const bcrypt = require('bcrypt-nodejs');
const UserRepository = require('src/user/userRepository');

class UserSecurity {
   constructor(database) {
      this.userRepository = new UserRepository(database);
   }

   /**
   * Create a new user in PlanFlix.
   * @param {User} user the new user you want to create
   * @param {String} clearPassword a password of the user
   * @returns {Promise}
   */
   createNewUser(user, clearPassword) {
      if (user.username.trim() === '') {
         throw new Error('The username is empty.');
      } else if (clearPassword.trim() === '') {
         throw new Error('The password is empty.');
      } else {
         return Promise.resolve()
            .then(() => this.userRepository.create(user))
            .then(() => UserSecurity.hashPassword(clearPassword))
            .then(hash => this.userRepository.changePassword(user, hash));
      }
   }

   /**
   * Login into PlanFlix.
   * @param {User} user the user you want to login
   * @param {String} clearPassword the user's password
   * @returns {Promise}
   */
   login(user, clearPassword) {
      return Promise.resolve()
         .then(() => this.userRepository.retrieveHash(user))
         .then(hash => UserSecurity.compareHashes(hash, clearPassword))
         .catch(() => { throw new Error('Wrong username or password.'); });
   }

   /**
   * Compare between a password and a hash password from database.
   * @param {String} hash the hash password from database
   * @param {String} clearPassword the user's password
   * @returns {Promise}
   */
   static compareHashes(hash, clearPassword) {
      return new Promise((resolve, reject) => {
         bcrypt.compare(clearPassword, hash, (error, matches) => {
            if (matches === true) {
               resolve();
            } else {
               reject();
            }
         });
      });
   }

   /**
   * Hashes a password.
   * @param {String} clearPassword the user's password
   * @returns {Promise}
   */
   static hashPassword(clearPassword) {
      return new Promise((resolve) => {
         bcrypt.hash(clearPassword, null, null, (error, hash) => {
            resolve(hash);
         });
      });
   }
}

module.exports = UserSecurity;