type OptionLite = { id: string; isCorrect: boolean };
type QuestionLite = {
  id: string;
  type: "MULTIPLE_CHOICE" | "SATA";
  options: OptionLite[];
};

export function scoreQuestion(
  question: QuestionLite,
  selectedIds: string[]
): number {
  const correctIds = question.options
    .filter((o) => o.isCorrect)
    .map((o) => o.id);

  if (question.type === "MULTIPLE_CHOICE") {
    return correctIds.includes(selectedIds[0]) ? 1 : 0;
  }

  // SATA: partial credit
  const correctSelected = selectedIds.filter((id) =>
    correctIds.includes(id)
  ).length;
  const incorrectSelected = selectedIds.filter(
    (id) => !correctIds.includes(id)
  ).length;
  return Math.max(0, correctSelected - incorrectSelected) / correctIds.length;
}

export function scoreQuiz(
  questions: QuestionLite[],
  answers: Record<string, string[]>
) {
  let total = 0;
  const perQuestion = questions.map((q) => {
    const points = scoreQuestion(q, answers[q.id] ?? []);
    total += points;
    return { questionId: q.id, points };
  });
  return { total, maxScore: questions.length, perQuestion };
}