class_name QuizSession
extends Resource

signal question_answered(is_correct: bool, card: Flashcard)
signal session_completed(results: Dictionary)
signal progress_updated(current: int, total: int)

@export var deck: Deck
@export var current_index: int = 0
@export var shuffled_cards: Array[Flashcard] = []
@export var session_correct: int = 0
@export var session_incorrect: int = 0
@export var start_time: float = 0.0
@export var is_active: bool = false

func start_session(deck_to_study: Deck, shuffle: bool = true) -> void:
	if not deck_to_study or deck_to_study.cards.is_empty():
		push_error("Cannot start session with empty or null deck")
		return

	deck = deck_to_study
	current_index = 0
	session_correct = 0
	session_incorrect = 0
	start_time = Time.get_ticks_msec() / 1000.0
	is_active = true

	shuffled_cards.clear()
	for card in deck.cards:
		shuffled_cards.append(card)

	if shuffle:
		shuffled_cards.shuffle()

	progress_updated.emit(current_index, shuffled_cards.size())

func get_current_card() -> Flashcard:
	if current_index < shuffled_cards.size():
		return shuffled_cards[current_index]
	return null

func answer_question(is_correct: bool) -> void:
	if not is_active:
		push_warning("Cannot answer question - session is not active")
		return

	var current_card = get_current_card()
	if not current_card:
		push_warning("No current card to answer")
		return

	if is_correct:
		session_correct += 1
	else:
		session_incorrect += 1

	question_answered.emit(is_correct, current_card)

	current_index += 1
	progress_updated.emit(current_index, shuffled_cards.size())

	if current_index >= shuffled_cards.size():
		complete_session()

func complete_session() -> void:
	if not is_active:
		return

	is_active = false
	var end_time = Time.get_ticks_msec() / 1000.0
	var duration = end_time - start_time

	var results = {
		"total_questions": shuffled_cards.size(),
		"correct": session_correct,
		"incorrect": session_incorrect,
		"accuracy": get_session_accuracy(),
		"duration_seconds": duration,
		"deck_id": deck.id if deck else "",
		"deck_name": deck.name if deck else ""
	}

	session_completed.emit(results)

func get_session_accuracy() -> float:
	var total = session_correct + session_incorrect
	if total == 0:
		return 0.0
	return (float(session_correct) / float(total)) * 100.0

func get_progress_percentage() -> float:
	if shuffled_cards.size() == 0:
		return 0.0
	return (float(current_index) / float(shuffled_cards.size())) * 100.0

func get_remaining_cards() -> int:
	return shuffled_cards.size() - current_index

func has_more_cards() -> bool:
	return current_index < shuffled_cards.size()

func reset_session(shuffle_again: bool = true) -> void:
	current_index = 0
	session_correct = 0
	session_incorrect = 0
	start_time = Time.get_ticks_msec() / 1000.0
	is_active = true

	if shuffle_again:
		shuffled_cards.shuffle()

	progress_updated.emit(current_index, shuffled_cards.size())