feat: expand backend admin marketplace and scaling

src/modules/chat/chat.service.ts

@@ -1,6 +1,9 @@
-import { BadRequestException, ForbiddenException, Injectable, NotFoundException } from '@nestjs/common';
+import { BadRequestException, ForbiddenException, Injectable, Logger, NotFoundException } from '@nestjs/common';
 import { Types } from 'mongoose';
 import { decodeOffsetCursor, encodeOffsetCursor } from '../../common/utils/cursor.util';
+import { buildPaginatedResponse } from '../../common/utils/pagination.util';
+import { resolveMongoSortDirection } from '../../common/utils/sort.util';
+import { NotificationsService } from '../notifications/notifications.service';
 import { UsersRepository } from '../users/users.repository';
 import { CreateConversationDto } from './dto/create-conversation.dto';
 import { MessageQueryDto } from './dto/message-query.dto';
@@ -9,9 +12,12 @@ import { ChatRepository } from './chat.repository';
 
 @Injectable()
 export class ChatService {
+  private readonly logger = new Logger(ChatService.name);
+
   constructor(
     private readonly chatRepository: ChatRepository,
     private readonly usersRepository: UsersRepository,
+    private readonly notificationsService: NotificationsService,
   ) {}
 
   async createConversation(currentUserId: string, dto: CreateConversationDto) {
@@ -61,9 +67,13 @@ export class ChatService {
     const limit = query.limit ?? 20;
     const cursorOffset = decodeOffsetCursor(query.cursor);
     const skip = cursorOffset ?? (page - 1) * limit;
+    const direction = resolveMongoSortDirection(query.sortOrder);
 
     const [items, total] = await Promise.all([
-      this.chatRepository.findConversationsForUser(currentUserId, skip, limit),
+      this.chatRepository.findConversationsForUser(currentUserId, skip, limit, {
+        lastMessageAt: direction,
+        updatedAt: direction,
+      }),
       this.chatRepository.countConversationsForUser(currentUserId),
     ]);
 
@@ -78,14 +88,15 @@ export class ChatService {
     const nextOffset = skip + mappedItems.length;
     const nextCursor = nextOffset < total ? encodeOffsetCursor(nextOffset) : null;
 
-    return {
-      items: mappedItems,
+    return buildPaginatedResponse(mappedItems, {
       page,
       limit,
       total,
-      totalPages: Math.ceil(total / limit) || 1,
+      offset: skip,
+      currentCursor: query.cursor ?? null,
       nextCursor,
-    };
+      mode: 'cursor',
+    });
   }
 
   async getMessages(currentUserId: string, conversationId: string, query: MessageQueryDto) {
@@ -94,9 +105,10 @@ export class ChatService {
     const limit = query.limit ?? 20;
     const cursorOffset = decodeOffsetCursor(query.cursor);
     const skip = cursorOffset ?? (page - 1) * limit;
+    const sort = { createdAt: resolveMongoSortDirection(query.sortOrder) } as Record<string, 1 | -1>;
 
     const [items, total] = await Promise.all([
-      this.chatRepository.findMessages(conversation.id, skip, limit),
+      this.chatRepository.findMessages(conversation.id, skip, limit, sort),
       this.chatRepository.countMessages(conversation.id),
     ]);
 
@@ -104,14 +116,15 @@ export class ChatService {
     const nextOffset = skip + items.length;
     const nextCursor = nextOffset < total ? encodeOffsetCursor(nextOffset) : null;
 
-    return {
-      items,
+    return buildPaginatedResponse(items, {
       page,
       limit,
       total,
-      totalPages: Math.ceil(total / limit) || 1,
+      offset: skip,
+      currentCursor: query.cursor ?? null,
       nextCursor,
-    };
+      mode: 'cursor',
+    });
   }
 
   async sendMessage(currentUserId: string, dto: SendMessageDto) {
@@ -144,6 +157,12 @@ export class ChatService {
       currentUserId,
       preview,
     );
+    await this.dispatchMessageNotifications(
+      currentUserId,
+      conversation.participantIds.map((id) => id.toString()),
+      conversation.id,
+      preview,
+    );
 
     return message;
   }
@@ -247,4 +266,32 @@ export class ChatService {
       }
     }
   }
+
+  private async dispatchMessageNotifications(
+    actorId: string,
+    participantIds: string[],
+    conversationId: string,
+    previewText: string,
+  ): Promise<void> {
+    for (const recipientId of participantIds) {
+      if (recipientId === actorId) {
+        continue;
+      }
+
+      try {
+        await this.notificationsService.createMessageNotification(
+          actorId,
+          recipientId,
+          conversationId,
+          previewText.slice(0, 160),
+        );
+      } catch (error) {
+        this.logger.warn(
+          `Message notification failed for actor=${actorId} recipient=${recipientId}: ${
+            error instanceof Error ? error.message : 'unknown error'
+          }`,
+        );
+      }
+    }
+  }
 }