design system token v0.1

components/theme-provider.tsx

@@ -1,11 +1,87 @@
 'use client'
 
 import * as React from 'react'
-import {
-  ThemeProvider as NextThemesProvider,
-  type ThemeProviderProps,
-} from 'next-themes'
 
-export function ThemeProvider({ children, ...props }: ThemeProviderProps) {
-  return <NextThemesProvider {...props}>{children}</NextThemesProvider>
+type Theme = 'light' | 'dark' | 'system'
+
+interface ThemeProviderProps {
+  children: React.ReactNode
+  defaultTheme?: Theme
+  storageKey?: string
+  attribute?: string
+}
+
+interface ThemeContextValue {
+  theme: Theme
+  resolvedTheme: 'light' | 'dark'
+  setTheme: (theme: Theme) => void
+}
+
+const ThemeContext = React.createContext<ThemeContextValue | undefined>(undefined)
+
+function getSystemTheme(): 'light' | 'dark' {
+  if (typeof window === 'undefined') return 'light'
+  return window.matchMedia('(prefers-color-scheme: dark)').matches
+    ? 'dark'
+    : 'light'
+}
+
+export function ThemeProvider({
+  children,
+  defaultTheme = 'system',
+  storageKey = 'greyhaven-theme',
+  attribute = 'class',
+}: ThemeProviderProps) {
+  const [theme, setThemeState] = React.useState<Theme>(() => {
+    if (typeof window === 'undefined') return defaultTheme
+    return (localStorage.getItem(storageKey) as Theme) || defaultTheme
+  })
+
+  const resolvedTheme = theme === 'system' ? getSystemTheme() : theme
+
+  const setTheme = React.useCallback(
+    (newTheme: Theme) => {
+      setThemeState(newTheme)
+      if (typeof window !== 'undefined') {
+        localStorage.setItem(storageKey, newTheme)
+      }
+    },
+    [storageKey],
+  )
+
+  React.useEffect(() => {
+    const root = document.documentElement
+
+    if (attribute === 'class') {
+      root.classList.remove('light', 'dark')
+      root.classList.add(resolvedTheme)
+    } else {
+      root.setAttribute(attribute, resolvedTheme)
+    }
+  }, [resolvedTheme, attribute])
+
+  // Listen for system theme changes when theme is 'system'
+  React.useEffect(() => {
+    if (theme !== 'system') return
+
+    const mediaQuery = window.matchMedia('(prefers-color-scheme: dark)')
+    const handler = () => setThemeState((prev) => (prev === 'system' ? 'system' : prev))
+
+    mediaQuery.addEventListener('change', handler)
+    return () => mediaQuery.removeEventListener('change', handler)
+  }, [theme])
+
+  return (
+    <ThemeContext.Provider value={{ theme, resolvedTheme, setTheme }}>
+      {children}
+    </ThemeContext.Provider>
+  )
+}
+
+export function useTheme() {
+  const context = React.useContext(ThemeContext)
+  if (!context) {
+    throw new Error('useTheme must be used within a ThemeProvider')
+  }
+  return context
 }