Files
Quizalarm/server/quiz-logic.js
T

125 lines
3.7 KiB
JavaScript

function normalizeText(text) {
if (!text) return '';
return text
.toLowerCase()
.replace(/[äÄ]/g, 'ae')
.replace(/[öÖ]/g, 'oe')
.replace(/[üÜ]/g, 'ue')
.replace(/ß/g, 'ss')
.replace(/[^a-z0-9]/g, '')
.trim();
}
function extractFieldValue(field, fallback) {
if (!field) return fallback || '';
if (typeof field === 'string') return field;
if (typeof field === 'object' && field.value !== undefined) return field.value;
return String(field);
}
function getTyp(question) {
return extractFieldValue(question['Typ'], 'MC').toLowerCase();
}
function checkFreitext(userAnswer, correctAnswer) {
return normalizeText(userAnswer) === normalizeText(correctAnswer);
}
function parseCorrectAnswers(question) {
const raw = (question['Richtige Antwort'] || '').trim();
const typ = getTyp(question);
if (typ === 'freitext') return [raw];
return raw
.split(',')
.map((s) => s.trim().toUpperCase())
.filter(Boolean);
}
function countOptions(question) {
let n = 0;
if (question['Antwort A']) n++;
if (question['Antwort B']) n++;
if (question['Antwort C']) n++;
if (question['Antwort D']) n++;
return n;
}
function shuffleArray(arr) {
const a = [...arr];
for (let i = a.length - 1; i > 0; i--) {
const j = Math.floor(Math.random() * (i + 1));
[a[i], a[j]] = [a[j], a[i]];
}
return a;
}
function calculateScore(question, selected, timeRemaining, totalTime, scoringMode) {
if (!selected || selected.length === 0) return { points: 0, correct: false };
let basis;
if (scoringMode === 'time' && totalTime > 0) {
const ratio = Math.max(0, Math.min(1, timeRemaining / totalTime));
basis = 500 + Math.round(ratio * 500);
} else {
basis = 1000;
}
const typ = getTyp(question);
const correctAnswers = parseCorrectAnswers(question);
if (typ === 'freitext') {
const ok = checkFreitext(selected[0], correctAnswers[0]);
return { points: ok ? basis : 0, correct: ok };
}
const correctSet = new Set(correctAnswers);
const totalCorrect = correctSet.size;
const totalIncorrect = countOptions(question) - totalCorrect;
let rightPicked = 0;
let wrongPicked = 0;
for (const s of selected) {
if (correctSet.has(s.toUpperCase())) rightPicked++;
else wrongPicked++;
}
let points = (rightPicked / Math.max(totalCorrect, 1)) * basis;
if (totalIncorrect > 0) {
points -= (wrongPicked / totalIncorrect) * (basis / 2);
}
points = Math.max(0, Math.round(points));
const fullyCorrect = rightPicked === totalCorrect && wrongPicked === 0;
return { points, correct: fullyCorrect };
}
function sanitizeQuestion(question) {
const typ = getTyp(question);
const sanitized = {
id: question.id,
frage: question['Frage'] || '',
typ: extractFieldValue(question['Typ'], 'MC'),
bild: null,
antworten: [],
kategorie: extractFieldValue(question['Kategorie'], ''),
};
// Rewrite image URL to use proxy
const bild = question['Bild'];
if (bild && Array.isArray(bild) && bild.length > 0 && bild[0].url) {
sanitized.bild = `/api/img?url=${encodeURIComponent(bild[0].url)}`;
}
if (typ !== 'freitext') {
const keys = ['A', 'B', 'C', 'D'];
for (const k of keys) {
const val = question[`Antwort ${k}`];
if (val) sanitized.antworten.push({ key: k, text: val });
}
sanitized.antworten = shuffleArray(sanitized.antworten);
}
return sanitized;
}
module.exports = { calculateScore, sanitizeQuestion, parseCorrectAnswers, normalizeText, shuffleArray, extractFieldValue };