import React, { createContext, useState, useEffect, ReactNode } from 'react';

type ThemeContextType = {
  isDarkMode: boolean;
  toggleTheme: () => void;
};

export const ThemeContext = createContext<ThemeContextType>({
  isDarkMode: false,
  toggleTheme: () => {},
});

export const ThemeProvider: React.FC<{ children: ReactNode }> = ({ children }) => {
  // Check user preference or system preference
  const [isDarkMode, setIsDarkMode] = useState(() => {
    const savedTheme = localStorage.getItem('theme');
    
    if (savedTheme) {
      return savedTheme === 'dark';
    }
    
    return window.matchMedia('(prefers-color-scheme: dark)').matches;
  });

  useEffect(() => {
    // Update localStorage and apply theme
    localStorage.setItem('theme', isDarkMode ? 'dark' : 'light');
    
    if (isDarkMode) {
      document.documentElement.classList.add('dark');
    } else {
      document.documentElement.classList.remove('dark');
    }
  }, [isDarkMode]);

  const toggleTheme = () => {
    setIsDarkMode(prev => !prev);
  };

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