"use client";

import React, { useRef, useState, useEffect } from "react";
import { Card, CardAction, CardDescription, CardFooter, CardHeader, CardTitle } from "@/components/ui/card";
import { Button } from "@/components/ui/button";
import { Badge } from "@/components/ui/badge";

import { ChevronLeft, ChevronRight } from "lucide-react";

export type VideoItem = {
  id: string | number;
  title: string;
  duration: string; // formatted like "4:12"
  thumbnailUrl: string;
};

type Props = {
  categoryTitle: string;
  videos: VideoItem[];
  visibleCount?: number; // defaults to 4
};

export default function VideoCarousel({
  categoryTitle,
  videos,
  visibleCount = 4,
}: Props) {
  const scrollerRef = useRef<HTMLDivElement | null>(null);
  const [canScrollLeft, setCanScrollLeft] = useState(false);
  const [canScrollRight, setCanScrollRight] = useState(false);

  useEffect(() => {
    const el = scrollerRef.current;
    if (!el) return;
    const update = () => {
      setCanScrollLeft(el.scrollLeft > 0);
      setCanScrollRight(el.scrollLeft + el.clientWidth < el.scrollWidth - 1);
    };
    update();
    el.addEventListener("scroll", update, { passive: true });
    window.addEventListener("resize", update);
    return () => {
      el.removeEventListener("scroll", update);
      window.removeEventListener("resize", update);
    };
  }, [videos]);

  const scrollByPage = (direction: "left" | "right") => {
    const el = scrollerRef.current;
    if (!el) return;
    const amount = el.clientWidth; // scroll by visible area so next "page" shows
    el.scrollBy({ left: direction === "left" ? -amount : amount, behavior: "smooth" });
  };

  // keyboard navigation
  useEffect(() => {
    const handler = (e: KeyboardEvent) => {
      if (e.key === "ArrowLeft") scrollByPage("left");
      if (e.key === "ArrowRight") scrollByPage("right");
    };
    window.addEventListener("keydown", handler);
    return () => window.removeEventListener("keydown", handler);
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, []);

  return (
    <section className="w-full">
      <div className="flex items-center justify-between mb-4">
        <h2 className="text-lg font-semibold">{categoryTitle}</h2>
        <div className="flex gap-2">
          <Button
            variant="outline"
            size="icon"
            aria-label="Scroll left"
            onClick={() => scrollByPage("left")}
            disabled={!canScrollLeft}
          >
            <ChevronLeft size={18} />
          </Button>
          <Button
            variant="outline"
            size="icon"
            aria-label="Scroll right"
            onClick={() => scrollByPage("right")}
            disabled={!canScrollRight}
          >
            <ChevronRight size={18} />
          </Button>
        </div>
      </div>

      <div className="relative">
        <div
          ref={scrollerRef}
          role="list"
          aria-label={`${categoryTitle} videos`}
          className="flex gap-4 overflow-x-auto scroll-smooth py-2 pb-4 -mx-2 px-2"
          style={{ scrollbarGutter: "stable" }}
        >
          {videos.map((v) => (
            <article
              key={v.id}
              role="listitem"
              className="shrink-0 w-[22%] min-w-[220px] max-w-[260px]"
            >
              <Card className="@container/card overflow-hidden">
                <div className="relative">
                  <img
                    src={v.thumbnailUrl}
                    alt={v.title}
                    className="w-full h-40 object-cover block"
                    loading="lazy"
                  />
                  <Badge className="absolute right-2 bottom-2">{v.duration}</Badge>
                </div>
                <CardHeader>
                  <CardTitle className="text-sm font-medium line-clamp-2" title={v.title}>
                    {v.title}
                  </CardTitle>
                  <CardAction>
                    {/* placeholder for action, e.g., menu or save */}
                  </CardAction>
                </CardHeader>
                <CardFooter className="px-3 py-2">
                  <div className="text-muted-foreground text-xs">{v.duration}</div>
                </CardFooter>
              </Card>
            </article>
          ))}
        </div>

        {/* small gradients on the sides to indicate scrollability */}
        <div className="pointer-events-none absolute left-0 top-0 bottom-0 w-8 bg-gradient-to-r from-white/90 to-transparent dark:from-slate-900/90" />
        <div className="pointer-events-none absolute right-0 top-0 bottom-0 w-8 bg-gradient-to-l from-white/90 to-transparent dark:from-slate-900/90" />
      </div>

    </section>
  );
}

/*
Usage example:

import VideoCarousel, { VideoItem } from "./VideoCarousel";

const videos: VideoItem[] = [
  { id: 1, title: "Fluffy cat plays with yarn", duration: "3:45", thumbnailUrl: "/thumb1.jpg" },
  { id: 2, title: "Cat napping compilation", duration: "2:12", thumbnailUrl: "/thumb2.jpg" },
  // ...more
];

<VideoCarousel categoryTitle="Cute Cats" videos={videos} visibleCount={4} />

Notes:
- This file assumes shadcn/ui components exist at the given paths. Replace imports if your project structure differs.
- Card widths are responsive: they use a percent width with a min-width to keep thumbnails readable on small screens.
- The scroller uses native smooth scrolling so it works well on touch devices and with keyboards.
*/