proposal-system/web/src/domain/pricingLibrary/use-cases.ts

// Pricing library domain — TanStack Query hooks + query keys (the only public surface).
import { keepPreviousData, useMutation, useQuery, useQueryClient } from '@tanstack/react-query';
import { toast } from 'react-toastify';
import { pricingLibraryApi } from './api';
import type {
  CreatePricingLibraryItemRequest,
  PricingLibraryListParams,
  UpdatePricingLibraryItemRequest,
} from './types';

export const pricingLibraryKeys = {
  all: ['pricingLibrary'] as const,
  lists: () => [...pricingLibraryKeys.all, 'list'] as const,
  list: (params: PricingLibraryListParams) => [...pricingLibraryKeys.lists(), params] as const,
};

/** Paginated pricing library list (PricingLibraryPage). keepPreviousData
 *  keeps rows/totalCount rendered while a new page fetches (prevents
 *  TablePagination's count collapsing to 0 mid-fetch). */
export function usePricingLibraryList(params: PricingLibraryListParams = {}) {
  return useQuery({
    queryKey: pricingLibraryKeys.list(params),
    queryFn: () => pricingLibraryApi.list(params),
    placeholderData: keepPreviousData,
  });
}

export function useCreatePricingLibraryItem() {
  const queryClient = useQueryClient();
  return useMutation({
    mutationFn: (data: CreatePricingLibraryItemRequest) => pricingLibraryApi.create(data),
    onSuccess: () => {
      queryClient.invalidateQueries({ queryKey: pricingLibraryKeys.lists() });
      toast.success('Pricing item created');
    },
    onError: (error: Error) => {
      toast.error(`Failed to create item: ${error.message}`);
    },
  });
}

export function useUpdatePricingLibraryItem() {
  const queryClient = useQueryClient();
  return useMutation({
    mutationFn: ({ id, data }: { id: string; data: UpdatePricingLibraryItemRequest }) =>
      pricingLibraryApi.update(id, data),
    onSuccess: () => {
      queryClient.invalidateQueries({ queryKey: pricingLibraryKeys.lists() });
      toast.success('Pricing item updated');
    },
    onError: (error: Error) => {
      toast.error(`Failed to update item: ${error.message}`);
    },
  });
}

export function useDeletePricingLibraryItem() {
  const queryClient = useQueryClient();
  return useMutation({
    mutationFn: (id: string) => pricingLibraryApi.remove(id),
    onSuccess: () => {
      queryClient.invalidateQueries({ queryKey: pricingLibraryKeys.lists() });
      toast.success('Pricing item deleted');
    },
    onError: (error: Error) => {
      toast.error(`Failed to delete item: ${error.message}`);
    },
  });
}