import clsx from 'clsx'
import { ChevronLeft, ChevronRight } from 'lucide-react'

interface PaginationProps {
  page: number          // 当前页（1-based）
  pageSize: number      // 每页条数
  total: number         // 总条数
  onPageChange: (page: number) => void
  onPageSizeChange?: (size: number) => void
  pageSizeOptions?: number[]
}

export default function Pagination({
  page,
  pageSize,
  total,
  onPageChange,
  onPageSizeChange,
  pageSizeOptions = [10, 20, 50],
}: PaginationProps) {
  const totalPages = Math.max(1, Math.ceil(total / pageSize))
  const start = total === 0 ? 0 : (page - 1) * pageSize + 1
  const end = Math.min(page * pageSize, total)

  // 生成页码按钮（最多显示 7 个）
  const pages: (number | '...')[] = []
  if (totalPages <= 7) {
    for (let i = 1; i <= totalPages; i++) pages.push(i)
  } else {
    pages.push(1)
    if (page > 3) pages.push('...')
    const s = Math.max(2, page - 1)
    const e = Math.min(totalPages - 1, page + 1)
    for (let i = s; i <= e; i++) pages.push(i)
    if (page < totalPages - 2) pages.push('...')
    pages.push(totalPages)
  }

  return (
    <div className="flex items-center justify-between gap-4 py-2">
      {/* 左侧：条数信息 + 每页条数选择 */}
      <div className="flex items-center gap-3 text-sm text-gray-500">
        <span>共 {total} 条</span>
        {onPageSizeChange && (
          <select
            className="border rounded px-1.5 py-0.5 text-sm text-gray-600 focus:outline-none focus:border-primary"
            value={pageSize}
            onChange={(e) => onPageSizeChange(Number(e.target.value))}
          >
            {pageSizeOptions.map((n) => (
              <option key={n} value={n}>{n} 条/页</option>
            ))}
          </select>
        )}
        <span>第 {start}-{end} 条</span>
      </div>

      {/* 右侧：页码导航 */}
      <div className="flex items-center gap-1">
        <button
          className="p-1 rounded text-gray-500 hover:text-gray-700 hover:bg-gray-100 disabled:opacity-30 disabled:cursor-not-allowed"
          disabled={page <= 1}
          onClick={() => onPageChange(page - 1)}
        >
          <ChevronLeft className="w-4 h-4" />
        </button>
        {pages.map((p, i) =>
          p === '...' ? (
            <span key={`ellipsis-${i}`} className="px-2 text-gray-500 text-sm">…</span>
          ) : (
            <button
              key={p}
              className={clsx(
                'min-w-[28px] h-7 rounded text-sm font-medium transition-colors',
                p === page
                  ? 'bg-primary text-white'
                  : 'text-gray-600 hover:bg-gray-100',
              )}
              onClick={() => onPageChange(p)}
            >
              {p}
            </button>
          ),
        )}
        <button
          className="p-1 rounded text-gray-500 hover:text-gray-700 hover:bg-gray-100 disabled:opacity-30 disabled:cursor-not-allowed"
          disabled={page >= totalPages}
          onClick={() => onPageChange(page + 1)}
        >
          <ChevronRight className="w-4 h-4" />
        </button>
      </div>
    </div>
  )
}
