# Domain Map: E-Commerce Platform

## Bounded Contexts

### 1. Customer Management

**Core Domain:** User accounts, profiles, preferences
**Owner:** Customer Team
**Ubiquitous Language:**

- Customer: Registered user with account
- Profile: Customer personal information
- Preferences: User settings and choices

**Entities:**

- Customer (id, email, name)
- Address (id, customer_id, street, city)
- PaymentMethod (id, customer_id, type, token)

**Bounded Context Diagram:**

### 2. Order Management
**Core Domain:** Order processing, fulfillment
**Owner:** Orders Team
**Ubiquitous Language:**
- Order: Purchase request with line items
- LineItem: Product quantity in order
- Fulfillment: Physical delivery of order

**Entities:**
- Order (id, customer_id, status, total)
- LineItem (id, order_id, product_id, quantity)
- Shipment (id, order_id, tracking_number)

### 3. Product Catalog
**Core Domain:** Product information, inventory
**Owner:** Catalog Team
**Ubiquitous Language:**
- Product: Sellable item
- SKU: Stock keeping unit
- Inventory: Available stock

**Entities:**
- Product (id, name, price, description)
- Inventory (sku, quantity, warehouse_id)

## Context Relationships

## Anti-Corruption Layers

### Order Management → Customer Management
**Problem:** Orders need customer data but shouldn't depend on Customer domain model

**Solution:** Customer Adapter
```typescript
// Order domain's view of customer
interface CustomerForOrder {
  id: string;
  shippingAddress: Address;
  billingAddress: Address;
}

// Adapter translates Customer domain to Order domain
class CustomerAdapter {
  async getCustomerForOrder(customerId: string): Promise<CustomerForOrder> {
    const customer = await customerService.getCustomer(customerId);
    return {
      id: customer.id,
      shippingAddress: this.toOrderAddress(customer.defaultShippingAddress),
      billingAddress: this.toOrderAddress(customer.defaultBillingAddress),
    };
  }
}

┌──────────────┐
│   Customer   │
└──────┬───────┘
       │
       ▼
┌──────────────┐      ┌────────────┐
│    Orders    │─────▶│  Products  │
└──────┬───────┘      └────────────┘
       │
       ▼
┌──────────────┐
│ Fulfillment  │
└──────────────┘

// Public interface exposed by Customer domain
interface CustomerService {
  getCustomer(id: string): Promise<Customer>;
  getCustomerAddresses(id: string): Promise<Address[]>;
}

// Events published
interface CustomerUpdated {
  customerId: string;
  email: string;
  name: string;
}

interface ProductService {
  getProduct(id: string): Promise<Product>;
  checkAvailability(sku: string, quantity: number): Promise<boolean>;
  reserveInventory(items: ReservationRequest[]): Promise<Reservation>;
}

// ❌ Before: Direct database access
const customer = await db.customers.findById(customerId);

// ✅ After: API call through adapter
const customer = await customerAdapter.getCustomerForOrder(customerId);

// Customer context
interface Customer {
  id: string;
  email: string;
  profile: CustomerProfile;
  preferences: CustomerPreferences;
}

// Order context (different model!)
interface OrderCustomer {
  id: string;
  shippingAddress: Address;
  billingAddress: Address;
}

// Shared kernel (minimal!)
class Money {
  constructor(public amount: number, public currency: string) {}
}

interface ProductCreated {
  productId: string;
  name: string;
  price: Money;
  publishedAt: Date;
}