Un modulo di corso con una verifica da fare a schermo

// The platform keeps each exercise's answers under its key; this learner checked three
// questions of the test, with two mistakes, and left the ordering one to do.
const tests = doc.exercises.filter((ex) => ex.style === 'test');
const mistakes = { 'test-statements': 2, 'test-distance': 1 }; // a wrong slot in each
const attempt = (ex) => ({ checked: true, n: 1, v: Object.fromEntries(ex.slots.map((slot, i) => {
  const right = exerciseSolutionValue(slot, ex);
  const wrong = slot.kind === 'truefalse' ? 3 - right : '180'; // 25 s × 8 km, slipped
  return [slot.key, mistakes[ex.anchor] === i ? wrong : right];
})) });
const kept = new Map(tests.filter((ex) => ex.anchor !== 'test-sequence')
  .map((ex) => [ex.anchor, JSON.stringify(attempt(ex))]));
const saved = new Map();
const platform = { // the three calls of localStorage, over the platform's record
  getItem: (key) => saved.get(key) ?? kept.get(key.split(':').pop()) ?? null,
  setItem: (key, value) => saved.set(key, value),
  removeItem: (key) => saved.delete(key),
};

const el = (tag, css, text) => Object.assign(document.createElement(tag),
  { textContent: text ?? '' }, { style: css });
const course = el('section', 'display: flex; flex-wrap: wrap; gap: 16px; justify-content: center;'
  + 'padding: 24px 16px 0; font: 13px/1.5 system-ui, sans-serif; color: #d9d5cc');
course.id = 'course';
const frame = el('div', 'width: min(700px, 94vw); height: 720px; overflow: auto;'
  + 'border-radius: 6px; background: #2a2e35');
frame.innerHTML = renderToHtml(doc, { mode: 'single', background: palette.paper, padding: 16,
  resourceImageUrl: imageUrl });
const card = el('aside', 'width: min(300px, 94vw); padding: 14px 16px; border-radius: 6px;'
  + 'border: 1px solid #2c3038; background: #15181d');
const results = new Map();
function report(result) { // every check, fresh start and solution shown
  if (result.style !== 'test') return;
  results.set(result.key, result);
  const all = [...results.values()];
  const [right, total] = all.reduce(([r, n], x) => [r + x.right, n + x.total], [0, 0]);
  const score = Math.round((100 * right) / total);
  const done = all.length === tests.length && all.every((x) => x.checked || x.locked);
  const verdict = !done ? t({ en: 'incomplete', es: 'sin terminar' })
    : score >= exercises.digital.passingScore ? t({ en: 'passed', es: 'aprobado' })
      : t({ en: 'failed', es: 'suspenso' });
  card.replaceChildren(el('h2', 'margin: 0; font-size: 15px; color: #f4f1ea',
    t({ en: 'What the platform hears', es: 'Lo que recibe la plataforma' })),
  el('p', 'margin: 6px 0; font-size: 22px; color: #f4f1ea', `${score} % · ${verdict}`),
  el('p', 'margin: 0 0 8px', t({ en: `${right} of ${total} answers right in the test, pass `
    + `mark ${exercises.digital.passingScore} %`, es: `${right} de ${total} respuestas bien en el `
    + `examen, aprueba con el ${exercises.digital.passingScore} %` })),
  ...all.map((x) => el('p', 'margin: 0; font-variant-numeric: tabular-nums',
    `${t({ en: 'Exercise', es: 'Ejercicio' })} ${x.number} · `
    + `${x.right}/${x.total} · ${x.checked || x.locked ? t({ en: 'checked', es: 'comprobado' })
      : t({ en: 'to do', es: 'por hacer' })}`)));
}
attachExercises(frame, { storageKey: 'restless-planet:4', store: platform, onResult: report });
course.append(frame, card);
document.getElementById('pages').before(course);
const first = frame.querySelector(`[data-pt-ex="${tests[0].id}"]`);
frame.scrollTop = first.getBoundingClientRect().top - frame.getBoundingClientRect().top - 120;

const epubFonts = (faces) => Promise.all(Object.entries(faces).flatMap(([family, specs]) =>
  specs.map(async (spec) => {
    const [weight, style, id] = [parseInt(spec, 10), spec.endsWith('i') ? 'italic' : 'normal',
      fontsourceId(family)];
    const res = await fetch(`${await fontsourceAt(id)}files/${id}-latin-${weight}-${style}.woff2`);
    if (!res.ok) throw new Error(`Fontsource has no ${family} ${weight} ${style}`);
    const bytes = new Uint8Array(await res.arrayBuffer());
    return { family, weight, style, format: 'woff2', bytes };
  })));
const metadata = { title: doc.metadata.title, subtitle: doc.metadata.subtitle, language: LANG,
  modified: new Date('2026-10-31T00:00:00Z') }; // fixed: the same bytes on every run
const fonts = await epubFonts(FONTS);
const resourceBytes = (fileId) => ({ bytes: imageBytes(fileId), mediaType: 'image/jpeg' });
const epub = await renderToEpub([doc], { layout: 'fixed', metadata, fonts, resourceBytes });
const offer = (bytes, name, type) => {
  const link = el('a', 'color: #d8a21a', `${name} · ${Math.round(bytes.length / 1024)} KB`);
  link.href = URL.createObjectURL(new Blob([bytes], { type }));
  link.download = name;
  document.getElementById('pt-actions').append(link);
};
offer(epub, `${RECIPE}.epub`, 'application/epub+zip');

// The module's headings as postext-scorm reads them; the last one, the test, runs to the end.
const sections = treeLeaves(scormTree([{ markdown }], config)[0]);
const exam = sections.at(-1);
const items = [
  { title: t({ en: 'Lesson and practice', es: 'Lección y práctica' }), doc: 0,
    range: { start: sections[0].range.start, end: exam.range.start } },
  { title: exam.title, doc: 0, range: exam.range }, // its score is the test's alone
];
const scorm = await renderToScorm([doc], { version: '2004', layout: 'fixed', items, metadata,
  fonts, resourceBytes }); // the pass mark comes from exercises.digital.passingScore
offer(scorm, `${RECIPE}-scorm.zip`, 'application/zip');