all the refactor

cmd/inventory/commit.go

@@ -0,0 +1,69 @@
+package main
+
+import (
+	"context"
+	"log"
+	"time"
+
+	"git.k6n.net/mats/go-redis-inventory/pkg/inventory"
+	contract "git.k6n.net/mats/platform/order"
+	"git.k6n.net/mats/platform/rabbit"
+	"github.com/redis/go-redis/v9"
+)
+
+// commitOrder applies an order.created event to inventory. The sale already
+// happened, so this is an unconditional permanent decrement (it may drive stock
+// negative — visible oversell, reconciled downstream as backorder), NOT a
+// check-and-reserve that could refuse. It then releases the cart's TTL hold and
+// emits the resulting level crossing. Idempotent per order via a Redis marker,
+// since the bus is at-least-once.
+func commitOrder(ctx context.Context, rdb *redis.Client, svc *inventory.RedisInventoryService, resv *inventory.RedisCartReservationService, conn *rabbit.Conn, country string, low int64, c contract.Created) {
+	if c.OrderID == "" {
+		return
+	}
+	// Idempotency: first writer wins; redelivery is a no-op.
+	fresh, err := rdb.SetNX(ctx, "invcommit:"+c.OrderID, "1", 30*24*time.Hour).Result()
+	if err != nil {
+		log.Printf("inventory: commit idempotency order=%s: %v", c.OrderID, err)
+		return
+	}
+	if !fresh {
+		return // already committed
+	}
+	// Default location for lines that don't carry their own: the order country
+	// (central stock), falling back to the service's configured country.
+	defaultLoc := c.Country
+	if defaultLoc == "" {
+		defaultLoc = country
+	}
+	for _, line := range c.Lines {
+		if line.SKU == "" || line.Quantity <= 0 {
+			continue
+		}
+		loc := inventory.LocationID(defaultLoc)
+		if line.Location != "" {
+			loc = inventory.LocationID(line.Location)
+		}
+		sku := inventory.SKU(line.SKU)
+		pipe := rdb.Pipeline()
+		if err := svc.DecrementInventory(ctx, pipe, sku, loc, int64(line.Quantity)); err != nil {
+			log.Printf("inventory: commit decrement sku=%s order=%s: %v", sku, c.OrderID, err)
+			continue
+		}
+		if _, err := pipe.Exec(ctx); err != nil {
+			log.Printf("inventory: commit exec sku=%s order=%s: %v", sku, c.OrderID, err)
+			continue
+		}
+		// Release the cart's TTL hold now the sale is committed (best-effort —
+		// it would expire on its own anyway).
+		if c.CartID != "" && resv != nil {
+			if err := resv.ReleaseForCart(ctx, sku, loc, inventory.CartID(c.CartID)); err != nil {
+				log.Printf("inventory: commit release sku=%s cart=%s: %v", sku, c.CartID, err)
+			}
+		}
+		// Emit the level crossing from the new on-hand.
+		if newQty, err := svc.GetInventory(ctx, sku, loc); err == nil {
+			emitLevelIfChanged(ctx, rdb, conn, country, low, string(sku), string(loc), newQty)
+		}
+	}
+}