export function getStudentDeckComparator(priority = null) {
  return function compareStudentDeck(sd1, sd2) {
    return (
      (priority && sd2.deck.prioritized - sd1.deck.prioritized) ||
      sd2.reviewCardCount - sd1.reviewCardCount ||
      sd2.newCardCount - sd1.newCardCount ||
      sd2.deck.cardCount - sd1.deck.cardCount
    );
  };
}

export function compareChapter(ch1, ch2) {
  return (
    ch2.reviewCardCount - ch1.reviewCardCount ||
    ch2.newCardCount - ch1.newCardCount ||
    ch2.cardCount - ch1.cardCount
  );
}