B2B-88: add starter kit structure and elements

lib/root-theme.ts

@@ -0,0 +1,49 @@
+import { cookies } from 'next/headers';
+
+import { z } from 'zod';
+
+/**
+ * @name Theme
+ * @description The theme mode enum.
+ */
+const Theme = z.enum(['light', 'dark', 'system'], {
+  description: 'The theme mode',
+});
+
+/**
+ * @name appDefaultThemeMode
+ * @description The default theme mode set by the application.
+ */
+const appDefaultThemeMode = Theme.safeParse(
+  process.env.NEXT_PUBLIC_DEFAULT_THEME_MODE,
+);
+
+/**
+ * @name fallbackThemeMode
+ * @description The fallback theme mode if none of the other options are available.
+ */
+const fallbackThemeMode = `light`;
+
+/**
+ * @name getRootTheme
+ * @description Get the root theme from the cookies or default theme.
+ * @returns The root theme.
+ */
+export async function getRootTheme() {
+  const cookiesStore = await cookies();
+  const themeCookieValue = cookiesStore.get('theme')?.value;
+  const theme = Theme.safeParse(themeCookieValue);
+
+  // pass the theme from the cookie if it exists
+  if (theme.success) {
+    return theme.data;
+  }
+
+  // pass the default theme from the environment variable if it exists
+  if (appDefaultThemeMode.success) {
+    return appDefaultThemeMode.data;
+  }
+
+  // in all other cases, fallback to the default theme
+  return fallbackThemeMode;
+}