const { NotFoundError, DatabaseError } = require('../../shared/errors');
const { Op } = require('sequelize');

class FriendshipsRepository {
  constructor({ sequelize }) {
    this.sequelize = sequelize;
    this.Friendship = sequelize.models.Friendship;
    this.User = sequelize.models.User;
  }

  async findByUserId(userId) {
    try {
      const friendships = await this.Friendship.findAll({
        where: {
          [Op.or]: [{ user1Id: userId }, { user2Id: userId }],
        },
        include: [
          { model: this.User, as: 'user1' },
          { model: this.User, as: 'user2' },
        ],
      });

      return friendships.map((friendship) => {
        const friend =
          friendship.user1.id === userId ? friendship.user2 : friendship.user1;
        return friend;
      });
    } catch (error) {
      throw new DatabaseError(`Failed to fetch friendships for user ${userId}`, error);
    }
  }

  async exists(user1Id, user2Id) {
    try {
      const minId = Math.min(user1Id, user2Id);
      const maxId = Math.max(user1Id, user2Id);

      const friendship = await this.Friendship.findOne({
        where: { user1Id: minId, user2Id: maxId },
      });

      return !!friendship;
    } catch (error) {
      throw new DatabaseError('Failed to check friendship existence', error);
    }
  }

  async create(user1Id, user2Id) {
    try {
      const minId = Math.min(user1Id, user2Id);
      const maxId = Math.max(user1Id, user2Id);

      return await this.Friendship.create({
        user1Id: minId,
        user2Id: maxId,
      });
    } catch (error) {
      throw new DatabaseError('Failed to create friendship', error);
    }
  }

  async delete(user1Id, user2Id) {
    try {
      const minId = Math.min(user1Id, user2Id);
      const maxId = Math.max(user1Id, user2Id);

      const result = await this.Friendship.destroy({
        where: { user1Id: minId, user2Id: maxId },
      });

      return result > 0;
    } catch (error) {
      throw new DatabaseError('Failed to delete friendship', error);
    }
  }
}

module.exports = FriendshipsRepository;