Initial commit

templates/theme-provider.tsx

@@ -0,0 +1,92 @@
+import { createContext, useContext, useEffect, useState, ReactNode } from 'react'
+
+type Theme = 'dark' | 'light' | 'system'
+
+type ThemeProviderProps = {
+  children: 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>(() => {
+    // Try localStorage first, fall back to sessionStorage, then default
+    try {
+      return (localStorage.getItem(storageKey) as Theme) ||
+             (sessionStorage.getItem(storageKey) as Theme) ||
+             defaultTheme
+    } catch (e) {
+      // Storage unavailable (incognito/privacy mode) - use default
+      return 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) => {
+      // Try to persist to localStorage, fall back to sessionStorage
+      try {
+        localStorage.setItem(storageKey, theme)
+      } catch (e) {
+        // localStorage unavailable (incognito) - use sessionStorage
+        try {
+          sessionStorage.setItem(storageKey, theme)
+        } catch (err) {
+          // Both unavailable - just update state without persistence
+          console.warn('Storage unavailable, theme preference will not persist')
+        }
+      }
+      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
+}