add comprehensive logging for exercise setup and state transitions across screens and ViewModels

app/src/main/java/eu/gaudian/translator/view/exercises/StartExerciseScreen.kt

@@ -58,6 +58,7 @@ import eu.gaudian.translator.model.Language
 import eu.gaudian.translator.model.TagCategory
 import eu.gaudian.translator.model.VocabularyCategory
 import eu.gaudian.translator.model.VocabularyStage
+import eu.gaudian.translator.utils.Log
 import eu.gaudian.translator.utils.findActivity
 import eu.gaudian.translator.view.composable.AppButton
 import eu.gaudian.translator.view.composable.AppIcons
@@ -117,6 +118,7 @@ fun StartExerciseScreen(
     var amount by remember { mutableStateOf(0) }
     androidx.compose.runtime.LaunchedEffect(totalItemCount) {
         amount = totalItemCount
+        Log.d("StartExercise", "Items to show updated: total=$totalItemCount, amount=$amount")
     }
 
     val updateConfig: (eu.gaudian.translator.viewmodel.ExerciseConfig) -> Unit = { config ->
@@ -213,12 +215,15 @@ fun StartExerciseScreen(
                 enabled = totalItemCount > 0 && amount > 0,
                 amount = amount,
                 onStart = {
+                    Log.d("StartExercise", "Start pressed. shuffleCards=${exerciseConfig.shuffleCards}, selectedAmount=$amount, items=${itemsToShow.size}, origin=${selectedOriginLanguage?.nameResId}, target=${selectedTargetLanguage?.nameResId}, pairs=${selectedPairsIds.size}, categories=${selectedCategoryIds.size}, stages=${selectedStages.size}")
                     val finalItems = if (exerciseConfig.shuffleCards) {
                         itemsToShow.shuffled().take(amount)
                     } else {
                         itemsToShow.take(amount)
                     }
 
+                    Log.d("StartExercise", "Final items prepared: count=${finalItems.size}")
+
                     exerciseViewModel.startExerciseWithConfig(
                         finalItems,
                         exerciseConfig.copy(
@@ -229,6 +234,7 @@ fun StartExerciseScreen(
                         )
                     )
 
+                    Log.d("StartExercise", "Navigating to vocabulary_exercise/false")
                     navController.navigate("vocabulary_exercise/false")
                 }
             )

app/src/main/java/eu/gaudian/translator/view/vocabulary/VocabularyExerciseHostScreen.kt

@@ -27,6 +27,7 @@ import androidx.compose.ui.res.stringResource
 import androidx.hilt.lifecycle.viewmodel.compose.hiltViewModel
 import androidx.navigation.NavController
 import eu.gaudian.translator.R
+import eu.gaudian.translator.utils.Log
 import eu.gaudian.translator.utils.findActivity
 import eu.gaudian.translator.view.composable.AppAlertDialog
 import eu.gaudian.translator.viewmodel.ScreenState
@@ -67,8 +68,10 @@ fun VocabularyExerciseHostScreen(
     }
 
     LaunchedEffect(categoryIdsAsJson, stageNamesAsJson, languageIdsAsJson, dailyOnly) {
+        Log.d("ExerciseHost", "LaunchedEffect filters: categories=$categoryIdsAsJson, stages=$stageNamesAsJson, languages=$languageIdsAsJson, dailyOnly=$dailyOnly")
         // Only reset and prepare if the host is opened via explicit filters.
         if (!categoryIdsAsJson.isNullOrBlank() || !stageNamesAsJson.isNullOrBlank() || !languageIdsAsJson.isNullOrBlank() || dailyOnly) {
+            Log.d("ExerciseHost", "Preparing exercise from filters")
             exerciseViewModel.resetExercise()
             vocabularyViewModel.prepareExercise(
                 categoryIdsAsJson,
@@ -76,10 +79,13 @@ fun VocabularyExerciseHostScreen(
                 languageIdsAsJson,
                 dailyOnly = dailyOnly,
             )
+        } else {
+            Log.d("ExerciseHost", "No filters provided; skipping prepareExercise")
         }
     }
 
     LaunchedEffect(cardSet, screenState, pendingConfig) {
+        Log.d("ExerciseHost", "State update: screenState=$screenState, cardSet=${cardSet?.cards?.size ?: 0}, pendingCount=${pendingConfig.exerciseItemCount}")
         if (cardSet != null && screenState == ScreenState.START) {
             val items = cardSet?.cards.orEmpty()
             if (items.isNotEmpty()) {
@@ -91,6 +97,7 @@ fun VocabularyExerciseHostScreen(
                 } else {
                     items.take(selectedCount)
                 }
+                Log.d("ExerciseHost", "Auto-starting exercise with ${finalItems.size} items")
                 exerciseViewModel.startExerciseWithConfig(
                     finalItems,
                     pendingConfig.copy(
@@ -98,22 +105,21 @@ fun VocabularyExerciseHostScreen(
                         originalExerciseItems = finalItems
                     )
                 )
+            } else {
+                Log.d("ExerciseHost", "CardSet present but empty")
             }
         }
     }
 
-    if (cardSet == null && screenState != ScreenState.START) {
-        Box(modifier = Modifier.fillMaxSize(), contentAlignment = Alignment.Center) {
-            CircularProgressIndicator()
-        }
-    } else {
     when (screenState) {
         ScreenState.START -> {
+            Log.d("ExerciseHost", "Rendering START screen")
             Box(modifier = Modifier.fillMaxSize(), contentAlignment = Alignment.Center) {
                 CircularProgressIndicator()
             }
         }
         ScreenState.EXERCISE -> {
+            Log.d("ExerciseHost", "Rendering EXERCISE screen")
             ExerciseScreen(
                 viewModel = exerciseViewModel,
                 onClose = onClose,
@@ -128,6 +134,7 @@ fun VocabularyExerciseHostScreen(
             )
         }
         ScreenState.RESULT -> {
+            Log.d("ExerciseHost", "Rendering RESULT screen")
             val totalItems by exerciseViewModel.totalItems.collectAsState()
             val originalItems by exerciseViewModel.originalItems.collectAsState()
             ResultScreen(
@@ -146,7 +153,6 @@ fun VocabularyExerciseHostScreen(
         }
     }
 }
-}
 
 
 

app/src/main/java/eu/gaudian/translator/viewmodel/VocabularyExerciseViewModel.kt

@@ -109,6 +109,7 @@ class VocabularyExerciseViewModel @Inject constructor(
         types: Set<VocabularyExerciseType>,
         shuffleLanguages: Boolean
     ) {
+        Log.d("ExerciseVM", "startExercise called: items=${items.size}, types=$types, shuffleLanguages=$shuffleLanguages")
         // Reset counters for the new exercise session
         _correctAnswers.value = 0
         _wrongAnswers.value = 0
@@ -161,6 +162,7 @@ class VocabularyExerciseViewModel @Inject constructor(
     }
 
     private fun loadExercise() {
+        Log.d("ExerciseVM", "loadExercise: index=$currentIndex, total=${currentItems.size}")
         if (currentIndex < currentItems.size) {
             // Ensure item categories align with exercise type by attempting a swap instead of replacement
             val randomType = exerciseTypes.random()
@@ -276,8 +278,10 @@ class VocabularyExerciseViewModel @Inject constructor(
                     )
                 }
             }
+            Log.d("ExerciseVM", "exerciseState set: type=$randomType, itemId=${itemToUse.id}")
         } else {
             _exerciseState.value = null // End of exercise
+            Log.d("ExerciseVM", "loadExercise: end of exercise, state cleared")
         }
     }
 
@@ -394,6 +398,7 @@ class VocabularyExerciseViewModel @Inject constructor(
     }
 
     fun onTrainingModeChanged(value: Boolean) {
+        Log.d("ExerciseVM", "onTrainingModeChanged: $value")
         _trainingMode.value = value
     }
 
@@ -401,24 +406,29 @@ class VocabularyExerciseViewModel @Inject constructor(
         items: List<VocabularyItem>,
         config: ExerciseConfig
     ) {
+        Log.d("ExerciseVM", "startExerciseWithConfig called: items=${items.size}, configCount=${config.exerciseItemCount}, shuffleCards=${config.shuffleCards}, shuffleLanguages=${config.shuffleLanguages}, trainingMode=${config.trainingMode}, dueTodayOnly=${config.dueTodayOnly}, types=${config.selectedExerciseTypes}")
         _exerciseConfig.value = config
         _pendingExerciseConfig.value = config
         _totalItems.value = items.size
         _originalItems.value = items
         startExercise(items, config.selectedExerciseTypes, config.shuffleLanguages)
         _screenState.value = ScreenState.EXERCISE
+        Log.d("ExerciseVM", "screenState set to EXERCISE; totalItems=${_totalItems.value}")
     }
 
     fun updatePendingExerciseConfig(config: ExerciseConfig) {
+        Log.d("ExerciseVM", "updatePendingExerciseConfig: count=${config.exerciseItemCount}, shuffleCards=${config.shuffleCards}, shuffleLanguages=${config.shuffleLanguages}, trainingMode=${config.trainingMode}, dueTodayOnly=${config.dueTodayOnly}, types=${config.selectedExerciseTypes}")
         _pendingExerciseConfig.value = config
     }
 
+
     fun finishExercise(score: Int, wrongAnswers: Int) {
         _exerciseResults.value = ExerciseResults(score, wrongAnswers)
         _screenState.value = ScreenState.RESULT
     }
 
     fun resetExercise() {
+        Log.d("ExerciseVM", "resetExercise called")
         _screenState.value = ScreenState.START
         _exerciseConfig.value = ExerciseConfig()
         _exerciseResults.value = ExerciseResults()
@@ -428,6 +438,7 @@ class VocabularyExerciseViewModel @Inject constructor(
         _exerciseState.value = null
         _totalItems.value = 0
         _originalItems.value = emptyList()
+        Log.d("ExerciseVM", "resetExercise completed; screenState=START")
     }
 
     fun retryWrongAnswers(originalItems: List<VocabularyItem>) {

app/src/main/java/eu/gaudian/translator/viewmodel/VocabularyViewModel.kt

@@ -714,6 +714,7 @@ class VocabularyViewModel @Inject constructor(
         languageIdsAsJson: String?,
         dailyOnly: Boolean = false
     ) {
+        Log.d("VocabularyVM", "prepareExercise: categories=$categoryIdsAsJson, stages=$stageNamesAsJson, languages=$languageIdsAsJson, dailyOnly=$dailyOnly")
         viewModelScope.launch {
             val categoryList = categoryIdsAsJson?.takeIf { it.isNotBlank() }
                 ?.split(",")
@@ -732,6 +733,7 @@ class VocabularyViewModel @Inject constructor(
                     allLangs.filter { it.nameResId in ids }
                 } ?: emptyList()
 
+            Log.d("VocabularyVM", "prepareExercise parsed: categories=${categoryList.size}, stages=${stageList.size}, languages=${languageList.size}")
             loadCardSet(categoryList, stageList, languageList, dailyOnly)
         }
     }
@@ -743,6 +745,7 @@ class VocabularyViewModel @Inject constructor(
         languages: List<Language>? = null,
         dailyOnly: Boolean = false
     ) {
+        Log.d(TAG, "loadCardSet invoked: categories=${categories?.size ?: 0}, stages=${stages?.size ?: 0}, languages=${languages?.map { it.nameResId }}, dailyOnly=$dailyOnly")
         Log.d(TAG, "Loading card set with languages: $languages, categories: ${categories?.size}, stages: ${stages?.size}")
         viewModelScope.launch {
             statusService.showLoadingMessage("Loading card set")
@@ -802,6 +805,8 @@ class VocabularyViewModel @Inject constructor(
                     dueTodayOnly = dailyOnly
                 ).first()
 
+                Log.d(TAG, "loadCardSet: filterVocabularyItems returned ${filteredItems.size} items")
+
                 Log.d(TAG, "loadCardSet: Filtering completed, found ${filteredItems.size} items")
 
                 if (filteredItems.isNotEmpty()) {