import { describe, expect, it } from "vitest";
import { initialCardState, reviewCard } from "../lib/learning/sm2.ts";

describe("SM-2 (répétition espacée)", () => {
  it("suit la progression 1j → 6j → ~15j pour des rappels « Bien »", () => {
    let s = initialCardState();
    let r = reviewCard(s, 4);
    expect(r.intervalDays).toBe(1);
    r = reviewCard(r, 4);
    expect(r.intervalDays).toBe(6);
    r = reviewCard(r, 4);
    expect(r.intervalDays).toBeGreaterThanOrEqual(13);
    expect(r.intervalDays).toBeLessThanOrEqual(17);
  });

  it("réinitialise la carte en cas d'échec (Encore) et compte la défaillance", () => {
    let s = { ef: 2.5, intervalDays: 30, reps: 5, lapses: 0 };
    const r = reviewCard(s, 2);
    expect(r.reps).toBe(0);
    expect(r.lapses).toBe(1);
    expect(r.dueInDays).toBe(0);
  });

  it("borne le facteur de facilité à 1.3 minimum", () => {
    let s = initialCardState();
    for (let i = 0; i < 20; i++) s = reviewCard(s, 2);
    expect(s.ef).toBeGreaterThanOrEqual(1.3);
  });

  it("« Facile » allonge davantage que « Difficile »", () => {
    const base = { ef: 2.5, intervalDays: 10, reps: 3, lapses: 0 };
    const easy = reviewCard({ ...base }, 5);
    const hard = reviewCard({ ...base }, 3);
    expect(easy.intervalDays).toBeGreaterThan(hard.intervalDays);
  });

  it("plafonne l'intervalle à 365 jours", () => {
    let s = { ef: 2.5, intervalDays: 300, reps: 8, lapses: 0 };
    const r = reviewCard(s, 5);
    expect(r.intervalDays).toBeLessThanOrEqual(365);
  });
});