extends Node

signal session_changed

var active_questions: Array = []
var answers: Array = []
var current_index := 0
var mode := "Tutor"
var system_name := "All Systems"
var seconds_remaining := 0.0
var block_started := false

func start_block(selected_system: String, block_size: int, selected_mode: String) -> void:
	system_name = selected_system
	mode = selected_mode
	active_questions = QuestionBankService.build_block(selected_system, block_size)
	answers.clear()
	answers.resize(active_questions.size())
	current_index = 0
	seconds_remaining = float(active_questions.size() * 90)
	block_started = true
	session_changed.emit()


func get_current_question() -> Dictionary:
	if active_questions.is_empty() or current_index < 0 or current_index >= active_questions.size():
		return {}
	return active_questions[current_index]


func answer_current(choice_id: String, eliminated: Array, flagged: bool) -> Dictionary:
	var question := get_current_question()
	if question.is_empty():
		return {}

	var answer := {
		"question": question.duplicate(true),
		"selected_choice_id": choice_id,
		"is_correct": choice_id == str(question.get("correct_choice_id", "")),
		"eliminated_choice_ids": eliminated.duplicate(),
		"flagged": flagged
	}
	answers[current_index] = answer
	session_changed.emit()
	return answer


func move_previous() -> bool:
	if current_index > 0:
		current_index -= 1
		session_changed.emit()
		return true
	return false


func move_next() -> bool:
	if current_index + 1 < active_questions.size():
		current_index += 1
		session_changed.emit()
		return true
	return false


func move_to(index: int) -> bool:
	if index >= 0 and index < active_questions.size():
		current_index = index
		session_changed.emit()
		return true
	return false


func get_progress_text() -> String:
	return "%d / %d" % [min(current_index + 1, active_questions.size()), active_questions.size()]


func finish_block() -> Dictionary:
	var final_answers: Array = []
	for index in range(active_questions.size()):
		if answers[index] == null:
			final_answers.append({
				"question": active_questions[index].duplicate(true),
				"selected_choice_id": "",
				"is_correct": false,
				"eliminated_choice_ids": [],
				"flagged": false
			})
		else:
			final_answers.append(answers[index])

	var results := ProgressionService.calculate_block_rewards(final_answers, mode, system_name)
	ProfileService.apply_block_results(results)
	block_started = false
	session_changed.emit()
	return results


func has_answered_current() -> bool:
	return get_answer_for_index(current_index) != null


func get_answer_for_index(index: int) -> Variant:
	if index < 0 or index >= answers.size():
		return null
	return answers[index]