import { useState, useEffect, useRef } from "react";
import { useRouterState } from "@tanstack/react-router";
import { useIsFetching, useIsMutating } from "@tanstack/react-query";
import { cn } from "@/lib/utils";

export function LoadingBar() {
  const isNavigating = useRouterState({ select: (s) => s.status === "pending" });
  const isFetching = useIsFetching();
  const isMutating = useIsMutating();

  const [visible, setVisible] = useState(false);
  const timerRef = useRef<ReturnType<typeof setTimeout>>(undefined);

  const loading = isNavigating || isFetching > 0 || isMutating > 0;

  useEffect(() => {
    if (loading) {
      timerRef.current = setTimeout(() => setVisible(true), 200);
    } else {
      clearTimeout(timerRef.current);
      setVisible(false);
    }
    return () => clearTimeout(timerRef.current);
  }, [loading]);

  return (
    <div
      className={cn(
        "fixed top-0 left-0 right-0 z-[100] h-0.5 transition-opacity duration-300",
        visible ? "opacity-100" : "opacity-0",
      )}
      aria-hidden="true"
    >
      <div className="loading-bar h-full w-full bg-primary" />
    </div>
  );
}
