app.js

if (process.env.NODE_ENV !== "production") {
    require('dotenv').config();
}

const express = require('express');
const path = require('path');
const mongoose = require('mongoose');
const ejsMate = require('ejs-mate');  //to help make a boilerplate
const session = require('express-session');  //to store session data in MongoStore
const flash = require('connect-flash');  //to display flash messages
const passport = require('passport');  //for authentication and authorization - adds many useful methods to req
const localStrategy = require('passport-local');
const ExpressError = require('./utils/ExpressError');  //custom made error template
const methodOverride = require('method-override');   //to make delete, put and patch request from html forms
const User = require('./models/user');
const mongoSanitize = require('express-mongo-sanitize');  //to prevent Mongo injection
const helmet = require('helmet');  //to prevent Cross-site-scripting
const MongoStore = require('connect-mongo');

const userRoutes = require('./routes/users');
const hospitalRoutes = require('./routes/hospitals');
const reviewRoutes = require('./routes/reviews')

const dbUrl = process.env.DB_URL || 'mongodb://localhost:27017/lifeline';
mongoose.connect(dbUrl, {
    useNewUrlParser: true,
    // useCreateIndex: true,
    useUnifiedTopology: true,
    // useFindAndModify: false
});

const db = mongoose.connection;
db.on("error", console.error.bind(console, "connection error:"));
db.once("open", () => {
    console.log("Database connected");
});

const app = express();

app.engine('ejs', ejsMate)
app.set('view engine', 'ejs');
app.set('views', path.join(__dirname, 'views'))  //setting up the views directory

app.use(express.urlencoded({ extended: true }));
app.use(methodOverride('_method'));
app.use(express.static(path.join(__dirname, 'public')));
app.use(
    mongoSanitize({
        replaceWith: '_',   //replacing '$' and ':' with '_' in the query
    }),
);

const secret = process.env.SECRET || "thisshouldbeabettersecret";

const sessionConfig = {
    store: MongoStore.create({
        mongoUrl: dbUrl,
        touchAfter: 24 * 36 * 60 // time period in seconds
    }),
    name: 'session',
    secret,
    resave: false,
    saveUninitialized: true,
    cookie: {
        httpOnly: true,
        // secure: true,
        expires: Date.now() + 1000 * 60 * 60 * 24 * 7,
        maxAge: 1000 * 60 * 60 * 24 * 7,
    }
}
app.use(session(sessionConfig));
app.use(flash());
app.use(helmet());

const scriptSrcUrls = [
    "https://stackpath.bootstrapcdn.com/",
    "https://api.tiles.mapbox.com/",
    "https://api.mapbox.com/",
    "https://kit.fontawesome.com/",
    "https://cdnjs.cloudflare.com/",
    "https://cdn.jsdelivr.net",
    "https://unpkg.com/aos@next/dist/aos.js",
];
const styleSrcUrls = [
    "https://kit-free.fontawesome.com/",
    "https://stackpath.bootstrapcdn.com/",
    "https://api.mapbox.com/",
    "https://api.tiles.mapbox.com/",
    "https://fonts.googleapis.com/",
    "https://use.fontawesome.com/",
    "https://cdn.jsdelivr.net",
    "https://unpkg.com/aos@next/dist/aos.css",
    "https://cdnjs.cloudflare.com/ajax/libs/animate.css/3.6.2/animate.min.css",
    "https://cdnjs.cloudflare.com/ajax/libs/font-awesome/5.13.1/css/all.min.css",
];
const connectSrcUrls = [
    "https://api.mapbox.com/",
    "https://a.tiles.mapbox.com/",
    "https://b.tiles.mapbox.com/",
    "https://events.mapbox.com/",
    "https://formspree.io/",
];
const fontSrcUrls = [
    "https://fonts.gstatic.com/",
    "https://cdnjs.cloudflare.com/",
];
app.use(
    helmet.contentSecurityPolicy({
        directives: {
            defaultSrc: [],
            connectSrc: ["'self'", ...connectSrcUrls],
            scriptSrc: ["'unsafe-inline'", "'self'", ...scriptSrcUrls],
            styleSrc: ["'self'", "'unsafe-inline'", ...styleSrcUrls],
            workerSrc: ["'self'", "blob:"],
            objectSrc: [],
            imgSrc: [
                "'self'",
                "blob:",
                "data:",
                "https://res.cloudinary.com/storm123/",
                "https://images.unsplash.com/",
            ],
            fontSrc: ["'self'", ...fontSrcUrls],
        },
    })
);


app.use(passport.initialize());
app.use(passport.session());
passport.use(new localStrategy(User.authenticate()));

passport.serializeUser(User.serializeUser());
passport.deserializeUser(User.deserializeUser());

app.use((req, res, next) => {
    res.locals.currentUser = req.user;
    res.locals.success = req.flash('success');
    res.locals.error = req.flash('error');
    next();
})

app.use('/', userRoutes);
app.use('/hospitals', hospitalRoutes);
app.use('/hospitals/:id/reviews', reviewRoutes);

app.get('/', (req, res) => {
    res.render('home');
})

app.all('*', (req, res, next) => {
    next(new ExpressError('Page Not Found', 404))
})

app.use((err, req, res, next) => {
    const { statusCode = 500 } = err;
    if (!err.message) err.message = 'Oh No, Something Went Wrong!'
    res.status(statusCode).render('error', { err })
})

const port = process.env.PORT || 3000;

app.listen(port, () => {
    console.log(`Serving on port ${port}`)
})