/* 大屏：时钟 + 全屏快捷键 */
(function () {
  'use strict';

  function pad(n) { return n < 10 ? '0' + n : '' + n; }

  function tick() {
    var d = new Date();
    var clock = document.querySelector('[data-clock]');
    if (clock) clock.textContent = pad(d.getHours()) + ':' + pad(d.getMinutes()) + ':' + pad(d.getSeconds());
    var dateEl = document.querySelector('[data-date]');
    if (dateEl) {
      dateEl.textContent = d.getFullYear() + '-' + pad(d.getMonth() + 1) + '-' + pad(d.getDate()) +
        ' 周' + '日一二三四五六'.charAt(d.getDay());
    }
  }
  tick();
  setInterval(tick, 1000);

  document.addEventListener('keydown', function (e) {
    if (e.key === 'f' || e.key === 'F') {
      if (document.fullscreenElement) {
        document.exitFullscreen();
      } else if (document.documentElement.requestFullscreen) {
        document.documentElement.requestFullscreen();
      }
    }
  });
})();