Simplifying structure of the class ApplicationManagerImpl

proposals/____-Simplifying-structure-of-the-class-ApplicationManagerImpl.md

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+# Simplifying the structure of the class `ApplicationManagerImpl`
+
+
+## Introduction
+
+Concentration of various functionality within one class violates the single responsibility principle and makes it difficult to work with the class file.
+`ApplicationManagerImpl.cc` contains more then 5000 lines of code that solve various problems and can be thematically categorized into separate classes.
+
+## Motivation
+
+Working with the ApplicationManagerImpl would be more convenient if some of the specific functionality would be moved into separate classes and these classes would be combined in a composition in the  ApplicationManagerImpl.
+With this approach, the ApplicationManagerImpl structure would be simpler and clearer.
+
+
+## Proposed solution
+
+As mentioned in the previous section, we could move some parts of `ApplicationManagerImpl.cc` to more approprite places.
+
+
+Proposed edits :
+
+
+Move next functions to utils
+
+```
+get_rand_from_range()
+DirectoryTypeToString() 
+InitDirectory()           
+IsReadWriteAllowed()      
+SaveBinary()
+IsSOStructValid()
+ConvertSOtoMessage()
+GenerateGrammarID()
+```
+
+
+Change next predicates to lambda functions where it is used, which will allow us to reduce the amount of code and make the code more expressive
+
+```
+device_id_comparator()
+PolicyAppIdComparator()
+ActiveAppPredicate()
+FullOrLimitedAppPredicate()
+LimitedMediaAppPredicate()
+LimitedNaviAppPredicate()
+LimitedVoiceAppPredicate()
+NaviAppPredicate()
+LimitedMobileProjectionPredicate()
+MobileProjectionPredicate()
+IsApplication()
+MobileAppIdPredicate()
+TakeDeviceHandle()
+```
+
+
+Move methods to new sub class `ApplicationDataProvider` since they are closely related
+```
+applications()
+pending_applications()
+reregister_applications()
+application()
+application_by_hmi_app()
+application_by_policy_id()
+pending_application_by_policy_id()
+application_by_name()
+reregister_application_by_policy_id()
+active_application()
+get_full_or_limited_application()
+get_limited_media_application()
+get_limited_navi_application()
+get_limited_voice_application()
+applications_with_navi() 
+get_limited_mobile_projection_application()
+applications_with_mobile_projection()
+applications_by_button()
+applications_by_name() 
+
+OnApplicationRegistered()
+OnApplicationSwitched()
+RegisterApplication()
+FinalizeAppRegistration()
+ActivateApplication()
+CreateApplications()
+set_application_id()
+SetUnregisterAllApplicationsReason()
+UnregisterAllApplications()
+RemoveAppsWaitingForRegistration()
+UnregisterApplication()
+OnAppUnauthorized()
+GetHashedAppID()
+ProcessApp()
+IsApplicationForbidden()
+GetAvailableSpaceForApp()
+OnApplicationListUpdateTimer()
+EraseAppFromReconnectionList()
+AddAppToRegisteredAppList()
+```
+
+
+Move methods to new class `GlobalPropertiesHandler` 
+
+```
+OnTimerSendTTSGlobalProperties()
+AddAppToTTSGlobalPropertiesList()
+RemoveAppFromTTSGlobalPropertiesList()
+ResetGlobalProperties()
+ResetAllApplicationGlobalProperties()
+CreateAllAppGlobalPropsIDList()
+ClearTTSGlobalPropertiesList()
+```
+
+
+
+Move methods to separate plugin `waypoints_plugin`
+```
+IsAppSubscribedForWayPoints()
+SubscribeAppForWayPoints()
+UnsubscribeAppFromWayPoints()
+SaveWayPointsMessage()
+IsAnyAppSubscribedForWayPoints()
+GetAppsSubscribedForWayPoints()
+```
+
+Move methods to new class `StreamingHandler`
+```
+CanAppStream()
+ForbidStreaming()
+OnAppStreaming()
+ProcessOnDataStreamingNotification()
+StartEndStreamTimer()
+EndNaviStreaming()
+DisallowStreaming()
+AllowStreaming()
+StartNaviService()
+StopNaviService()
+OnServiceStartedCallback()
+OnServiceEndedCallback()
+ProcessServiceStatusUpdate()
+HandleRejectedServiceStatus()
+EndNaviServices()
+```
+
+Move methods to new class `HmiHandler`
+```
+IsHmiLevelFullAllowed()
+OnHMIReady()
+GetDefaultHmiLevel()
+GenerateNewHMIAppID()
+RemoveHMIFakeParameters()
+hmi_so_factory()
+hmi_capabilities()
+HMIStateAllowsStreaming()
+OnHMIStateChanged()
+ProcessPostponedMessages()
+IsHMICooperating()
+SetHMICooperating()
+CompareAppHMIType()
+OnUpdateHMIAppType()
+ChangeAppsHMILevel()
+GetNextHMICorrelationID()
+```
+
+Move methods to new class `MobileHandler`
+```
+GetNextMobileCorrelationID()
+GetCorrectMobileIDFromMessage()
+mobile_so_factory()
+```
+
+
+Move methods to new class `DevicesHandler`
+```
+ConnectToDevice()
+OnWebEngineDeviceCreated()
+GetDeviceName()
+GetDeviceTransportType()
+RemoveDevice()
+OnDeviceSwitchingStart()
+OnDeviceSwitchingFinish()
+GetUserConsentForDevice()
+OnDeviceListUpdated()
+```
+
+
+Move methods to new class `SecurityHandler`
+```
+OnHandshakeDone()
+OnPTUFailed()
+OnGetSystemTimeFailed()
+OnCertificateUpdateRequired()
+GetPolicyCertificateData()
+GetHandshakeContext()
+OnCertDecryptFinished()
+OnCertDecryptFailed()
+```
+
+
+Move methods to new class `ApplicationsHandler`
+```
+
+```
+
+After these edits, the ApplicationManagerImpl class will be engaged in organizing the interaction of the new classes described above
+
+![img][uml-diagram]
+
+
+
+## Potential downsides
+
+New files for each new class will be created and added to repository
+
+
+## Impact on existing code
+Only ApplicationManagerImpl class of SDL Core will be impacted.
+
+
+## Alternatives considered
+Leave ApplicationManagerImpl as is
+
+
+[uml-diagram]: ../assets/proposals/appManagerImpl_refactor/app_manager_uml.png