; set; } = null;
         protected override string GetListPolicyName { get; set; } = null;
 
+        private readonly IProductPurchasableStatusProvider _productPurchasableStatusProvider;
         private readonly IAttributeOptionIdsSerializer _attributeOptionIdsSerializer;
         private readonly IProductStoreRepository _productStoreRepository;
         private readonly IProductCategoryRepository _productCategoryRepository;
         private readonly IProductRepository _repository;
 
         public ProductAppService(
+            IProductPurchasableStatusProvider productPurchasableStatusProvider,
             IAttributeOptionIdsSerializer attributeOptionIdsSerializer,
             IProductStoreRepository productStoreRepository,
             IProductCategoryRepository productCategoryRepository,
             IProductRepository repository) : base(repository)
         {
+            _productPurchasableStatusProvider = productPurchasableStatusProvider;
             _attributeOptionIdsSerializer = attributeOptionIdsSerializer;
             _productStoreRepository = productStoreRepository;
             _productCategoryRepository = productCategoryRepository;
@@ -351,6 +354,15 @@ namespace EasyAbp.EShop.Products.Products
             return ObjectMapper.Map<Product, ProductDto>(product);
         }
 
+        public async Task<GetProductPurchasableStatusResult> GetPurchasableStatusAsync(Guid productId, Guid productSkuId, Guid storeId)
+        {
+            var product = await _repository.GetAsync(productId);
+
+            var productSku = product.ProductSkus.Single(sku => sku.Id == productSkuId);
+
+            return await _productPurchasableStatusProvider.GetPurchasableStatusAsync(product, productSku, storeId);
+        }
+
         protected virtual async Task UpdateProductCategoriesAsync(Guid productId, IEnumerable<Guid> categoryIds)
         {
             await _productCategoryRepository.DeleteAsync(x => x.ProductId.Equals(productId));

modules/EasyAbp.EShop.Products/src/EasyAbp.EShop.Products.Domain.Shared/EasyAbp/EShop/Products/Products/GetProductPurchasableStatusResult.cs

+namespace EasyAbp.EShop.Products.Products
+{
+    public class GetProductPurchasableStatusResult
+    {
+        public ProductPurchasableStatus PurchasableStatus { get; set; }
+        
+        public string Reason { get; set; }
+    }
+}
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modules/EasyAbp.EShop.Products/src/EasyAbp.EShop.Products.Domain.Shared/EasyAbp/EShop/Products/Products/ProductPurchasableStatus.cs

+namespace EasyAbp.EShop.Products.Products
+{
+    public enum ProductPurchasableStatus
+    {
+        CanBePurchased = 1,
+        CanNotBePurchased = 2
+    }
+}
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modules/EasyAbp.EShop.Products/src/EasyAbp.EShop.Products.Domain/EasyAbp/EShop/Products/Products/IProductPurchasableStatusProvider.cs

+using System;
+using System.Threading.Tasks;
+
+namespace EasyAbp.EShop.Products.Products
+{
+    public interface IProductPurchasableStatusProvider
+    {
+        Task CheckPurchasableAsync(Product product, ProductSku productSku, Guid storeId);
+
+        Task<GetProductPurchasableStatusResult> GetPurchasableStatusAsync(Product product, ProductSku productSku,
+            Guid storeId);
+    }
+}
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modules/EasyAbp.EShop.Products/src/EasyAbp.EShop.Products.Domain/EasyAbp/EShop/Products/Products/ProductIsNotPurchasableException.cs

+using System;
+using Volo.Abp;
+
+namespace EasyAbp.EShop.Products.Products
+{
+    public class ProductIsNotPurchasableException : BusinessException
+    {
+        public ProductIsNotPurchasableException(Guid id, string reason) : base(
+            message: $"Product {id} cannot be purchased, the reason is: {reason}")
+        {
+        }
+    }
+}
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modules/EasyAbp.EShop.Products/src/EasyAbp.EShop.Products.Domain/EasyAbp/EShop/Products/Products/ProductPurchasableStatusProvider.cs

+using System;
+using System.Threading.Tasks;
+using Volo.Abp.DependencyInjection;
+
+namespace EasyAbp.EShop.Products.Products
+{
+    public class ProductPurchasableStatusProvider : IProductPurchasableStatusProvider, ITransientDependency
+    {
+        public async Task CheckPurchasableAsync(Product product, ProductSku productSku, Guid storeId)
+        {
+            var result = await GetPurchasableStatusAsync(product, productSku, storeId);
+            
+            if  (result.PurchasableStatus != ProductPurchasableStatus.CanBePurchased)
+            {
+                throw new ProductIsNotPurchasableException(product.Id, result.Reason);
+            }
+        }
+
+        public async Task<GetProductPurchasableStatusResult> GetPurchasableStatusAsync(Product product, ProductSku productSku, Guid storeId)
+        {
+            // Todo: Determine whether the product can be purchased.
+            return new GetProductPurchasableStatusResult
+            {
+                PurchasableStatus = ProductPurchasableStatus.CanBePurchased,
+                Reason = null
+            };
+        }
+    }
+}
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