var LocalStrategy = require('passport-local').Strategy;
passport.use(
    new LocalStrategy(
        {
            usernameField: 'username',
            passwordField: 'password',
        },
        (username, password, done) => {
            let session = driver.session();
            session
                .run(
                    'MATCH (u:User) WHERE u.username = {username} AND u.password = {password} RETURN u as user',
                    { username, password }
                )
                .then(results => {
                    try {
                        let user = results.records[0].get('user').properties;
                        done(null, user);
                    } catch (err) {
                        done(null, false);
                    } finally {
                        session.close();
                    }
                })
                .catch(err => {
                    session.close();
                    done(err);
                });
        }
    )
);

passport.serializeUser(function(user, done) {
    done(null, user.username);
});

passport.deserializeUser(async (username, done) => {
    let session = driver.session();
    try {
        let results = await session.run(
            'MATCH (u:User) WHERE u.username = {username} RETURN u AS user;',
            { username }
        );
        let user = results.records[0].get('user').properties;
        done(null, user);
    } catch (err) {
        done(err, false);
    } finally {
        session.close();
    }
});

app.use(passport.initialize());
app.use(passport.session());

const auth = (req, res, next) => {
    if (!req.isAuthenticated()) {
        res.sendStatus(401);
        res.end();
    } else {
        next();
    }
};

app.post('/login', passport.authenticate('local'), (req, res) => {
    res.send(_.omit(req.user, 'password'));
    res.end();
});

app.get('/logout', function(req, res) {
    req.logout();
    res.redirect('/login');
});

app.get('/authenticated', auth, (req, res) => {
    res.send(_.omit(req.user, 'password'));
    res.end();
});

app.post('/signup', async (req, res) => {
    let { username, password, password_repeat, email } = req.body;
    if (password !== password_repeat) {
        res.sendStatus(409);
        res.end();
    } else {
        try {
            let session = driver.session();
            let results = await session.run(
                `
				CREATE (u:User { username: {username}, password: {password}, email: {email} })
				RETURN u AS user;
			`,
                { username, password, email }
            );

            let user = results.records[0].get('user').properties;
            req.login(user, err => {
                if (!err) {
                    res.send(_.omit(user, 'password'));
                    res.end();
                } else res.redirect('/login');
            });
        } catch (err) {
            console.error(err);
            res.status(400).send({ error: 'Username already exists.' });
            res.end();
        } finally {
            session.close();
        }
    }
});