Add core game retry flow and question stats

scripts/autoload/question_bank_service.gd

@@ -1,15 +1,20 @@
 extends Node
 
 const DEFAULT_QUESTIONS_API_URL := "https://s3q.ranaze.com/api/questions/search"
+const RETRY_DELAYS := [2, 5, 10, 20, 30]
 
 signal questions_changed
 signal questions_load_failed(message: String)
 
 var questions: Array = []
 var request: HTTPRequest
+var retry_timer: Timer
 var questions_api_url := DEFAULT_QUESTIONS_API_URL
 var is_loading := false
 var last_error := ""
+var load_state := "idle"
+var retry_attempt := 0
+var next_retry_seconds := 0
 
 func _ready() -> void:
 	questions_api_url = str(ProjectSettings.get_setting("step3/questions_api_url", DEFAULT_QUESTIONS_API_URL))
@@ -17,13 +22,24 @@ func _ready() -> void:
 	request.request_completed.connect(_on_api_questions_loaded)
 	add_child(request)
 
+	retry_timer = Timer.new()
+	retry_timer.one_shot = true
+	retry_timer.timeout.connect(_on_retry_timer_timeout)
+	add_child(retry_timer)
 
-func load_questions_from_api() -> void:
+
+func load_questions_from_api(reset_retry: bool = true) -> void:
 	if AuthState.access_token.is_empty():
-		_set_load_error("Login required before loading questions.")
+		_set_load_error("Login required before loading questions.", false)
 		return
 
+	if reset_retry:
+		retry_attempt = 0
+		next_retry_seconds = 0
+		retry_timer.stop()
+
 	is_loading = true
+	load_state = "retrying" if retry_attempt > 0 else "loading"
 	last_error = ""
 	questions.clear()
 	questions_changed.emit()
@@ -63,6 +79,31 @@ func _on_api_questions_loaded(result: int, response_code: int, _headers: PackedS
 
 	questions = api_questions
 	last_error = ""
+	load_state = "ready"
+	retry_attempt = 0
+	next_retry_seconds = 0
+	retry_timer.stop()
+	questions_changed.emit()
+
+
+func retry_now() -> void:
+	retry_attempt = 0
+	next_retry_seconds = 0
+	retry_timer.stop()
+	load_questions_from_api(false)
+
+
+func clear_questions() -> void:
+	if request != null:
+		request.cancel_request()
+	if retry_timer != null:
+		retry_timer.stop()
+	questions.clear()
+	is_loading = false
+	last_error = ""
+	load_state = "idle"
+	retry_attempt = 0
+	next_retry_seconds = 0
 	questions_changed.emit()
 
 
@@ -101,14 +142,34 @@ func has_questions() -> bool:
 	return not questions.is_empty()
 
 
-func _set_load_error(message: String) -> void:
+func _set_load_error(message: String, schedule_retry: bool = true) -> void:
 	is_loading = false
 	last_error = message
 	push_warning(message)
 	questions_load_failed.emit(message)
+	if schedule_retry and not AuthState.access_token.is_empty():
+		_schedule_retry()
+	else:
+		load_state = "failed"
+		next_retry_seconds = 0
 	questions_changed.emit()
 
 
+func _schedule_retry() -> void:
+	var delay_index := retry_attempt
+	if delay_index >= RETRY_DELAYS.size():
+		delay_index = RETRY_DELAYS.size() - 1
+	next_retry_seconds = int(RETRY_DELAYS[delay_index])
+	retry_attempt += 1
+	load_state = "retrying"
+	retry_timer.start(float(next_retry_seconds))
+
+
+func _on_retry_timer_timeout() -> void:
+	next_retry_seconds = 0
+	load_questions_from_api(false)
+
+
 func _is_valid_question(item: Variant) -> bool:
 	if typeof(item) != TYPE_DICTIONARY:
 		return false
@@ -132,6 +193,7 @@ func _normalize_api_question(item: Variant) -> Dictionary:
 		"correct_choice_id": str(item.get("correctChoiceId", item.get("correct_choice_id", ""))),
 		"explanation": str(item.get("explanation", "")),
 		"choice_explanations": item.get("choiceExplanations", item.get("choice_explanations", {})),
+		"choice_selection_percentages": item.get("choiceSelectionPercentages", item.get("choice_selection_percentages", {})),
 		"discipline": str(item.get("discipline", "")),
 		"system": str(item.get("system", "")),
 		"difficulty": int(item.get("difficulty", 1)),