(대표님/최겸) 20250702 변경사항 업데이트

1 files changed, 1006 insertions, 0 deletions

diff --git a/lib/qna/service.ts b/lib/qna/service.ts
new file mode 100644
index 00000000..d9c877c6
--- /dev/null
+++ b/lib/qna/service.ts
@@ -0,0 +1,1006 @@
+"use server";
+
+import { revalidateTag, unstable_noStore } from "next/cache";
+import { getServerSession } from "next-auth/next";
+import { authOptions } from "@/app/api/auth/[...nextauth]/route";
+import db from "@/db/db";
+import { qna, qnaAnswer, qnaComments } from "@/db/schema/qna";
+import { qnaView, qnaAnswerView, qnaCommentView } from "@/db/schema";
+import { 
+  eq, 
+  desc, 
+  asc, 
+  and, 
+  or, 
+  ilike, 
+  inArray, 
+  gte, 
+  lte,
+  isNull,
+  isNotNull,
+  count,
+  sql
+} from "drizzle-orm";
+import { unstable_cache } from "@/lib/unstable-cache";
+import { filterColumns } from "@/lib/filter-columns";
+import type { 
+  GetQnaSchema, 
+  CreateQnaSchema, 
+  UpdateQnaSchema,
+  CreateAnswerSchema,
+  UpdateAnswerSchema,
+  CreateCommentSchema,
+  UpdateCommentSchema,
+} from "./validation";
+
+/* ================================================================
+   Helper Functions
+================================================================ */
+
+/**
+ * 인증된 사용자 정보 가져오기
+ */
+async function getAuthenticatedUser() {
+  const session = await getServerSession(authOptions);
+  if (!session?.user?.id) {
+    throw new Error("인증이 필요합니다.");
+  }
+  return parseInt(session.user.id);
+}
+
+/**
+ * 현재 사용자 ID 가져오기 (비로그인 허용)
+ */
+async function getCurrentUserId() {
+  try {
+    const session = await getServerSession(authOptions);
+    return session?.user?.id ? parseInt(session.user.id) : null;
+  } catch {
+    return null;
+  }
+}
+
+/* ================================================================
+   Repository Functions (트랜잭션 지원)
+================================================================ */
+
+/**
+ * Q&A 목록 조회 Repository
+ */
+async function selectQnaList(
+  tx: any,
+  options: {
+    where?: any;
+    orderBy?: any[];
+    offset: number;
+    limit: number;
+  }
+) {
+  const { where, orderBy = [desc(qnaView.createdAt)], offset, limit } = options;
+  
+  return await tx
+    .select()
+    .from(qnaView)
+    .where(where)
+    .orderBy(...orderBy)
+    .offset(offset)
+    .limit(limit);
+}
+
+/**
+ * Q&A 총 개수 조회 Repository
+ */
+async function countQnaList(tx: any, where?: any) {
+  const [result] = await tx
+    .select({ count: count() })
+    .from(qnaView)
+    .where(where);
+  return result.count;
+}
+
+/**
+ * Q&A 상세 조회 Repository
+ */
+async function selectQnaDetail(tx: any, id: number) {
+  const [question] = await tx
+    .select()
+    .from(qnaView)
+    .where(eq(qnaView.id, id));
+  
+  return question || null;
+}
+
+/**
+ * 답변 목록 조회 Repository
+ */
+async function selectAnswersByQnaId(tx: any, qnaId: number) {
+  return await tx
+    .select()
+    .from(qnaAnswerView)
+    .where(eq(qnaAnswerView.qnaId, qnaId))
+    .orderBy(desc(qnaAnswerView.createdAt));
+}
+
+/**
+ * 댓글 목록 조회 Repository (계층형)
+ */
+async function selectCommentsByAnswerId(tx: any, answerId: number) {
+  return await tx
+    .select()
+    .from(qnaCommentView)
+    .where(eq(qnaCommentView.answerId, answerId))
+    .orderBy(asc(qnaCommentView.createdAt)); // 댓글은 오래된 순으로
+}
+
+/**
+ * 내가 답변한 질문 ID 목록 조회
+ */
+async function getMyAnsweredQnaIds(tx: any, userId: number, qnaIds: number[]) {
+  if (qnaIds.length === 0) return [];
+  
+  const results = await tx
+    .select({ qnaId: qnaAnswer.qnaId })
+    .from(qnaAnswer)
+    .where(
+      and(
+        eq(qnaAnswer.author, userId),
+        inArray(qnaAnswer.qnaId, qnaIds),
+        eq(qnaAnswer.isDeleted, false)
+      )
+    );
+  
+  return results.map(r => r.qnaId);
+}
+
+/* ================================================================
+   1) Q&A 목록 조회 (고급 필터링/정렬 지원)
+================================================================ */
+
+export async function getQnaList(input: GetQnaSchema) {
+  return unstable_cache(
+    async () => {
+      try {
+        const offset = (input.page - 1) * input.perPage;
+        const advancedTable = input.flags.includes("advancedTable") || true;
+
+        // 현재 사용자 ID (내 답변 여부 확인용)
+        const currentUserId = await getCurrentUserId();
+
+        // 고급 필터링 WHERE 절 구성
+        const advancedWhere = advancedTable
+          ? filterColumns({
+              table: qnaView,
+              filters: input.filters,
+              joinOperator: input.joinOperator,
+            })
+          : undefined;
+
+        // 전역 검색 WHERE 절
+        let globalWhere;
+        if (input.search) {
+          const searchPattern = `%${input.search}%`;
+          globalWhere = or(
+            ilike(qnaView.title, searchPattern),
+            ilike(qnaView.content, searchPattern),
+            ilike(qnaView.authorName, searchPattern),
+            ilike(qnaView.companyName, searchPattern)
+          );
+        }
+
+        // Q&A 특화 필터링
+        const qnaSpecificWhere = and(
+          // 도메인 필터
+          input.authorDomain.length > 0 
+            ? inArray(qnaView.authorDomain, input.authorDomain)
+            : undefined,
+          
+          // 벤더 타입 필터
+          input.vendorType.length > 0
+            ? inArray(qnaView.vendorType, input.vendorType)
+            : undefined,
+          
+          // 답변 유무 필터 (뷰에서 이미 계산된 값 사용)
+          input.hasAnswers === "answered" 
+            ? eq(qnaView.hasAnswers, true)
+            : input.hasAnswers === "unanswered"
+            ? eq(qnaView.hasAnswers, false)
+            : undefined,
+          
+          // 내 질문만 보기
+          input.myQuestions === "true" && currentUserId
+            ? eq(qnaView.author, currentUserId)
+            : undefined,
+          
+          // 날짜 범위 필터
+        );
+
+        // 최종 WHERE 절 결합
+        const finalWhere = and(
+          advancedWhere,
+          globalWhere,
+          qnaSpecificWhere
+        );
+
+        // 정렬 설정
+        const orderBy = input.sort.length > 0
+          ? input.sort.map((item) =>
+              item.desc 
+                ? desc(qnaView[item.id as keyof typeof qnaView]) 
+                : asc(qnaView[item.id as keyof typeof qnaView])
+            )
+          : [desc(qnaView.lastActivityAt), desc(qnaView.createdAt)]; // 최근 활동순으로 기본 정렬
+
+        // 트랜잭션 내에서 데이터 조회
+        const { data, total } = await db.transaction(async (tx) => {
+          const data = await selectQnaList(tx, {
+            where: finalWhere,
+            orderBy,
+            offset,
+            limit: input.perPage,
+          });
+
+          const total = await countQnaList(tx, finalWhere);
+
+          // 내가 답변한 질문들 표시 (로그인한 경우만)
+          let dataWithMyAnswers = data;
+          if (currentUserId && data.length > 0) {
+            const qnaIds = data.map(q => q.id);
+            const myAnsweredIds = await getMyAnsweredQnaIds(tx, currentUserId, qnaIds);
+            
+            dataWithMyAnswers = data.map(q => ({
+              ...q,
+              hasMyAnswer: myAnsweredIds.includes(q.id),
+              isMyQuestion: currentUserId === q.author,
+            }));
+          } else {
+            dataWithMyAnswers = data.map(q => ({
+              ...q,
+              hasMyAnswer: false,
+              isMyQuestion: false,
+            }));
+          }
+
+          return { data: dataWithMyAnswers, total };
+        });
+
+        const pageCount = Math.ceil(total / input.perPage);
+
+        return { 
+          data, 
+          pageCount, 
+          total,
+          // 메타 정보 추가
+          meta: {
+            currentPage: input.page,
+            perPage: input.perPage,
+            hasNextPage: input.page < pageCount,
+            hasPrevPage: input.page > 1,
+          }
+        };
+      } catch (err) {
+        console.error("Q&A 목록 조회 실패:", err);
+        return { 
+          data: [], 
+          pageCount: 0, 
+          total: 0,
+          meta: {
+            currentPage: 1,
+            perPage: input.perPage,
+            hasNextPage: false,
+            hasPrevPage: false,
+          }
+        };
+      }
+    },
+    [JSON.stringify(input)], // 캐싱 키
+    {
+      revalidate: 1800, // 30분 캐싱
+      tags: ["qna", "qna-list"],
+    }
+  )();
+}
+
+/* ================================================================
+   2) Q&A 상세 조회
+================================================================ */
+
+export async function getQnaById(id: number) {
+  return unstable_cache(
+    async () => {
+      try {
+        const currentUserId = await getCurrentUserId();
+
+        return await db.transaction(async (tx) => {
+          // 질문 정보 조회 (뷰 사용으로 단순화)
+          const question = await selectQnaDetail(tx, id);
+          if (!question) return null;
+
+          // 답변 목록 조회 (뷰 사용으로 단순화)
+          const answers = await selectAnswersByQnaId(tx, id);
+
+          // 각 답변의 댓글들 조회 및 계층 구조 생성
+          const answersWithComments = await Promise.all(
+            answers.map(async (answer) => {
+              const comments = await selectCommentsByAnswerId(tx, answer.id);
+
+              // 댓글 계층 구조 생성 (뷰에서 이미 계층 정보 제공)
+              const commentMap = new Map();
+              const rootComments: any[] = [];
+
+              // 먼저 모든 댓글을 Map에 저장
+              comments.forEach(comment => {
+                commentMap.set(comment.id, { 
+                  ...comment, 
+                  children: [],
+                  isMyComment: currentUserId === comment.author,
+                });
+              });
+
+              // 계층 구조 생성
+              comments.forEach(comment => {
+                const commentWithChildren = commentMap.get(comment.id);
+                if (comment.parentCommentId) {
+                  const parent = commentMap.get(comment.parentCommentId);
+                  if (parent) {
+                    parent.children.push(commentWithChildren);
+                  }
+                } else {
+                  rootComments.push(commentWithChildren);
+                }
+              });
+
+              return {
+                ...answer,
+                comments: rootComments,
+                isMyAnswer: currentUserId === answer.author,
+              };
+            })
+          );
+
+          return {
+            ...question,
+            answers: answersWithComments,
+            isMyQuestion: currentUserId === question.author,
+            // 뷰에서 이미 계산된 통계 정보 활용
+            totalInteractions: question.totalAnswers + question.totalComments,
+          };
+        });
+      } catch (err) {
+        console.error("Q&A 상세 조회 실패:", err);
+        return null;
+      }
+    },
+    [`qna-detail-${id}`],
+    {
+      revalidate: 1800, // 30분 캐싱
+      tags: ["qna", `qna-${id}`],
+    }
+  )();
+}
+
+/* ================================================================
+   3) Q&A 생성/수정/삭제 (CRUD 액션들)
+================================================================ */
+
+/**
+ * 새로운 Q&A 질문 생성
+ */
+export async function createQna(input: CreateQnaSchema) {
+  try {
+    const userId = await getAuthenticatedUser();
+
+    const [newQna] = await db.insert(qna).values({
+      title: input.title,
+      content: input.content,
+      category: input.category,
+      author: userId,
+    }).returning();
+
+    revalidateTag("qna");
+    revalidateTag("qna-list");
+    
+    return { 
+      success: true, 
+      data: newQna,
+      message: "질문이 성공적으로 등록되었습니다."
+    };
+  } catch (err) {
+    console.error("질문 생성 실패:", err);
+    return { 
+      success: false, 
+      error: err instanceof Error ? err.message : "질문 등록에 실패했습니다.",
+      data: null
+    };
+  }
+}
+
+/**
+ * Q&A 질문 수정
+ */
+export async function updateQna(id: number, input: UpdateQnaSchema) {
+  unstable_noStore();
+  try {
+    const userId = await getAuthenticatedUser();
+    
+    // 권한 확인
+    const [existing] = await db
+      .select({ 
+        author: qna.author,
+        title: qna.title 
+      })
+      .from(qna)
+      .where(eq(qna.id, id));
+
+    if (!existing) {
+      return { success: false, error: "질문을 찾을 수 없습니다." };
+    }
+
+    if (existing.author !== userId) {
+      return { success: false, error: "수정 권한이 없습니다." };
+    }
+
+    const [updated] = await db
+      .update(qna)
+      .set({ 
+        ...input,
+        updatedAt: new Date()
+      })
+      .where(eq(qna.id, id))
+      .returning();
+
+    revalidateTag("qna");
+    revalidateTag("qna-list");
+    revalidateTag(`qna-${id}`);
+    
+    return { 
+      success: true, 
+      data: updated,
+      message: "질문이 성공적으로 수정되었습니다."
+    };
+  } catch (err) {
+    console.error("질문 수정 실패:", err);
+    return { 
+      success: false, 
+      error: err instanceof Error ? err.message : "질문 수정에 실패했습니다."
+    };
+  }
+}
+
+/**
+ * Q&A 질문 삭제 (소프트 삭제)
+ */
+export async function deleteQna(id: number) {
+  unstable_noStore();
+  try {
+    const userId = await getAuthenticatedUser();
+    
+    // 권한 확인
+    const [existing] = await db
+      .select({ 
+        author: qna.author,
+        title: qna.title 
+      })
+      .from(qna)
+      .where(eq(qna.id, id));
+
+    if (!existing) {
+      return { success: false, error: "질문을 찾을 수 없습니다." };
+    }
+
+    if (existing.author !== userId) {
+      return { success: false, error: "삭제 권한이 없습니다." };
+    }
+
+    await db
+      .update(qna)
+      .set({ 
+        isDeleted: true, 
+        deletedAt: new Date() 
+      })
+      .where(eq(qna.id, id));
+    
+    revalidateTag("qna");
+    revalidateTag("qna-list");
+    revalidateTag(`qna-${id}`);
+    
+    return { 
+      success: true,
+      message: "질문이 성공적으로 삭제되었습니다."
+    };
+  } catch (err) {
+    console.error("질문 삭제 실패:", err);
+    return { 
+      success: false, 
+      error: err instanceof Error ? err.message : "질문 삭제에 실패했습니다."
+    };
+  }
+}
+
+/* ================================================================
+   4) 답변 관련 CRUD 액션들
+================================================================ */
+
+/**
+ * 답변 생성
+ */
+export async function createAnswer(input: CreateAnswerSchema) {
+  unstable_noStore();
+  try {
+    const userId = await getAuthenticatedUser();
+
+    // 질문 존재 여부 확인
+    const [questionExists] = await db
+      .select({ id: qna.id })
+      .from(qna)
+      .where(and(
+        eq(qna.id, input.qnaId),
+        eq(qna.isDeleted, false)
+      ));
+
+    if (!questionExists) {
+      return { success: false, error: "존재하지 않는 질문입니다." };
+    }
+
+    const [newAnswer] = await db.insert(qnaAnswer).values({
+      qnaId: input.qnaId,
+      content: input.content,
+      author: userId,
+    }).returning();
+    
+    revalidateTag("qna");
+    revalidateTag("qna-list");
+    revalidateTag(`qna-${input.qnaId}`);
+    
+    return { 
+      success: true, 
+      data: newAnswer,
+      message: "답변이 성공적으로 등록되었습니다."
+    };
+  } catch (error) {
+    console.error("답변 생성 실패:", error);
+    return { 
+      success: false, 
+      error: error instanceof Error ? error.message : "답변 등록에 실패했습니다."
+    };
+  }
+}
+
+/**
+ * 답변 수정
+ */
+export async function updateAnswer(id: number, input: UpdateAnswerSchema) {
+  unstable_noStore();
+  try {
+    const userId = await getAuthenticatedUser();
+    
+    // 권한 확인
+    const [existing] = await db
+      .select({ 
+        author: qnaAnswer.author,
+        qnaId: qnaAnswer.qnaId 
+      })
+      .from(qnaAnswer)
+      .where(eq(qnaAnswer.id, id));
+
+    if (!existing) {
+      return { success: false, error: "답변을 찾을 수 없습니다." };
+    }
+
+    if (existing.author !== userId) {
+      return { success: false, error: "수정 권한이 없습니다." };
+    }
+
+    const [updated] = await db
+      .update(qnaAnswer)
+      .set({ 
+        content: input.content,
+        updatedAt: new Date()
+      })
+      .where(eq(qnaAnswer.id, id))
+      .returning();
+    
+    revalidateTag("qna");
+    revalidateTag("qna-list");
+    revalidateTag(`qna-${existing.qnaId}`);
+    
+    return { 
+      success: true, 
+      data: updated,
+      message: "답변이 성공적으로 수정되었습니다."
+    };
+  } catch (err) {
+    console.error("답변 수정 실패:", err);
+    return { 
+      success: false, 
+      error: err instanceof Error ? err.message : "답변 수정에 실패했습니다."
+    };
+  }
+}
+
+/**
+ * 답변 삭제
+ */
+export async function deleteAnswer(id: number) {
+  unstable_noStore();
+  try {
+    const userId = await getAuthenticatedUser();
+    
+    // 권한 확인
+    const [existing] = await db
+      .select({ 
+        author: qnaAnswer.author,
+        qnaId: qnaAnswer.qnaId 
+      })
+      .from(qnaAnswer)
+      .where(eq(qnaAnswer.id, id));
+
+    if (!existing) {
+      return { success: false, error: "답변을 찾을 수 없습니다." };
+    }
+
+    if (existing.author !== userId) {
+      return { success: false, error: "삭제 권한이 없습니다." };
+    }
+
+    // 하드 삭제 (답변은 CASCADE로 댓글도 함께 삭제)
+    await db.delete(qnaAnswer).where(eq(qnaAnswer.id, id));
+    
+    revalidateTag("qna");
+    revalidateTag("qna-list");
+    revalidateTag(`qna-${existing.qnaId}`);
+    
+    return { 
+      success: true,
+      message: "답변이 성공적으로 삭제되었습니다."
+    };
+  } catch (err) {
+    console.error("답변 삭제 실패:", err);
+    return { 
+      success: false, 
+      error: err instanceof Error ? err.message : "답변 삭제에 실패했습니다."
+    };
+  }
+}
+
+/* ================================================================
+   5) 댓글 관련 CRUD 액션들
+================================================================ */
+
+/**
+ * 댓글 생성
+ */
+export async function createComment(input: CreateCommentSchema) {
+  unstable_noStore();
+  try {
+    const userId = await getAuthenticatedUser();
+
+    // 답변 존재 여부 확인
+    const [answerExists] = await db
+      .select({ 
+        id: qnaAnswer.id,
+        qnaId: qnaAnswer.qnaId 
+      })
+      .from(qnaAnswer)
+      .where(and(
+        eq(qnaAnswer.id, input.answerId),
+        eq(qnaAnswer.isDeleted, false)
+      ));
+
+    if (!answerExists) {
+      return { success: false, error: "존재하지 않는 답변입니다." };
+    }
+
+    // 부모 댓글 존재 여부 확인 (대댓글인 경우)
+    if (input.parentCommentId) {
+      const [parentExists] = await db
+        .select({ id: qnaComments.id })
+        .from(qnaComments)
+        .where(and(
+          eq(qnaComments.id, input.parentCommentId),
+          eq(qnaComments.answerId, input.answerId),
+          eq(qnaComments.isDeleted, false)
+        ));
+
+      if (!parentExists) {
+        return { success: false, error: "존재하지 않는 부모 댓글입니다." };
+      }
+    }
+
+    const [newComment] = await db.insert(qnaComments).values({
+      ...input,
+      author: userId,
+    }).returning();
+    
+    revalidateTag("qna");
+    revalidateTag("qna-list");
+    revalidateTag(`qna-${answerExists.qnaId}`);
+    
+    return { 
+      success: true, 
+      data: newComment,
+      message: "댓글이 성공적으로 등록되었습니다."
+    };
+  } catch (error) {
+    console.error("댓글 작성 실패:", error);
+    return { 
+      success: false, 
+      error: error instanceof Error ? error.message : "댓글 등록에 실패했습니다."
+    };
+  }
+}
+
+/**
+ * 댓글 수정
+ */
+export async function updateComment(id: number, input: UpdateCommentSchema) {
+  unstable_noStore();
+  try {
+    const userId = await getAuthenticatedUser();
+    
+    // 권한 확인 및 질문 ID 가져오기
+    const [existing] = await db
+      .select({ 
+        author: qnaComments.author,
+        answerId: qnaComments.answerId,
+        qnaId: qnaAnswer.qnaId
+      })
+      .from(qnaComments)
+      .leftJoin(qnaAnswer, eq(qnaComments.answerId, qnaAnswer.id))
+      .where(eq(qnaComments.id, id));
+
+    if (!existing) {
+      return { success: false, error: "댓글을 찾을 수 없습니다." };
+    }
+
+    if (existing.author !== userId) {
+      return { success: false, error: "수정 권한이 없습니다." };
+    }
+
+    const [updated] = await db
+      .update(qnaComments)
+      .set({ 
+        content: input.content,
+        updatedAt: new Date()
+      })
+      .where(eq(qnaComments.id, id))
+      .returning();
+    
+    revalidateTag("qna");
+    revalidateTag("qna-list");
+    revalidateTag(`qna-${existing.qnaId}`);
+    
+    return { 
+      success: true, 
+      data: updated,
+      message: "댓글이 성공적으로 수정되었습니다."
+    };
+  } catch (error) {
+    console.error("댓글 수정 실패:", error);
+    return { 
+      success: false, 
+      error: error instanceof Error ? error.message : "댓글 수정에 실패했습니다."
+    };
+  }
+}
+
+/**
+ * 댓글 삭제
+ */
+export async function deleteComment(id: number) {
+  unstable_noStore();
+  try {
+    const userId = await getAuthenticatedUser();
+    
+    // 권한 확인 및 질문 ID 가져오기
+    const [existing] = await db
+      .select({ 
+        author: qnaComments.author,
+        answerId: qnaComments.answerId,
+        qnaId: qnaAnswer.qnaId
+      })
+      .from(qnaComments)
+      .leftJoin(qnaAnswer, eq(qnaComments.answerId, qnaAnswer.id))
+      .where(eq(qnaComments.id, id));
+
+    if (!existing) {
+      return { success: false, error: "댓글을 찾을 수 없습니다." };
+    }
+
+    if (existing.author !== userId) {
+      return { success: false, error: "삭제 권한이 없습니다." };
+    }
+
+    // 하드 삭제 (대댓글도 CASCADE로 함께 삭제)
+    await db.delete(qnaComments).where(eq(qnaComments.id, id));
+    
+    revalidateTag("qna");
+    revalidateTag("qna-list");
+    revalidateTag(`qna-${existing.qnaId}`);
+    
+    return { 
+      success: true,
+      message: "댓글이 성공적으로 삭제되었습니다."
+    };
+  } catch (error) {
+    console.error("댓글 삭제 실패:", error);
+    return { 
+      success: false, 
+      error: error instanceof Error ? error.message : "댓글 삭제에 실패했습니다."
+    };
+  }
+}
+
+/* ================================================================
+   6) 답변별 댓글 목록 조회
+================================================================ */
+
+export async function getCommentsByAnswerId(answerId: number) {
+  return unstable_cache(
+    async () => {
+      try {
+        const currentUserId = await getCurrentUserId();
+        
+        return await db.transaction(async (tx) => {
+          const comments = await selectCommentsByAnswerId(tx, answerId);
+          
+          // 댓글 계층 구조 생성
+          const commentMap = new Map();
+          const rootComments: any[] = [];
+
+          // 모든 댓글을 Map에 저장
+          comments.forEach(comment => {
+            commentMap.set(comment.id, { 
+              ...comment, 
+              children: [],
+              isMyComment: currentUserId === comment.author,
+            });
+          });
+
+          // 계층 구조 생성
+          comments.forEach(comment => {
+            const commentWithChildren = commentMap.get(comment.id);
+            if (comment.parentCommentId) {
+              const parent = commentMap.get(comment.parentCommentId);
+              if (parent) {
+                parent.children.push(commentWithChildren);
+              }
+            } else {
+              rootComments.push(commentWithChildren);
+            }
+          });
+
+          return rootComments;
+        });
+      } catch (error) {
+        console.error("댓글 조회 실패:", error);
+        return [];
+      }
+    },
+    [`comments-${answerId}`],
+    {
+      revalidate: 1800, // 30분 캐싱
+      tags: ["qna", `comments-${answerId}`],
+    }
+  )();
+}
+
+/* ================================================================
+   7) 통계 및 메타 정보 조회
+================================================================ */
+
+/**
+ * Q&A 대시보드 통계 조회
+ */
+export async function getQnaStats() {
+  return unstable_cache(
+    async () => {
+      try {
+        // 뷰를 사용하여 간단하게 통계 조회
+        const [stats] = await db
+          .select({
+            totalQuestions: count(),
+            answeredQuestions: sql<number>`COUNT(CASE WHEN ${qnaView.hasAnswers} = true THEN 1 END)`,
+            unansweredQuestions: sql<number>`COUNT(CASE WHEN ${qnaView.hasAnswers} = false THEN 1 END)`,
+            popularQuestions: sql<number>`COUNT(CASE WHEN ${qnaView.isPopular} = true THEN 1 END)`,
+            totalAnswers: sql<number>`SUM(${qnaView.totalAnswers})`,
+            totalComments: sql<number>`SUM(${qnaView.totalComments})`,
+          })
+          .from(qnaView);
+
+        // 최근 활동 통계
+        const [recentStats] = await db
+          .select({
+            questionsThisWeek: sql<number>`COUNT(CASE WHEN ${qnaView.createdAt} >= NOW() - INTERVAL '7 days' THEN 1 END)`,
+            questionsThisMonth: sql<number>`COUNT(CASE WHEN ${qnaView.createdAt} >= NOW() - INTERVAL '30 days' THEN 1 END)`,
+            activeQuestionsThisWeek: sql<number>`COUNT(CASE WHEN ${qnaView.lastActivityAt} >= NOW() - INTERVAL '7 days' THEN 1 END)`,
+          })
+          .from(qnaView);
+
+        return {
+          ...stats,
+          ...recentStats,
+          // 추가 계산 통계
+          answerRate: stats.totalQuestions > 0 
+            ? Math.round((stats.answeredQuestions / stats.totalQuestions) * 100) 
+            : 0,
+          avgAnswersPerQuestion: stats.totalQuestions > 0 
+            ? Math.round((stats.totalAnswers || 0) / stats.totalQuestions * 100) / 100
+            : 0,
+        };
+      } catch (err) {
+        console.error("Q&A 통계 조회 실패:", err);
+        return {
+          totalQuestions: 0,
+          answeredQuestions: 0,
+          unansweredQuestions: 0,
+          popularQuestions: 0,
+          totalAnswers: 0,
+          totalComments: 0,
+          questionsThisWeek: 0,
+          questionsThisMonth: 0,
+          activeQuestionsThisWeek: 0,
+          answerRate: 0,
+          avgAnswersPerQuestion: 0,
+        };
+      }
+    },
+    ["qna-stats"],
+    {
+      revalidate: 3600, // 1시간 캐싱
+      tags: ["qna", "qna-stats"],
+    }
+  )();
+}
+
+/**
+ * 사용자별 Q&A 활동 통계
+ */
+export async function getMyQnaActivity() {
+  try {
+    const userId = await getAuthenticatedUser();
+    
+    return unstable_cache(
+      async () => {
+        const [myStats] = await db
+          .select({
+            myQuestions: count(),
+            myAnsweredQuestions: sql<number>`COUNT(CASE WHEN ${qnaView.hasAnswers} = true THEN 1 END)`,
+          })
+          .from(qnaView)
+          .where(eq(qnaView.author, userId));
+
+        const [myAnswers] = await db
+          .select({
+            totalAnswers: count(),
+          })
+          .from(qnaAnswerView)
+          .where(eq(qnaAnswerView.author, userId));
+
+        const [myComments] = await db
+          .select({
+            totalComments: count(),
+          })
+          .from(qnaCommentView)
+          .where(eq(qnaCommentView.author, userId));
+
+        return {
+          ...myStats,
+          ...myAnswers,
+          ...myComments,
+        };
+      },
+      [`my-qna-activity-${userId}`],
+      {
+        revalidate: 1800, // 30분 캐싱
+        tags: ["qna", `user-activity-${userId}`],
+      }
+    )();
+  } catch (err) {
+    return {
+      myQuestions: 0,
+      myAnsweredQuestions: 0,
+      totalAnswers: 0,
+      totalComments: 0,
+    };
+  }
+}
\ No newline at end of file