paginate.ts

const getPagination = (currentPage: number, totalPages: number) => {
  const BOUNDARY = 5;
  const MIN_PAGE = 1;
  const MAX_PAGE = Math.max(MIN_PAGE, totalPages);

  const prevPage = currentPage > MIN_PAGE ? currentPage - 1 : null;
  const nextPage = currentPage < MAX_PAGE ? currentPage + 1 : null;

  let prevPages: number[] = [];
  let nextPages: number[] = [];

  for (let i = Math.max(MIN_PAGE + 1, currentPage - BOUNDARY); i < currentPage; i++) {
    prevPages.push(i);
  }

  for (let i = currentPage + 1; i <= Math.min(MAX_PAGE - 1, currentPage + BOUNDARY); i++) {
    nextPages.push(i);
  }

  return {
    prevPage,
    nextPage,
    nextPages,
    prevPages,
  };
};