"use client";

import { animate, useInView } from "motion/react";
import { useEffect, useRef, useState } from "react";
import { cn } from "@/lib/utils";

export interface AnimatedNumberProps {
  value: number;
  duration?: number;
  format?: (n: number) => string;
  className?: string;
  startOnView?: boolean;
}

export function AnimatedNumber({
  value,
  duration = 1.2,
  format = (n) => Math.round(n).toLocaleString(),
  className,
  startOnView = true,
}: AnimatedNumberProps) {
  const ref = useRef<HTMLSpanElement>(null);
  const inView = useInView(ref, { once: true, amount: 0.6 });
  const [display, setDisplay] = useState(0);
  const fromRef = useRef(0);

  useEffect(() => {
    if (startOnView && !inView) return;
    const controls = animate(fromRef.current, value, {
      duration,
      ease: [0.16, 1, 0.3, 1],
      onUpdate: (v) => setDisplay(v),
    });
    fromRef.current = value;
    return () => controls.stop();
  }, [value, duration, inView, startOnView]);

  return (
    <span ref={ref} className={cn("tabular-nums", className)}>
      {format(display)}
    </span>
  );
}