// Applies the theme: the visitor's saved choice if there is one, otherwise the site defaults.
(function () {
  var root = document.documentElement;
  var dark = window.matchMedia('(prefers-color-scheme: dark)');
  var modes = ['light', 'dark', 'auto'];
  var current = {};

  function apply(prefs) {
    current = prefs || {};
    var mode = modes.indexOf(current.mode) >= 0 ? current.mode : root.dataset.defaultMode;
    root.dataset.bsTheme = mode === 'auto' ? (dark.matches ? 'dark' : 'light') : mode;
    root.dataset.accent = current.accent || root.dataset.defaultAccent;
  }

  var saved = {};
  try { saved = JSON.parse(localStorage.getItem('portal-appearance')) || {}; } catch (e) {}
  apply(saved);
  dark.addEventListener('change', function () { apply(current); });

  window.portalTheme = { key: 'portal-appearance', apply: apply, current: function () { return current; } };
})();