Initial commit

backend-node/services/friends.service.js

@@ -0,0 +1,102 @@
+const { ValidationError, ConflictError } = require('../shared/errors');
+const { Op } = require('sequelize');
+
+class FriendsService {
+  constructor({
+    friendshipsRepository,
+    friendRequestsRepository,
+    usersRepository,
+    sequelize,
+  }) {
+    this.friendshipsRepository = friendshipsRepository;
+    this.friendRequestsRepository = friendRequestsRepository;
+    this.usersRepository = usersRepository;
+    this.sequelize = sequelize;
+  }
+
+  async getFriendsByUserId(userId) {
+    return await this.friendshipsRepository.findByUserId(userId);
+  }
+
+  async getPendingRequests(userId) {
+    return await this.friendRequestsRepository.findPendingByUserId(userId);
+  }
+
+  async sendFriendRequest(fromUserId, identifier) {
+    let toUser;
+
+    if (typeof identifier === 'number' || !isNaN(identifier)) {
+      toUser = await this.usersRepository.findById(parseInt(identifier, 10));
+    } else {
+      toUser = await this.usersRepository.findOne({
+        [Op.or]: [{ name: identifier }, { email: identifier }],
+      });
+
+      if (!toUser) {
+        throw new ValidationError(
+          'User not found with provided name or email'
+        );
+      }
+    }
+
+    if (toUser.id === fromUserId) {
+      throw new ValidationError('Cannot send friend request to yourself');
+    }
+
+    const friendshipExists = await this.friendshipsRepository.exists(
+      fromUserId,
+      toUser.id
+    );
+    if (friendshipExists) {
+      throw new ConflictError('You are already friends with this user');
+    }
+
+    const existingRequest = await this.friendRequestsRepository.findExisting(
+      fromUserId,
+      toUser.id
+    );
+    if (existingRequest) {
+      throw new ConflictError('Friend request already exists');
+    }
+
+    return await this.friendRequestsRepository.create(fromUserId, toUser.id);
+  }
+
+  async acceptFriendRequest(requestId, userId) {
+    const request = await this.friendRequestsRepository.findById(requestId);
+
+    if (request.toUserId !== userId) {
+      throw new ValidationError('You can only accept requests sent to you');
+    }
+
+    if (request.status !== 'PENDING') {
+      throw new ValidationError('This request has already been processed');
+    }
+
+    const t = await this.sequelize.transaction();
+    try {
+      await this.friendRequestsRepository.updateStatus(requestId, 'ACCEPTED');
+      await this.friendshipsRepository.create(request.fromUserId, request.toUserId);
+      await this.friendRequestsRepository.delete(requestId);
+      await t.commit();
+
+      return { message: 'Friend request accepted successfully' };
+    } catch (error) {
+      await t.rollback();
+      throw error;
+    }
+  }
+
+  async rejectFriendRequest(requestId, userId) {
+    const request = await this.friendRequestsRepository.findById(requestId);
+
+    if (request.toUserId !== userId && request.fromUserId !== userId) {
+      throw new ValidationError('You can only manage your own requests');
+    }
+
+    await this.friendRequestsRepository.delete(requestId);
+    return { message: 'Friend request rejected successfully' };
+  }
+}
+
+module.exports = FriendsService;