pos-system/services/order-service-net/docs/en

Order Service

Order orchestration with Strategy Pattern for multi-vertical commerce.

Overview

Order Service is the "brain" of the platform, orchestrating orders across multiple business verticals using the Strategy Pattern. It routes each line item to the appropriate vertical engine (Inventory, Booking, F&B Engine) based on product type.

Key Features

• Strategy Pattern - Routes orders by product type without if-else chains
• Hybrid Orders - Single order with mixed items (Physical + Service + Food)
• Transaction Coordination - Validate → Pay → Execute workflow
• Event-Driven - Publishes integration events for downstream services

Architecture Context

graph TB
    POS["POS / Web"] --> ORDER["📝 Order Service"]
    ORDER --> CATALOG["📦 Catalog Service"]
    ORDER --> MERCHANT["🏪 Merchant Service"]
    ORDER --> WALLET["💰 Wallet Service"]
    ORDER --> INVENTORY["🏭 Inventory Service"]
    ORDER --> BOOKING["📅 Booking Service"]
    ORDER --> FNB["🍳 F&B Engine"]
    
    style ORDER fill:#e74c3c,stroke:#c0392b,color:#fff

Prerequisites

Requirement	Version
.NET SDK	10.0.101+
Docker	24.0+
PostgreSQL	15+
RabbitMQ	3.12+

Quick Start

cd services/order-service-net
cp .env.example .env
dotnet restore
dotnet run --project src/OrderService.API

Project Structure

order-service-net/
├── src/
│   ├── OrderService.API/
│   │   ├── Application/
│   │   │   ├── Strategies/          # Line item strategies
│   │   │   ├── Commands/            # CreateOrder, CancelOrder
│   │   │   └── Queries/             # GetOrder, ListOrders
│   │   └── Controllers/
│   ├── OrderService.Domain/
│   │   ├── AggregatesModel/
│   │   │   └── OrderAggregate/      # Order, OrderItem
│   │   └── Events/
│   └── OrderService.Infrastructure/
└── tests/

API Endpoints

Method	Endpoint	Description
POST	/api/v1/orders	Create order
GET	/api/v1/orders/{id}	Get order details
GET	/api/v1/orders	List orders by shop
POST	/api/v1/orders/{id}/pay	Process payment
POST	/api/v1/orders/{id}/cancel	Cancel order
PATCH	/api/v1/orders/{id}/items/{itemId}/status	Update item status

Strategy Pattern

ILineItemStrategy Interface

public interface ILineItemStrategy
{
    ProductType SupportedType { get; }
    Task ValidateAsync(OrderItem item, Guid shopId);
    Task ExecuteAsync(OrderItem item, Guid shopId);
}

Available Strategies

Strategy	Product Type	Target Service
RetailStrategy	Physical	Inventory Service
ServiceStrategy	Service	Booking Service
FnbStrategy	PreparedFood	F&B Engine

Order Processing Flow

sequenceDiagram
    participant POS
    participant Order as Order Service
    participant Catalog as Catalog Service
    participant Strategy as Strategy Factory
    participant Target as Target Service

    POS->>Order: Create Order
    Order->>Catalog: Get Product Types
    
    loop For each LineItem
        Order->>Strategy: Get Strategy by Type
        Strategy->>Target: Validate
        Target-->>Strategy: OK
    end
    
    Order->>Order: Process Payment
    
    loop For each LineItem
        Order->>Strategy: Get Strategy by Type
        Strategy->>Target: Execute
    end
    
    Order-->>POS: Order Completed

Domain Model

Order Aggregate

public class Order : Entity, IAggregateRoot
{
    public Guid ShopId { get; private set; }
    public Guid? CustomerId { get; private set; }
    public OrderStatus Status { get; private set; }
    public decimal TotalAmount { get; private set; }
    
    private readonly List<OrderItem> _items;
    public IReadOnlyCollection<OrderItem> Items => _items.AsReadOnly();
    
    public void AddItem(Product product, int quantity);
    public void MarkAsPaid();
    public void Cancel(string reason);
}

Integration Events

Event	Trigger	Subscribers
OrderCreatedEvent	Order placed	Analytics
OrderPaidEvent	Payment success	Wallet, Notification
OrderCancelledEvent	Order cancelled	Inventory (rollback)
KitchenTicketCreatedEvent	F&B item added	F&B Engine

Related Services

• Catalog Service - Product data
• Inventory Service - Stock management
• Booking Service - Appointments
• F&B Engine - Kitchen display

Resources

• Multi-vertical Architecture
• Strategy Pattern

License

Proprietary - GoodGo Platform