新增订单待支付与支付确认后端流程

backend/internal/modules/order/service.go

@@ -7,6 +7,8 @@ var (
 	ErrInvalidRentHours      = errors.New("invalid rent hours")
 	ErrListingUnavailable    = errors.New("listing unavailable")
 	ErrCannotRentOwnListing  = errors.New("cannot rent own listing")
+	ErrInsufficientBalance   = errors.New("insufficient balance")
+	ErrOrderCannotPay        = errors.New("order cannot pay")
 	ErrOrderCannotCancel     = errors.New("order cannot cancel")
 	ErrOrderCannotHandoff    = errors.New("order cannot handoff")
 	ErrOrderCannotReceive    = errors.New("order cannot receive")
@@ -42,6 +44,16 @@ func (s *Service) Cancel(userID uint64, orderID uint64) error {
 	return s.repo.Cancel(userID, orderID)
 }
 
+func (s *Service) Pay(userID uint64, orderID uint64) error {
+	if s.repo == nil {
+		return ErrDependencyUnavailable
+	}
+	if orderID == 0 {
+		return ErrOrderCannotPay
+	}
+	return s.repo.Pay(userID, orderID)
+}
+
 func (s *Service) SubmitHandoff(userID uint64, orderID uint64, req SubmitHandoffRequest) (*HandoffRecordDTO, error) {
 	if s.repo == nil {
 		return nil, ErrDependencyUnavailable