MokoCassiopeia/src/media/js/darkmode-toggle.js

/* Copyright (C) 2025 Moko Consulting <hello@mokoconsulting.tech>

 This file is part of a Moko Consulting project.

 SPDX-License-Identifier: GPL-3.0-or-later

 This program is free software; you can redistribute it and/or modify  it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or
 (at your option) any later version.

 This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

 You should have received a copy of the GNU General Public License along with this program. If not, see https://www.gnu.org/licenses/ .

 # FILE INFORMATION
 DEFGROUP: Joomla.Template.Site
 INGROUP: Moko-Cassiopeia
 PATH: ./media/templates/site/moko-cassiopeia/js/darkmode-toggle.js
 VERSION: 03.05.00
 BRIEF: JavaScript logic for dark mode toggle functionality in Moko-Cassiopeia
 */

(function () {
	'use strict';

	var STORAGE_KEY = 'theme';
	var docEl = document.documentElement;
	var mql = window.matchMedia('(prefers-color-scheme: dark)');

	function getStored() { try { return localStorage.getItem(STORAGE_KEY); } catch (e) { return null; } }
	function setStored(v) { try { localStorage.setItem(STORAGE_KEY, v); } catch (e) {} }
	function clearStored() { try { localStorage.removeItem(STORAGE_KEY); } catch (e) {} }
	function systemTheme() { return mql.matches ? 'dark' : 'light'; }

	function applyTheme(theme) {
		docEl.setAttribute('data-bs-theme', theme);
		docEl.setAttribute('data-aria-theme', theme);
		var meta = document.querySelector('meta[name="theme-color"]');
		if (meta) {
			meta.setAttribute('content', theme === 'dark' ? '#0f1115' : '#ffffff');
		}
		var sw = document.getElementById('mokoThemeSwitch');
		if (sw) {
			sw.setAttribute('aria-checked', theme === 'dark' ? 'true' : 'false');
		}
	}

	function initTheme() {
		var stored = getStored();
		applyTheme(stored ? stored : systemTheme());
	}

	function posClassFromBody() {
		var pos = (document.body.getAttribute('data-theme-fab-pos') || 'br').toLowerCase();
		if (!/^(br|bl|tr|tl)$/.test(pos)) pos = 'br';
		return 'pos-' + pos;
	}

	function buildToggle() {
		if (document.getElementById('mokoThemeFab')) return;

		var wrap = document.createElement('div');
		wrap.id = 'mokoThemeFab';
		wrap.className = posClassFromBody();

		// Light label
		var lblL = document.createElement('span');
		lblL.className = 'label';
		lblL.textContent = 'Light';

		// Switch
		var switchWrap = document.createElement('button');
		switchWrap.id = 'mokoThemeSwitch';
		switchWrap.type = 'button';
		switchWrap.setAttribute('role', 'switch');
		switchWrap.setAttribute('aria-label', 'Toggle dark mode');
		switchWrap.setAttribute('aria-checked', 'false'); // updated after init

		var track = document.createElement('span');
		track.className = 'switch';
		var knob = document.createElement('span');
		knob.className = 'knob';
		track.appendChild(knob);
		switchWrap.appendChild(track);

		// Dark label
		var lblD = document.createElement('span');
		lblD.className = 'label';
		lblD.textContent = 'Dark';

		// Auto button
		var auto = document.createElement('button');
		auto.id = 'mokoThemeAuto';
		auto.type = 'button';
		auto.className = 'btn btn-sm btn-link text-decoration-none px-2';
		auto.setAttribute('aria-label', 'Follow system theme');
		auto.textContent = 'Auto';

		// Behavior
		switchWrap.addEventListener('click', function () {
			var current = (docEl.getAttribute('data-bs-theme') || 'light').toLowerCase();
			var next = current === 'dark' ? 'light' : 'dark';
			applyTheme(next);
			setStored(next);
		});

		auto.addEventListener('click', function () {
			clearStored();
			applyTheme(systemTheme());
		});

		// Respond to OS changes only when not user-forced
		var onMql = function () {
			if (!getStored()) applyTheme(systemTheme());
		};
		if (typeof mql.addEventListener === 'function') mql.addEventListener('change', onMql);
		else if (typeof mql.addListener === 'function') mql.addListener(onMql);

		// Initial state
		var initial = getStored() || systemTheme();
		switchWrap.setAttribute('aria-checked', initial === 'dark' ? 'true' : 'false');

		// Mount
		wrap.appendChild(lblL);
		wrap.appendChild(switchWrap);
		wrap.appendChild(lblD);
		wrap.appendChild(auto);
		document.body.appendChild(wrap);

		// Debug helper
		window.mokoThemeFabStatus = function () {
			var el = document.getElementById('mokoThemeFab');
			if (!el) return { mounted: false };
			var r = el.getBoundingClientRect();
			return {
				mounted: true,
				rect: { top: r.top, left: r.left, width: r.width, height: r.height },
				zIndex: window.getComputedStyle(el).zIndex,
				posClass: el.className
			};
		};

		// Outline if invisible
		setTimeout(function () {
			var r = wrap.getBoundingClientRect();
			if (r.width < 10 || r.height < 10) {
				wrap.classList.add('debug-outline');
				console.warn('[moko] Theme FAB mounted but appears too small — check CSS collisions.');
			}
		}, 50);
	}

	function init() {
		initTheme();
		buildToggle();
	}

	if (document.readyState === 'loading') {
		document.addEventListener('DOMContentLoaded', init);
	} else {
		init();
	}
})();