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

// Proposals 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 { proposalsApi } from './api';
import type { CreateProposalRequest, ProposalDetail, ProposalFilters } from './types';

export const proposalsKeys = {
  all: ['proposals'] as const,
  lists: () => [...proposalsKeys.all, 'list'] as const,
  list: (filters: ProposalFilters) => [...proposalsKeys.lists(), filters] as const,
  detail: (id: string) => [...proposalsKeys.all, id] as const,
  stats: () => [...proposalsKeys.all, 'stats'] as const,
  vendors: (id: string) => [...proposalsKeys.all, id, 'vendors'] as const,
};

/** Paginated/filtered proposal list (ProposalListPage, AdminDashboard queue,
 *  Dashboard recent). keepPreviousData mirrors usePaginatedList's
 *  keep-rows-while-loading behavior across page changes. */
export function useProposals(filters: ProposalFilters = {}) {
  return useQuery({
    queryKey: proposalsKeys.list(filters),
    queryFn: () => proposalsApi.getAll(filters),
    placeholderData: keepPreviousData,
  });
}

export function useProposal(id: string | undefined) {
  return useQuery({
    queryKey: proposalsKeys.detail(id ?? ''),
    queryFn: () => proposalsApi.getById(id!),
    enabled: !!id,
  });
}

export function useProposalStats() {
  return useQuery({
    queryKey: proposalsKeys.stats(),
    queryFn: () => proposalsApi.getStats(),
  });
}

/** Vendor proposals attached to a proposal (VendorDataPanel). */
export function useVendorProposals(proposalId: string | undefined) {
  return useQuery({
    queryKey: proposalsKeys.vendors(proposalId ?? ''),
    queryFn: () => proposalsApi.getVendors(proposalId!),
    enabled: !!proposalId,
  });
}

export interface CreateProposalVariables {
  request: CreateProposalRequest;
  /** Optional vendor PDF uploaded alongside the proposal. */
  vendorFile?: File | null;
}

/**
 * Create a proposal, optionally uploading a vendor PDF via presigned URL.
 * Mirrors ProposalFormPage: a failed attachment upload warns but does not
 * fail the mutation; success invalidates all proposal queries and toasts.
 * Page-specific side effects (navigate) belong in the call site's onSuccess.
 */
export function useCreateProposal() {
  const queryClient = useQueryClient();
  return useMutation({
    mutationFn: async ({ request, vendorFile }: CreateProposalVariables): Promise<ProposalDetail> => {
      const proposal = await proposalsApi.create(request);

      if (vendorFile) {
        try {
          const { uploadUrl, vendorProposalId } = await proposalsApi.uploadAttachment(
            proposal.id,
            vendorFile.name
          );
          // Throws on S3 rejection (non-2xx) so a failed upload is never confirmed.
          await proposalsApi.uploadToPresignedUrl(uploadUrl, vendorFile);
          await proposalsApi.confirmUpload(proposal.id, vendorProposalId);
        } catch {
          toast.warning(
            `Proposal ${proposal.proposalNumber} was created, but vendor PDF upload failed. You can re-upload from the proposal detail page.`
          );
        }
      }

      return proposal;
    },
    onSuccess: (proposal) => {
      queryClient.invalidateQueries({ queryKey: proposalsKeys.all });
      toast.success(`Proposal ${proposal.proposalNumber} submitted`);
    },
    onError: (error: Error) => {
      toast.error(error.message || 'Failed to submit proposal');
    },
  });
}