第 4 阶段：订单、交接与账务--1

backend/internal/modules/order/service.go

@@ -0,0 +1,77 @@
+package order
+
+import "errors"
+
+var (
+	ErrDependencyUnavailable = errors.New("dependency unavailable")
+	ErrInvalidRentHours      = errors.New("invalid rent hours")
+	ErrListingUnavailable    = errors.New("listing unavailable")
+	ErrCannotRentOwnListing  = errors.New("cannot rent own listing")
+	ErrOrderCannotCancel     = errors.New("order cannot cancel")
+	ErrOrderCannotHandoff    = errors.New("order cannot handoff")
+	ErrOrderCannotReceive    = errors.New("order cannot receive")
+	ErrPermissionDenied      = errors.New("permission denied")
+)
+
+type Service struct {
+	repo *Repository
+}
+
+func NewService(repo *Repository) *Service {
+	return &Service{repo: repo}
+}
+
+func (s *Service) Create(userID uint64, req CreateRequest) (*OrderDTO, error) {
+	if s.repo == nil {
+		return nil, ErrDependencyUnavailable
+	}
+	if req.ListingID == 0 || req.RentHours <= 0 {
+		return nil, ErrInvalidRentHours
+	}
+	return s.repo.Create(userID, req)
+}
+
+func (s *Service) Cancel(userID uint64, orderID uint64) error {
+	if s.repo == nil {
+		return ErrDependencyUnavailable
+	}
+	return s.repo.Cancel(userID, orderID)
+}
+
+func (s *Service) SubmitHandoff(userID uint64, orderID uint64, req SubmitHandoffRequest) (*HandoffRecordDTO, error) {
+	if s.repo == nil {
+		return nil, ErrDependencyUnavailable
+	}
+	if orderID == 0 || req.Content == "" {
+		return nil, ErrOrderCannotHandoff
+	}
+	return s.repo.SubmitHandoff(userID, orderID, req)
+}
+
+func (s *Service) ConfirmReceive(userID uint64, orderID uint64) error {
+	if s.repo == nil {
+		return ErrDependencyUnavailable
+	}
+	return s.repo.ConfirmReceive(userID, orderID)
+}
+
+func (s *Service) HandoffRecords(userID uint64, orderID uint64) ([]HandoffRecordDTO, error) {
+	if s.repo == nil {
+		return nil, ErrDependencyUnavailable
+	}
+	return s.repo.HandoffRecords(userID, orderID)
+}
+
+func (s *Service) ListForUser(userID uint64) ([]OrderDTO, error) {
+	if s.repo == nil {
+		return nil, ErrDependencyUnavailable
+	}
+	return s.repo.ListForUser(userID)
+}
+
+func (s *Service) FindForUser(userID uint64, orderID uint64) (*OrderDTO, error) {
+	if s.repo == nil {
+		return nil, ErrDependencyUnavailable
+	}
+	return s.repo.FindForUser(userID, orderID)
+}