openreader/src/contexts/ThemeContext.tsx
2025-02-19 12:32:16 -07:00

95 lines
2.8 KiB
TypeScript

'use client';
import { createContext, useContext, useEffect, useState, ReactNode, useLayoutEffect } from 'react';
const THEMES = ['system', 'light', 'dark', 'ocean', 'forest', 'sunset', 'sea', 'mint'] as const;
type Theme = (typeof THEMES)[number];
interface ThemeContextType {
theme: Theme;
setTheme: (theme: Theme) => void;
}
const ThemeContext = createContext<ThemeContextType | undefined>(undefined);
const getSystemTheme = () => {
if (typeof window === 'undefined') return 'light';
return window.matchMedia('(prefers-color-scheme: dark)').matches ? 'dark' : 'light';
};
const getEffectiveTheme = (theme: Theme): Theme => {
if (theme === 'system') {
return getSystemTheme();
}
return theme;
};
export function ThemeProvider({ children }: { children: ReactNode }) {
const [theme, setTheme] = useState<Theme>('system');
const [mounted, setMounted] = useState(false);
// Initialize theme as early as possible to prevent flash
useLayoutEffect(() => {
const stored = localStorage.getItem('theme') as Theme;
const initialTheme = stored && THEMES.includes(stored) ? stored : 'system';
setTheme(initialTheme);
const effectiveTheme = getEffectiveTheme(initialTheme);
document.documentElement.classList.remove(...THEMES);
document.documentElement.classList.add(effectiveTheme);
document.documentElement.style.colorScheme = effectiveTheme;
if (!stored) {
localStorage.setItem('theme', initialTheme);
}
setMounted(true);
}, []);
const handleThemeChange = (newTheme: Theme) => {
const root = window.document.documentElement;
const effectiveTheme = getEffectiveTheme(newTheme);
root.classList.remove(...THEMES);
root.classList.add(effectiveTheme);
root.style.colorScheme = effectiveTheme;
localStorage.setItem('theme', newTheme);
setTheme(newTheme);
};
useEffect(() => {
const mediaQuery = window.matchMedia('(prefers-color-scheme: dark)');
const handleChange = () => {
if (theme === 'system') {
const effectiveTheme = getSystemTheme();
const root = window.document.documentElement;
root.classList.remove(...THEMES);
root.classList.add(effectiveTheme);
root.style.colorScheme = effectiveTheme;
}
};
mediaQuery.addEventListener('change', handleChange);
return () => mediaQuery.removeEventListener('change', handleChange);
}, [theme]);
// Prevent flash during SSR
if (!mounted) {
return null;
}
return (
<ThemeContext.Provider value={{ theme, setTheme: handleThemeChange }}>
{children}
</ThemeContext.Provider>
);
}
export function useTheme() {
const context = useContext(ThemeContext);
if (context === undefined) {
throw new Error('useTheme must be used within a ThemeProvider');
}
return context;
}
export { THEMES };