const LIGHT_THEME = 'light-theme';

const DARK_THEME = 'dark-theme';

​

const ThemeContext = React.createContext();

​

function ThemeWrapper({ children }) {

  const [theme, setTheme] = React.useState(LIGHT_THEME);

  

  const applyTheme = (newTheme) => {

    document.getElementById('app').className = newTheme;

    setTheme(newTheme);

  }

  

  return (

    <ThemeContext.Provider value={{ theme, applyTheme }}>

      {children}

    </ThemeContext.Provider>

  )

}

​