"use client";

import Image from "next/image";
import Link from "next/link";
import { useEffect, useMemo, useState } from "react";

const MANUAL_EXCLUSION_LIST = [
  "alsten-golfklubb",
  "askim-golfklubb",
  "bergen-golfklubb",
  "eidskog-golfklubb",
  "eiker-golfklubb",
  "floro-golfklubb",
  "garder-golfklubb",
  "hafjell-golfklubb",
  "halden-golfklubb",
  "haugesund-golfklubb",
  "hinnoy-golfklubb",
  "hitra-golfklubb",
  "hurum-golfklubb",
  "imjelt-pitch-putt",
  "karmoy-golfklubb",
  "kristiansund-og-omegn-golfklubb",
  "lommedalen-golfklubb",
  "laerdal-golfklubb",
  "moa-golfsenter",
  "modum-golfklubb",
  "nes-golfklubb-09",
  "nittedal-golfklubb",
  "selbu-golfklubb",
  "stryn-golfklubb",
  "sunnfjord-golfklubb",
  "tysnes-golfklubb",
  "vanylven-golfklubb",
  "vesteralen-golfklubb",
  "vestlia-golf",
];

const GOOD_STATUSES = ["aapen", "aapner_snart", "stenger_snart", "aapen_med_vintergreener"];
const BAD_STATUSES = ["nedlagt", "under_utvikling"];

type CourseStatus = {
  status?: string;
};

type Facility = {
  id: number;
  slug: string;
  name: string;
  image_url?: string | null;
  course_statuses?: CourseStatus[] | null;
};

export default function HeroSlider({ facilities }: { facilities: Facility[] }) {
  const [currentIndex, setCurrentIndex] = useState(0);

  const sliderItems = useMemo(() => {
    if (!Array.isArray(facilities) || facilities.length === 0) return [];

    const validFacilities = facilities.filter((facility) => {
      if (MANUAL_EXCLUSION_LIST.includes(facility.slug)) return false;
      const image = String(facility.image_url || "").toLowerCase();
      if (!image || image.includes("standard")) return false;

      const statuses = Array.isArray(facility.course_statuses) ? facility.course_statuses : [];
      const hasForbiddenStatus = statuses.some((status) =>
        BAD_STATUSES.includes(String(status?.status || "").toLowerCase())
      );

      return !hasForbiddenStatus;
    });

    const priority = validFacilities.filter((facility) => {
      const statuses = Array.isArray(facility.course_statuses) ? facility.course_statuses : [];
      return statuses.some((status) => GOOD_STATUSES.includes(String(status?.status || "").toLowerCase()));
    });

    const fallback = validFacilities.filter((facility) => !priority.includes(facility));

    const now = new Date();
    const seed = Number(`${now.getFullYear()}${now.getMonth()}${now.getDate()}${now.getHours()}`);

    const seededShuffle = (items: Facility[]) =>
      [...items].sort((a, b) => ((a.id * seed) % 101) - ((b.id * seed) % 101));

    const selected = [...seededShuffle(priority), ...seededShuffle(fallback)].slice(0, 5);
    return selected;
  }, [facilities]);

  useEffect(() => {
    if (sliderItems.length <= 1) return;
    const interval = setInterval(() => {
      setCurrentIndex((previous) => (previous + 1) % sliderItems.length);
    }, 8000);
    return () => clearInterval(interval);
  }, [sliderItems.length]);

  if (sliderItems.length === 0) return null;

  return (
    <section className="relative min-h-[420px] overflow-hidden bg-[#25312A] sm:min-h-[520px] lg:min-h-[620px]">
      {sliderItems.map((facility, index) => (
        <div
          key={facility.id}
          className={`absolute inset-0 transition-opacity duration-1000 ${
            index === currentIndex ? "opacity-100" : "pointer-events-none opacity-0"
          }`}
        >
          <Image
            src={facility.image_url || "/Toppbilde-standard.jpg"}
            alt={facility.name}
            fill
            priority={index === currentIndex}
            sizes="100vw"
            className="object-cover object-center"
          />
          <div className="absolute inset-0 bg-gradient-to-t from-[#25312A]/70 via-[#25312A]/10 to-[#25312A]/20" />
        </div>
      ))}

      <div className="absolute inset-0 z-10 mx-auto flex max-w-[1400px] flex-col justify-between px-4 py-5 sm:px-6 sm:py-7 lg:px-8 lg:py-10">
        <div className="flex justify-end">
          <div className="max-w-[14rem] text-right sm:max-w-[22rem] lg:max-w-[48rem]">
            <h1 className="text-sm font-bold uppercase leading-tight tracking-tight text-white sm:text-3xl lg:text-5xl">
              <span>TeeOff.no gir deg komplett oversikt over </span>
              <Link
                href="/golfbaner"
                className="font-extrabold transition hover:text-white"
                style={{ color: "#FF5722" }}
                aria-label="Se alle golfbaner"
              >
                ALLE
              </Link>
              <span> norske golfbaner!</span>
            </h1>
          </div>
        </div>

        <div className="flex flex-col items-center gap-4">
          <Link
            href={`/golfbaner/${sliderItems[currentIndex].slug}`}
            className="btn btn-lg btn-primary text-center text-xl tracking-tight shadow-lg sm:px-8 sm:text-3xl lg:text-4xl"
          >
            {sliderItems[currentIndex].name}
          </Link>

          <div className="flex gap-3">
            {sliderItems.map((_, index) => (
              <button
                key={index}
                type="button"
                onClick={() => setCurrentIndex(index)}
                aria-label={`Vis bilde ${index + 1}`}
                className={`h-1.5 rounded-full transition-all ${
                  index === currentIndex ? "w-12 bg-[#8BC34A]" : "w-5 bg-white/35"
                }`}
              />
            ))}
          </div>
        </div>
      </div>
    </section>
  );
}