import { motion } from "framer-motion";

interface Props {
  page: number; // 1-based
  pageCount: number;
  onPage: (page: number) => void;
}

/** Build a windowed page list with ellipses, e.g. 1 … 4 5 6 … 12 */
function pageItems(page: number, count: number): (number | "…")[] {
  if (count <= 7) return Array.from({ length: count }, (_, i) => i + 1);
  const items: (number | "…")[] = [1];
  const start = Math.max(2, page - 1);
  const end = Math.min(count - 1, page + 1);
  if (start > 2) items.push("…");
  for (let i = start; i <= end; i++) items.push(i);
  if (end < count - 1) items.push("…");
  items.push(count);
  return items;
}

export function Pagination({ page, pageCount, onPage }: Props) {
  if (pageCount <= 1) return null;
  const items = pageItems(page, pageCount);

  return (
    <div className="mt-6 flex items-center justify-center gap-1.5">
      <button
        onClick={() => onPage(page - 1)}
        disabled={page === 1}
        className="focusable grid h-9 w-9 place-items-center rounded-xl border-[1.5px] border-line bg-surface text-ink transition-opacity hover:bg-surface-2 disabled:opacity-30"
        aria-label="Previous page"
      >
        ‹
      </button>

      {items.map((it, i) =>
        it === "…" ? (
          <span key={`e${i}`} className="px-1 text-sm text-muted">
            …
          </span>
        ) : (
          <button
            key={it}
            onClick={() => onPage(it)}
            aria-current={it === page}
            className="focusable relative grid h-9 min-w-9 place-items-center rounded-xl px-2 text-sm font-semibold"
          >
            {it === page && (
              <motion.span
                layoutId="page-pill"
                transition={{ type: "spring", stiffness: 480, damping: 32 }}
                className="absolute inset-0 rounded-xl bg-accent"
              />
            )}
            <span
              className={`relative z-10 ${
                it === page ? "text-accent-ink" : "text-muted hover:text-ink"
              }`}
            >
              {it}
            </span>
          </button>
        ),
      )}

      <button
        onClick={() => onPage(page + 1)}
        disabled={page === pageCount}
        className="focusable grid h-9 w-9 place-items-center rounded-xl border-[1.5px] border-line bg-surface text-ink transition-opacity hover:bg-surface-2 disabled:opacity-30"
        aria-label="Next page"
      >
        ›
      </button>
    </div>
  );
}