# Use Case ## Overview The **EBusiness** application is a comprehensive e-commerce solution built using FlexBase Framework, demonstrating real-world implementation of enterprise features. This application showcases how to build scalable, maintainable business applications following Domain-Driven Design (DDD) principles and Clean Architecture patterns. ## Application Architecture ### **Domain Focus** * **E-Commerce Business**: Complete online shopping platform * **Multi-Tenant Support**: Serve multiple customers with isolated data * **Event-Driven Architecture**: Asynchronous processing for scalability * **CQRS Pattern**: Separate read and write operations for performance ### **Key Business Capabilities** * **Order Management**: Complete order lifecycle from creation to fulfillment * **Product Catalog**: Product management with inventory tracking * **Customer Management**: User registration, authentication, and profile management * **Payment Processing**: Secure payment handling and transaction management * **Inventory Management**: Stock tracking and low inventory alerts * **Reporting & Analytics**: Business intelligence and reporting capabilities ## Feature Implementation List ### 1. **Order Management Features** #### **Command Features (Data Modification)** * **AddOrder** - Create new customer orders * **Flow**: `POST /api/Orders/AddOrder` * **Handler**: `AddOrderHandler.cs` * **Event**: `OrderCreatedEvent` (Eventual) * **Use Case**: Customer places order, inventory reserved, confirmation sent * **UpdateOrder** - Modify existing orders * **Flow**: `PUT /api/Orders/UpdateOrder` * **Handler**: `UpdateOrderHandler.cs` * **Event**: `OrderUpdatedEvent` (Eventual) * **Use Case**: Update order details, change shipping address * **CancelOrder** - Cancel pending orders * **Flow**: `PUT /api/Orders/CancelOrder` * **Handler**: `CancelOrderHandler.cs` * **Event**: `OrderCancelledEvent` (Eventual) * **Use Case**: Customer cancels order, inventory released * **ProcessOrder** - Process order for fulfillment * **Flow**: `PUT /api/Orders/ProcessOrder` * **Handler**: `ProcessOrderHandler.cs` * **Event**: `OrderProcessedEvent` (Eventual) * **Use Case**: Warehouse processes order, shipping label generated #### **Query Features (Data Retrieval)** * **GetOrderById** - Retrieve specific order details * **Flow**: `GET /api/Orders/GetOrderById/{id}` * **Query**: `GetOrderByIdQuery.cs` * **Use Case**: Customer views order details, admin order lookup * **GetOrders** - List all orders with filtering * **Flow**: `GET /api/Orders/GetOrders` * **Query**: `GetOrdersQuery.cs` * **Use Case**: Admin order management, customer order history * **GetOrdersPaged** - Paginated order list * **Flow**: `GET /api/Orders/GetOrdersPaged` * **Query**: `GetOrdersPagedQuery.cs` * **Use Case**: Large order lists with pagination support * **GetCustomerOrders** - Orders for specific customer * **Flow**: `GET /api/Orders/GetCustomerOrders/{customerId}` * **Query**: `GetCustomerOrdersQuery.cs` * **Use Case**: Customer order history, account management ### 2. **Product Management Features** #### **Command Features (Data Modification)** * **AddProduct** - Create new products * **Flow**: `POST /api/Products/AddProduct` * **Handler**: `AddProductHandler.cs` * **Event**: `ProductCreatedEvent` (Eventual) * **Use Case**: Admin adds new product to catalog * **UpdateProduct** - Modify product information * **Flow**: `PUT /api/Products/UpdateProduct` * **Handler**: `UpdateProductHandler.cs` * **Event**: `ProductUpdatedEvent` (Eventual) * **Use Case**: Update product details, pricing, descriptions * **UpdateInventory** - Adjust product stock levels * **Flow**: `PUT /api/Products/UpdateInventory` * **Handler**: `UpdateInventoryHandler.cs` * **Event**: `InventoryUpdatedEvent` (Eventual) * **Use Case**: Stock adjustments, receiving shipments * **DeactivateProduct** - Soft delete products * **Flow**: `PUT /api/Products/DeactivateProduct` * **Handler**: `DeactivateProductHandler.cs` * **Event**: `ProductDeactivatedEvent` (Eventual) * **Use Case**: Discontinue products, seasonal items #### **Query Features (Data Retrieval)** * **GetProductById** - Retrieve specific product * **Flow**: `GET /api/Products/GetProductById/{id}` * **Query**: `GetProductByIdQuery.cs` * **Use Case**: Product detail pages, admin product management * **GetProducts** - List products with filtering * **Flow**: `GET /api/Products/GetProducts` * **Query**: `GetProductsQuery.cs` * **Use Case**: Product catalog browsing, search results * **GetProductsPaged** - Paginated product list * **Flow**: `GET /api/Products/GetProductsPaged` * **Query**: `GetProductsPagedQuery.cs` * **Use Case**: Large product catalogs with pagination * **SearchProducts** - Product search functionality * **Flow**: `GET /api/Products/SearchProducts` * **Query**: `SearchProductsQuery.cs` * **Use Case**: Customer product search, admin product lookup ### 3. **Customer Management Features** #### **Command Features (Data Modification)** * **RegisterCustomer** - Create new customer accounts * **Flow**: `POST /api/Customers/RegisterCustomer` * **Handler**: `RegisterCustomerHandler.cs` * **Event**: `CustomerRegisteredEvent` (Eventual) * **Use Case**: New customer registration, welcome email sent * **UpdateCustomer** - Modify customer information * **Flow**: `PUT /api/Customers/UpdateCustomer` * **Handler**: `UpdateCustomerHandler.cs` * **Event**: `CustomerUpdatedEvent` (Eventual) * **Use Case**: Profile updates, address changes * **DeactivateCustomer** - Soft delete customer accounts * **Flow**: `PUT /api/Customers/DeactivateCustomer` * **Handler**: `DeactivateCustomerHandler.cs` * **Event**: `CustomerDeactivatedEvent` (Eventual) * **Use Case**: Account closure, compliance requirements #### **Query Features (Data Retrieval)** * **GetCustomerById** - Retrieve specific customer * **Flow**: `GET /api/Customers/GetCustomerById/{id}` * **Query**: `GetCustomerByIdQuery.cs` * **Use Case**: Customer profile pages, admin customer lookup * **GetCustomers** - List customers with filtering * **Flow**: `GET /api/Customers/GetCustomers` * **Query**: `GetCustomersQuery.cs` * **Use Case**: Admin customer management, customer support * **GetCustomersPaged** - Paginated customer list * **Flow**: `GET /api/Customers/GetCustomersPaged` * **Query**: `GetCustomersPagedQuery.cs` * **Use Case**: Large customer databases with pagination ### 4. **Payment Processing Features** #### **Command Features (Data Modification)** * **ProcessPayment** - Handle payment transactions * **Flow**: `POST /api/Payments/ProcessPayment` * **Handler**: `ProcessPaymentHandler.cs` * **Event**: `PaymentProcessedEvent` (Eventual) * **Use Case**: Credit card processing, order payment * **RefundPayment** - Process payment refunds * **Flow**: `POST /api/Payments/RefundPayment` * **Handler**: `RefundPaymentHandler.cs` * **Event**: `PaymentRefundedEvent` (Eventual) * **Use Case**: Order cancellations, returns processing #### **Query Features (Data Retrieval)** * **GetPaymentById** - Retrieve payment details * **Flow**: `GET /api/Payments/GetPaymentById/{id}` * **Query**: `GetPaymentByIdQuery.cs` * **Use Case**: Payment verification, transaction lookup * **GetPayments** - List payments with filtering * **Flow**: `GET /api/Payments/GetPayments` * **Query**: `GetPaymentsQuery.cs` * **Use Case**: Financial reporting, transaction history ### 5. **Inventory Management Features** #### **Command Features (Data Modification)** * **AdjustInventory** - Modify stock levels * **Flow**: `PUT /api/Inventory/AdjustInventory` * **Handler**: `AdjustInventoryHandler.cs` * **Event**: `InventoryAdjustedEvent` (Eventual) * **Use Case**: Stock adjustments, receiving shipments * **ReserveInventory** - Reserve stock for orders * **Flow**: `PUT /api/Inventory/ReserveInventory` * **Handler**: `ReserveInventoryHandler.cs` * **Event**: `InventoryReservedEvent` (Eventual) * **Use Case**: Order processing, stock allocation #### **Query Features (Data Retrieval)** * **GetInventoryLevels** - Check stock levels * **Flow**: `GET /api/Inventory/GetInventoryLevels` * **Query**: `GetInventoryLevelsQuery.cs` * **Use Case**: Stock monitoring, low inventory alerts * **GetLowStockItems** - Identify items needing restocking * **Flow**: `GET /api/Inventory/GetLowStockItems` * **Query**: `GetLowStockItemsQuery.cs` * **Use Case**: Purchasing decisions, inventory alerts ## Event-Driven Processing ### **Event Subscribers** * **OrderCreatedSubscriber** - Handles order creation events * **Actions**: Send confirmation email, reserve inventory, update analytics * **PaymentProcessedSubscriber** - Handles payment events * **Actions**: Update order status, send receipt, trigger fulfillment * **InventoryLowSubscriber** - Handles low inventory events * **Actions**: Send alerts to purchasing, update product status * **CustomerRegisteredSubscriber** - Handles customer registration * **Actions**: Send welcome email, create customer profile, update marketing ## Technology Implementation ### **Framework Components** * **FlexBase Framework**: Core enterprise framework * **Entity Framework Core**: Data access and ORM * **NServiceBus**: Message bus and event handling * **ASP.NET Core**: Web API and controllers * **AutoMapper**: Object mapping and DTOs ### **Database Support** * **SQL Server**: Primary database * **MySQL**: Alternative database option * **PostgreSQL**: Cross-platform database support * **Multi-Tenant**: Isolated data per customer ### **Message Bus Options** * **RabbitMQ**: High-performance messaging * **Azure Service Bus**: Cloud-native messaging * **SQL Server Transport**: Database-based messaging * **Learning Transport**: Development and testing ## Business Value ### **Scalability** * **Horizontal Scaling**: Add more instances as needed * **Database Scaling**: Separate read/write databases * **Message Bus Scaling**: Handle high message volumes ### **Maintainability** * **Clear Separation**: Commands vs Queries * **Domain Focus**: Business logic in domain layer * **Testability**: Each component can be tested independently ### **Performance** * **CQRS**: Optimized read and write operations * **Event Sourcing**: Track all changes for audit * **Caching**: Fast data retrieval for frequently accessed data *** **This EBusiness application demonstrates how FlexBase Framework enables rapid development of enterprise-grade applications with clean architecture, scalable design, and maintainable code!** 🚀 --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. 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