'use client'

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

type Theme = 'light' | 'dark'

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

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

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

  useEffect(() => {
    // On mount, read theme from localStorage or default to light
    const savedTheme = localStorage.getItem('theme') as Theme
    if (savedTheme) {
      setTheme(savedTheme)
      document.documentElement.setAttribute('data-theme', savedTheme)
    }
  }, [])

  const toggleTheme = () => {
    const newTheme = theme === 'light' ? 'dark' : 'light'
    setTheme(newTheme)
    localStorage.setItem('theme', newTheme)
    document.documentElement.setAttribute('data-theme', newTheme)
  }

  return (
    <ThemeContext.Provider value={{ theme, toggleTheme }}>
      {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
}