(function () {
  var resume = document.getElementById('resume');
  var scaler = document.getElementById('resume-scaler');
  var wrapper = document.getElementById('resume-wrapper');
  if (!resume || !scaler || !wrapper) return;

  function getViewportWidth() {
    var candidates = [
      wrapper.getBoundingClientRect().width,
      document.documentElement.getBoundingClientRect().width,
      document.body.getBoundingClientRect().width,
      window.innerWidth,
      document.documentElement.clientWidth
    ];

    if (window.visualViewport && window.visualViewport.width) {
      candidates.push(window.visualViewport.width);
    }

    var valid = candidates.filter(function (w) {
      return typeof w === 'number' && w > 0;
    });

    if (!valid.length) return 360;

    // 部分国产浏览器（如 vivo）会虚报更大的 layout 宽度，取最小值更接近真实可视区域
    return Math.min.apply(null, valid);
  }

  function fit() {
    scaler.style.transform = '';
    scaler.style.width = '';
    scaler.style.height = '';
    scaler.classList.remove('is-scaled');
    wrapper.style.width = '100%';
    wrapper.style.maxWidth = '100%';
    wrapper.style.height = '';

    var a4Width = resume.offsetWidth;
    var a4Height = resume.offsetHeight;
    if (a4Width <= 0 || a4Height <= 0) return;

    var vw = getViewportWidth();
    var scale = vw / a4Width;

    if (scale < 1) {
      var scaledWidth = Math.ceil(a4Width * scale);
      var scaledHeight = Math.ceil(a4Height * scale);

      scaler.classList.add('is-scaled');
      scaler.style.width = a4Width + 'px';
      scaler.style.height = a4Height + 'px';
      scaler.style.transform = 'scale(' + scale + ')';
      wrapper.style.width = scaledWidth + 'px';
      wrapper.style.maxWidth = '100%';
      wrapper.style.height = scaledHeight + 'px';
    } else {
      wrapper.style.width = '';
      wrapper.style.maxWidth = '100vw';
    }
  }

  var timer = null;
  function scheduleFit() {
    if (timer) clearTimeout(timer);
    timer = setTimeout(fit, 80);
  }

  function fitWhenReady() {
    requestAnimationFrame(function () {
      requestAnimationFrame(fit);
    });
  }

  window.addEventListener('resize', scheduleFit);
  window.addEventListener('orientationchange', fitWhenReady);
  window.addEventListener('load', fitWhenReady);

  if (window.visualViewport) {
    window.visualViewport.addEventListener('resize', scheduleFit);
  }

  if (document.fonts && document.fonts.ready) {
    document.fonts.ready.then(fitWhenReady);
  }

  fitWhenReady();
})();