promotions

pkg/cart/cart-grain.go

@@ -28,16 +28,16 @@ type ItemMeta struct {
 }
 
 type CartItem struct {
-	Id          uint32  `json:"id"`
-	ItemId      uint32  `json:"itemId,omitempty"`
-	ParentId    *uint32 `json:"parentId,omitempty"`
-	Sku         string  `json:"sku"`
-	Price       Price   `json:"price"`
-	TotalPrice  Price   `json:"totalPrice"`
-	SellerId    string  `json:"sellerId,omitempty"`
-	OrgPrice    *Price  `json:"orgPrice,omitempty"`
-	Cgm         string  `json:"cgm,omitempty"`
-	Tax         int
+	Id          uint32    `json:"id"`
+	ItemId      uint32    `json:"itemId,omitempty"`
+	ParentId    *uint32   `json:"parentId,omitempty"`
+	Sku         string    `json:"sku"`
+	Price       Price     `json:"price"`
+	TotalPrice  Price     `json:"totalPrice"`
+	SellerId    string    `json:"sellerId,omitempty"`
+	OrgPrice    *Price    `json:"orgPrice,omitempty"`
+	Cgm         string    `json:"cgm,omitempty"`
+	Tax         int       `json:"tax"`
 	Stock       uint16    `json:"stock"`
 	Quantity    uint16    `json:"qty"`
 	Discount    *Price    `json:"discount,omitempty"`
@@ -97,6 +97,31 @@ type Marking struct {
 	Text string `json:"text"`
 }
 
+// AppliedPromotion records a single promotion action's effect on the cart. It is
+// rebuilt every time promotions are (re-)applied so the API result exposes a
+// per-promotion breakdown rather than only the aggregate TotalDiscount.
+//
+// An entry is one of two kinds, both living in the same list:
+//   - applied  (Pending=false): the action took effect now. Discount holds the
+//     amount taken off (nil for non-monetary effects such as free_shipping).
+//   - pending  (Pending=true):  the action has NOT qualified yet but is within
+//     reach. Progress carries effect-specific data describing what's left to
+//     unlock it — e.g. {"remaining": 120000, "threshold": 500000} for a
+//     cart-total nudge. Keeping it an open map lets new effect types surface
+//     their own progress fields without changing this struct. This powers
+//     "spend X more for ..." nudges generically.
+type AppliedPromotion struct {
+	PromotionId string `json:"promotionId,omitempty"`
+	Name        string `json:"name,omitempty"`
+	ActionId    string `json:"actionId,omitempty"`
+	Type        string `json:"type,omitempty"`
+	Label       string `json:"label,omitempty"`
+	Discount    *Price `json:"discount,omitempty"`
+
+	Pending  bool                   `json:"pending,omitempty"`
+	Progress map[string]interface{} `json:"progress,omitempty"`
+}
+
 type CartGrain struct {
 	mu                sync.RWMutex
 	lastItemId        uint32
@@ -117,6 +142,7 @@ type CartGrain struct {
 	OrderReference string `json:"orderReference,omitempty"`
 
 	Vouchers            []*Voucher                      `json:"vouchers,omitempty"`
+	AppliedPromotions   []AppliedPromotion              `json:"appliedPromotions,omitempty"`
 	Notifications       []CartNotification              `json:"cartNotification,omitempty"`
 	SubscriptionDetails map[string]*SubscriptionDetails `json:"subscriptionDetails,omitempty"`
 
@@ -245,6 +271,7 @@ func (c *CartGrain) FindItemWithSku(sku string) (*CartItem, bool) {
 func (c *CartGrain) UpdateTotals() {
 	c.TotalPrice = NewPrice()
 	c.TotalDiscount = NewPrice()
+	c.AppliedPromotions = nil
 
 	for _, item := range c.Items {
 		rowTotal := MultiplyPrice(item.Price, int64(item.Quantity))