27. Mini platforma e-learningowa

{
  "courses": [
    {
      "id": 1,
      "title": "Podstawy PHP",
      "description": "Zmienne, tablice, pętle i formularze",
      "lessons": [
        {
          "id": 1,
          "title": "Zmienne i typy danych",
          "content": "W PHP zmienne zaczynają się od znaku dolara..."
        }
      ],
      "quiz": [
        {
          "id": 1,
          "question": "Jak zadeklarować zmienną w PHP?",
          "options": ["$nazwa", "#nazwa", "@nazwa", "var nazwa"],
          "correct": 0
        }
      ]
    }
  ]
}

function markLessonComplete(int $courseId, int $lessonId): void {
    session_start();
    $_SESSION['progress'][$courseId][$lessonId] = true;
}

function getLessonProgress(int $courseId, array $lessons): array {
    session_start();
    $completed = $_SESSION['progress'][$courseId] ?? [];
    $total = count($lessons);
    $done = count($completed);
    return ['done' => $done, 'total' => $total, 'percent' => $total > 0 ? round($done / $total * 100) : 0];
}

function gradeQuiz(array $questions, array $answers): array {
    $correct = 0;
    foreach ($questions as $q) {
        $userAnswer = (int)($answers[$q['id']] ?? -1);
        if ($userAnswer === $q['correct']) $correct++;
    }
    $total = count($questions);
    return ['correct' => $correct, 'total' => $total, 'percent' => round($correct / $total * 100)];
}