import { useId, useState } from "react";
import { ArchitectureFigure } from "./ArchitectureFigure";

type Slide = { source: string; alt: string };

export function FigureGallery({ slides }: { slides: Slide[] }) {
  const [active, setActive] = useState(0);
  const viewport = useId();
  const slide = slides[active];
  if (!slide) return null;

  function move(offset: number) {
    setActive((current) => (current + offset + slides.length) % slides.length);
  }

  return (
    <section
      className="figure-gallery"
      role="region"
      aria-roledescription="轮播"
      aria-label="文档配图"
      onKeyDown={(event) => {
        if ((event.target as HTMLElement).closest("dialog")) return;
        if (event.key === "ArrowLeft" || event.key === "ArrowRight") {
          event.preventDefault();
          move(event.key === "ArrowLeft" ? -1 : 1);
        }
      }}
    >
      <div
        id={viewport}
        role="group"
        aria-roledescription="幻灯片"
        aria-label={`第 ${active + 1} 张，共 ${slides.length} 张`}
      >
        <ArchitectureFigure key={slide.source} source={slide.source} alt={slide.alt} />
      </div>
      <div className="figure-gallery-controls">
        <button type="button" className="figure-gallery-arrow" aria-label="上一张图片" aria-controls={viewport} onClick={() => move(-1)}>
          <span aria-hidden="true">‹</span>
        </button>
        <div className="figure-gallery-dots" role="group" aria-label="选择图片">
          {slides.map((item, index) => (
            <button
              key={item.source}
              type="button"
              className="figure-gallery-dot"
              aria-label={`显示第 ${index + 1} 张图片`}
              aria-current={index === active ? "true" : undefined}
              aria-controls={viewport}
              onClick={() => setActive(index)}
            >
              <span aria-hidden="true" />
            </button>
          ))}
        </div>
        <button type="button" className="figure-gallery-arrow" aria-label="下一张图片" aria-controls={viewport} onClick={() => move(1)}>
          <span aria-hidden="true">›</span>
        </button>
      </div>
      <p className="sr-only" role="status" aria-live="polite" aria-atomic="true">
        第 {active + 1} 张，共 {slides.length} 张：{slide.alt}
      </p>
    </section>
  );
}