"use client";

import {
  motion,
  useAnimationFrame,
  useMotionValue,
  useScroll,
  useSpring,
  useTransform,
} from "motion/react";
import { useEffect, useRef, useState } from "react";

interface ScrollVelocityTextProps {
  text: string;
  baseVelocity?: number;
  className?: string;
}

function wrap(min: number, max: number, v: number) {
  const rangeSize = max - min;
  return ((((v - min) % rangeSize) + rangeSize) % rangeSize) + min;
}

export default function ScrollVelocityText({
  text,
  baseVelocity = 2,
  className = "",
}: ScrollVelocityTextProps) {
  const baseX = useMotionValue(0);
  const { scrollY } = useScroll();
  const scrollVelocity = useMotionValue(0);
  const smoothVelocity = useSpring(scrollVelocity, {
    damping: 50,
    stiffness: 300,
  });
  const velocityFactor = useTransform(smoothVelocity, [0, 1000], [0, 5], {
    clamp: false,
  });

  const [repetitions, setRepetitions] = useState(4);
  const containerRef = useRef<HTMLDivElement>(null);

  useEffect(() => {
    const handleResize = () => {
      setRepetitions(Math.ceil(window.innerWidth / 400) + 2);
    };
    handleResize();
    window.addEventListener("resize", handleResize);
    return () => window.removeEventListener("resize", handleResize);
  }, []);

  // Track scroll velocity
  const prevScrollY = useRef(0);
  useEffect(() => {
    return scrollY.on("change", (latest) => {
      const delta = latest - prevScrollY.current;
      prevScrollY.current = latest;
      scrollVelocity.set(Math.abs(delta));
    });
  }, [scrollY, scrollVelocity]);

  const directionFactor = useRef(1);

  const x = useTransform(baseX, (v) => `${wrap(-25, 0, v)}%`);

  useAnimationFrame((_, delta) => {
    let moveBy = directionFactor.current * baseVelocity * (delta / 1000);

    const vf = velocityFactor.get();
    if (vf < 0) {
      directionFactor.current = -1;
    } else if (vf > 0) {
      directionFactor.current = 1;
    }

    moveBy += directionFactor.current * moveBy * vf;
    baseX.set(baseX.get() + moveBy);
  });

  return (
    <div
      ref={containerRef}
      className={`overflow-hidden whitespace-nowrap ${className}`}
    >
      <motion.div className="inline-flex" style={{ x }}>
        {[...Array(repetitions)].map((_, i) => (
          <span
            key={i}
            className="mr-8 inline-block font-display text-[clamp(3rem,10vw,8rem)] font-extrabold uppercase leading-none tracking-[-0.04em]"
          >
            {text}
            <span className="mx-8 inline-block text-[var(--slash)]">
              &#x2022;
            </span>
          </span>
        ))}
      </motion.div>
    </div>
  );
}