🏷️ Coupons

Staff can create discount coupons that customers apply at checkout.

🎫 Coupon Types

Type	Behavior
PERCENTAGE	📊 Discount by percentage (e.g., 10% off)
FIXED	💵 Discount by a fixed amount (e.g., $5 off)
FREE_DELIVERY	🚚 Waive the delivery fee

📝 Coupon Fields

Field	Description
code	Unique coupon code (e.g., WELCOME10)
type	PERCENTAGE, FIXED, or FREE_DELIVERY
value	Discount amount or percentage
minOrder	Minimum order subtotal to qualify
maxDiscount	Cap for percentage discounts
usageLimit	Maximum total uses (null = unlimited)
usageCount	Current number of uses
perCustomer	Maximum uses per customer (default: 1)
startsAt	Start date (optional)
expiresAt	Expiration date (optional)
isActive	Enable/disable the coupon

✅ Validation Rules

When a customer applies a coupon, the system checks:

1. 🔍 Code exists and is active
2. 📅 Date range — current time is between startsAt and expiresAt
3. 🔢 Usage limit — usageCount < usageLimit
4. 👤 Per-customer limit — customer hasn't exceeded perCustomer uses
5. 💰 Minimum order — cart subtotal ≥ minOrder

If validation fails, the API returns a descriptive error message.

🛒 Applying at Checkout

POST /api/coupons/validate
{
  "code": "WELCOME10",
  "orderTotal": 25.00
}

Returns the discount amount if valid. The coupon is linked to the order when it's created.

🔐 Permissions

Action	Who Can Do It
✅ Validate coupon	Anyone
📋 List coupons	Staff
✏️ Create/update coupons	Staff
🗑️ Delete coupons	Manager, Super Admin

📡 API

See Coupons API for the complete endpoint reference.