ai pubsub

pkg/cart/cart-grain.go

@@ -3,9 +3,11 @@ package cart
 import (
 	"encoding/json"
 	"slices"
+	"strings"
 	"sync"
 	"time"
 
+	"git.tornberg.me/go-cart-actor/pkg/actor"
 	messages "git.tornberg.me/go-cart-actor/pkg/messages"
 	"git.tornberg.me/go-cart-actor/pkg/voucher"
 )
@@ -184,6 +186,40 @@ func (c *CartGrain) GetCurrentState() (*CartGrain, error) {
 	return c, nil
 }
 
+// Notify handles incoming events, e.g., inventory changes.
+func (c *CartGrain) Notify(event actor.Event) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	// Example: if event is inventory change for a SKU in the cart
+	if strings.HasPrefix(event.Topic, "inventory:") {
+		sku := strings.TrimPrefix(event.Topic, "inventory:")
+		for _, item := range c.Items {
+			if item.Sku == sku {
+				// Update stock status based on payload, e.g., if payload is bool available
+				if available, ok := event.Payload.(bool); ok {
+					if available {
+						item.Stock = StockStatus(1) // assuming 1 is in stock
+					} else {
+						item.Stock = StockStatus(0) // out of stock
+					}
+				}
+				break
+			}
+		}
+	}
+}
+
+func (c *CartGrain) UpdateSubscriptions(pubsub *actor.PubSub) {
+	pubsub.UnsubscribeAll(c.GetId())
+	skuSet := make(map[string]bool)
+	for _, item := range c.Items {
+		skuSet[item.Sku] = true
+	}
+	for sku := range skuSet {
+		pubsub.Subscribe("inventory:"+sku, c.GetId())
+	}
+}
+
 func (c *CartGrain) GetState() ([]byte, error) {
 	return json.Marshal(c)
 }