HackFlowy/config/passport.js

// config/passport.js

// load all the things we need
// var LocalStrategy    = require('passport-local').Strategy;
var GoogleStrategy = require('passport-google-oauth').OAuth2Strategy;

// load up the user model
var User       = require('../models/User.js');

// load the auth variables
var configAuth = require('./auth');

module.exports = function(passport) {

	// used to serialize the user for the session
    passport.serializeUser(function(user, done) {
        done(null, user.id);
    });

    // used to deserialize the user
    passport.deserializeUser(function(id, done) {
        User.findById(id, function(err, user) {
            done(err, user);
        });
    });
    
	// code for login (use('local-login', new LocalStategy))
	// code for signup (use('local-signup', new LocalStategy))
	// code for facebook (use('facebook', new FacebookStrategy))
	// code for twitter (use('twitter', new TwitterStrategy))

	// =========================================================================
    // GOOGLE ==================================================================
    // =========================================================================
    passport.use(new GoogleStrategy({

        clientID        : configAuth.googleAuth.clientID,
        clientSecret    : configAuth.googleAuth.clientSecret,
        callbackURL     : configAuth.googleAuth.callbackURL,

    },
    function(token, refreshToken, profile, done) {

		// make the code asynchronous
		// User.findOne won't fire until we have all our data back from Google
		process.nextTick(function() {

	        // try to find the user based on their google id
	        User.findOne({ 'google.id' : profile.id }, function(err, user) {
	            if (err)
	                return done(err);

	            if (user) { // if a user is found, log them in
	                return done(null, user);
	            } 
	            
	            else {
	                // if the user isnt in our database, create a new user
	                var newUser          = new User();

	                // set all of the relevant information
	                newUser.google.id    = profile.id;
	                newUser.google.token = token;
	                newUser.google.name  = profile.displayName;
	                newUser.google.email = profile.emails[0].value; // pull the first email

	                // save the user
	                newUser.save(function(err) {
	                    if (err)
	                        throw err;
	                    return done(null, newUser);
	                });
	            }
	        });
	    });

    }));

};