stats.js

// TileLoom local statistics, kept in localStorage.
// Move records (best word, bingos, averages) count every human move made on
// this device. Game records and streaks count vs-Computer games only, from
// the human's perspective.

'use strict';

const Stats = (() => {
  const KEY = 'tileloom-stats-v1';
  const EMPTY = {
    vsAI: { easy: { w: 0, l: 0, t: 0 }, medium: { w: 0, l: 0, t: 0 }, hard: { w: 0, l: 0, t: 0 } },
    streak: { current: 0, best: 0 },
    bestWord: null,   // { word, score }
    bestGame: null,   // { score }
    bingos: 0,
    moves: 0,
    points: 0,
  };

  function fresh() { return JSON.parse(JSON.stringify(EMPTY)); }

  function load() {
    try {
      const s = JSON.parse(localStorage.getItem(KEY));
      if (s && s.vsAI && s.streak) return s;
    } catch (e) { /* corrupt or missing */ }
    return fresh();
  }

  let data = load();

  function save() {
    try { localStorage.setItem(KEY, JSON.stringify(data)); } catch (e) { /* ignore */ }
  }

  function recordMove(result) {
    data.moves++;
    data.points += result.total;
    if (result.bingo) data.bingos++;
    const top = result.words.slice().sort((a, b) => b.score - a.score)[0];
    if (top && (!data.bestWord || top.score > data.bestWord.score)) {
      data.bestWord = { word: top.word, score: top.score };
    }
    save();
  }

  function recordGame(difficulty, humanScore, aiScore) {
    const d = data.vsAI[difficulty] || (data.vsAI[difficulty] = { w: 0, l: 0, t: 0 });
    if (humanScore > aiScore) {
      d.w++;
      data.streak.current++;
      data.streak.best = Math.max(data.streak.best, data.streak.current);
    } else if (humanScore < aiScore) {
      d.l++;
      data.streak.current = 0;
    } else {
      d.t++;
      data.streak.current = 0;
    }
    if (!data.bestGame || humanScore > data.bestGame.score) {
      data.bestGame = { score: humanScore };
    }
    save();
  }

  function reset() {
    data = fresh();
    save();
  }

  return { recordMove, recordGame, reset, get data() { return data; } };
})();