import { ChevronLeft, ChevronRight, ChevronsLeft, ChevronsRight } from "lucide-react";
import { PAGE_SIZES } from "~/components/console/use-list-pagination.ts";
import { Button } from "~/components/ui/button.tsx";
import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from "~/components/ui/select.tsx";
import { cn } from "~/lib/utils.ts";

export type PaginationProps = {
  page: number;
  pageSize: number;
  /** With hasMore, total is the loaded count, not a complete total. */
  total: number;
  hasMore?: boolean;
  busy?: boolean;
  onPageChange: (page: number) => void;
  onPageSizeChange?: (size: number) => void;
  className?: string;
  /** 一页放得下时整块不显示(卡片网格下面单独一行「共 N 条」显得悬空) */
  hideSingle?: boolean;
};
export function pageNumbers(page: number, pages: number): (number | "…")[] {
  const values = new Set([1, pages, page - 1, page, page + 1]);
  const valid = [...values].filter((n) => n >= 1 && n <= pages).sort((a, b) => a - b);
  return valid.flatMap((n, i): (number | "…")[] => (i && n - valid[i - 1] > 1 ? ["…", n] : [n]));
}
/**
 * 表格、卡片列表与游标列表共用的分页。
 * 一页就放得下(只有 1 页、没有更多)时不显示翻页按钮,只留总数;连每页条数也用不上(不超过最小档)时只剩总数;
 * 没有任何条目时整块不渲染(空态已经说明)。翻页按钮按容器宽度收起(`@container`):窄卡片里不折成两行。
 */
export function Pagination({
  page,
  pageSize,
  total,
  hasMore = false,
  busy = false,
  onPageChange,
  onPageSizeChange,
  className,
  hideSingle = false,
}: PaginationProps) {
  const loadedPages = Math.max(1, Math.ceil(total / pageSize));
  const pages = loadedPages + (hasMore ? 1 : 0);
  const from = total ? (page - 1) * pageSize + 1 : 0;
  const to = Math.min(page * pageSize, total);
  if (!total && !hasMore) return null;
  const single = pages <= 1;
  const showSize = !!onPageSizeChange && total > PAGE_SIZES[0];
  if (single && hideSingle && !showSize) return null;
  return (
    <div className={cn("@container border-t border-border/60", className)}>
      <nav
        aria-label="列表分页"
        aria-busy={busy}
        className="flex flex-wrap items-center justify-between gap-x-3 gap-y-2 px-4 py-2.5 @lg:flex-nowrap"
      >
        <div className="flex min-w-0 items-center gap-3 text-meta whitespace-nowrap text-muted-foreground">
          <span aria-live="polite" className="tabular-nums">
            {hasMore ? `已加载 ${total} 条` : `共 ${total} 条`}
            {single ? null : (
              <span className="hidden @md:inline">
                {" "}
                · {from}–{to} 条
              </span>
            )}
          </span>
          {showSize ? (
            <div className="flex items-center gap-2">
              <span className="hidden @sm:inline">每页</span>
              <Select
                value={String(pageSize)}
                disabled={busy}
                onValueChange={(value) => onPageSizeChange?.(Number(value))}
              >
                <SelectTrigger size="sm" aria-label="每页条数" className="min-w-22 text-caption text-foreground">
                  <SelectValue />
                </SelectTrigger>
                <SelectContent position="popper" align="start" collisionPadding={16}>
                  {PAGE_SIZES.map((size) => (
                    <SelectItem key={size} value={String(size)}>
                      {size} 条
                    </SelectItem>
                  ))}
                </SelectContent>
              </Select>
            </div>
          ) : null}
        </div>
        {single ? null : (
          <div className="ml-auto flex shrink-0 items-center gap-1">
            <Button
              type="button"
              size="sm"
              variant="ghost"
              aria-label="第一页"
              className="hidden @xl:inline-flex"
              disabled={busy || page <= 1}
              onClick={() => onPageChange(1)}
            >
              <ChevronsLeft className="h-4 w-4" />
            </Button>
            <Button
              type="button"
              size="sm"
              variant="outline"
              aria-label="上一页"
              disabled={busy || page <= 1}
              onClick={() => onPageChange(page - 1)}
            >
              <ChevronLeft className="h-4 w-4" />
              <span className="hidden @2xl:inline">上一页</span>
            </Button>
            {pageNumbers(page, pages).map((n, i) =>
              n === "…" ? (
                <span key={`gap-${i}`} aria-hidden className="px-1 text-muted-foreground">
                  …
                </span>
              ) : (
                <Button
                  key={n}
                  type="button"
                  size="sm"
                  variant={n === page ? "outline" : "ghost"}
                  aria-label={`第 ${n} 页`}
                  aria-current={n === page ? "page" : undefined}
                  disabled={busy}
                  onClick={() => onPageChange(n)}
                >
                  {n}
                </Button>
              ),
            )}
            <Button
              type="button"
              size="sm"
              variant="outline"
              aria-label="下一页"
              disabled={busy || page >= pages}
              onClick={() => onPageChange(page + 1)}
            >
              <span className="hidden @2xl:inline">下一页</span>
              <ChevronRight className="h-4 w-4" />
            </Button>
            {!hasMore ? (
              <Button
                type="button"
                size="sm"
                variant="ghost"
                aria-label="最后一页"
                className="hidden @xl:inline-flex"
                disabled={busy || page >= pages}
                onClick={() => onPageChange(pages)}
              >
                <ChevronsRight className="h-4 w-4" />
              </Button>
            ) : null}
          </div>
        )}
      </nav>
    </div>
  );
}