import * as React from "react";

const MOBILE_BREAKPOINT = 768;

export function useIsMobile(): boolean | undefined {
  const [isMobile, setIsMobile] = React.useState<boolean | undefined>(undefined);

  React.useEffect(() => {
    // Guard against server-side rendering
    if (typeof window === 'undefined') return;
    
    const mql = window.matchMedia(`(max-width: ${MOBILE_BREAKPOINT - 1}px)`);
    
    // Use MediaQueryList.matches instead of window.innerWidth for consistency
    const onChange = () => {
      setIsMobile(mql.matches);
    };
    
    // Set initial value
    setIsMobile(mql.matches);
    
    // Listen for changes
    mql.addEventListener("change", onChange);
    
    // Cleanup listener on unmount
    return () => mql.removeEventListener("change", onChange);
  }, []);

  return isMobile;
}