White-Box SSD for Fetch 3rd Party Sensor Data UC

@startuml
actor Time

box External APIs
  actor MINTS
  actor OpenAQ
  actor Breezometer
end box

box Database Hook
  participant Main
  participant FetchDataTask
  participant APIClient
  participant CapturedPollutant
  participant APIRepository
end box

participant ":System\nDatabase" as Database

title Fetch 3rd Party Sensor Data

Main ->> APIRepository : initialize API clients associated with supported pollutants
Main ->> Time : schedule fetch data task

loop database hook is active
  opt 5 minutes have passed since the last scheduled event
    Time ->> FetchDataTask : scheduled event triggered

    FetchDataTask -> Database : fetchListOfSensors()
    Database -->> FetchDataTask : sensors

    loop for each sensor in sensors
      loop pollutant ∈ {co, no2, o3, pm2.5, pm10, so2}
        FetchDataTask -> CapturedPollutant ** : create

        FetchDataTask -> APIRepository : findAPIsFor(pollutant)
        APIRepository -->> FetchDataTask : APIs

        opt MINTS ∈ APIs
          FetchDataTask -> APIClient : getLatestData(since, sensor, pollutant)
          note right: since = last timestamp since\ndatabase has been queried
          APIClient -> MINTS : getLatestData(since, sensor, pollutant)
          MINTS -->> APIClient : latestData
          APIClient -->> FetchDataTask : latestData
          opt latestData is not blank
            FetchDataTask ->> CapturedPollutant : setValue(value)
          end opt
        end opt

        opt OpenAQ ∈ APIs ^ data is blank
          FetchDataTask -> APIClient : getLatestData(since, sensor, pollutant)
          APIClient -> OpenAQ : getLatestData(since, sensor, pollutant)
          OpenAQ -->> APIClient : latestData
          APIClient -->> FetchDataTask : latestData
          opt latestData is not blank
            FetchDataTask ->> CapturedPollutant : setValue(value)
          end opt
        end

        opt Breezometer ∈ APIs ^ data is blank
          FetchDataTask -> APIClient : getLatestData(since, sensor, pollutant)
          APIClient -> Breezometer : getLatestData(since, sensor, pollutant)
          Breezometer -->> APIClient : latestData
          APIClient -->> FetchDataTask : latestData
          FetchDataTask ->> CapturedPollutant : setValue(value)
        end

        FetchDataTask ->> Database : add(capturedPollutant)
      end
    end
  end
end
@enduml