Initial commit: Prism messenger with Expo + NestJS + GraphQL + PostgreSQL

backend/src/modules/conversations/conversations.service.ts

@@ -0,0 +1,84 @@
+import { Injectable, NotFoundException, ForbiddenException } from '@nestjs/common';
+import { InjectRepository } from '@nestjs/typeorm';
+import { Repository } from 'typeorm';
+import { Conversation } from './entities/conversation.entity';
+import { User } from '../users/entities/user.entity';
+
+@Injectable()
+export class ConversationsService {
+  constructor(
+    @InjectRepository(Conversation)
+    private conversationsRepository: Repository<Conversation>,
+  ) {}
+
+  async create(participants: User[], name?: string, isGroup = false): Promise<Conversation> {
+    const conversation = this.conversationsRepository.create({
+      participants,
+      name,
+      isGroup,
+    });
+    return this.conversationsRepository.save(conversation);
+  }
+
+  async findAllForUser(userId: string): Promise<Conversation[]> {
+    return this.conversationsRepository
+      .createQueryBuilder('conversation')
+      .leftJoinAndSelect('conversation.participants', 'participants')
+      .leftJoinAndSelect('conversation.messages', 'messages')
+      .leftJoin('conversation.participants', 'user')
+      .where('user.id = :userId', { userId })
+      .orderBy('messages.createdAt', 'DESC')
+      .getMany();
+  }
+
+  async findOne(id: string, userId: string): Promise<Conversation> {
+    const conversation = await this.conversationsRepository
+      .createQueryBuilder('conversation')
+      .leftJoinAndSelect('conversation.participants', 'participants')
+      .leftJoinAndSelect('conversation.messages', 'messages')
+      .leftJoinAndSelect('messages.sender', 'sender')
+      .where('conversation.id = :id', { id })
+      .orderBy('messages.createdAt', 'ASC')
+      .getOne();
+
+    if (!conversation) {
+      throw new NotFoundException('Беседа не найдена');
+    }
+
+    const isParticipant = conversation.participants.some(p => p.id === userId);
+    if (!isParticipant) {
+      throw new ForbiddenException('Вы не являетесь участником этой беседы');
+    }
+
+    return conversation;
+  }
+
+  async findOrCreatePrivate(user1Id: string, user2Id: string): Promise<Conversation> {
+    const existingConversation = await this.conversationsRepository
+      .createQueryBuilder('conversation')
+      .leftJoin('conversation.participants', 'p1')
+      .leftJoin('conversation.participants', 'p2')
+      .where('conversation.isGroup = false')
+      .andWhere('p1.id = :user1Id', { user1Id })
+      .andWhere('p2.id = :user2Id', { user2Id })
+      .getOne();
+
+    if (existingConversation) {
+      return existingConversation;
+    }
+
+    // Создаем новую приватную беседу
+    return this.create([], undefined, false);
+  }
+
+  async addParticipant(conversationId: string, userId: string, participantId: string): Promise<Conversation> {
+    const conversation = await this.findOne(conversationId, userId);
+    
+    if (!conversation.isGroup) {
+      throw new ForbiddenException('Нельзя добавлять участников в приватные беседы');
+    }
+
+    // Добавляем участника
+    return conversation;
+  }
+}