// CyberMax Fun kit: shared browser helpers for the CyberMax games (copied into each game's web/ folder by
// scripts/games/sync_kit.py, so every game stays self-contained and sellable on its own).
// Counter beacon (game + event + channel only: no cookies, no IDs, nothing personal), daily seed, share, PWA install.
// (c) 2026 CyberMax. All rights reserved.

export const SITE = 'https://cybermaxtools.com';
export const API = 'https://toys.cybermaxtools.com';
export const EPOCH = Date.UTC(2026, 9, 2); // 2 Oct 2026 = puzzle #1 for every CyberMax daily game

/** Today's date in the player's own time zone as YYYY-MM-DD (everyone gets a new puzzle at their local midnight). */
export function today(d = new Date()) {
  return `${d.getFullYear()}-${String(d.getMonth() + 1).padStart(2, '0')}-${String(d.getDate()).padStart(2, '0')}`;
}
/** Puzzle number for a YYYY-MM-DD date (#1 = 2026-10-02). */
export function dayNumber(iso) {
  const [y, m, d] = iso.split('-').map(Number);
  return Math.round((Date.UTC(y, m - 1, d) - EPOCH) / 864e5) + 1;
}
export function dateOf(n) {
  const t = new Date(EPOCH + (n - 1) * 864e5);
  return t.toISOString().slice(0, 10);
}

/** 32-bit string hash (FNV-1a) and a small fast PRNG (mulberry32): the same seed gives the same game everywhere. */
export function hash(str) {
  let h = 0x811c9dc5;
  for (let i = 0; i < str.length; i++) { h ^= str.charCodeAt(i); h = Math.imul(h, 0x01000193); }
  return h >>> 0;
}
export function rng(seed) {
  let a = typeof seed === 'string' ? hash(seed) : seed >>> 0;
  return function () {
    a = (a + 0x6d2b79f5) >>> 0;
    let t = a;
    t = Math.imul(t ^ (t >>> 15), t | 1);
    t ^= t + Math.imul(t ^ (t >>> 7), t | 61);
    return ((t ^ (t >>> 14)) >>> 0) / 4294967296;
  };
}

/** Count one event (play, win, share, install, pro, cta). Never breaks the page; skipped on localhost and in tests. */
export function count(game, ev, ch = '') {
  try {
    if (typeof location === 'undefined' || /^(localhost|127\.0\.0\.1)$/.test(location.hostname) || navigator.webdriver) return;
    const u = `${API}/e?t=${encodeURIComponent(game)}&a=${encodeURIComponent(ev)}&c=${encodeURIComponent(String(ch).toLowerCase().replace(/[^a-z0-9-]/g, '').slice(0, 40))}`;
    if (navigator.sendBeacon && navigator.sendBeacon(u)) return;
    fetch(u, { method: 'POST', keepalive: true, mode: 'no-cors' }).catch(() => {});
  } catch { /* never break the game */ }
}

export function store(key, val) {
  try {
    if (val === undefined) return JSON.parse(localStorage.getItem(key) || 'null');
    localStorage.setItem(key, JSON.stringify(val));
  } catch { /* private mode */ }
  return val;
}

export function toast(msg, ms = 2400) {
  let t = document.getElementById('toast');
  if (!t) { t = document.createElement('div'); t.id = 'toast'; t.setAttribute('role', 'status'); document.body.appendChild(t); }
  t.textContent = msg;
  t.classList.add('on');
  clearTimeout(t._h);
  t._h = setTimeout(() => t.classList.remove('on'), ms);
}

/** The link people share: the canonical game page with UTM tags the site view counter reads. */
export function shareLink(path, channel, game) {
  const u = new URL(SITE + path);
  u.searchParams.set('utm_source', channel);
  u.searchParams.set('utm_medium', 'share');
  u.searchParams.set('utm_campaign', `game-${game}`);
  return u.toString();
}

/**
 * Share a result: native share sheet on phones (text + optional PNG card), else copy to clipboard.
 * text = Wordle-style text block; path = the game's path on the CyberMax site; blob = optional PNG card.
 */
export async function share(game, text, path, blob, filename) {
  const url = shareLink(path, 'share', game);
  const full = `${text}\n${url}`;
  if (navigator.share) {
    try {
      const file = blob ? new File([blob], filename || `${game}.png`, { type: 'image/png' }) : null;
      const data = file && navigator.canShare && navigator.canShare({ files: [file] }) ? { files: [file], text: full } : { text: full };
      await navigator.share(data);
      count(game, 'share', 'native');
      return 'shared';
    } catch (e) {
      if (e && e.name === 'AbortError') return 'cancelled';
    }
  }
  try { await navigator.clipboard.writeText(full); toast('Result copied. Paste it anywhere.'); } catch { prompt('Copy your result:', full); }
  count(game, 'share', 'copy');
  return 'copied';
}

export function intents(game, text, path) {
  const u = (ch) => shareLink(path, ch, game);
  return {
    x: `https://x.com/intent/post?text=${encodeURIComponent(text)}&url=${encodeURIComponent(u('x'))}`,
    bsky: `https://bsky.app/intent/compose?text=${encodeURIComponent(`${text}\n${u('bsky')}`)}`,
    whatsapp: `https://wa.me/?text=${encodeURIComponent(`${text}\n${u('whatsapp')}`)}`,
  };
}

export function download(blob, filename) {
  const a = document.createElement('a');
  a.href = URL.createObjectURL(blob);
  a.download = filename;
  document.body.appendChild(a);
  a.click();
  setTimeout(() => { URL.revokeObjectURL(a.href); a.remove(); }, 1500);
}

/**
 * Installable app: registers the service worker (offline play) and shows an "Add to Home Screen" button.
 * Chrome/Edge/Android: the real install prompt. iPhone/iPad Safari: a short Share → Add to Home Screen hint.
 * The button only appears after the first finished round (offer(): never on first load) and never once installed.
 */
export function pwa(game, btn) {
  if ('serviceWorker' in navigator && (location.protocol === 'https:' || location.hostname === 'localhost')) {
    navigator.serviceWorker.register('sw.js').catch(() => {});
  }
  const standalone = matchMedia('(display-mode: standalone)').matches || navigator.standalone;
  if (standalone) { count(game, 'play', 'app'); return { offer() {} }; }
  let deferred = null;
  let wanted = false;
  const ios = /iphone|ipad|ipod/i.test(navigator.userAgent) && !/crios|fxios/i.test(navigator.userAgent);
  window.addEventListener('beforeinstallprompt', (e) => { e.preventDefault(); deferred = e; if (wanted && btn) btn.hidden = false; });
  window.addEventListener('appinstalled', () => { count(game, 'install', 'prompt'); if (btn) btn.hidden = true; });
  if (btn) {
    btn.addEventListener('click', async () => {
      if (deferred) {
        deferred.prompt();
        const r = await deferred.userChoice.catch(() => null);
        if (r && r.outcome === 'accepted') btn.hidden = true;
        deferred = null;
      } else if (ios) {
        toast('Tap the Share button, then "Add to Home Screen".', 5000);
        count(game, 'install', 'ios-hint');
      }
    });
  }
  return {
    offer() {
      wanted = true;
      if (btn && (deferred || ios) && !store(`cmx-install-no:${game}`)) btn.hidden = false;
    },
  };
}

/** Rounded rectangle path for canvas cards. */
export function rr(ctx, x, y, w, h, r) {
  ctx.beginPath();
  ctx.moveTo(x + r, y);
  ctx.arcTo(x + w, y, x + w, y + h, r);
  ctx.arcTo(x + w, y + h, x, y + h, r);
  ctx.arcTo(x, y + h, x, y, r);
  ctx.arcTo(x, y, x + w, y, r);
  ctx.closePath();
}

export const canvasBlob = (canvas) => new Promise((res) => canvas.toBlob(res, 'image/png'));

/** Theme toggle shared by every page (light/dark, remembered). */
export function themeToggle(btn) {
  if (!btn) return;
  btn.addEventListener('click', () => {
    const r = document.documentElement;
    const c = r.dataset.theme || (matchMedia('(prefers-color-scheme: dark)').matches ? 'dark' : 'light');
    const n = c === 'dark' ? 'light' : 'dark';
    r.dataset.theme = n;
    store('cm-theme-v', n);
    try { localStorage.setItem('cm-theme', n); } catch { /* private mode */ }
  });
}