"use client";

import { useCallback, useEffect, useState } from "react";
import Image from "next/image";
import useEmblaCarousel from "embla-carousel-react";
import { CaretLeftIcon, CaretRightIcon } from "@phosphor-icons/react/dist/ssr";
import styles from "./Slider.module.css";

type Slide = {
  heading: string;
  text: string;
  image: string;
};

type SliderProps = {
  slides: Slide[];
  imageAlt: string;
};

export function Slider({ slides, imageAlt }: SliderProps) {
  const [emblaRef, emblaApi] = useEmblaCarousel({
    align: "start",
    loop: false,
    duration: 28,
  });

  const [selectedIndex, setSelectedIndex] = useState(0);
  const [scrollSnaps, setScrollSnaps] = useState<number[]>([]);
  const [canScrollPrev, setCanScrollPrev] = useState(false);
  const [canScrollNext, setCanScrollNext] = useState(false);

  const scrollPrevious = useCallback(() => {
    emblaApi?.scrollPrev();
  }, [emblaApi]);

  const scrollNext = useCallback(() => {
    emblaApi?.scrollNext();
  }, [emblaApi]);

  const scrollTo = useCallback(
    (index: number) => {
      emblaApi?.scrollTo(index);
    },
    [emblaApi],
  );

  const updateSelectedSlide = useCallback(() => {
    if (!emblaApi) {
      return;
    }

    setSelectedIndex(emblaApi.selectedScrollSnap());
    setCanScrollPrev(emblaApi.canScrollPrev());
    setCanScrollNext(emblaApi.canScrollNext());
  }, [emblaApi]);

  const initializeNavigation = useCallback(() => {
    if (!emblaApi) {
      return;
    }

    setScrollSnaps(emblaApi.scrollSnapList());
    updateSelectedSlide();
  }, [emblaApi, updateSelectedSlide]);

  useEffect(() => {
    if (!emblaApi) {
      return;
    }

    initializeNavigation();

    emblaApi.on("reInit", initializeNavigation);
    emblaApi.on("select", updateSelectedSlide);

    return () => {
      emblaApi.off("reInit", initializeNavigation);
      emblaApi.off("select", updateSelectedSlide);
    };
  }, [emblaApi, initializeNavigation, updateSelectedSlide]);

  if (slides.length === 0) {
    return null;
  }

  return (
    <section
      className={styles.slider}
      aria-roledescription="carousel"
      aria-label="Weitere Informationen"
    >
      <div className={styles.viewport} ref={emblaRef}>
        <div className={styles.container}>
          {slides.map((slide, index) => (
            <article
              key={`${slide.heading}-${index}`}
              className={styles.slide}
              aria-hidden={selectedIndex !== index}
            >
              <div className={styles.split}>
                <div className={styles.textPanel}>
                  <h3 className={styles.heading}>{slide.heading}</h3>
                  <p className={styles.text}>{slide.text}</p>
                </div>

                <div className={styles.imagePanel}>
                  <Image
                    src={slide.image}
                    alt={imageAlt}
                    fill
                    sizes="(max-width: 700px) 100vw, 50vw"
                    className={styles.image}
                  />
                </div>
              </div>
            </article>
          ))}
        </div>
      </div>

      {slides.length > 1 && (
        <div className={styles.controls}>
          <button
            type="button"
            className={styles.arrow}
            onClick={scrollPrevious}
            disabled={!canScrollPrev}
            suppressHydrationWarning
            aria-label="Vorheriger Slide"
          >
            <CaretLeftIcon size={20} weight="bold" aria-hidden="true" />
          </button>

          <div className={styles.dots} aria-label="Slide auswählen">
            {scrollSnaps.map((_, index) => (
              <button
                key={index}
                type="button"
                className={`${styles.dot} ${
                  selectedIndex === index ? styles.dotActive : ""
                }`}
                onClick={() => scrollTo(index)}
                aria-label={`Slide ${index + 1} von ${slides.length}`}
                aria-current={selectedIndex === index ? "true" : undefined}
              />
            ))}
          </div>

          <button
            type="button"
            className={styles.arrow}
            onClick={scrollNext}
            disabled={!canScrollNext}
            suppressHydrationWarning
            aria-label="Nächster Slide"
          >
            <CaretRightIcon size={20} weight="bold" aria-hidden="true" />
          </button>
        </div>
      )}
    </section>
  );
}