proposal-system/web/src/hooks/usePaginatedList.ts

import { useCallback, useEffect, useMemo, useRef, useState } from 'react';
import { DEBOUNCE_SEARCH, DEFAULT_PAGE, DEFAULT_PAGE_SIZE } from '../constants';

interface PaginatedResult<T> {
  items: T[];
  totalCount: number;
}

type FetchFn<T> = (params: Record<string, unknown>) => Promise<PaginatedResult<T>>;

export function usePaginatedList<T>(fetchFn: FetchFn<T>, extraParams: Record<string, unknown> = {}) {
  const [rows, setRows] = useState<T[]>([]);
  const [search, setSearch] = useState('');
  const [debouncedSearch, setDebouncedSearch] = useState('');
  const [page, setPage] = useState(DEFAULT_PAGE);
  const [pageSize, setPageSize] = useState(DEFAULT_PAGE_SIZE);
  const [totalCount, setTotalCount] = useState(0);
  const [loading, setLoading] = useState(true);
  const [err, setErr] = useState('');
  const debounceRef = useRef<ReturnType<typeof setTimeout> | null>(null);

  const extraKey = JSON.stringify(extraParams);

  useEffect(() => {
    if (debounceRef.current) clearTimeout(debounceRef.current);
    debounceRef.current = setTimeout(() => {
      setDebouncedSearch(search);
      setPage(1);
    }, DEBOUNCE_SEARCH);
    return () => {
      if (debounceRef.current) clearTimeout(debounceRef.current);
    };
  }, [search]);

  const reload = useCallback(() => {
    setLoading(true);
    setErr('');
    fetchFn({ search: debouncedSearch, page, pageSize, ...extraParams })
      .then(({ items, totalCount }) => {
        setRows(items);
        setTotalCount(totalCount);
      })
      .catch((e: Error) => setErr(e.message || 'Failed to load'))
      .finally(() => setLoading(false));
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, [fetchFn, debouncedSearch, page, pageSize, extraKey]);

  useEffect(() => {
    reload();
  }, [reload]);

  return useMemo(
    () => ({
      rows,
      search,
      setSearch,
      page,
      setPage,
      pageSize,
      setPageSize,
      totalCount,
      loading,
      err,
      reload,
    }),
    [rows, search, page, pageSize, totalCount, loading, err, reload]
  );
}