Fix simulated exam question flow

scripts/ui/question_player.gd

@@ -1452,15 +1452,12 @@ func _skip_current_question() -> void:
 		return
 	if BlockSessionService.session_kind != "core":
 		if BlockSessionService.session_kind == "simulation":
+			selected_choice = ""
+			current_answer = {}
 			_save_simulation_current_response()
-		var target_index := _next_revisitable_index()
+		var target_index := _next_pending_simulation_index() if BlockSessionService.session_kind == "simulation" else _next_revisitable_index()
 		if target_index >= 0 and BlockSessionService.move_to(target_index):
 			_load_question()
-		elif BlockSessionService.session_kind == "simulation" and not simulation_submit_pending:
-			simulation_submit_pending = true
-			next_button.disabled = true
-			next_button.text = "Submitting..."
-			ExamSimulationService.submit_block()
 		else:
 			_finish()
 		return
@@ -1492,6 +1489,18 @@ func _next_revisitable_index() -> int:
 	return (BlockSessionService.current_index + 1) % question_count
 
 
+func _next_pending_simulation_index() -> int:
+	var question_count := BlockSessionService.active_questions.size()
+	if question_count == 0:
+		return -1
+	for offset in range(1, question_count + 1):
+		var candidate := (BlockSessionService.current_index + offset) % question_count
+		var answer = BlockSessionService.get_answer_for_index(candidate)
+		if answer == null or str(answer.get("selected_choice_id", "")) == "":
+			return candidate
+	return -1
+
+
 func _choice_gui_input(event: InputEvent, index: int) -> void:
 	if pending_correct_advance or followup_required or _is_correct_answer_locked():
 		return
@@ -1539,12 +1548,15 @@ func _toggle_eliminate_selected() -> void:
 
 func _submit_or_next() -> void:
 	if BlockSessionService.session_kind == "simulation":
+		if selected_choice == "":
+			return
 		_save_simulation_current_response()
-		if BlockSessionService.current_index + 1 < BlockSessionService.active_questions.size():
-			BlockSessionService.move_next()
+		var pending_index := _next_pending_simulation_index()
+		if pending_index >= 0:
+			BlockSessionService.move_to(pending_index)
 			_load_question()
 			return
-		elif not simulation_submit_pending:
+		if not simulation_submit_pending:
 			simulation_submit_pending = true
 			next_button.disabled = true
 			next_button.text = "Submitting..."
@@ -1706,6 +1718,9 @@ func _on_random_question_failed(message: String) -> void:
 
 
 func _show_answer_review() -> void:
+	if BlockSessionService.session_kind == "simulation":
+		_clear_answer_review()
+		return
 	_show_explanation()
 	_show_references(BlockSessionService.get_current_question().get("references", []))
 	_ensure_answer_review_followups()
@@ -1844,6 +1859,9 @@ func _render_review_followups() -> void:
 	if review_followups_content == null:
 		return
 	_clear_container_children(review_followups_content)
+	if BlockSessionService.session_kind == "simulation":
+		review_followups_section.visible = false
+		return
 	if not BlockSessionService.show_review_followups:
 		review_followups_section.visible = false
 		return
@@ -3327,7 +3345,8 @@ func _refresh_submit_state() -> void:
 	if next_button == null:
 		return
 	if BlockSessionService.session_kind == "simulation":
-		next_button.disabled = false
+		next_button.disabled = selected_choice == ""
+		next_button.text = "Submit Block" if selected_choice != "" and _next_pending_simulation_index() < 0 else "Next"
 		return
 	if pending_correct_advance or followup_required:
 		next_button.disabled = true

tests/post_answer_review_test.gd

@@ -341,6 +341,14 @@ func _test_revisitable_navigation_prefers_unanswered_questions() -> void:
 	session.answers[1] = {"selected_choice_id": "B"}
 	session.current_index = 2
 	_assert(player._next_revisitable_index() == 0, "skip should wrap rather than reload the same unanswered question")
+	session.answers = [{"selected_choice_id": "A"}, null, {"selected_choice_id": "C"}]
+	session.current_index = 2
+	_assert(player._next_pending_simulation_index() == 1, "simulation should cycle an earlier skipped question back")
+	session.answers[1] = {"selected_choice_id": "B"}
+	_assert(player._next_pending_simulation_index() == -1, "simulation should submit only after every question has an answer")
+	session.answers[2] = {"selected_choice_id": ""}
+	session.current_index = 2
+	_assert(player._next_pending_simulation_index() == 2, "the only skipped simulation question should remain pending")
 	player.free()
 	session.active_questions = prior_questions
 	session.answers = prior_answers