'use strict';

const _ = require('lodash');
const req = require('http').IncomingMessage.prototype;

module.exports = ({ serialize, deserialize }) => {
  if (!_.isFunction(serialize) || !_.isFunction(deserialize)) {
    throw new TypeError('Both arguments need to be functions');
  }

  req.login = function (user) {
    if (!req.session) Promise.reject(new Error('Session middleware not in use'));
    
    return serialize(user).then((result) => {
      req.session.user = result;
    }).catch((err) => {
      delete req.sesson.user;

      throw err;
    });
  }

  req.logout = function () {
    delete req.session.user;
    delete req.user;
  }

  req.isAuthenticated = function () {
    return this.session && this.session.user;
  }

  req.isUnauthenticated = function () {
    return !this.isAuthenticated();
  }

  // option1
  req.getUser = function () {
    if (this.__user) return Promise.resolve(this.__user);

    if (!req.session || !req.session.user) return Promise.resolve(null);

    return deserialize(this.session.user).then((user) => {
      this.__user = user;

      return user;
    });
  }
  
  Object.defineProperty(req, 'user', {
    get() {
      if (this.__user) return Promise.resolve(this.__user);

      if (!req.session || !req.session.user) return Promise.resolve(null);
      
      return deserialize(this.session.user).then((user) => {
        this.__user = user;
        
        return user;
    });
}