'use client';

import { motion, useScroll, useSpring } from 'framer-motion';
import { useState, useEffect } from 'react';

export default function BackToTop() {
  const [isVisible, setIsVisible] = useState(false);
  const { scrollYProgress } = useScroll();
  const scaleX = useSpring(scrollYProgress, {
    stiffness: 100,
    damping: 30,
    restDelta: 0.001,
  });

  useEffect(() => {
    const toggleVisibility = () => {
      if (window.pageYOffset > 300) {
        setIsVisible(true);
      } else {
        setIsVisible(false);
      }
    };

    window.addEventListener('scroll', toggleVisibility);
    return () => window.removeEventListener('scroll', toggleVisibility);
  }, []);

  const scrollToTop = () => {
    window.scrollTo({
      top: 0,
      behavior: 'smooth',
    });
  };

  return (
    <>
      {/* Progress bar */}
      <motion.div
        className="fixed top-0 left-0 right-0 h-1 bg-gradient-to-r from-purple-500 to-cyan-500 transform origin-left z-50"
        style={{ scaleX }}
      />

      {/* Back to top button */}
      {isVisible && (
        <motion.button
          onClick={scrollToTop}
          className="fixed bottom-8 right-8 p-4 rounded-full glass hover:bg-white/10 text-purple-400 hover:text-purple-300 transition-colors shadow-lg z-40 group"
          initial={{ opacity: 0, y: 20 }}
          animate={{ opacity: 1, y: 0 }}
          exit={{ opacity: 0, y: 20 }}
          whileHover={{ scale: 1.1 }}
          whileTap={{ scale: 0.9 }}
          aria-label="Back to top"
        >
          <svg
            className="w-6 h-6"
            fill="none"
            stroke="currentColor"
            viewBox="0 0 24 24"
          >
            <path
              strokeLinecap="round"
              strokeLinejoin="round"
              strokeWidth={2}
              d="M5 10l7-7m0 0l7 7m-7-7v18"
            />
          </svg>

          {/* Tooltip */}
          <span className="absolute bottom-full right-0 mb-2 px-3 py-1 text-xs text-white bg-gray-900 rounded-lg opacity-0 group-hover:opacity-100 transition-opacity whitespace-nowrap">
            Back to top
          </span>
        </motion.button>
      )}
    </>
  );
}
