Add feature flag for gating NPS Survey (#5302)

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check off every point from the Essential Checklist! -->
## Explanation
Add feature flag for gating NPS Survey

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- Explain what your PR does. If this PR fixes an existing bug, please
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- "Fixes #bugnum:" in the explanation so that GitHub can auto-close the
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## Essential Checklist
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#bugnum: ...".)
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domain/src/main/java/org/oppia/android/domain/exploration/ExplorationActiveTimeController.kt

@@ -19,6 +19,8 @@ import org.oppia.android.util.data.AsyncResult
 import org.oppia.android.util.data.DataProvider
 import org.oppia.android.util.data.DataProviders
 import org.oppia.android.util.data.DataProviders.Companion.transform
+import org.oppia.android.util.platformparameter.EnableNpsSurvey
+import org.oppia.android.util.platformparameter.PlatformParameterValue
 import org.oppia.android.util.system.OppiaClock
 import org.oppia.android.util.threading.BackgroundDispatcher
 import java.util.UUID
@@ -57,7 +59,8 @@ class ExplorationActiveTimeController @Inject constructor(
   private val dataProviders: DataProviders,
   private val oppiaLogger: OppiaLogger,
   private val exceptionsController: ExceptionsController,
-  @BackgroundDispatcher private val backgroundCoroutineDispatcher: CoroutineDispatcher
+  @BackgroundDispatcher private val backgroundCoroutineDispatcher: CoroutineDispatcher,
+  @EnableNpsSurvey private val enableNpsSurvey: PlatformParameterValue<Boolean>
 ) : ExplorationProgressListener, ApplicationLifecycleListener {
   private var isAppInForeground: Boolean = false
   private var explorationStarted: Boolean = false
@@ -82,27 +85,35 @@ class ExplorationActiveTimeController @Inject constructor(
 
   override fun onExplorationStarted(profileId: ProfileId, topicId: String) {
     this.explorationStarted = true
-    startSessionTimer(
-      profileId = profileId,
-      topicId = topicId,
-      isAppInForeground = getIsAppInForeground(),
-      explorationStarted = true
-    )
+    if (enableNpsSurvey.value) {
+      startSessionTimer(
+        profileId = profileId,
+        topicId = topicId,
+        isAppInForeground = getIsAppInForeground(),
+        explorationStarted = true
+      )
+    }
   }
 
   override fun onExplorationEnded() {
     this.explorationStarted = false
-    stopSessionTimerAsync(getIsExplorationStarted())
+    if (enableNpsSurvey.value) {
+      stopSessionTimerAsync(getIsExplorationStarted())
+    }
   }
 
   override fun onAppInForeground() {
     this.isAppInForeground = true
-    resumeSessionTimer(getIsExplorationStarted())
+    if (enableNpsSurvey.value) {
+      resumeSessionTimer(getIsExplorationStarted())
+    }
   }
 
   override fun onAppInBackground() {
     this.isAppInForeground = false
-    pauseSessionTimerAsync()
+    if (enableNpsSurvey.value) {
+      pauseSessionTimerAsync()
+    }
   }
 
   private fun getIsAppInForeground() = this.isAppInForeground

domain/src/main/java/org/oppia/android/domain/platformparameter/PlatformParameterAlphaKenyaModule.kt

@@ -15,6 +15,8 @@ import org.oppia.android.util.platformparameter.ENABLE_DOWNLOADS_SUPPORT_DEFAULT
 import org.oppia.android.util.platformparameter.ENABLE_EDIT_ACCOUNTS_OPTIONS_UI_DEFAULT_VALUE
 import org.oppia.android.util.platformparameter.ENABLE_EXTRA_TOPIC_TABS_UI_DEFAULT_VALUE
 import org.oppia.android.util.platformparameter.ENABLE_INTERACTION_CONFIG_CHANGE_STATE_RETENTION_DEFAULT_VALUE
+import org.oppia.android.util.platformparameter.ENABLE_NPS_SURVEY
+import org.oppia.android.util.platformparameter.ENABLE_NPS_SURVEY_DEFAULT_VALUE
 import org.oppia.android.util.platformparameter.ENABLE_PERFORMANCE_METRICS_COLLECTION
 import org.oppia.android.util.platformparameter.ENABLE_PERFORMANCE_METRICS_COLLECTION_DEFAULT_VALUE
 import org.oppia.android.util.platformparameter.ENABLE_SPOTLIGHT_UI_DEFAULT_VALUE
@@ -27,6 +29,7 @@ import org.oppia.android.util.platformparameter.EnableFastLanguageSwitchingInLes
 import org.oppia.android.util.platformparameter.EnableInteractionConfigChangeStateRetention
 import org.oppia.android.util.platformparameter.EnableLearnerStudyAnalytics
 import org.oppia.android.util.platformparameter.EnableLoggingLearnerStudyIds
+import org.oppia.android.util.platformparameter.EnableNpsSurvey
 import org.oppia.android.util.platformparameter.EnablePerformanceMetricsCollection
 import org.oppia.android.util.platformparameter.EnableSpotlightUi
 import org.oppia.android.util.platformparameter.FAST_LANGUAGE_SWITCHING_IN_LESSON
@@ -307,4 +310,15 @@ class PlatformParameterAlphaKenyaModule {
       NPS_SURVEY_MINIMUM_AGGREGATE_LEARNING_TIME_IN_A_TOPIC_IN_MINUTES_DEFAULT_VALUE
     )
   }
+
+  @Provides
+  @EnableNpsSurvey
+  fun provideEnableNpsSurvey(
+    platformParameterSingleton: PlatformParameterSingleton
+  ): PlatformParameterValue<Boolean> {
+    return platformParameterSingleton.getBooleanPlatformParameter(ENABLE_NPS_SURVEY)
+      ?: PlatformParameterValue.createDefaultParameter(
+        ENABLE_NPS_SURVEY_DEFAULT_VALUE
+      )
+  }
 }

domain/src/main/java/org/oppia/android/domain/platformparameter/PlatformParameterAlphaModule.kt

@@ -15,6 +15,8 @@ import org.oppia.android.util.platformparameter.ENABLE_DOWNLOADS_SUPPORT_DEFAULT
 import org.oppia.android.util.platformparameter.ENABLE_EDIT_ACCOUNTS_OPTIONS_UI_DEFAULT_VALUE
 import org.oppia.android.util.platformparameter.ENABLE_EXTRA_TOPIC_TABS_UI_DEFAULT_VALUE
 import org.oppia.android.util.platformparameter.ENABLE_INTERACTION_CONFIG_CHANGE_STATE_RETENTION_DEFAULT_VALUE
+import org.oppia.android.util.platformparameter.ENABLE_NPS_SURVEY
+import org.oppia.android.util.platformparameter.ENABLE_NPS_SURVEY_DEFAULT_VALUE
 import org.oppia.android.util.platformparameter.ENABLE_PERFORMANCE_METRICS_COLLECTION
 import org.oppia.android.util.platformparameter.ENABLE_PERFORMANCE_METRICS_COLLECTION_DEFAULT_VALUE
 import org.oppia.android.util.platformparameter.EXTRA_TOPIC_TABS_UI
@@ -26,6 +28,7 @@ import org.oppia.android.util.platformparameter.EnableFastLanguageSwitchingInLes
 import org.oppia.android.util.platformparameter.EnableInteractionConfigChangeStateRetention
 import org.oppia.android.util.platformparameter.EnableLearnerStudyAnalytics
 import org.oppia.android.util.platformparameter.EnableLoggingLearnerStudyIds
+import org.oppia.android.util.platformparameter.EnableNpsSurvey
 import org.oppia.android.util.platformparameter.EnablePerformanceMetricsCollection
 import org.oppia.android.util.platformparameter.EnableSpotlightUi
 import org.oppia.android.util.platformparameter.FAST_LANGUAGE_SWITCHING_IN_LESSON
@@ -302,4 +305,15 @@ class PlatformParameterAlphaModule {
       NPS_SURVEY_MINIMUM_AGGREGATE_LEARNING_TIME_IN_A_TOPIC_IN_MINUTES_DEFAULT_VALUE
     )
   }
+
+  @Provides
+  @EnableNpsSurvey
+  fun provideEnableNpsSurvey(
+    platformParameterSingleton: PlatformParameterSingleton
+  ): PlatformParameterValue<Boolean> {
+    return platformParameterSingleton.getBooleanPlatformParameter(ENABLE_NPS_SURVEY)
+      ?: PlatformParameterValue.createDefaultParameter(
+        ENABLE_NPS_SURVEY_DEFAULT_VALUE
+      )
+  }
 }

domain/src/main/java/org/oppia/android/domain/platformparameter/PlatformParameterModule.kt

@@ -15,6 +15,8 @@ import org.oppia.android.util.platformparameter.ENABLE_DOWNLOADS_SUPPORT_DEFAULT
 import org.oppia.android.util.platformparameter.ENABLE_EDIT_ACCOUNTS_OPTIONS_UI_DEFAULT_VALUE
 import org.oppia.android.util.platformparameter.ENABLE_EXTRA_TOPIC_TABS_UI_DEFAULT_VALUE
 import org.oppia.android.util.platformparameter.ENABLE_INTERACTION_CONFIG_CHANGE_STATE_RETENTION_DEFAULT_VALUE
+import org.oppia.android.util.platformparameter.ENABLE_NPS_SURVEY
+import org.oppia.android.util.platformparameter.ENABLE_NPS_SURVEY_DEFAULT_VALUE
 import org.oppia.android.util.platformparameter.ENABLE_PERFORMANCE_METRICS_COLLECTION
 import org.oppia.android.util.platformparameter.ENABLE_PERFORMANCE_METRICS_COLLECTION_DEFAULT_VALUE
 import org.oppia.android.util.platformparameter.ENABLE_SPOTLIGHT_UI_DEFAULT_VALUE
@@ -27,6 +29,7 @@ import org.oppia.android.util.platformparameter.EnableFastLanguageSwitchingInLes
 import org.oppia.android.util.platformparameter.EnableInteractionConfigChangeStateRetention
 import org.oppia.android.util.platformparameter.EnableLearnerStudyAnalytics
 import org.oppia.android.util.platformparameter.EnableLoggingLearnerStudyIds
+import org.oppia.android.util.platformparameter.EnableNpsSurvey
 import org.oppia.android.util.platformparameter.EnablePerformanceMetricsCollection
 import org.oppia.android.util.platformparameter.EnableSpotlightUi
 import org.oppia.android.util.platformparameter.FAST_LANGUAGE_SWITCHING_IN_LESSON
@@ -304,4 +307,15 @@ class PlatformParameterModule {
       NPS_SURVEY_MINIMUM_AGGREGATE_LEARNING_TIME_IN_A_TOPIC_IN_MINUTES_DEFAULT_VALUE
     )
   }
+
+  @Provides
+  @EnableNpsSurvey
+  fun provideEnableNpsSurvey(
+    platformParameterSingleton: PlatformParameterSingleton
+  ): PlatformParameterValue<Boolean> {
+    return platformParameterSingleton.getBooleanPlatformParameter(ENABLE_NPS_SURVEY)
+      ?: PlatformParameterValue.createDefaultParameter(
+        ENABLE_NPS_SURVEY_DEFAULT_VALUE
+      )
+  }
 }

domain/src/test/java/org/oppia/android/domain/audio/AudioPlayerControllerTest.kt

@@ -73,6 +73,7 @@ import org.oppia.android.util.logging.SyncStatusModule
 import org.oppia.android.util.networking.NetworkConnectionUtilDebugModule
 import org.oppia.android.util.platformparameter.EnableLearnerStudyAnalytics
 import org.oppia.android.util.platformparameter.EnableLoggingLearnerStudyIds
+import org.oppia.android.util.platformparameter.EnableNpsSurvey
 import org.oppia.android.util.platformparameter.PlatformParameterValue
 import org.robolectric.Shadows
 import org.robolectric.annotation.Config
@@ -856,6 +857,12 @@ class AudioPlayerControllerTest {
         defaultValue = enableFeature
       )
     }
+
+    @Provides
+    @EnableNpsSurvey
+    fun provideEnableNpsSurvey(): PlatformParameterValue<Boolean> {
+      return PlatformParameterValue.createDefaultParameter(defaultValue = true)
+    }
   }
 
   // TODO(#89): Move this to a common test application component.

domain/src/test/java/org/oppia/android/domain/exploration/ExplorationActiveTimeControllerTest.kt

@@ -9,6 +9,7 @@ import dagger.BindsInstance
 import dagger.Component
 import dagger.Module
 import dagger.Provides
+import org.junit.Before
 import org.junit.Test
 import org.junit.runner.RunWith
 import org.oppia.android.app.model.ProfileId
@@ -96,6 +97,11 @@ class ExplorationActiveTimeControllerTest {
   private val firstTestProfile = ProfileId.newBuilder().setInternalId(0).build()
   private val secondTestProfile = ProfileId.newBuilder().setInternalId(1).build()
 
+  @Before
+  fun setUp() {
+    TestPlatformParameterModule.forceEnableNpsSurvey(true)
+  }
+
   @Test
   fun testSessionTimer_explorationStartedCallbackReceived_startsSessionTimer() {
     setUpTestApplicationComponent()

domain/src/test/java/org/oppia/android/domain/exploration/ExplorationProgressControllerTest.kt

@@ -109,6 +109,7 @@ import org.oppia.android.util.logging.SyncStatusModule
 import org.oppia.android.util.networking.NetworkConnectionUtilDebugModule
 import org.oppia.android.util.platformparameter.EnableLearnerStudyAnalytics
 import org.oppia.android.util.platformparameter.EnableLoggingLearnerStudyIds
+import org.oppia.android.util.platformparameter.EnableNpsSurvey
 import org.oppia.android.util.platformparameter.PlatformParameterValue
 import org.robolectric.annotation.Config
 import org.robolectric.annotation.LooperMode
@@ -3189,6 +3190,12 @@ class ExplorationProgressControllerTest {
       // Enable study IDs by default in tests.
       return PlatformParameterValue.createDefaultParameter(defaultValue = true)
     }
+
+    @Provides
+    @EnableNpsSurvey
+    fun provideEnableNpsSurvey(): PlatformParameterValue<Boolean> {
+      return PlatformParameterValue.createDefaultParameter(defaultValue = true)
+    }
   }
 
   // TODO(#89): Move this to a common test application component.

domain/src/test/java/org/oppia/android/domain/exploration/ExplorationProgressModuleTest.kt

@@ -17,6 +17,7 @@ import org.junit.runner.RunWith
 import org.oppia.android.domain.exploration.testing.ExplorationStorageTestModule
 import org.oppia.android.domain.oppialogger.LogStorageModule
 import org.oppia.android.testing.TestLogReportingModule
+import org.oppia.android.testing.platformparameter.TestPlatformParameterModule
 import org.oppia.android.testing.robolectric.RobolectricModule
 import org.oppia.android.testing.threading.TestDispatcherModule
 import org.oppia.android.testing.time.FakeOppiaClockModule
@@ -92,7 +93,8 @@ class ExplorationProgressModuleTest {
       TestModule::class, TestLogModule::class, RobolectricModule::class,
       FakeOppiaClockModule::class, ExplorationProgressModule::class, TestDispatcherModule::class,
       LocaleProdModule::class, TestLogReportingModule::class, LogStorageModule::class,
-      NetworkConnectionUtilDebugModule::class, ExplorationStorageTestModule::class
+      NetworkConnectionUtilDebugModule::class, ExplorationStorageTestModule::class,
+      TestPlatformParameterModule::class
     ]
   )
   interface TestApplicationComponent : DataProvidersInjector {

domain/src/test/java/org/oppia/android/domain/survey/SurveyGatingControllerTest.kt

@@ -81,6 +81,7 @@ class SurveyGatingControllerTest {
 
   @Before
   fun setUp() {
+    TestPlatformParameterModule.forceEnableNpsSurvey(true)
     setUpTestApplicationComponent()
     profileTestHelper.initializeProfiles()
   }

testing/src/main/java/org/oppia/android/testing/platformparameter/TestPlatformParameterModule.kt

@@ -13,6 +13,7 @@ import org.oppia.android.util.platformparameter.ENABLE_DOWNLOADS_SUPPORT_DEFAULT
 import org.oppia.android.util.platformparameter.ENABLE_EDIT_ACCOUNTS_OPTIONS_UI_DEFAULT_VALUE
 import org.oppia.android.util.platformparameter.ENABLE_EXTRA_TOPIC_TABS_UI_DEFAULT_VALUE
 import org.oppia.android.util.platformparameter.ENABLE_INTERACTION_CONFIG_CHANGE_STATE_RETENTION_DEFAULT_VALUE
+import org.oppia.android.util.platformparameter.ENABLE_NPS_SURVEY_DEFAULT_VALUE
 import org.oppia.android.util.platformparameter.ENABLE_PERFORMANCE_METRICS_COLLECTION_DEFAULT_VALUE
 import org.oppia.android.util.platformparameter.EnableAppAndOsDeprecation
 import org.oppia.android.util.platformparameter.EnableDownloadsSupport
@@ -22,6 +23,7 @@ import org.oppia.android.util.platformparameter.EnableFastLanguageSwitchingInLes
 import org.oppia.android.util.platformparameter.EnableInteractionConfigChangeStateRetention
 import org.oppia.android.util.platformparameter.EnableLearnerStudyAnalytics
 import org.oppia.android.util.platformparameter.EnableLoggingLearnerStudyIds
+import org.oppia.android.util.platformparameter.EnableNpsSurvey
 import org.oppia.android.util.platformparameter.EnablePerformanceMetricsCollection
 import org.oppia.android.util.platformparameter.EnableSpotlightUi
 import org.oppia.android.util.platformparameter.FAST_LANGUAGE_SWITCHING_IN_LESSON_DEFAULT_VALUE
@@ -263,6 +265,12 @@ class TestPlatformParameterModule {
       return PlatformParameterValue.createDefaultParameter(minimumLearningTime)
     }
 
+  @Provides
+  @EnableNpsSurvey
+  fun provideEnableNpsSurvey(): PlatformParameterValue<Boolean> {
+    return PlatformParameterValue.createDefaultParameter(enableNpsSurvey)
+  }
+
   companion object {
     private var enableDownloadsSupport = ENABLE_DOWNLOADS_SUPPORT_DEFAULT_VALUE
     private var enableEditAccountsOptionsUi = ENABLE_EDIT_ACCOUNTS_OPTIONS_UI_DEFAULT_VALUE
@@ -280,6 +288,7 @@ class TestPlatformParameterModule {
     private var minimumLearningTime =
       NPS_SURVEY_MINIMUM_AGGREGATE_LEARNING_TIME_IN_A_TOPIC_IN_MINUTES_DEFAULT_VALUE
     private var gracePeriodInDays = NPS_SURVEY_GRACE_PERIOD_IN_DAYS_DEFAULT_VALUE
+    private var enableNpsSurvey = ENABLE_NPS_SURVEY_DEFAULT_VALUE
 
     @VisibleForTesting(otherwise = VisibleForTesting.NONE)
     fun forceEnableDownloadsSupport(value: Boolean) {
@@ -334,6 +343,12 @@ class TestPlatformParameterModule {
       enableSpotlightUi = value
     }
 
+    /** Enables forcing [EnableNpsSurvey] feature flag from tests. */
+    @VisibleForTesting(otherwise = VisibleForTesting.NONE)
+    fun forceEnableNpsSurvey(value: Boolean) {
+      enableNpsSurvey = value
+    }
+
     @VisibleForTesting(otherwise = VisibleForTesting.NONE)
     fun reset() {
       enableDownloadsSupport = ENABLE_DOWNLOADS_SUPPORT_DEFAULT_VALUE

utility/src/main/java/org/oppia/android/util/platformparameter/FeatureFlagConstants.kt

@@ -156,3 +156,13 @@ const val APP_AND_OS_DEPRECATION = "android_enable_app_and_os_deprecation"
  * Default value for the feature flag corresponding to [EnableAppAndOsDeprecation].
  */
 const val ENABLE_APP_AND_OS_DEPRECATION_DEFAULT_VALUE = false
+
+/** Qualifier for the feature flag that toggles the the NPS Survey. */
+@Qualifier
+annotation class EnableNpsSurvey
+
+/** Name of the feature flag that toggles the NPS Survey. */
+const val ENABLE_NPS_SURVEY = "enable_nps_survey"
+
+/** Default value of the feature flag corresponding to [EnableNpsSurvey]. */
+const val ENABLE_NPS_SURVEY_DEFAULT_VALUE = false