// src/providers/theme-provider.tsx
import { createContext, useContext, useEffect, useState } from 'react';

type Theme = 'light' | 'dark';

interface ThemeContextType {
  theme: Theme;
  toggleTheme: () => void;
  setTheme: (theme: Theme) => void;
}

const ThemeContext = createContext<ThemeContextType | null>(null);

export function ThemeProvider({ children }: { children: React.ReactNode }) {
  const [theme, setThemeState] = useState<Theme>(() => {
    // localStorage se initial theme lo
    return (localStorage.getItem('theme') as Theme) ?? 'light';
  });

  useEffect(() => {
    // DOM aur localStorage sync karo
    document.documentElement.classList.toggle('dark', theme === 'dark');
    localStorage.setItem('theme', theme);
  }, [theme]);

  const setTheme = (newTheme: Theme) => setThemeState(newTheme);

  const toggleTheme = () =>
    setThemeState((prev) => (prev === 'light' ? 'dark' : 'light'));

  return (
    <ThemeContext.Provider value={{ theme, toggleTheme, setTheme }}>
      {children}
    </ThemeContext.Provider>
  );
}

// Custom hook
export function useTheme() {
  const context = useContext(ThemeContext);
  if (!context) throw new Error('useTheme must be used within ThemeProvider');
  return context;
}