feat: Updated purchase page

admin/internal/cloudprov/cloudprov.go

@@ -15,6 +15,7 @@ import (
 	"context"
 	"fmt"
 
+	"github.com/google/uuid"
 	"github.com/mrhid6/vantage/admin/internal/db"
 	sharedmodels "github.com/mrhid6/vantage/shared/models"
 	"github.com/mrhid6/vantage/shared/provision"
@@ -32,11 +33,29 @@ import (
 // On owner-insert failure the instance is rolled back, so a failed provision
 // never leaves a slug permanently occupied by an instance nobody owns.
 func CreateInstance(ctx context.Context, name, ownerEmail, ownerPasswordHash, hqUserID string) (*sharedmodels.Instance, error) {
-	inst, err := provision.CreateInstance(ctx, db.ControlDB(), name)
+	return CreateInstanceWithID(ctx, uuid.NewString(), name, ownerEmail, ownerPasswordHash, hqUserID)
+}
+
+// CreateInstanceWithID provisions a cloud instance under a caller-supplied ID and
+// its owner. It backs the paid-cloud flow, where the ID is a placeholder created
+// before payment and provisioning runs on the confirmed-payment webhook (see
+// provision.CreateInstanceWithID).
+//
+// It is idempotent, because a webhook can be retried after provisioning partly
+// completed: the instance is created only if absent, and the owner only if the
+// instance has none yet. A second call therefore converges to the same state
+// rather than colliding on the per-instance email unique index.
+func CreateInstanceWithID(ctx context.Context, instanceID, name, ownerEmail, ownerPasswordHash, hqUserID string) (*sharedmodels.Instance, error) {
+	inst, err := provision.CreateInstanceWithID(ctx, db.ControlDB(), instanceID, name)
 	if err != nil {
 		return nil, err
 	}
 
+	// A retry that already created the owner must not create a second one.
+	if _, err := OwnerUserID(ctx, inst.InstanceID); err == nil {
+		return inst, nil
+	}
+
 	u, err := provision.CreateUserWithHash(ctx, db.ControlDB(), inst.InstanceID,
 		ownerEmail, ownerPasswordHash, sharedmodels.RoleOwner, sharedmodels.AuthHQ)
 	if err != nil {