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 findLastCorrectAttempt(attempts: RecordedInteraction[]): RecordedInteraction | undefined {
	for (let index = attempts.length - 1; index >= 0; index--) {
		const attempt = attempts[index];
		if (attempt.result === 'correct') return attempt;
	}
	return undefined;
}

function hasAlreadyAnsweredWith(attempts: RecordedInteraction[], answer: string): boolean {
	return attempts.some((attempt) => attempt.learnerResponse === answer);
}

function isAlreadyResolved(fullId: string): boolean {
	return (
		scormState.store.isObjectivePassed(fullId) ||
		findLastCorrectAttempt(getHistory(fullId)) !== undefined
	);
}

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

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

export function defineMultiChoiceQuestion<
	const Options extends readonly { key: string; label: string }[]
>(q: {
	id: string;
	question: string;
	options: Options;
	correctAnswer: Options[number]['key'];
	weight?: number;
}): Question & {
	readonly options: Options;
	readonly correctAnswer: Options[number]['key'];
} {
	const slide = coursePlayer.activeSlide!;

	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 {
		...q,
		weight,
		fullId,
		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);
		}
	};
}