vendor/github.com/go-kit/kit/examples/shipping/handling/service.go

   1 // Package handling provides the use-case for registering incidents. Used by
   2 // views facing the people handling the cargo along its route.
   3 package handling
   4
   5 import (
   6         "errors"
   7         "time"
   8
   9         "github.com/go-kit/kit/examples/shipping/cargo"
  10         "github.com/go-kit/kit/examples/shipping/inspection"
  11         "github.com/go-kit/kit/examples/shipping/location"
  12         "github.com/go-kit/kit/examples/shipping/voyage"
  13 )
  14
  15 // ErrInvalidArgument is returned when one or more arguments are invalid.
  16 var ErrInvalidArgument = errors.New("invalid argument")
  17
  18 // EventHandler provides a means of subscribing to registered handling events.
  19 type EventHandler interface {
  20         CargoWasHandled(cargo.HandlingEvent)
  21 }
  22
  23 // Service provides handling operations.
  24 type Service interface {
  25         // RegisterHandlingEvent registers a handling event in the system, and
  26         // notifies interested parties that a cargo has been handled.
  27         RegisterHandlingEvent(completed time.Time, id cargo.TrackingID, voyageNumber voyage.Number,
  28                 unLocode location.UNLocode, eventType cargo.HandlingEventType) error
  29 }
  30
  31 type service struct {
  32         handlingEventRepository cargo.HandlingEventRepository
  33         handlingEventFactory    cargo.HandlingEventFactory
  34         handlingEventHandler    EventHandler
  35 }
  36
  37 func (s *service) RegisterHandlingEvent(completed time.Time, id cargo.TrackingID, voyageNumber voyage.Number,
  38         loc location.UNLocode, eventType cargo.HandlingEventType) error {
  39         if completed.IsZero() || id == "" || loc == "" || eventType == cargo.NotHandled {
  40                 return ErrInvalidArgument
  41         }
  42
  43         e, err := s.handlingEventFactory.CreateHandlingEvent(time.Now(), completed, id, voyageNumber, loc, eventType)
  44         if err != nil {
  45                 return err
  46         }
  47
  48         s.handlingEventRepository.Store(e)
  49         s.handlingEventHandler.CargoWasHandled(e)
  50
  51         return nil
  52 }
  53
  54 // NewService creates a handling event service with necessary dependencies.
  55 func NewService(r cargo.HandlingEventRepository, f cargo.HandlingEventFactory, h EventHandler) Service {
  56         return &service{
  57                 handlingEventRepository: r,
  58                 handlingEventFactory:    f,
  59                 handlingEventHandler:    h,
  60         }
  61 }
  62
  63 type handlingEventHandler struct {
  64         InspectionService inspection.Service
  65 }
  66
  67 func (h *handlingEventHandler) CargoWasHandled(event cargo.HandlingEvent) {
  68         h.InspectionService.InspectCargo(event.TrackingID)
  69 }
  70
  71 // NewEventHandler returns a new instance of a EventHandler.
  72 func NewEventHandler(s inspection.Service) EventHandler {
  73         return &handlingEventHandler{
  74                 InspectionService: s,
  75         }
  76 }