৯ । User সার্ভিস তৈরি করা

// services/userService.js

const User = require("../models/User");
const { isUserExistsByEmail, findUserById, validateUserUpdateOrDelete } = require("../helpers/userHelper");
const ApiError = require("../utils/ApiError");
const HTTP_STATUS_CODES = require("../constants/httpStatus");

const userService = {


  /**
   * Create a user
   * @param {Object} userData - User information
   * @param {Object} [options] - Optional transaction object
   * @returns {Promise<User>}
   */
  createUser: async (userData, options = {}) => {
    const userExists = await isUserExistsByEmail(userData.email);
    if (userExists) {
      throw new ApiError(
        HTTP_STATUS_CODES.BAD_REQUEST,
        "User with this email already exists"
      );
    }
    return User.create(userData, options);
  },

    /**
   * Get all users
   * @returns {Promise<User[]>} - List of users
   */
   getAllUsers : async () => {
      try {
        const users = await User.findAll(); // Ensure `User` is correctly defined here
        return users;
      } catch (error) {
        console.error("Error fetching all users:", error);
        throw error;
      }
    },

    /**
 * Get a user by ID
 * @param {number} userId - User's ID
 * @returns {Promise<User>}
 */
getUserById: async (userId) => {
  return await User.findByPk(userId); // Use `findByPk` to fetch user by ID
},

  /**
   * Get a user by email
   * @param {string} email - User's email
   * @returns {Promise<User>}
   */

  
  getUserByEmail: async (email) => {
    return await findUserById(email);
  },

  /**
   * Update a user by ID
   * @param {number} userId - User ID
   * @param {Object} updateData - Data to update
   * @returns {Promise<number>} - Number of affected rows
   */
  updateUser: async (userId, updateData) => {
    await validateUserUpdateOrDelete(userId);
    const [affectedRows] = await User.update(updateData, { where: { id: userId } });
    return affectedRows;
  },

  /**
   * Delete a user by ID
   * @param {number} userId - User ID
   * @returns {Promise<number>} - Number of deleted rows
   */
  deleteUser: async (userId) => {
    await validateUserUpdateOrDelete(userId);
    const deletedRows = await User.destroy({ where: { id: userId } });
    return deletedRows;
  },
};

module.exports = userService;