import { Grade, createDeck } from "femto-fsrs";

// === Create a new deck
const { newCard, gradeCard } = createDeck();

// === Initiate a new card with an initial grade of "GOOD":
const initialGrade = Grade.GOOD;
const myCard = newCard(initialGrade);

// === Grade the card as "easy" two days later.
//     Returns a new card that replaces the old one.
const daysSinceReview = 2;
const nextCard = gradeCard(myCard, daysSinceReview, Grade.EASY);
// The "I" attribute represents "I" like in the FSRS paper.
// It is the next review date at which the probability
// of success is 90% (assuming you used default parameters).
const nextReview = nextCard.I.toFixed(2);
// Print results:
console.log(`Card will be due for review in ${nextReview} day(s)`);