Comment System মানে
শুধু table এ row insert
না — এটা ভুল।

// ❌ Most people do this const comment = await db.query( `SELECT * FROM comments WHERE content_id = ?`, [contentId] ); // Then for each comment, get replies: for (const c of comments) { c.replies = await db.query( `SELECT * FROM replies WHERE comment_id = ?`, [c.id] ); } // 100 comments = 101 DB queries 😱 // N+1 Problem!

// Prisma Schema model classComment { id String @id @default(uuid()) comment String // Who wrote it (mutually exclusive) studentId String? adminId String? student Student? @relation(...) admin Admin? @relation(...) // Where it belongs classContentId String? // Admission/FRB cycleContentId String? // Academic // 🔑 Self-reference = nested reply parentId String? parent classComment? @relation("CommentReplies", fields: [parentId], ...) replies classComment[] @relation("CommentReplies") // Soft delete isDeleted Boolean @default(false) createdAt DateTime @default(now()) updatedAt DateTime @updatedAt }

// getSingleCommentfromDb() async function getReplies(commentId) { const replies = await prisma.classComment.findMany({ where: { parentId: commentId, isDeleted: false, // soft-deleted বাদ }, orderBy: { createdAt: 'asc' }, select: selectFields, }); // Recursively fetch each reply's children return Promise.all( replies.map(async (r) => ({ ...r, replies: await getReplies(r.id), })) ); } // Root comments first (parentId: null) const parentComments = await prisma.classComment .findMany({ where: { OR: [ { classContentId: id }, { cycleContentId: id }, // dual content! ], parentId: null, isDeleted: false, }, orderBy: { createdAt: 'desc' }, select: selectFields, }); // Attach nested replies return Promise.all( parentComments.map(async (c) => ({ ...c, replies: await getReplies(c.id), })) );

// One DB round-trip, 5 queries parallel const [ totalCount, comments, filteredTotalCount, repliedComments, todayComments, ] = await prisma.$transaction([ // 1. সব parent comment count (unfiltered) prisma.classComment.count({ where: totalCountWhere }), // 2. Actual data (paginated, filtered) prisma.classComment.findMany({ where: listWhere, orderBy, skip, take, select: getAllselectFieldsForGetAllComments, }), // 3. Filtered total (for pagination) prisma.classComment.count({ where: listWhere }), // 4. Replied count (admin replied করেছে) prisma.classComment.count({ where: repliedCountWhere }), // 5. Today's comments (24h window) prisma.classComment.count({ where: todayCountWhere }), ]); const pendingComments = totalCount - repliedComments; // pending derive করা — আলাদা query লাগে না!

// Admin scope: শুধু assigned courses if (user?.adminId) { const accessibleCourses = await prisma.courseAdmin.findMany({ where: { adminId: user.adminId, isDeleted: false }, select: { courseId: true }, }); accessibleCourseIds = accessibleCourses .map((c) => c.courseId); } // Host-based platform separation if (hostName === config.frb_host_name) { // FRB: Academic + FRB product classContentRelation = { courseSubjectChapter: { courseSubject: { course: { AND: [ { Category: { contains: 'Academic' } }, { productName: { contains: 'FRB' } }, { id: { in: accessibleCourseIds } }, ]} }} }; } else if (hostName === config.academic_host_name) { // Academic: cycleContent path cycleContentRelation = { ... }; } else { // Admission: non-academic category classContentRelation = { ... }; }

// ✅ Soft Delete — data থাকে, hide হয় const deleteCommentFromDb = async (id) => { await prisma.classComment.update({ where: { id }, data: { isDeleted: true }, // not DELETE! }); return {}; }; // Notification flow on reply: const replyToCommentIntoDb = async (payload) => { const result = await prisma.classComment .create({ data: replayData }); // Non-blocking notification (try/catch) try { await replayCommandSentToNotification( replayData ); } catch (error) { console.log("Notif error:", error.message); // Reply succeeds even if notif fails } return response; };

// nestedSelectFields.js export const nestedSelectFields = (fields = []) => { const select = {}; fields.forEach((fieldPath) => { const keys = fieldPath.split('.'); let current = select; while (keys.length > 0) { const key = keys.shift(); if (!current[key]) { current[key] = keys.length > 0 ? { select: {} } : true; } if (keys.length > 0) { current = current[key].select; } } }); return select; };

// 20 lines of nested objects select: { id: true, student: { select: { name: true, profilePhoto: true, } }, replies: { select: { admin: { select: { name: true } } } } }

nestedSelectFields([ "id", "student.name", "student.profilePhoto", "replies.admin.name", "replies.student.name", ]) // → same nested Prisma object // Auto-generated! Error-free.

router.post('/', // Gate 1: JWT verify + role check authorizationMiddleware.authorize([ Enums.roles.ADMIN, Enums.roles.STUDENT, Enums.roles.SUPERADMIN, ]), // Gate 2: Zod schema validation validationRequest( CommentValidationSchema .createCommentValidationSchema ), // Gate 3: Student restriction check checkRestriction( RestrictionType.MEDIA_COMMENT ), CommentController.createComment ); // Zod: one of classContentId OR cycleContentId body.refine( (data) => data.classContentId || data.cycleContentId, { message: 'Either content id required' } );