/* babies_app/countdown-banner.js */
(() => {
  const KV_KEY   = 'family_date';
  const READ_URL = '/api/kv/family_date';
  const MS_2H    = 2 * 3600_000; // 2 小时自动过期

  let plan = null;
  let timer = null;

  function fmt(ms) {
    if (ms <= 0) return 'Time to meet!';
    const d = Math.floor(ms / 86400_000);
    const h = Math.floor((ms % 86400_000) / 3600_000);
    const m = Math.floor((ms % 3600_000) / 60000);
    const s = Math.floor((ms % 60000) / 1000);
    const arr = [];
    if (d) arr.push(`${d}d`);
    if (h || d) arr.push(`${h}h`);
    if (m || h || d) arr.push(`${m}m`);
    arr.push(`${s}s`);
    return arr.join(' ') + ' ✨';
  }

  async function fetchPlan() {
    try {
      const res = await fetch(READ_URL);
      if (!res.ok) return null;
      const txt = await res.text();
      const p = txt ? JSON.parse(txt) : null;
      if (p && p.date && Date.now() - p.date < MS_2H) return p;
    } catch {}
    return null;
  }

  async function refreshPlan() {
    plan = await fetchPlan();
    render();
  }

  function render() {
    const banner = document.getElementById('banner');
    if (!banner) return;
    if (plan && plan.date) {
      const diff = plan.date - Date.now();
      banner.textContent = `Family at ${plan.place} – ${plan.day} ${plan.time} | ${fmt(diff)}`;
    } else {
      banner.textContent = 'Family Date – no plan yet';
    }
  }

  function tick() {
    if (!plan || !plan.date) return;
    render();
    if (plan.date - Date.now() <= 0) {
      clearInterval(timer);
      timer = null;
    }
  }

  /* 公共 API */
  window.refreshPlan = refreshPlan;

  /* 初始化 */
  refreshPlan().then(() => {
    if (plan && plan.date) {
      timer = setInterval(tick, 1000);
    }
    document.dispatchEvent(new CustomEvent('planLoaded'));
  });
})();