import { coursePlayer } from '$core/player';
import { scormState, type RecordedInteraction } from '$core/scorm/index.js';
import type { Question } from './types.js';

const DEFAULT_WEIGHT = 1;

function getHistory(fullId: string): RecordedInteraction[] {
	return scormState.store.interactionHistory[fullId] ?? [];
}

function isAlreadyResolved(fullId: string): boolean {
	if (scormState.store.isObjectivePassed(fullId)) return true;
	const history = getHistory(fullId);
	return history.some((a) => a.result === 'correct');
}

function hasAlreadyAnsweredWith(fullId: string, answer: string): boolean {
	return getHistory(fullId).some((a) => a.learnerResponse === answer);
}

function submitAnswer(options: {
	fullId: string;
	answer: string;
	correctAnswer: string;
	weight: number;
}): void {
	if (isAlreadyResolved(options.fullId)) return;
	if (hasAlreadyAnsweredWith(options.fullId, options.answer)) return;

	scormState.store.recordInteraction({
		id: options.fullId,
		type: 'true-false',
		learnerResponse: options.answer,
		correctResponse: options.correctAnswer,
		result: options.answer === options.correctAnswer ? 'correct' : 'incorrect',
		weighting: options.weight
	});
}

function getSlideOrThrow() {
	const slide = coursePlayer.activeSlide;
	if (!slide) {
		throw new Error(
			'defineTrueFalseQuestion() must be called inside a component rendered by the course player'
		);
	}
	return slide;
}

export function defineTrueFalseQuestion(q: {
	id: string;
	question: string;
	correctAnswer: 'true' | 'false';
	weight?: number;
}): Question {
	const slide = getSlideOrThrow();
	const fullId = `q:${slide.lessonId}:${slide.id}:${q.id}`;
	const weight = q.weight ?? DEFAULT_WEIGHT;

	let selectedAnswer = $state<string | undefined>();
	let localPassed = $state(scormState.store.isObjectivePassed(fullId));

	return {
		fullId,
		id: q.id,
		question: q.question,
		weight,
		get selectedAnswer(): string | undefined {
			return selectedAnswer;
		},
		set selectedAnswer(value: string | undefined) {
			if (localPassed) return;
			selectedAnswer = value;
		},
		handleSubmit() {
			if (selectedAnswer === undefined) return;
			localPassed = selectedAnswer === q.correctAnswer;
			submitAnswer({
				fullId,
				answer: selectedAnswer,
				correctAnswer: q.correctAnswer,
				weight
			});
		},
		get isPassed(): boolean {
			return localPassed;
		},
		get attempts(): RecordedInteraction[] {
			return getHistory(fullId);
		}
	};
}