Black-Box SSD for Find Static Route UC

@startuml
actor Traveler
actor "Google Directions API" as Directions
actor "Google Maps API" as Maps

box Front-End
  participant ":System\nAndroid Cell Phone" as Android
end box

box Back-End
  participant ":System\nBack-End Server" as Server
end box

loop while sd1
  ref over Traveler, Server : sd1: View Pollutant Map

  Traveler -> Android : selectNavMode(navMode)
  Android -->> Traveler : display nav input view

  opt if user wants to origin from location other than current location
    loop while user entering origin
      Traveler -> Android : updateOriginTextBox(input)
      Android -> Maps : requestLocations(originTextBox)
      Maps -->> Android : originLocations
      Android -->> Traveler : showPossibleLocations(originLocations)
      break
        Traveler -> Android : selectOrigin(originLocation)
      end
    end
  end

  loop while user entering destination
    Traveler -> Android : updateDestinationTextBox(input)
    Android -> Maps : requestLocations(destinationTextBox)
    Maps -->> Android : destinationLocations
    Android -->> Traveler : showPossibleLocations(destinationLocations)
    break
      Traveler -> Android : selectDestination(destinationLocation)
    end
  end

  Traveler -> Android : provideEndpoints(origin, destination)
  Android -> Server : requestRoute(origin, destination, navMode, preferences)
  Server -> Directions : requestNavRoutes(navMode)
  Directions -->> Server : fastRoute
  Server -> Server : getPollutants(location)

  Server -> Server : calculateSafestRoute(origin, destination, fastRoute)
  Server -->> Android : fastRoute, safeRoute, hasPollution

  opt if hasPollution
    Android ->> Traveler : showLessSafeWarning
  end

  Android -->> Traveler : showRoutesView(fastRoute, safeRoute)

  opt if user selects more info
    Traveler -> Android : askRouteDetails
    Android -->> Traveler : showRouteDetails(directions, hazards, duration, tolls)
  end

  opt if user clears route
    Traveler -> Android : clearRoute
    Android -->> Traveler : showMapView
  end
end
@enduml