Swipe-to-close lightbox

import { useEffect, useRef, useState, type RefObject } from "react";
import { AnimatePresence, motion, useMotionValue, useReducedMotion, useTransform } from "framer-motion";
import { X } from "lucide-react";

const WORKS = [
  {
    id: "bruma",
    title: "Bruma",
    meta: "Digital oil · 120 × 150 cm",
    art: "radial-gradient(80% 60% at 30% 18%, #f0f9ff 0%, transparent 60%), radial-gradient(90% 70% at 85% 95%, #0e5a73 0%, transparent 62%), linear-gradient(180deg, #bfe3f5 0%, #56b3d9 45%, #144a5c 100%)",
  },
  {
    id: "brasa",
    title: "Brasa",
    meta: "Digital oil · 90 × 90 cm",
    art: "radial-gradient(70% 55% at 70% 25%, #ffe6a8 0%, transparent 60%), radial-gradient(100% 80% at 5% 100%, #6e1423 0%, transparent 60%), linear-gradient(160deg, #fb9a4b 0%, #e2344f 55%, #470b1f 100%)",
  },
  {
    id: "marea",
    title: "Tide",
    meta: "Digital oil · 90 × 90 cm",
    art: "radial-gradient(80% 60% at 20% 85%, #c9bcff 0%, transparent 60%), radial-gradient(70% 60% at 90% 10%, #f5b4f5 0%, transparent 55%), linear-gradient(200deg, #2b2a7a 0%, #6a35d8 50%, #1b1745 100%)",
  },
];

const GRAIN = "url(\"data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='180' height='180'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='0.8' numOctaves='3' stitchTiles='stitch'/></filter><rect width='100%' height='100%' filter='url(%23n)'/></svg>\")";

const morph = { type: "spring" as const, stiffness: 320, damping: 32, mass: 0.9 };

const FOCUSABLE =
  'a[href],button:not([disabled]),input:not([disabled]),select,textarea,[tabindex]:not([tabindex="-1"])';

// Modal accesible: enfoca el primer control (o el marcado con data-autofocus), atrapa Tab, cierra con Esc y devuelve el foco
function useDialog(ref: RefObject<HTMLElement | null>, open: boolean, onClose: () => void) {
  const close = useRef(onClose);
  useEffect(() => {
    close.current = onClose;
  });
  useEffect(() => {
    if (!open) return;
    const previous = document.activeElement as HTMLElement | null;
    const node = ref.current;
    const first =
      node?.querySelector<HTMLElement>("[data-autofocus]") ?? node?.querySelector<HTMLElement>(FOCUSABLE);
    first?.focus({ preventScroll: true });
    const onKey = (e: KeyboardEvent) => {
      if (e.key === "Escape") {
        e.preventDefault();
        close.current();
        return;
      }
      if (e.key !== "Tab" || !node) return;
      const items = Array.from(node.querySelectorAll<HTMLElement>(FOCUSABLE));
      if (!items.length) return;
      const firstItem = items[0];
      const lastItem = items[items.length - 1];
      if (!firstItem || !lastItem) return;
      if (!node.contains(document.activeElement)) {
        e.preventDefault();
        firstItem.focus();
      } else if (e.shiftKey && document.activeElement === firstItem) {
        e.preventDefault();
        lastItem.focus();
      } else if (!e.shiftKey && document.activeElement === lastItem) {
        e.preventDefault();
        firstItem.focus();
      }
    };
    document.addEventListener("keydown", onKey);
    return () => {
      document.removeEventListener("keydown", onKey);
      previous?.focus({ preventScroll: true });
    };
  }, [open, ref]);
}

interface LightboxProps {
  /** Píxeles de arrastre vertical para cerrar */
  threshold?: number;
  caption?: boolean;
  radius?: number;
}

export default function Lightbox({
  threshold = 110,
  caption = true,
  radius = 18,
}: LightboxProps) {
  const [openId, setOpenId] = useState<string | null>(null);
  const panel = useRef<HTMLDivElement>(null);
  const y = useMotionValue(0);
  const fade = useTransform(y, [-260, 0, 260], [0, 1, 0]);
  const shrink = useTransform(y, [-260, 0, 260], [0.8, 1, 0.8]);
  const reduce = useReducedMotion();
  const work = WORKS.find((w) => w.id === openId);
  const transition = reduce ? { duration: 0 } : morph;
  const close = () => setOpenId(null);
  useDialog(panel, !!work, close);
  useEffect(() => {
    if (work) y.set(0);
  }, [work, y]);

  return (
    <div className="flex w-full flex-col items-center bg-[#f7f7f7] p-5 text-[#1d1d1f] dark:bg-[#0a0a0a] dark:text-[#f5f5f7]">
      <div className="w-full max-w-[420px]">
        <div className="mb-4 flex items-end justify-between">
          <div>
            <p className="text-[11px] font-medium uppercase tracking-[0.22em] text-[#86868b]">Collection</p>
            <h2 className="mt-1 text-[22px] font-semibold tracking-[-0.03em]">Autumn light</h2>
          </div>
          <span className="text-[12px] text-[#86868b]">{WORKS.length} obras</span>
        </div>
        <div className="grid aspect-[4/3] w-full grid-cols-5 grid-rows-2 gap-2">
          {WORKS.map((w, i) => (
            <motion.button
              key={w.id}
              type="button"
              layoutId={"work-" + w.id}
              transition={transition}
              aria-label={"Open " + w.title}
              aria-haspopup="dialog"
              onClick={() => setOpenId(w.id)}
              whileHover={{ scale: 1.015 }}
              whileTap={{ scale: 0.98 }}
              className={"relative overflow-hidden outline-none shadow-[0_1px_2px_rgba(0,0,0,0.1),0_10px_30px_-12px_rgba(0,0,0,0.35)] focus-visible:ring-2 focus-visible:ring-[#0071e3] focus-visible:ring-offset-2 " + (i === 0 ? "col-span-3 row-span-2" : "col-span-2")}
              style={{ borderRadius: 16, background: w.art }}
            >
              <span aria-hidden className="pointer-events-none absolute inset-0 opacity-[0.22] mix-blend-overlay" style={{ backgroundImage: GRAIN }} />
            </motion.button>
          ))}
        </div>
        <p className="mt-4 text-[12px] text-[#86868b]">Tap a piece · drag to close</p>
      </div>

      <AnimatePresence>
        {work && (
          // fixed: el visor ocupa toda la ventana
          <motion.div
            key="viewer"
            ref={panel}
            role="dialog"
            aria-modal="true"
            aria-label={work.title}
            className="fixed inset-0 z-50 flex flex-col text-white"
          >
            <motion.div
              aria-hidden
              className="absolute inset-0"
              initial={{ opacity: 0 }}
              animate={{ opacity: 1 }}
              exit={{ opacity: 0 }}
              transition={{ duration: reduce ? 0 : 0.25 }}
            >
              <motion.div className="absolute inset-0 bg-[#050505]" style={{ opacity: fade }} onClick={close} />
            </motion.div>
            <motion.div initial={{ opacity: 0 }} animate={{ opacity: 1 }} exit={{ opacity: 0 }} className="relative flex justify-end p-3">
              <motion.div style={{ opacity: fade }}>
                <button type="button" aria-label="Close" onClick={close} className="grid h-9 w-9 place-items-center rounded-full bg-white/10 text-white ring-1 ring-inset ring-white/15 backdrop-blur-md transition hover:bg-white/20">
                  <X className="h-4 w-4" strokeWidth={1.5} />
                </button>
              </motion.div>
            </motion.div>
            <div className="pointer-events-none relative flex min-h-0 flex-1 items-center justify-center px-6">
              <motion.div
                layoutId={"work-" + work.id}
                transition={transition}
                drag="y"
                dragConstraints={{ top: 0, bottom: 0 }}
                dragElastic={0.9}
                onDragEnd={(_, info) => {
                  if (Math.abs(info.offset.y) > threshold || Math.abs(info.velocity.y) > 700) close();
                }}
                className="pointer-events-auto relative aspect-[4/5] h-full max-h-[440px] max-w-full cursor-grab touch-none overflow-hidden shadow-[0_40px_100px_-20px_rgba(0,0,0,0.7)] active:cursor-grabbing"
                style={{ y, scale: shrink, borderRadius: radius, background: work.art }}
              >
                <span aria-hidden className="pointer-events-none absolute inset-0 opacity-[0.22] mix-blend-overlay" style={{ backgroundImage: GRAIN }} />
              </motion.div>
            </div>
            <motion.div
              initial={{ opacity: 0, y: 8 }}
              animate={{ opacity: 1, y: 0, transition: { delay: reduce ? 0 : 0.12 } }}
              exit={{ opacity: 0, transition: { duration: 0.1 } }}
              className="relative px-6 pb-5 pt-4 text-center"
            >
              <motion.div style={{ opacity: fade }}>
                {caption ? (
                  <>
                    <p className="text-[15px] font-medium">{work.title}</p>
                    <p className="mt-0.5 text-[12px] text-white/55">{work.meta}</p>
                  </>
                ) : (
                  <p className="text-[12px] text-white/55">Drag to close</p>
                )}
              </motion.div>
            </motion.div>
          </motion.div>
        )}
      </AnimatePresence>
    </div>
  );
}