app.js

const express = require('express');
const path = require('path');
const exphbs = require('express-handlebars');
const mongoose = require('mongoose');
const session = require('express-session');
const MongoStore = require('connect-mongo');
const passport = require('passport');
const LocalStrategy = require('passport-local').Strategy;
const GitHubStrategy = require('passport-github2').Strategy;
const bcrypt = require('bcryptjs');
const User = require('./models/User');
require('dotenv').config();

const app = express();

// Handlebars Configuration
app.engine('hbs', exphbs.engine({
    extname: 'hbs',
    layoutsDir: path.join(__dirname, 'views', 'layouts'),
    partialsDir: path.join(__dirname, 'views', 'partials'),
    helpers: {
        eq: (a, b) => a === b, // Add eq helper function for equality comparison
    },
}));
app.set('view engine', 'hbs');
app.set('views', path.join(__dirname, 'views'));

// Middleware
app.use(express.urlencoded({ extended: true })); // For form data
app.use(express.json()); // For JSON data
app.use(express.static(path.join(__dirname, 'public')));

// Connect to MongoDB
mongoose.connect(process.env.MONGO_URI, {
    useNewUrlParser: true,
    useUnifiedTopology: true,
})
    .then(() => console.log('MongoDB Connected'))
    .catch((err) => console.log('MongoDB Error:', err));

// Configure Session
app.use(
    session({
        secret: process.env.SESSION_SECRET || 'your_secret_key', // Replace with a strong secret
        resave: false,
        saveUninitialized: false,
        store: MongoStore.create({
            mongoUrl: process.env.MONGO_URI, // Use the same MongoDB URI
        }),
        cookie: { maxAge: 1000 * 60 * 60 * 24 }, // 1 day
    })
);

// Initialize Passport
app.use(passport.initialize());
app.use(passport.session());

// Passport Local Strategy for username/password authentication
passport.use(new LocalStrategy(
    { usernameField: 'username' }, // You can change the field name if necessary
    async (username, password, done) => {
        try {
            const user = await User.findOne({ username });
            if (!user) {
                return done(null, false, { message: 'Invalid username or password' });
            }

            const isMatch = await bcrypt.compare(password, user.password);
            if (!isMatch) {
                return done(null, false, { message: 'Invalid username or password' });
            }

            return done(null, user);
        } catch (err) {
            return done(err);
        }
    }
));

// Passport GitHub OAuth Strategy
passport.use(new GitHubStrategy({
    clientID: process.env.GITHUB_CLIENT_ID,
    clientSecret: process.env.GITHUB_CLIENT_SECRET,
    callbackURL: 'http://localhost:3000/auth/github/callback', // Adjust for production
}, async (accessToken, refreshToken, profile, done) => {
    try {
        let user = await User.findOne({ username: profile.username });
        if (!user) {
            user = new User({
                username: profile.username,
                role: 'user', // Default role for new users
            });
            await user.save();
        }
        return done(null, user);
    } catch (err) {
        return done(err);
    }
}));

// Serialize and Deserialize user
passport.serializeUser((user, done) => {
    done(null, user.id);
});

passport.deserializeUser(async (id, done) => {
    try {
        const user = await User.findById(id);
        done(null, user);
    } catch (err) {
        done(err);
    }
});

// Routes
const indexRouter = require('./routes/index');
const authRouter = require('./routes/auth');

app.use('/', indexRouter);
app.use('/auth', authRouter); // Add authentication routes

module.exports = app;