"use client";

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

type Theme = 'light' | 'dark';

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

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

export const ThemeProvider: React.FC<{ children: React.ReactNode }> = ({ children }) => {
  const [theme, setTheme] = useState<Theme>('light');

  useEffect(() => {
    const savedTheme = localStorage.getItem('theme') as Theme | null;
    const initialTheme = savedTheme || 'light';
    
    setTheme(initialTheme);
    
    // Set class in case head script missed it or was not run
    if (initialTheme === 'dark') {
      document.documentElement.classList.add('dark');
    } else {
      document.documentElement.classList.remove('dark');
    }
  }, []);

  const toggleTheme = () => {
    const nextTheme = theme === 'light' ? 'dark' : 'light';
    setTheme(nextTheme);
    localStorage.setItem('theme', nextTheme);

    if (nextTheme === 'dark') {
      document.documentElement.classList.add('dark');
    } else {
      document.documentElement.classList.remove('dark');
    }
  };

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

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