"use client";

import { cn } from "@/utils/ui";
import {
  TAB_KEYS,
  tabs,
  useAssetsPanelStore,
} from "../../../stores/assets-panel-store";
import {
  Tooltip,
  TooltipContent,
  TooltipTrigger,
} from "@/components/ui/tooltip";
import { useEffect, useRef, useState } from "react";

export function TabBar() {
  const { activeTab, setActiveTab } = useAssetsPanelStore();
  const scrollRef = useRef<HTMLDivElement>(null);
  const [showTopFade, setShowTopFade] = useState(false);
  const [showBottomFade, setShowBottomFade] = useState(false);

  const checkScrollPosition = () => {
    const element = scrollRef.current;
    if (!element) return;

    const { scrollTop, scrollHeight, clientHeight } = element;
    setShowTopFade(scrollTop > 0);
    setShowBottomFade(scrollTop < scrollHeight - clientHeight - 1);
  };

  useEffect(() => {
    const element = scrollRef.current;
    if (!element) return;

    checkScrollPosition();
    element.addEventListener("scroll", checkScrollPosition);

    const resizeObserver = new ResizeObserver(checkScrollPosition);
    resizeObserver.observe(element);

    return () => {
      element.removeEventListener("scroll", checkScrollPosition);
      resizeObserver.disconnect();
    };
  }, []);

  return (
    <div className="relative flex">
      <div
        ref={scrollRef}
        className="scrollbar-hidden relative flex h-full w-full flex-col items-center justify-start gap-5 overflow-y-auto px-4 py-4"
      >
        {TAB_KEYS.map((tabKey) => {
          const tab = tabs[tabKey];
          return (
            <div
              className={cn(
                "flex cursor-pointer flex-col items-center gap-0.5",
                activeTab === tabKey
                  ? "text-primary !opacity-100"
                  : "text-muted-foreground",
              )}
              onClick={() => setActiveTab(tabKey)}
              key={tabKey}
            >
              <Tooltip delayDuration={10}>
                <TooltipTrigger asChild>
                  <tab.icon className="size-[1.1rem]! opacity-100 hover:opacity-75" />
                </TooltipTrigger>
                <TooltipContent
                  side="right"
                  align="center"
                  variant="sidebar"
                  sideOffset={8}
                >
                  <div className="text-foreground text-sm leading-none font-medium">
                    {tab.label}
                  </div>
                </TooltipContent>
              </Tooltip>
            </div>
          );
        })}
      </div>

      <FadeOverlay direction="top" show={showTopFade} />
      <FadeOverlay direction="bottom" show={showBottomFade} />
    </div>
  );
}

function FadeOverlay({
  direction,
  show,
}: {
  direction: "top" | "bottom";
  show: boolean;
}) {
  return (
    <div
      className={cn(
        "pointer-events-none absolute right-0 left-0 h-6 transition-opacity duration-200",
        direction === "top" && show
          ? "from-panel top-0 bg-gradient-to-b to-transparent"
          : "from-panel bottom-0 bg-gradient-to-t to-transparent",
      )}
    />
  );
}