document.documentElement.classList.add('js');

function readThemePreference(key, fallback) {
  try {
    return localStorage.getItem(key) || fallback;
  } catch (error) {
    return fallback;
  }
}

const moduleName = document.documentElement.dataset.module || '';
const mainThemeMode = readThemePreference('nexus.theme', 'day');
const mainThemeAccent = readThemePreference('nexus.accent', 'logo');
const moduleThemeMode = moduleName ? readThemePreference(`nexus.module.${moduleName}.theme`, 'inherit') : mainThemeMode;
const moduleThemeAccent = moduleName ? readThemePreference(`nexus.module.${moduleName}.accent`, 'inherit') : mainThemeAccent;

function normalizeThemeValue(value, allowed, fallback) {
  return allowed.includes(value) ? value : fallback;
}

function storedTheme() {
  const rawMode = moduleName ? readThemePreference(`nexus.module.${moduleName}.theme`, 'inherit') : readThemePreference('nexus.theme', 'day');
  const rawAccent = moduleName ? readThemePreference(`nexus.module.${moduleName}.accent`, 'inherit') : readThemePreference('nexus.accent', 'logo');
  const mode = moduleName ? normalizeThemeValue(rawMode, ['inherit', 'day', 'night'], 'inherit') : normalizeThemeValue(rawMode, ['day', 'night'], 'day');
  const accent = moduleName ? normalizeThemeValue(rawAccent, ['inherit', 'logo', 'pink', 'cyan', 'orange', 'green'], 'inherit') : normalizeThemeValue(rawAccent, ['logo', 'pink', 'cyan', 'orange', 'green'], 'logo');
  return { mode, accent };
}

function applyTheme(mode, accent, persist = true) {
  const allowedModes = moduleName ? ['inherit', 'day', 'night'] : ['day', 'night'];
  const allowedAccents = moduleName ? ['inherit', 'logo', 'pink', 'cyan', 'orange', 'green'] : ['logo', 'pink', 'cyan', 'orange', 'green'];
  const normalizedMode = normalizeThemeValue(mode, allowedModes, moduleName ? 'inherit' : 'day');
  const normalizedAccent = normalizeThemeValue(accent, allowedAccents, moduleName ? 'inherit' : 'logo');
  const effectiveMode = normalizedMode === 'inherit' ? mainThemeMode : normalizedMode;
  const effectiveAccent = normalizedAccent === 'inherit' ? mainThemeAccent : normalizedAccent;
  document.documentElement.dataset.theme = effectiveMode;
  document.documentElement.dataset.accent = effectiveAccent;
  try {
    if (persist) {
      if (moduleName) {
        if (normalizedMode === 'inherit') {
          localStorage.removeItem(`nexus.module.${moduleName}.theme`);
        } else {
          localStorage.setItem(`nexus.module.${moduleName}.theme`, normalizedMode);
        }
        if (normalizedAccent === 'inherit') {
          localStorage.removeItem(`nexus.module.${moduleName}.accent`);
        } else {
          localStorage.setItem(`nexus.module.${moduleName}.accent`, normalizedAccent);
        }
      } else {
        localStorage.setItem('nexus.theme', normalizedMode);
        localStorage.setItem('nexus.accent', normalizedAccent);
      }
    }
  } catch (error) {
    // Ignore blocked storage; the current page still receives the theme.
  }
  return { mode: normalizedMode, accent: normalizedAccent };
}

const initialTheme = applyTheme(moduleThemeMode, moduleThemeAccent, false);

const themeModeSelect = document.querySelector('[data-theme-mode]');
const themeAccentSelect = document.querySelector('[data-theme-accent]');

if (themeModeSelect) {
  themeModeSelect.value = initialTheme.mode;
  themeModeSelect.addEventListener('change', () => {
    const current = storedTheme();
    applyTheme(themeModeSelect.value, current.accent);
  });
}

if (themeAccentSelect) {
  themeAccentSelect.value = initialTheme.accent;
  themeAccentSelect.addEventListener('change', () => {
    const current = storedTheme();
    applyTheme(current.mode, themeAccentSelect.value);
  });
}

for (const element of document.querySelectorAll('[data-reveal]')) {
  element.classList.add('reveal');
}