fsrs4anki_scheduler.js

// FSRS4Anki v3.14.3 Scheduler Qt6
set_version();
// The latest version will be released on https://github.com/open-spaced-repetition/fsrs4anki

// Configuration Start

const deckParams = [
  {
    // Default parameters of FSRS4Anki for global
    "deckName": "global config for FSRS4Anki",
    "w": [1, 1, 5, -0.5, -0.5, 0.2, 1.4, -0.12, 0.8, 2, -0.2, 0.2, 1],
    // The above parameters can be optimized via FSRS4Anki optimizer.
    // For details about the parameters, please see: https://github.com/open-spaced-repetition/fsrs4anki/wiki/Free-Spaced-Repetition-Scheduler
    // User's custom parameters for global
    "requestRetention": 0.9, // recommended setting: 0.8 ~ 0.9
    "maximumInterval": 36500,
    "easyBonus": 1.3,
    "hardInterval": 1.2,
    // FSRS only modifies the long-term scheduling. So (re)learning steps in deck options work as usual.
    // I recommend setting steps shorter than 1 day.
  },
  {
    // Example 1: User's custom parameters for this deck and its sub-decks.
    // Need to add <div id=deck deck_name="{{Deck}}"></div> to your card's front template's first line.
    "deckName": "ALL::Learning::English::Reading",
    "w": [1.1475, 1.401, 5.1483, -1.4221, -1.2282, 0.035, 1.4668, -0.1286, 0.7539, 1.9671, -0.2307, 0.32, 0.9451],
    "requestRetention": 0.9,
    "maximumInterval": 36500,
    "easyBonus": 1.3,
    "hardInterval": 1.2,
  },
  {
    // Example 2: User's custom parameters for this deck and its sub-decks.
    // Don't omit any keys.
    "deckName": "ALL::Archive",
    "w": [1.2879, 0.5135, 4.9532, -1.502, -1.0922, 0.0081, 1.3771, -0.0294, 0.6718, 1.8335, -0.4066, 0.7291, 0.5517],
    "requestRetention": 0.9,
    "maximumInterval": 36500,
    "easyBonus": 1.3,
    "hardInterval": 1.2,
  }
];

// To turn off FSRS in specific decks, fill them into the skip_decks list below.
// And add <div id=deck deck_name="{{Deck}}"></div> to your card's front template's first line.
// Please don't remove it even if you don't need it.
const skip_decks = ["ALL::Learning::ML::NNDL", "ALL::Learning::English"];

// "Fuzz" is a small random delay applied to new intervals to prevent cards from
// sticking together and always coming up for review on the same day
const enable_fuzz = true;

// FSRS supports displaying memory states of cards.
// Enable it for debugging if you encounter something wrong.
const display_memory_state = false;

// Configuration End

debugger;

// display if FSRS is enabled
if (display_memory_state) {
  const prev = document.getElementById('FSRS_status')
  if (prev) { prev.remove(); }
  var fsrs_status = document.createElement('span');
  fsrs_status.innerHTML = "<br>FSRS enabled";
  fsrs_status.id = "FSRS_status";
  fsrs_status.style.cssText = "font-size:12px;opacity:0.5;font-family:monospace;text-align:left;line-height:1em;";
  document.body.appendChild(fsrs_status);
  document.getElementById("qa").style.cssText += "min-height:50vh;";
}
let params = {};
// get the name of the card's deck
if (document.getElementById("deck") !== null) {
  const deck_name = document.getElementById("deck").getAttribute("deck_name");
  if (display_memory_state) {
    fsrs_status.innerHTML += "<br>Deck name: " + deck_name;
  }
  for (const i of skip_decks) {
    if (deck_name.startsWith(i)) {
      fsrs_status.innerHTML = fsrs_status.innerHTML.replace("FSRS enabled", "FSRS disabled");
      return;
    }
  }
  // Arrange the deckParams of sub-decks in front of their parent decks.
  deckParams.sort(function(a, b) {
    return -a.deckName.localeCompare(b.deckName);
  });
  for (let i = 0; i < deckParams.length; i++) {
    if (deck_name.startsWith(deckParams[i]["deckName"])) {
      params = deckParams[i];
      break;
    }
  }
} else {
  if (display_memory_state) {
    fsrs_status.innerHTML += "<br>Deck name not found";
  }
}
if (Object.keys(params).length === 0) {
  params = deckParams.find(deck => deck.deckName === "global config for FSRS4Anki");
}
var w = params["w"];
var requestRetention = params["requestRetention"];
var maximumInterval = params["maximumInterval"];
var easyBonus = params["easyBonus"];
var hardInterval = params["hardInterval"];
// auto-calculate intervalModifier
const intervalModifier = Math.log(requestRetention) / Math.log(0.9);
// global fuzz factor for all ratings.
const fuzz_factor = set_fuzz_factor();
const ratings = {
  "again": 1,
  "hard": 2,
  "good": 3,
  "easy": 4
};
// For new cards
if (is_new()) {
  init_states();
  const good_interval = next_interval(customData.good.s);
  const easy_interval = Math.max(next_interval(customData.easy.s * easyBonus), good_interval + 1);
  if (states.good.normal?.review) {
    states.good.normal.review.scheduledDays = good_interval;
  }
  if (states.easy.normal?.review) {
    states.easy.normal.review.scheduledDays = easy_interval;
  }
  // For learning/relearning cards
} else if (is_learning()) {
  // Init states if the card didn't contain customData
  if (is_empty()) {
    init_states();
  }
  const good_interval = next_interval(customData.good.s);
  const easy_interval = Math.max(next_interval(customData.easy.s * easyBonus), good_interval + 1);
  if (states.good.normal?.review) {
    states.good.normal.review.scheduledDays = good_interval;
  }
  if (states.easy.normal?.review) {
    states.easy.normal.review.scheduledDays = easy_interval;
  }
  // For review cards
} else if (is_review()) {
  // Convert the interval and factor to stability and difficulty if the card didn't contain customData
  if (is_empty()) {
    convert_states();
  }
  const interval = states.current.normal?.review.elapsedDays ? states.current.normal.review.elapsedDays : states.current.filtered.rescheduling.originalState.review.elapsedDays;
  const last_d = customData.again.d;
  const last_s = customData.again.s;
  const retrievability = Math.exp(Math.log(0.9) * interval / last_s);
  if (display_memory_state) {
    fsrs_status.innerHTML += "<br>D: " + last_d + "<br>S: " + last_s + "<br>R: " + (retrievability * 100).toFixed(2) + "%";
  }
  customData.again.d = next_difficulty(last_d, "again");
  customData.again.s = next_forget_stability(customData.again.d, last_s, retrievability);
  customData.hard.d = next_difficulty(last_d, "hard");
  customData.hard.s = next_recall_stability(customData.hard.d, last_s, retrievability);
  customData.good.d = next_difficulty(last_d, "good");
  customData.good.s = next_recall_stability(customData.good.d, last_s, retrievability);
  customData.easy.d = next_difficulty(last_d, "easy");
  customData.easy.s = next_recall_stability(customData.easy.d, last_s, retrievability);
  let hard_interval = next_interval(last_s * hardInterval);
  let good_interval = next_interval(customData.good.s);
  let easy_interval = next_interval(customData.easy.s * easyBonus)
  hard_interval = Math.min(hard_interval, good_interval)
  good_interval = Math.max(good_interval, hard_interval + 1);
  easy_interval = Math.max(easy_interval, good_interval + 1);
  if (states.hard.normal?.review) {
    states.hard.normal.review.scheduledDays = hard_interval;
  }
  if (states.good.normal?.review) {
    states.good.normal.review.scheduledDays = good_interval;
  }
  if (states.easy.normal?.review) {
    states.easy.normal.review.scheduledDays = easy_interval;
  }
}
function constrain_difficulty(difficulty) {
  return Math.min(Math.max(difficulty.toFixed(2), 1), 10);
}
function apply_fuzz(ivl) {
  if (!enable_fuzz || ivl < 2.5) return ivl;
  ivl = Math.round(ivl);
  const min_ivl = Math.max(2, Math.round(ivl * 0.95 - 1));
  const max_ivl = Math.round(ivl * 1.05 + 1);
  return Math.floor(fuzz_factor * (max_ivl - min_ivl + 1) + min_ivl);
}
function next_interval(stability) {
  const new_interval = apply_fuzz(stability * intervalModifier);
  return Math.min(Math.max(Math.round(new_interval), 1), maximumInterval);
}
function next_difficulty(d, rating) {
  let next_d = d + w[4] * (ratings[rating] - 3);
  return constrain_difficulty(mean_reversion(w[2], next_d));
}
function mean_reversion(init, current) {
  return w[5] * init + (1 - w[5]) * current;
}
function next_recall_stability(d, s, r) {
  return +(s * (1 + Math.exp(w[6]) *
    (11 - d) *
    Math.pow(s, w[7]) *
    (Math.exp((1 - r) * w[8]) - 1))).toFixed(2);
}
function next_forget_stability(d, s, r) {
  return +(w[9] * Math.pow(d, w[10]) * Math.pow(
    s, w[11]) * Math.exp((1 - r) * w[12])).toFixed(2);
}
function init_states() {
  customData.again.d = init_difficulty("again");
  customData.again.s = init_stability("again");
  customData.hard.d = init_difficulty("hard");
  customData.hard.s = init_stability("hard");
  customData.good.d = init_difficulty("good");
  customData.good.s = init_stability("good");
  customData.easy.d = init_difficulty("easy");
  customData.easy.s = init_stability("easy");
}
function init_difficulty(rating) {
  return +constrain_difficulty(w[2] + w[3] * (ratings[rating] - 3)).toFixed(2);
}
function init_stability(rating) {
  return +Math.max(w[0] + w[1] * (ratings[rating] - 1), 0.1).toFixed(2);
}
function convert_states() {
  const scheduledDays = states.current.normal ? states.current.normal.review.scheduledDays : states.current.filtered.rescheduling.originalState.review.scheduledDays;
  const easeFactor = states.current.normal ? states.current.normal.review.easeFactor : states.current.filtered.rescheduling.originalState.review.easeFactor;
  const old_s = +Math.max(scheduledDays, 0.1).toFixed(2);
  const old_d = constrain_difficulty(11 - (easeFactor - 1) / (Math.exp(w[6]) * Math.pow(old_s, w[7]) * (Math.exp(0.1 * w[8]) - 1)));
  customData.again.d = old_d;
  customData.again.s = old_s;
  customData.hard.d = old_d;
  customData.hard.s = old_s;
  customData.good.d = old_d;
  customData.good.s = old_s;
  customData.easy.d = old_d;
  customData.easy.s = old_s;
}
function is_new() {
  if (states.current.normal?.new !== undefined) {
    if (states.current.normal?.new !== null) {
      return true;
    }
  }
  if (states.current.filtered?.rescheduling?.originalState !== undefined) {
    if (Object.hasOwn(states.current.filtered?.rescheduling?.originalState, 'new')) {
      return true;
    }
  }
  return false;
}
function is_learning() {
  if (states.current.normal?.learning !== undefined) {
    if (states.current.normal?.learning !== null) {
      return true;
    }
  }
  if (states.current.filtered?.rescheduling?.originalState !== undefined) {
    if (Object.hasOwn(states.current.filtered?.rescheduling?.originalState, 'learning')) {
      return true;
    }
  }
  if (states.current.normal?.relearning !== undefined) {
    if (states.current.normal?.relearning !== null) {
      return true;
    }
  }
  if (states.current.filtered?.rescheduling?.originalState !== undefined) {
    if (Object.hasOwn(states.current.filtered?.rescheduling?.originalState, 'relearning')) {
      return true;
    }
  }
  return false;
}
function is_review() {
  if (states.current.normal?.review !== undefined) {
    if (states.current.normal?.review !== null) {
      return true;
    }
  }
  if (states.current.filtered?.rescheduling?.originalState !== undefined) {
    if (Object.hasOwn(states.current.filtered?.rescheduling?.originalState, 'review')) {
      return true;
    }
  }
  return false;
}
function is_empty() {
  return !customData.again.d | !customData.again.s | !customData.hard.d | !customData.hard.s | !customData.good.d | !customData.good.s | !customData.easy.d | !customData.easy.s;
}
function set_version() {
  const version = "3.14.3";
  customData.again.v = version;
  customData.hard.v = version;
  customData.good.v = version;
  customData.easy.v = version;
}
function set_fuzz_factor() {
  // Note: Originally copied from seedrandom.js package (https://github.com/davidbau/seedrandom)
  !function (f, a, c) { var s, l = 256, p = "random", d = c.pow(l, 6), g = c.pow(2, 52), y = 2 * g, h = l - 1; function n(n, t, r) { function e() { for (var n = u.g(6), t = d, r = 0; n < g;)n = (n + r) * l, t *= l, r = u.g(1); for (; y <= n;)n /= 2, t /= 2, r >>>= 1; return (n + r) / t } var o = [], i = j(function n(t, r) { var e, o = [], i = typeof t; if (r && "object" == i) for (e in t) try { o.push(n(t[e], r - 1)) } catch (n) { } return o.length ? o : "string" == i ? t : t + "\0" }((t = 1 == t ? { entropy: !0 } : t || {}).entropy ? [n, S(a)] : null == n ? function () { try { var n; return s && (n = s.randomBytes) ? n = n(l) : (n = new Uint8Array(l), (f.crypto || f.msCrypto).getRandomValues(n)), S(n) } catch (n) { var t = f.navigator, r = t && t.plugins; return [+new Date, f, r, f.screen, S(a)] } }() : n, 3), o), u = new m(o); return e.int32 = function () { return 0 | u.g(4) }, e.quick = function () { return u.g(4) / 4294967296 }, e.double = e, j(S(u.S), a), (t.pass || r || function (n, t, r, e) { return e && (e.S && v(e, u), n.state = function () { return v(u, {}) }), r ? (c[p] = n, t) : n })(e, i, "global" in t ? t.global : this == c, t.state) } function m(n) { var t, r = n.length, u = this, e = 0, o = u.i = u.j = 0, i = u.S = []; for (r || (n = [r++]); e < l;)i[e] = e++; for (e = 0; e < l; e++)i[e] = i[o = h & o + n[e % r] + (t = i[e])], i[o] = t; (u.g = function (n) { for (var t, r = 0, e = u.i, o = u.j, i = u.S; n--;)t = i[e = h & e + 1], r = r * l + i[h & (i[e] = i[o = h & o + t]) + (i[o] = t)]; return u.i = e, u.j = o, r })(l) } function v(n, t) { return t.i = n.i, t.j = n.j, t.S = n.S.slice(), t } function j(n, t) { for (var r, e = n + "", o = 0; o < e.length;)t[h & o] = h & (r ^= 19 * t[h & o]) + e.charCodeAt(o++); return S(t) } function S(n) { return String.fromCharCode.apply(0, n) } if (j(c.random(), a), "object" == typeof module && module.exports) { module.exports = n; try { s = require("crypto") } catch (n) { } } else "function" == typeof define && define.amd ? define(function () { return n }) : c["seed" + p] = n }("undefined" != typeof self ? self : this, [], Math);
  // MIT License
  // Copyright 2019 David Bau.
  // Permission is hereby granted, free of charge, to any person obtaining a copy
  // of this software and associated documentation files (the "Software"), to deal
  // in the Software without restriction, including without limitation the rights
  // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  // copies of the Software, and to permit persons to whom the Software is
  // furnished to do so, subject to the following conditions:
  // The above copyright notice and this permission notice shall be included in all
  // copies or substantial portions of the Software.
  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  // SOFTWARE.
  let seed = !customData.again.seed | !customData.hard.seed | !customData.good.seed | !customData.easy.seed ? document.getElementById("qa").innerText : customData.good.seed;
  const generator = new Math.seedrandom(seed);
  const fuzz_factor = generator();
  seed = Math.round(fuzz_factor * 10000);
  customData.again.seed = (seed + 1) % 10000;
  customData.hard.seed = (seed + 2) % 10000;
  customData.good.seed = (seed + 3) % 10000;
  customData.easy.seed = (seed + 4) % 10000;
  return fuzz_factor;
}