auth.js

const bcrypt = require('bcrypt');
const passport = require('koa-passport');
const FacebookStrategy = require('passport-facebook').Strategy;
const LocalStrategy = require('passport-local').Strategy;
const config = require('../serverConfig');
const { db } = require('../server');
const { promisify } = require('util');

const getAsync = promisify(db.get).bind(db);

passport.serializeUser((user, done) => {
  done(null, user.id);
});

passport.deserializeUser(async (id, done) => {
  try {
    let user = null;
    await getAsync('usersMockDatabase').then((users) => {
      user = JSON.parse(users).find(currUser => currUser.id === id);
    });
    if (user) {
      done(null, user);
    } else {
      done(null, false);
    }
  } catch (err) {
    done(err);
  }
});

passport.use(
  new LocalStrategy(
    {
      usernameField: 'email',
      passwordField: 'password',
    },
    async (email, password, done) => {
      let user = null;
      await getAsync('usersMockDatabase').then((users) => {
        const currUsers = JSON.parse(users);

        // if redis session expired, create database with one user
        if (!currUsers || currUsers.length < 1) {
          db.set('usersMockDatabase', [
            {
              id: 1,
              email: 'chouomam@chouman.com',
              // "test" -- generated by bcrypt calculator
              password: '$2a$04$4yQfCo8kMpH24T2iQkw9p.hPjcz10m.FcWmgkOhkXNPSpbwHZ877S',
              userName: 'Chouomam',
            },
          ]);
        }

        user = currUsers.find(currUser => currUser.email === email);
      });
      if (!user) {
        done({ type: 'email', message: 'No such user found' }, false);
        return;
      }
      if (bcrypt.compareSync(password, user.password)) {
        done(null, { id: user.id, email: user.email, userName: user.userName });
      } else {
        done({ type: 'password', message: 'Passwords did not match' }, false);
      }
    },
  ),
);

passport.use(
  new FacebookStrategy(
    {
      clientID: config.facebookAuth.clientID,
      clientSecret: config.facebookAuth.clientSecret,
      callbackURL: config.facebookAuth.callbackURL,
      profileFields: [
        'id',
        'displayName',
        'picture.width(200).height(200)',
        'first_name',
        'middle_name',
        'last_name',
        'gender',
        'link',
        'email',
        'location',
        'friends',
      ],
    },
    (accessToken, refreshToken, profile, done) => {
      process.nextTick(async () => {
        const facebookUser = {
          id: Math.random(),
          userName: profile.displayName,
          email: profile.emails[0].value,
          imgUrl: profile.photos[0].value,
          imgHeight: 200,
          imgWidth: 200,
          userProfileId: profile.id,
        };
        await getAsync('usersMockDatabase').then((users) => {
          // save new user into database
          const currUsers = JSON.parse(users);
          currUsers.push(facebookUser);
          db.set('usersMockDatabase', JSON.stringify(currUsers));
        });
        return done(null, facebookUser);
      });
    },
  ),
);

exports.getLoggedUser = async (ctx) => {
  if (ctx.isAuthenticated()) {
    const reqUserId = ctx.req.user.id;
    let user = null;
    await getAsync('usersMockDatabase').then((users) => {
      user = JSON.parse(users).find(currUser => currUser.id === reqUserId);
    });
    if (user) {
      delete user.password;
      ctx.response.body = user;
    } else {
      const statusCode = 500;
      ctx.throw(statusCode, "User doesn't exist");
    }
  } else {
    ctx.redirect('/');
  }
};