From d6620fa712cedb1a8918c3e292ec02239d0c726a Mon Sep 17 00:00:00 2001
From: thePR0M3TH3AN <53631862+PR0M3TH3AN@users.noreply.github.com>
Date: Tue, 14 Oct 2025 14:42:58 -0400
Subject: [PATCH] Add theme controller to synchronize theme toggles

---
 js/index.js           |   9 ++
 js/themeController.js | 272 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 281 insertions(+)
 create mode 100644 js/themeController.js

diff --git a/js/index.js b/js/index.js
index 3a9d183a..21f21a3b 100644
--- a/js/index.js
+++ b/js/index.js
@@ -12,6 +12,10 @@ import {
   applyDesignSystemAttributes,
   subscribeToDesignSystemChanges,
 } from "./designSystem.js";
+import {
+  initThemeController,
+  refreshThemeControls,
+} from "./themeController.js";
 import {
   prepareStaticModal,
   openStaticModal,
@@ -21,8 +25,10 @@ import {
 validateInstanceConfig();
 
 applyDesignSystemAttributes();
+initThemeController();
 subscribeToDesignSystemChanges(() => {
   applyDesignSystemAttributes();
+  refreshThemeControls(document);
 });
 
 let application = null;
@@ -148,6 +154,7 @@ async function loadModal(url) {
     const modalContainer = document.getElementById("modalContainer");
     if (modalContainer) {
       applyDesignSystemAttributes(modalContainer);
+      refreshThemeControls(modalContainer);
     }
     console.log(url, "loaded");
   } catch (err) {
@@ -163,6 +170,7 @@ async function loadSidebar(url, containerId) {
     if (container) {
       container.innerHTML = html;
       applyDesignSystemAttributes(container);
+      refreshThemeControls(container);
     }
     console.log(url, "loaded into", containerId);
   } catch (err) {
@@ -178,6 +186,7 @@ async function loadDisclaimer(url, containerId) {
     if (container) {
       container.insertAdjacentHTML("beforeend", html);
       applyDesignSystemAttributes(container);
+      refreshThemeControls(container);
     }
     console.log(url, "disclaimer loaded into", containerId);
   } catch (err) {
diff --git a/js/themeController.js b/js/themeController.js
new file mode 100644
index 00000000..1c32332c
--- /dev/null
+++ b/js/themeController.js
@@ -0,0 +1,272 @@
+const STORAGE_KEY = "bitvid:theme";
+const FALLBACK_THEME = "dark";
+const VALID_THEMES = new Set(["light", "dark"]);
+const FALLBACK_META_COLORS = {
+  dark: "#0f172a",
+  light: "#f8fafc",
+};
+const TOGGLE_SELECTORS = [
+  "[data-theme-toggle]",
+  "[data-action=\"toggle-theme\"]",
+  ".js-theme-toggle",
+  "#themeToggle",
+];
+
+const boundToggles = new WeakSet();
+const registeredToggles = new Set();
+let currentTheme = null;
+let storageListenerBound = false;
+
+const isBrowser = () =>
+  typeof window !== "undefined" && typeof document !== "undefined";
+
+const normalizeTheme = (value) => {
+  if (typeof value !== "string") {
+    return null;
+  }
+  const normalized = value.trim().toLowerCase();
+  if (normalized === "default" || normalized === "") {
+    return FALLBACK_THEME;
+  }
+  if (VALID_THEMES.has(normalized)) {
+    return normalized;
+  }
+  return null;
+};
+
+const readStoredTheme = () => {
+  if (!isBrowser()) {
+    return null;
+  }
+  try {
+    const stored = window.localStorage.getItem(STORAGE_KEY);
+    return normalizeTheme(stored);
+  } catch (error) {
+    console.warn("Unable to read stored theme preference:", error);
+    return null;
+  }
+};
+
+const persistTheme = (theme) => {
+  if (!isBrowser()) {
+    return;
+  }
+  try {
+    window.localStorage.setItem(STORAGE_KEY, theme);
+  } catch (error) {
+    console.warn("Unable to persist theme preference:", error);
+  }
+};
+
+const getRootElement = () => {
+  if (!isBrowser()) {
+    return null;
+  }
+  const { documentElement } = document;
+  if (documentElement instanceof HTMLElement) {
+    return documentElement;
+  }
+  return null;
+};
+
+const updateThemeColorMeta = (theme) => {
+  if (!isBrowser()) {
+    return;
+  }
+
+  const themeMeta = document.querySelector('meta[name="theme-color"]');
+  if (!themeMeta) {
+    return;
+  }
+
+  const root = getRootElement();
+  if (!root) {
+    return;
+  }
+
+  let computedColor = "";
+  try {
+    if (typeof window.getComputedStyle === "function") {
+      computedColor = getComputedStyle(root)
+        .getPropertyValue("--color-page")
+        .trim();
+    }
+  } catch (error) {
+    console.warn("Unable to compute theme color token:", error);
+  }
+
+  const fallback = FALLBACK_META_COLORS[theme] || FALLBACK_META_COLORS[FALLBACK_THEME];
+  const nextColor = computedColor || fallback;
+  if (nextColor) {
+    themeMeta.setAttribute("content", nextColor);
+  }
+};
+
+const syncTogglePresentation = (toggle, theme) => {
+  if (!(toggle instanceof HTMLElement)) {
+    return;
+  }
+  toggle.dataset.themeState = theme;
+  toggle.setAttribute("aria-pressed", theme === "dark" ? "true" : "false");
+
+  const actionLabel =
+    theme === "dark" ? "Switch to light theme" : "Switch to dark theme";
+  toggle.setAttribute("aria-label", actionLabel);
+  toggle.setAttribute("title", actionLabel);
+
+  const labelTarget =
+    toggle.querySelector("[data-theme-toggle-label]") || toggle.querySelector(".sr-only");
+  if (labelTarget) {
+    labelTarget.textContent = actionLabel;
+  }
+
+  const iconTarget =
+    toggle.querySelector("[data-theme-toggle-icon]") || toggle.querySelector('[aria-hidden="true"]');
+  if (iconTarget) {
+    const iconForLight = toggle.dataset.iconLight || "☀️";
+    const iconForDark = toggle.dataset.iconDark || "🌙";
+    iconTarget.textContent = theme === "dark" ? iconForLight : iconForDark;
+  }
+};
+
+const cleanupRegisteredToggles = () => {
+  if (!isBrowser()) {
+    registeredToggles.clear();
+    return;
+  }
+  registeredToggles.forEach((toggle) => {
+    if (!(toggle instanceof HTMLElement) || !document.contains(toggle)) {
+      registeredToggles.delete(toggle);
+    }
+  });
+};
+
+const syncRegisteredToggles = (theme) => {
+  cleanupRegisteredToggles();
+  registeredToggles.forEach((toggle) => {
+    syncTogglePresentation(toggle, theme);
+  });
+};
+
+const bindToggle = (toggle) => {
+  if (!(toggle instanceof HTMLElement) || boundToggles.has(toggle)) {
+    return;
+  }
+
+  toggle.addEventListener("click", (event) => {
+    event.preventDefault();
+    const nextTheme = currentTheme === "dark" ? "light" : "dark";
+    setTheme(nextTheme);
+  });
+
+  toggle.dataset.themeToggleBound = "true";
+  boundToggles.add(toggle);
+};
+
+const collectToggleElements = (root = document) => {
+  if (!isBrowser()) {
+    return [];
+  }
+
+  const elements = new Set();
+  const scope = root && typeof root.querySelectorAll === "function" ? root : document;
+
+  TOGGLE_SELECTORS.forEach((selector) => {
+    try {
+      scope.querySelectorAll(selector).forEach((element) => {
+        if (element instanceof HTMLElement) {
+          elements.add(element);
+        }
+      });
+    } catch (error) {
+      console.warn(`Invalid selector for theme toggle: ${selector}`, error);
+    }
+  });
+
+  if (root instanceof HTMLElement) {
+    TOGGLE_SELECTORS.forEach((selector) => {
+      if (root.matches(selector)) {
+        elements.add(root);
+      }
+    });
+  }
+
+  return Array.from(elements);
+};
+
+const applyTheme = (theme, { persist = true } = {}) => {
+  const normalized = normalizeTheme(theme) || FALLBACK_THEME;
+  currentTheme = normalized;
+
+  const root = getRootElement();
+  if (root) {
+    root.dataset.theme = normalized;
+  }
+
+  if (persist) {
+    persistTheme(normalized);
+  }
+
+  updateThemeColorMeta(normalized);
+  syncRegisteredToggles(normalized);
+  return normalized;
+};
+
+export const setTheme = (theme) => {
+  if (!isBrowser()) {
+    currentTheme = normalizeTheme(theme) || FALLBACK_THEME;
+    return currentTheme;
+  }
+
+  return applyTheme(theme, { persist: true });
+};
+
+export const refreshThemeControls = (root = document) => {
+  if (!isBrowser()) {
+    return;
+  }
+
+  const toggles = collectToggleElements(root);
+  toggles.forEach((toggle) => {
+    registeredToggles.add(toggle);
+    bindToggle(toggle);
+    syncTogglePresentation(toggle, currentTheme || FALLBACK_THEME);
+  });
+};
+
+const resolveInitialTheme = () => {
+  if (!isBrowser()) {
+    return FALLBACK_THEME;
+  }
+  const root = getRootElement();
+  const datasetTheme = root ? normalizeTheme(root.dataset.theme) : null;
+  return datasetTheme || readStoredTheme() || FALLBACK_THEME;
+};
+
+const handleStorageEvent = (event) => {
+  if (!event || event.key !== STORAGE_KEY) {
+    return;
+  }
+  const nextTheme = normalizeTheme(event.newValue) || FALLBACK_THEME;
+  if (nextTheme === currentTheme) {
+    return;
+  }
+  applyTheme(nextTheme, { persist: false });
+};
+
+export const initThemeController = () => {
+  if (!isBrowser()) {
+    currentTheme = FALLBACK_THEME;
+    return;
+  }
+
+  if (!storageListenerBound) {
+    window.addEventListener("storage", handleStorageEvent);
+    storageListenerBound = true;
+  }
+
+  const initialTheme = resolveInitialTheme();
+  applyTheme(initialTheme, { persist: true });
+  refreshThemeControls(document);
+};
+