import { useState, type ReactNode } from 'react';
import { Pagination } from '../Pagination/Pagination';
import styles from './Table.module.css';

export interface TableColumn<T> {
  key: string;
  header: ReactNode;
  render: (row: T) => ReactNode;
  width?: string | number;
  align?: 'left' | 'center' | 'right';
}

export interface TableProps<T> {
  columns: TableColumn<T>[];
  data: T[];
  rowKey: (row: T) => string | number;
  loading?: boolean;
  emptyMessage?: string;
  className?: string;
  /** Enable built-in client-side pagination with this default page size */
  pageSize?: number;
  /** Offer a page-size selector when pagination is enabled */
  pageSizeOptions?: number[];
}

export function Table<T>({
  columns,
  data,
  rowKey,
  loading = false,
  emptyMessage = 'No data.',
  className,
  pageSize: defaultPageSize,
  pageSizeOptions,
}: TableProps<T>) {
  const [page, setPage] = useState(1);
  const [pageSize, setPageSize] = useState(defaultPageSize ?? 0);

  const paginated = defaultPageSize !== undefined && !loading;
  const visibleData = paginated ? data.slice((page - 1) * pageSize, page * pageSize) : data;

  // Reset to page 1 when data changes and current page would be empty
  const lastPage = pageSize > 0 ? Math.ceil(data.length / pageSize) : 1;
  const safePage = Math.min(page, Math.max(1, lastPage));

  return (
    <div className={`${styles.wrapper} ${className ?? ''}`}>
      <table className={styles.table}>
        <thead>
          <tr>
            {columns.map((col) => (
              <th
                key={col.key}
                className={styles.th}
                style={{
                  width: col.width,
                  textAlign: col.align ?? 'left',
                }}
              >
                {col.header}
              </th>
            ))}
          </tr>
        </thead>
        <tbody>
          {loading ? (
            <tr>
              <td colSpan={columns.length} className={styles.empty}>
                Loading…
              </td>
            </tr>
          ) : visibleData.length === 0 ? (
            <tr>
              <td colSpan={columns.length} className={styles.empty}>
                {emptyMessage}
              </td>
            </tr>
          ) : (
            visibleData.map((row) => (
              <tr key={rowKey(row)} className={styles.tr}>
                {columns.map((col) => (
                  <td
                    key={col.key}
                    className={styles.td}
                    style={{ textAlign: col.align ?? 'left' }}
                  >
                    {col.render(row)}
                  </td>
                ))}
              </tr>
            ))
          )}
        </tbody>
      </table>
      {paginated && data.length > 0 && (
        <Pagination
          page={safePage}
          pageSize={pageSize}
          total={data.length}
          onPageChange={setPage}
          onPageSizeChange={
            pageSizeOptions
              ? (size) => {
                  setPageSize(size);
                  setPage(1);
                }
              : undefined
          }
          pageSizeOptions={pageSizeOptions}
        />
      )}
    </div>
  );
}