progress on client site

site/src/components/theme-provider.tsx

@@ -0,0 +1,71 @@
+import { createContext, useContext, useEffect, useState } from 'react'
+
+type Theme = 'dark' | 'light' | 'system'
+
+type ThemeProviderProps = {
+	children: React.ReactNode
+	defaultTheme?: Theme
+	storageKey?: string
+}
+
+type ThemeProviderState = {
+	theme: Theme
+	setTheme: (theme: Theme) => void
+}
+
+const initialState: ThemeProviderState = {
+	theme: 'system',
+	setTheme: () => null,
+}
+
+const ThemeProviderContext = createContext<ThemeProviderState>(initialState)
+
+export function ThemeProvider({
+	children,
+	defaultTheme = 'system',
+	storageKey = 'vite-ui-theme',
+	...props
+}: ThemeProviderProps) {
+	const [theme, setTheme] = useState<Theme>(
+		() => (localStorage.getItem(storageKey) as Theme) || defaultTheme
+	)
+
+	useEffect(() => {
+		const root = window.document.documentElement
+
+		root.classList.remove('light', 'dark')
+
+		if (theme === 'system') {
+			const systemTheme = window.matchMedia('(prefers-color-scheme: dark)').matches
+				? 'dark'
+				: 'light'
+
+			root.classList.add(systemTheme)
+			return
+		}
+
+		root.classList.add(theme)
+	}, [theme])
+
+	const value = {
+		theme,
+		setTheme: (theme: Theme) => {
+			localStorage.setItem(storageKey, theme)
+			setTheme(theme)
+		},
+	}
+
+	return (
+		<ThemeProviderContext.Provider {...props} value={value}>
+			{children}
+		</ThemeProviderContext.Provider>
+	)
+}
+
+export const useTheme = () => {
+	const context = useContext(ThemeProviderContext)
+
+	if (context === undefined) throw new Error('useTheme must be used within a ThemeProvider')
+
+	return context
+}