decentralised_book_index/assets/vendor/dark_mode.js

const localStorageKey = 'theme';

const isDark = () => {
	if (localStorage.getItem(localStorageKey) === 'dark') return true;
	if (localStorage.getItem(localStorageKey) === 'light') return false;
	return window.matchMedia('(prefers-color-scheme: dark)').matches;
}

const setupThemeToggle = () => {
	toggleVisibility = (dark) => {
		const themeToggleDarkIcon = document.getElementById('theme-toggle-dark-icon');
		const themeToggleLightIcon = document.getElementById('theme-toggle-light-icon');
		if (themeToggleDarkIcon == null || themeToggleLightIcon == null) return;
	        const show = dark ? themeToggleLightIcon : themeToggleDarkIcon;
	        const hide = dark ? themeToggleDarkIcon : themeToggleLightIcon;
		show.classList.remove('hidden', 'text-transparent');
		hide.classList.add('hidden', 'text-transparent');
		if (dark) {
			document.documentElement.classList.add('dark')
		} else {
			document.documentElement.classList.remove('dark')
		}
		try { localStorage.setItem(localStorageKey, dark ? 'dark' : 'light') } catch (_err) { }
	}
	toggleVisibility(isDark())
	document.getElementById('theme-toggle').addEventListener('click', function () {
		toggleVisibility(!isDark())
	});
}

const darkModeHook = {
  mounted() {
		setupThemeToggle();
	},
	updated() {
	},
}

export default darkModeHook;