authenticate.js

const passport=require('passport');
const LocalStrategy= require('passport-local').Strategy;
const User=require('./models/users');
var JwtStrategy=require('passport-jwt').Strategy;
var ExtractJwt=require('passport-jwt').ExtractJwt;
var jwt=require('jsonwebtoken');
var FacebookTokenStrategy=require('passport-facebook-token');

var config=require('./config');

exports.local=passport.use(new LocalStrategy(User.authenticate()));
passport.serializeUser(User.serializeUser());
passport.deserializeUser(User.deserializeUser());


exports.getToken=function(user){
    return jwt.sign(user,config.secretKey,
        {expiresIn:3600});
};

var opts={};
opts.jwtFromRequest=ExtractJwt.fromAuthHeaderAsBearerToken();
opts.secretOrKey=config.secretKey;

exports.jwtPassport=passport.use(new JwtStrategy(opts,
    (jwt_payload,done)=>{
        console.log("JWT payload:",jwt_payload);
        User.findOne({_id:jwt_payload._id},(err,user)=>{
            if(err){
                return done(err,false);
            }
            else if(user){
                return done(null,user);
            }
            else{
                return done(null,false);
            }
        });
    }));

    exports.verifyUser=passport.authenticate('jwt',{session:false});

    exports.verifyAdmin=(req,res,next)=>{
        if(req.user.admin==true){
           return next();
        }
        else{
            err = new Error('You are not authorized to perform this operation!');
            err.status = 403;
            return next(err);

        }
    };

    exports.facebookPassport=passport.use(new FacebookTokenStrategy({
            clientID: config.facebook.clientId,
            clientSecret: config.facebook.clientSecret
    },(accessToken, refreshToken , profile,done)=>{
        User.findOne({facebookId: profile.id},(err,user)=>{
            if(err){
                return done(err,false);
            }
            if(!err && user!=null){
                return done(null, user);
            }
            else{
                user=new User({username: profile.displayName});
                user.facebookId=profile.id;
                user.firstname=profile.name.givenName;
                user.lastname=profile.name.familyName;
                user.save((err,user)=>{
                    if(err){
                      return done(err,false);
                    }    
                    else return done(null,user);     
                })
            }
        })
    }
      
));