// Anki-style spaced repetition (SM-2) over flashcard lists.
// List metadata and schedules live in localStorage; the -er verb cards come from verbs.db.
const SRS_KEY = "frenchJourney.srs";
const LISTS_KEY = "frenchJourney.flashcardLists";
const FORCE_KEY = "frenchJourney.forceCard";
const DEFAULT_LIST_ID = "er-verbs";
const TODAY_ID = "today";
// --- Scheduler constants (Anki defaults) ---
const MIN = 60000, DAY = 86400000;
const LEARN_STEPS = [1, 10]; // minutes (new cards)
const RELEARN_STEPS = [10]; // minutes (lapsed cards)
const HARD_LEARN_DELAY = 6; // minutes; keeps Hard distinct from Again on new cards
const GRAD_INT = 1; // days, graduating interval (Good)
const EASY_INT = 4; // days, graduating interval (Easy)
const START_EASE = 2.5;
const EASY_BONUS = 1.3;
const HARD_FACTOR = 1.2;
const MIN_EASE = 1.3;
const NEW_PER_DAY = 20;
const cardEl = document.getElementById("card");
const countsEl = document.getElementById("counts");
const showRow = document.getElementById("show-row");
const gradeRow = document.getElementById("grade-row");
const listGridEl = document.getElementById("list-grid");
const todayPanelEl = document.getElementById("today-panel");
const undoEl = document.getElementById("undo");
let listCards = {};
let lists = [];
let selectedListId = DEFAULT_LIST_ID;
let store = { cards: {}, meta: { date: "", newCount: 0 } };
let active = null; // current card being shown
let revealed = false;
let undo = null;
let forcedCardKey = null;
// ---------- persistence ----------
function load() {
try {
const s = JSON.parse(localStorage.getItem(SRS_KEY));
if (s && s.cards) store = s;
} catch {}
migrateLegacySchedule();
loadLists();
forcedCardKey = localStorage.getItem(FORCE_KEY);
rolloverDay();
}
function save() { localStorage.setItem(SRS_KEY, JSON.stringify(store)); }
function saveLists() { localStorage.setItem(LISTS_KEY, JSON.stringify(lists)); }
function today() { return new Date().toISOString().slice(0, 10); }
function rolloverDay() {
if (store.meta.date !== today()) store.meta = Object.assign({}, store.meta, { date: today(), newCount: 0 });
}
function loadLists() {
try {
const saved = JSON.parse(localStorage.getItem(LISTS_KEY));
if (Array.isArray(saved)) lists = saved.filter((l) => l && l.id && l.title);
} catch {}
if (!lists.some((l) => l.id === DEFAULT_LIST_ID)) {
lists.unshift({ id: DEFAULT_LIST_ID, title: "-er verbs", source: "verbs-db", createdAt: Date.now() });
}
if (!lists.length) lists = [{ id: DEFAULT_LIST_ID, title: "-er verbs", source: "verbs-db", createdAt: Date.now() }];
saveLists();
}
function migrateLegacySchedule() {
if (store.meta && store.meta.listMigration === 1) return;
const migrated = {};
for (const [key, value] of Object.entries(store.cards || {})) {
migrated[key.includes(":") ? key : `${DEFAULT_LIST_ID}:${key}`] = value;
}
store.cards = migrated;
store.meta = Object.assign({}, store.meta, { listMigration: 1 });
save();
}
// ---------- scheduler ----------
function fresh() {
return { state: "new", ease: START_EASE, interval: 0, step: 0, due: 0, reps: 0, lapses: 0, lapsed: 1 };
}
// Returns a NEW schedule object for `prev` given a grade, without mutating.
function schedule(prev, grade, now) {
const c = Object.assign(fresh(), prev);
if (c.state === "new") { c.state = "learning"; c.step = 0; }
const learning = c.state === "learning" || c.state === "relearning";
if (learning) {
const steps = c.state === "relearning" ? RELEARN_STEPS : LEARN_STEPS;
if (grade === "again") {
c.step = 0;
c.due = now;
} else if (grade === "hard") {
const nextStep = steps[Math.min(c.step + 1, steps.length - 1)];
c.due = now + Math.max(HARD_LEARN_DELAY, nextStep / 2) * MIN;
} else if (grade === "good") {
c.step += 1;
if (c.step >= steps.length) {
c.state = "review";
c.interval = c.lapsed && prev && prev.state === "relearning" ? Math.max(1, c.lapsed) : GRAD_INT;
c.due = now + c.interval * DAY;
c.reps += 1;
} else {
c.due = now + steps[c.step] * MIN;
}
} else { // easy -> graduate immediately
c.state = "review";
c.interval = EASY_INT;
c.due = now + c.interval * DAY;
c.reps += 1;
}
return c;
}
// review state
if (grade === "again") {
c.lapses += 1;
c.ease = Math.max(MIN_EASE, c.ease - 0.2);
c.lapsed = Math.max(1, Math.round(c.interval * 0)); // 0% new interval -> floor 1d on relearn
c.state = "relearning";
c.step = 0;
c.due = now + RELEARN_STEPS[0] * MIN;
} else if (grade === "hard") {
c.ease = Math.max(MIN_EASE, c.ease - 0.15);
c.interval = Math.max(c.interval + 1, Math.round(c.interval * HARD_FACTOR));
c.due = now + c.interval * DAY;
c.reps += 1;
} else if (grade === "good") {
c.interval = Math.max(c.interval + 1, Math.round(c.interval * c.ease));
c.due = now + c.interval * DAY;
c.reps += 1;
} else { // easy
c.interval = Math.max(c.interval + 1, Math.round(c.interval * c.ease * EASY_BONUS));
c.ease += 0.15;
c.due = now + c.interval * DAY;
c.reps += 1;
}
return c;
}
function fmtUntil(ms) {
if (ms < 0) ms = 0;
if (ms === 0) return "now";
if (ms < DAY) {
const mins = Math.round(ms / MIN);
if (mins < 1) return "<1m";
if (mins < 60) return mins + "m";
return Math.round(mins / 60) + "h";
}
const days = ms / DAY;
if (days < 30) return Math.round(days) + "d";
if (days < 365) return (days / 30).toFixed(1).replace(/\.0$/, "") + "mo";
return (days / 365).toFixed(1).replace(/\.0$/, "") + "y";
}
// ---------- audio ----------
function speakFrench(text) {
if (!("speechSynthesis" in window) || !text) return;
window.speechSynthesis.cancel();
const utterance = new SpeechSynthesisUtterance(text);
utterance.lang = "fr-FR";
utterance.rate = 0.9;
window.speechSynthesis.speak(utterance);
}
function listenButton(text) {
return ``;
}
function wireListenButtons() {
cardEl.querySelectorAll("[data-speak]").forEach((button) => {
button.onclick = (e) => {
e.stopPropagation();
speakFrench(button.dataset.speak);
};
});
}
// ---------- queue ----------
function activeList() { return lists.find((l) => l.id === selectedListId); }
function cardsForList(id) { return listCards[id] || []; }
function studyCards() {
if (selectedListId === TODAY_ID) return lists.flatMap((l) => cardsForList(l.id));
return cardsForList(selectedListId);
}
function cardKey(v) { return `${v.listId}:${v.id}`; }
function schedOf(v) { return store.cards[cardKey(v)]; }
function listTitle(id) {
const l = lists.find((x) => x.id === id);
return l ? l.title : "Unknown list";
}
function pickNext() {
const now = Date.now();
const cards = studyCards();
if (!cards.length) return { done: true, empty: true, wait: null };
const forced = forcedCardKey && cards.find((card) => cardKey(card) === forcedCardKey);
if (forced) return { card: forced, forced: true };
const learnDue = [], reviewDue = [], news = [];
let learnAhead = Infinity;
for (const v of cards) {
const s = schedOf(v);
if (!s) { news.push(v); continue; }
const isLearn = s.state === "learning" || s.state === "relearning";
if (s.due <= now) {
if (isLearn) learnDue.push(v); else reviewDue.push(v);
} else if (isLearn) {
learnAhead = Math.min(learnAhead, s.due - now);
}
}
learnDue.sort((a, b) => schedOf(a).due - schedOf(b).due);
reviewDue.sort((a, b) => schedOf(a).due - schedOf(b).due);
if (learnDue.length) return { card: learnDue[0] };
if (reviewDue.length) return { card: reviewDue[0] };
if (selectedListId === TODAY_ID) return { done: true, wait: learnAhead === Infinity ? null : learnAhead };
if (news.length) return { card: news[0] };
return { done: true, wait: learnAhead === Infinity ? null : learnAhead };
}
function counts(cards = studyCards(), includeNew = selectedListId !== TODAY_ID) {
const now = Date.now();
let learning = 0, due = 0, newSeen = 0;
for (const v of cards) {
const s = schedOf(v);
if (!s) { newSeen++; continue; }
if (s.state === "learning" || s.state === "relearning") learning++;
else if (s.due <= now) due++;
}
const newLeft = includeNew ? newSeen : 0;
return { newLeft, learning, due };
}
function renderCounts() {
const c = counts();
countsEl.innerHTML = `
New ${c.newLeft}Learning ${c.learning}To review ${c.due}`;
}
// ---------- rendering ----------
function render({ speak = true } = {}) {
renderLists();
renderToday();
renderCounts();
renderUndo();
const next = pickNext();
if (next.done) {
active = null;
showRow.hidden = true;
gradeRow.hidden = true;
cardEl.className = "fc-card done";
cardEl.innerHTML = `
✓${next.empty ? "This list is empty" : "All caught up"}${next.empty
? "Add cards later by asking me to fill this list."
: next.wait != null
? "Next card due in " + fmtUntil(next.wait)
: selectedListId === TODAY_ID
? "No more reviews due today."
: "No more cards for today. Come back tomorrow."}