package cargo
import (
"time"
"github.com/go-kit/kit/examples/shipping/location"
"github.com/go-kit/kit/examples/shipping/voyage"
)
// Delivery is the actual transportation of the cargo, as opposed to the
// customer requirement (RouteSpecification) and the plan (Itinerary).
type Delivery struct {
Itinerary Itinerary
RouteSpecification RouteSpecification
RoutingStatus RoutingStatus
TransportStatus TransportStatus
NextExpectedActivity HandlingActivity
LastEvent HandlingEvent
LastKnownLocation location.UNLocode
CurrentVoyage voyage.Number
ETA time.Time
IsMisdirected bool
IsUnloadedAtDestination bool
}
// UpdateOnRouting creates a new delivery snapshot to reflect changes in
// routing, i.e. when the route specification or the itinerary has changed but
// no additional handling of the cargo has been performed.
func (d Delivery) UpdateOnRouting(rs RouteSpecification, itinerary Itinerary) Delivery {
return newDelivery(d.LastEvent, itinerary, rs)
}
// IsOnTrack checks if the delivery is on track.
func (d Delivery) IsOnTrack() bool {
return d.RoutingStatus == Routed && !d.IsMisdirected
}
// DeriveDeliveryFrom creates a new delivery snapshot based on the complete
// handling history of a cargo, as well as its route specification and
// itinerary.
func DeriveDeliveryFrom(rs RouteSpecification, itinerary Itinerary, history HandlingHistory) Delivery {
lastEvent, _ := history.MostRecentlyCompletedEvent()
return newDelivery(lastEvent, itinerary, rs)
}
// newDelivery creates a up-to-date delivery based on an handling event,
// itinerary and a route specification.
func newDelivery(lastEvent HandlingEvent, itinerary Itinerary, rs RouteSpecification) Delivery {
var (
routingStatus = calculateRoutingStatus(itinerary, rs)
transportStatus = calculateTransportStatus(lastEvent)
lastKnownLocation = calculateLastKnownLocation(lastEvent)
isMisdirected = calculateMisdirectedStatus(lastEvent, itinerary)
isUnloadedAtDestination = calculateUnloadedAtDestination(lastEvent, rs)
currentVoyage = calculateCurrentVoyage(transportStatus, lastEvent)
)
d := Delivery{
LastEvent: lastEvent,
Itinerary: itinerary,
RouteSpecification: rs,
RoutingStatus: routingStatus,
TransportStatus: transportStatus,
LastKnownLocation: lastKnownLocation,
IsMisdirected: isMisdirected,
IsUnloadedAtDestination: isUnloadedAtDestination,
CurrentVoyage: currentVoyage,
}
d.NextExpectedActivity = calculateNextExpectedActivity(d)
d.ETA = calculateETA(d)
return d
}
// Below are internal functions used when creating a new delivery.
func calculateRoutingStatus(itinerary Itinerary, rs RouteSpecification) RoutingStatus {
if itinerary.Legs == nil {
return NotRouted
}
if rs.IsSatisfiedBy(itinerary) {
return Routed
}
return Misrouted
}
func calculateMisdirectedStatus(event HandlingEvent, itinerary Itinerary) bool {
if event.Activity.Type == NotHandled {
return false
}
return !itinerary.IsExpected(event)
}
func calculateUnloadedAtDestination(event HandlingEvent, rs RouteSpecification) bool {
if event.Activity.Type == NotHandled {
return false
}
return event.Activity.Type == Unload && rs.Destination == event.Activity.Location
}
func calculateTransportStatus(event HandlingEvent) TransportStatus {
switch event.Activity.Type {
case NotHandled:
return NotReceived
case Load:
return OnboardCarrier
case Unload:
return InPort
case Receive:
return InPort
case Customs:
return InPort
case Claim:
return Claimed
}
return Unknown
}
func calculateLastKnownLocation(event HandlingEvent) location.UNLocode {
return event.Activity.Location
}
func calculateNextExpectedActivity(d Delivery) HandlingActivity {
if !d.IsOnTrack() {
return HandlingActivity{}
}
switch d.LastEvent.Activity.Type {
case NotHandled:
return HandlingActivity{Type: Receive, Location: d.RouteSpecification.Origin}
case Receive:
l := d.Itinerary.Legs[0]
return HandlingActivity{Type: Load, Location: l.LoadLocation, VoyageNumber: l.VoyageNumber}
case Load:
for _, l := range d.Itinerary.Legs {
if l.LoadLocation == d.LastEvent.Activity.Location {
return HandlingActivity{Type: Unload, Location: l.UnloadLocation, VoyageNumber: l.VoyageNumber}
}
}
case Unload:
for i, l := range d.Itinerary.Legs {
if l.UnloadLocation == d.LastEvent.Activity.Location {
if i < len(d.Itinerary.Legs)-1 {
return HandlingActivity{Type: Load, Location: d.Itinerary.Legs[i+1].LoadLocation, VoyageNumber: d.Itinerary.Legs[i+1].VoyageNumber}
}
return HandlingActivity{Type: Claim, Location: l.UnloadLocation}
}
}
}
return HandlingActivity{}
}
func calculateCurrentVoyage(transportStatus TransportStatus, event HandlingEvent) voyage.Number {
if transportStatus == OnboardCarrier && event.Activity.Type != NotHandled {
return event.Activity.VoyageNumber
}
return voyage.Number("")
}
func calculateETA(d Delivery) time.Time {
if !d.IsOnTrack() {
return time.Time{}
}
return d.Itinerary.FinalArrivalTime()
}