// entities/document/api/queries.ts
import "server-only";
import { makeError } from "@/error/make-error";
import { actionSuccess, actionFailure, type Result } from "@/error/result";
import { handleServerError } from "@/error/handler.server";
 
export const getDocument = async (
  docId: string,
): Promise<Result<DocumentDTO>> => {
  try {
    const doc = await db.collection("documents").doc(docId).get();
 
    if (!doc.exists) {
      return actionFailure(
        makeError({
          code: "NOT_FOUND",
          details: { resource: "document" },
          message: "요청하신 문서를 찾을 수 없습니다.",
        }),
      );
    }
 
    return actionSuccess(doc.data() as DocumentDTO);
  } catch (error) {
    // "모든 처리는 handleError로" — 서버에서도 예외 없음
    handleServerError(error, { ux: "none" });
    throw new Error("데이터를 불러오는 중 문제가 발생했습니다.", {
      cause: error,
    });
  }
};

// app/documents/[docId]/page.tsx
import { handleServerError } from "@/error/handler.server";
 
export default async function DocumentPage({
  params,
}: {
  params: Promise<{ docId: string }>;
}) {
  const { docId } = await params;
  const result = await getDocument(docId);
 
  if (!result.ok) {
    // serverPresenter가 no-op이므로 UX 부수효과 없음
    const error = handleServerError(result.error);
    return <NotFoundView message={error.message} />;
  }
 
  return <DocumentViewer document={result.data} />;
}

// app/documents/[docId]/page.tsx
import {
  dehydrate,
  HydrationBoundary,
  QueryClient,
} from "@tanstack/react-query";
 
export default async function DocumentPage({
  params,
}: {
  params: Promise<{ docId: string }>;
}) {
  const { docId } = await params;
  const queryClient = new QueryClient();
 
  await queryClient.prefetchQuery({
    queryKey: ["document", docId],
    queryFn: () => getDocument(docId),
  });
 
  return (
    <HydrationBoundary state={dehydrate(queryClient)}>
      <DocumentClientViewer docId={docId} />
    </HydrationBoundary>
  );
}

// features/document-viewer/ui/DocumentClientViewer.tsx
"use client";
import { useQuery } from "@tanstack/react-query";
import { networkBoundaryResult } from "@/error/network-boundary";
import { handleError } from "@/error/handler";
import type { Result } from "@/error/result";
 
export const DocumentClientViewer = ({ docId }: { docId: string }) => {
  // 💡 아키텍처 규칙: 우리 구조에서 queryFn은 Result<T>를 반환합니다.
  // 따라서 data는 성공(ok: true) 또는 비즈니스 에러(ok: false)를 모두 포함합니다.
  // 인프라 에러(Track 2)만 reject되어 isError / throwOnError 대상이 됩니다.
  // React Query의 기본 멘탈 모델("data = 성공")과 다르므로 주의하세요.
  const { data: result } = useQuery({
    queryKey: ["document", docId],
    queryFn: () =>
      networkBoundaryResult<DocumentDTO>(`/api/documents/${docId}`),
    throwOnError: true,
  });
 
  if (!result) return null;
 
  if (!result.ok) {
    const error = handleError(result.error);
    return <div className="text-yellow-600">안내: {error.message}</div>;
  }
 
  return <div>{result.data.title}</div>;
};

// features/document-editor/ui/CreateDocumentForm.tsx
"use client";
import { useMutation, useQueryClient } from "@tanstack/react-query";
import { networkBoundaryResult } from "@/error/network-boundary";
import { handleError } from "@/error/handler";
 
export const CreateDocumentForm = () => {
  const queryClient = useQueryClient();
 
  const mutation = useMutation({
    mutationFn: (payload: CreateDocumentPayload) =>
      networkBoundaryResult<DocumentDTO>("/api/documents", {
        method: "POST",
        body: JSON.stringify(payload),
        headers: { "Content-Type": "application/json" },
      }),
    onSuccess: (result) => {
      if (!result.ok) {
        const error = handleError(result.error);
        if (error.code === "VALIDATION") {
          setFieldErrors(error.details.fieldErrors);
        }
        return;
      }
      toast.success("문서가 생성되었습니다.");
      queryClient.invalidateQueries({ queryKey: ["documents"] });
    },
    throwOnError: true,
  });
 
  // ...
};