Fix #4042: Implement success criteria metrics for lesson checkpointing (

#5336)

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check off every point from the Essential Checklist! -->
## Explanation
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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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Fixes #4042

This PR implements the success criteria metrics required for lesson
checkpointing as described
[here](https://docs.google.com/document/d/1d8yjwz76mngtsPRxC7fubgLKg8mfA7kG1sWRWdbiaVw/edit#bookmark=id.2zyjd5vygmcv).
A high level overview of the implementation is documented on the issue
thread
[here](#4042 (comment)).

#### Changes to FakeAnalyticsEventLogger
- `fun getOldestEvents(count: Int): List<EventLog>` is necessary to
retrieve a list of a pre-defined count of oldest events from all the
logged events.
- `fun getLoggedEvent(predicate: (EventLog) -> Boolean): EventLog?`
serves to acquire a reference to a logged event when the context of the
event is known, but the event index is uncertain or potentially
surrounded by other events. Thus, extracting the event via index might
be difficult.

## Essential Checklist
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- [x] The PR title and explanation each start with "Fix #bugnum: " (If
this PR fixes part of an issue, prefix the title with "Fix part of
#bugnum: ...".)
- [x] Any changes to
[scripts/assets](https://github.com/oppia/oppia-android/tree/develop/scripts/assets)
files have their rationale included in the PR explanation.
- [x] The PR follows the [style
guide](https://github.com/oppia/oppia-android/wiki/Coding-style-guide).
- [x] The PR does not contain any unnecessary code changes from Android
Studio
([reference](https://github.com/oppia/oppia-android/wiki/Guidance-on-submitting-a-PR#undo-unnecessary-changes)).
- [x] The PR is made from a branch that's **not** called "develop" and
is up-to-date with "develop".
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## For UI-specific PRs only
<!-- Delete these section if this PR does not include UI-related
changes. -->
If your PR includes UI-related changes, then:
- Add screenshots for portrait/landscape for both a tablet & phone of
the before & after UI changes
- For the screenshots above, include both English and pseudo-localized
(RTL) screenshots (see [RTL
guide](https://github.com/oppia/oppia-android/wiki/RTL-Guidelines))
- Add a video showing the full UX flow with a screen reader enabled (see
[accessibility
guide](https://github.com/oppia/oppia-android/wiki/Accessibility-A11y-Guide))
- For PRs introducing new UI elements or color changes, both light and
dark mode screenshots must be included
- Add a screenshot demonstrating that you ran affected Espresso tests
locally & that they're passing

---------

Co-authored-by: Adhiambo Peres <[email protected]>

app/src/main/java/org/oppia/android/app/player/exploration/ExplorationActivityPresenter.kt

@@ -37,6 +37,7 @@ import org.oppia.android.app.viewmodel.ViewModelProvider
 import org.oppia.android.databinding.ExplorationActivityBinding
 import org.oppia.android.domain.exploration.ExplorationDataController
 import org.oppia.android.domain.oppialogger.OppiaLogger
+import org.oppia.android.domain.oppialogger.analytics.LearnerAnalyticsLogger
 import org.oppia.android.domain.survey.SurveyGatingController
 import org.oppia.android.domain.translation.TranslationController
 import org.oppia.android.util.accessibility.AccessibilityService
@@ -60,6 +61,7 @@ class ExplorationActivityPresenter @Inject constructor(
   private val fontScaleConfigurationUtil: FontScaleConfigurationUtil,
   private val translationController: TranslationController,
   private val oppiaLogger: OppiaLogger,
+  private val learnerAnalyticsLogger: LearnerAnalyticsLogger,
   private val resourceHandler: AppLanguageResourceHandler,
   private val surveyGatingController: SurveyGatingController
 ) {
@@ -328,7 +330,7 @@ class ExplorationActivityPresenter @Inject constructor(
       return
     }
     // If checkpointing is enabled, get the current checkpoint state to show an appropriate dialog
-    // fragment.
+    // fragment and log lesson saved advertently event.
     showDialogFragmentBasedOnCurrentCheckpointState()
   }
 
@@ -514,9 +516,11 @@ class ExplorationActivityPresenter @Inject constructor(
     } else {
       when (checkpointState) {
         CheckpointState.CHECKPOINT_SAVED_DATABASE_NOT_EXCEEDED_LIMIT -> {
+          learnerAnalyticsLogger.explorationAnalyticsLogger.value?.logLessonSavedAdvertently()
           stopExploration(isCompletion = false)
         }
         CheckpointState.CHECKPOINT_SAVED_DATABASE_EXCEEDED_LIMIT -> {
+          learnerAnalyticsLogger.explorationAnalyticsLogger.value?.logLessonSavedAdvertently()
           showProgressDatabaseFullDialogFragment()
         }
         else -> showUnsavedExplorationDialogFragment()

app/src/sharedTest/java/org/oppia/android/app/player/exploration/ExplorationActivityTest.kt

@@ -68,6 +68,7 @@ import org.oppia.android.app.application.testing.TestingBuildFlavorModule
 import org.oppia.android.app.devoptions.DeveloperOptionsModule
 import org.oppia.android.app.devoptions.DeveloperOptionsStarterModule
 import org.oppia.android.app.help.HelpActivity
+import org.oppia.android.app.model.EventLog.Context.ActivityContextCase.LESSON_SAVED_ADVERTENTLY_CONTEXT
 import org.oppia.android.app.model.ExplorationActivityParams
 import org.oppia.android.app.model.OppiaLanguage
 import org.oppia.android.app.model.ProfileId
@@ -128,6 +129,7 @@ import org.oppia.android.domain.topic.TEST_TOPIC_ID_0
 import org.oppia.android.domain.translation.TranslationController
 import org.oppia.android.domain.workmanager.WorkManagerConfigurationModule
 import org.oppia.android.testing.BuildEnvironment
+import org.oppia.android.testing.FakeAnalyticsEventLogger
 import org.oppia.android.testing.OppiaTestRule
 import org.oppia.android.testing.RunOn
 import org.oppia.android.testing.TestLogReportingModule
@@ -222,6 +224,9 @@ class ExplorationActivityTest {
   @Inject
   lateinit var fakeAccessibilityService: FakeAccessibilityService
 
+  @Inject
+  lateinit var fakeAnalyticsEventLogger: FakeAnalyticsEventLogger
+
   private val internalProfileId: Int = 0
 
   @Before
@@ -1932,6 +1937,129 @@ class ExplorationActivityTest {
     assertThat(explorationActivityTestRule.activity.isFinishing).isTrue()
   }
 
+  @Test
+  fun testExpActivity_startNewExploration_pressBack_logsLessonSavedAdvertentlyEvent() {
+    setUpAudioForFractionLesson()
+    explorationActivityTestRule.launchActivity(
+      createExplorationActivityIntent(
+        internalProfileId,
+        FRACTIONS_TOPIC_ID,
+        FRACTIONS_STORY_ID_0,
+        FRACTIONS_EXPLORATION_ID_0,
+        shouldSavePartialProgress = true
+      )
+    )
+    explorationDataController.startPlayingNewExploration(
+      internalProfileId,
+      FRACTIONS_TOPIC_ID,
+      FRACTIONS_STORY_ID_0,
+      FRACTIONS_EXPLORATION_ID_0
+    )
+    testCoroutineDispatchers.runCurrent()
+
+    pressBack()
+    testCoroutineDispatchers.runCurrent()
+
+    val lessonSavedAdvertentlyEventCount = fakeAnalyticsEventLogger.countEvents {
+      it.context.activityContextCase == LESSON_SAVED_ADVERTENTLY_CONTEXT
+    }
+    assertThat(lessonSavedAdvertentlyEventCount).isEqualTo(1)
+  }
+
+  @Test
+  fun testExpActivity_startNewExploration_pressToolbarBackIcon_logsLessonSavedAdvertentlyEvent() {
+    setUpAudioForFractionLesson()
+    markAllSpotlightsSeen()
+    explorationActivityTestRule.launchActivity(
+      createExplorationActivityIntent(
+        internalProfileId,
+        FRACTIONS_TOPIC_ID,
+        FRACTIONS_STORY_ID_0,
+        FRACTIONS_EXPLORATION_ID_0,
+        shouldSavePartialProgress = true
+      )
+    )
+    explorationDataController.startPlayingNewExploration(
+      internalProfileId,
+      FRACTIONS_TOPIC_ID,
+      FRACTIONS_STORY_ID_0,
+      FRACTIONS_EXPLORATION_ID_0
+    )
+    testCoroutineDispatchers.runCurrent()
+
+    // Click on 'X' icon on toolbar.
+    onView(withContentDescription(R.string.nav_app_bar_navigate_up_description)).perform(click())
+    testCoroutineDispatchers.runCurrent()
+
+    explorationDataController.stopPlayingExploration(isCompletion = false)
+    testCoroutineDispatchers.runCurrent()
+
+    val lessonSavedAdvertentlyEventCount = fakeAnalyticsEventLogger.countEvents {
+      it.context.activityContextCase == LESSON_SAVED_ADVERTENTLY_CONTEXT
+    }
+    assertThat(lessonSavedAdvertentlyEventCount).isEqualTo(1)
+  }
+
+  @Test
+  fun testExpActivity_replayExploration_pressBack_doesNotLogLessonSavedAdvertentlyEvent() {
+    setUpAudioForFractionLesson()
+    explorationActivityTestRule.launchActivity(
+      createExplorationActivityIntent(
+        internalProfileId,
+        FRACTIONS_TOPIC_ID,
+        FRACTIONS_STORY_ID_0,
+        FRACTIONS_EXPLORATION_ID_0,
+        shouldSavePartialProgress = false
+      )
+    )
+    explorationDataController.replayExploration(
+      internalProfileId,
+      FRACTIONS_TOPIC_ID,
+      FRACTIONS_STORY_ID_0,
+      FRACTIONS_EXPLORATION_ID_0
+    )
+    testCoroutineDispatchers.runCurrent()
+
+    pressBack()
+    testCoroutineDispatchers.runCurrent()
+
+    val lessonSavedAdvertentlyEventCount = fakeAnalyticsEventLogger.countEvents {
+      it.context.activityContextCase == LESSON_SAVED_ADVERTENTLY_CONTEXT
+    }
+    assertThat(lessonSavedAdvertentlyEventCount).isEqualTo(0)
+  }
+
+  @Test
+  fun testExpActivity_replayExp_pressToolbarBackIcon_doesNotLogLessonSavedAdvertentlyEvent() {
+    setUpAudioForFractionLesson()
+    markAllSpotlightsSeen()
+    explorationActivityTestRule.launchActivity(
+      createExplorationActivityIntent(
+        internalProfileId,
+        FRACTIONS_TOPIC_ID,
+        FRACTIONS_STORY_ID_0,
+        FRACTIONS_EXPLORATION_ID_0,
+        shouldSavePartialProgress = false
+      )
+    )
+    explorationDataController.replayExploration(
+      internalProfileId,
+      FRACTIONS_TOPIC_ID,
+      FRACTIONS_STORY_ID_0,
+      FRACTIONS_EXPLORATION_ID_0
+    )
+    testCoroutineDispatchers.runCurrent()
+
+    // Click on 'X' icon on toolbar.
+    onView(withContentDescription(R.string.nav_app_bar_navigate_up_description)).perform(click())
+    testCoroutineDispatchers.runCurrent()
+
+    val lessonSavedAdvertentlyEventCount = fakeAnalyticsEventLogger.countEvents {
+      it.context.activityContextCase == LESSON_SAVED_ADVERTENTLY_CONTEXT
+    }
+    assertThat(lessonSavedAdvertentlyEventCount).isEqualTo(0)
+  }
+
   @Test
   @RunOn(TestPlatform.ROBOLECTRIC) // TODO(#3858): Enable for Espresso.
   fun testExpActivity_englishContentLang_contentIsInEnglish() {

domain/src/main/java/org/oppia/android/domain/exploration/ExplorationProgressController.kt

@@ -443,6 +443,15 @@ class ExplorationProgressController @Inject constructor(
                 ControllerState(
                   ExplorationProgress(),
                   message.isRestart,
+                  // The [message.explorationCheckpoint] is [ExplorationCheckpoint.getDefaultInstance()]
+                  // in the following 3 cases.
+                  //  - New exploration is started.
+                  //  - Saved Exploration is restarted.
+                  //  - Completed exploration is replayed.
+                  // The [message.explorationCheckpoint] will contain the exploration checkpoint
+                  // only when a saved exploration is resumed.
+                  isResume = message.explorationCheckpoint
+                    != ExplorationCheckpoint.getDefaultInstance(),
                   message.sessionId,
                   message.ephemeralStateFlow,
                   commandQueue,
@@ -634,6 +643,14 @@ class ExplorationProgressController @Inject constructor(
           topPendingState.interaction, userAnswer, answerOutcome.labelledAsCorrectAnswer
         )
 
+        // Log correct & incorrect answer submission in a resumed exploration.
+        if (isResume) {
+          if (answerOutcome.labelledAsCorrectAnswer)
+            explorationAnalyticsLogger.logResumeLessonSubmitCorrectAnswer()
+          else
+            explorationAnalyticsLogger.logResumeLessonSubmitIncorrectAnswer()
+        }
+
         // Follow the answer's outcome to another part of the graph if it's different.
         val ephemeralState = computeBaseCurrentEphemeralState()
         when {
@@ -947,9 +964,11 @@ class ExplorationProgressController @Inject constructor(
 
     deferred.invokeOnCompletion {
       val checkpointState = if (it == null) {
+        explorationAnalyticsLogger.logProgressSavingSuccess()
         deferred.getCompleted()
       } else {
         oppiaLogger.e("Lightweight checkpointing", "Failed to save checkpoint in exploration", it)
+        explorationAnalyticsLogger.logProgressSavingFailure()
         // CheckpointState is marked as CHECKPOINT_UNSAVED because the deferred did not
         // complete successfully.
         CheckpointState.CHECKPOINT_UNSAVED
@@ -1094,6 +1113,7 @@ class ExplorationProgressController @Inject constructor(
   private class ControllerState(
     val explorationProgress: ExplorationProgress,
     val isRestart: Boolean,
+    val isResume: Boolean,
     val sessionId: String,
     val ephemeralStateFlow: MutableStateFlow<AsyncResult<EphemeralState>>,
     val commandQueue: SendChannel<ControllerMessage<*>>,

domain/src/main/java/org/oppia/android/domain/oppialogger/analytics/LearnerAnalyticsLogger.kt

@@ -245,6 +245,31 @@ class LearnerAnalyticsLogger @Inject constructor(
       getExpectedStateLogger()?.logFinishExploration()
     }
 
+    /** Logs that the current exploration progress has been saved successfully. */
+    fun logProgressSavingSuccess() {
+      getExpectedStateLogger()?.logProgressSavingSuccess()
+    }
+
+    /** Logs that the current exploration progress has failed to save. */
+    fun logProgressSavingFailure() {
+      getExpectedStateLogger()?.logProgressSavingFailure()
+    }
+
+    /** Logs that the user has left the lesson advertently (attempted to save). */
+    fun logLessonSavedAdvertently() {
+      getExpectedStateLogger()?.logLessonSavedAdvertently()
+    }
+
+    /** Logs that correct answer was submitted in a resumed lesson. */
+    fun logResumeLessonSubmitCorrectAnswer() {
+      getExpectedStateLogger()?.logResumeLessonSubmitCorrectAnswer()
+    }
+
+    /** Logs that incorrect answer was submitted in a resumed lesson. */
+    fun logResumeLessonSubmitIncorrectAnswer() {
+      getExpectedStateLogger()?.logResumeLessonSubmitIncorrectAnswer()
+    }
+
     /**
      * Begins analytics logging for the specified [newState], returning the [StateAnalyticsLogger]
      * that can be used to log events for the [State].
@@ -306,6 +331,31 @@ class LearnerAnalyticsLogger @Inject constructor(
       logStateEvent(EventBuilder::setFinishExplorationContext)
     }
 
+    /** Logs that the current exploration progress has been saved successfully. */
+    internal fun logProgressSavingSuccess() {
+      logStateEvent(EventBuilder::setProgressSavingSuccessContext)
+    }
+
+    /** Logs that the current exploration progress has failed to save. */
+    internal fun logProgressSavingFailure() {
+      logStateEvent(EventBuilder::setProgressSavingFailureContext)
+    }
+
+    /** Logs that the user has left the lesson advertently (attempted to save). */
+    internal fun logLessonSavedAdvertently() {
+      logStateEvent(EventBuilder::setLessonSavedAdvertentlyContext)
+    }
+
+    /** Logs that correct answer was submitted in a resumed lesson. */
+    internal fun logResumeLessonSubmitCorrectAnswer() {
+      logStateEvent(EventBuilder::setResumeLessonSubmitCorrectAnswerContext)
+    }
+
+    /** Logs that incorrect answer was submitted in a resumed lesson. */
+    internal fun logResumeLessonSubmitIncorrectAnswer() {
+      logStateEvent(EventBuilder::setResumeLessonSubmitIncorrectAnswerContext)
+    }
+
     /** Logs that this card has been started. */
     fun logStartCard() {
       logStateEvent(linkedSkillId, ::createCardContext, EventBuilder::setStartCardContext)