server.js

const express = require('express');
const app = express();

const dotenv = require('dotenv');
const cookieParser = require('cookie-parser');
const rateLimit = require('express-rate-limit');
const helmet = require('helmet');
const mongoSanitize = require('express-mongo-sanitize');
const xssClean = require('xss-clean');
const hpp = require('hpp');
const cors = require('cors');
const bodyParser = require('body-parser');

const connectDatabase = require('./config/database');
const ErrorHandler = require('./utils/errorHandler');

// Setting up config.env file variables
dotenv.config({ path: './config/config.env' })

// Handling Uncaught Exception
process.on('uncaughtException', err => {
    console.log(`ERROR: ${err.message}`);
    console.log('Shutting down due to uncaught exception.')
    process.exit(1);
});

// Connecting to databse
connectDatabase();

// Set up body parser
app.use(bodyParser.urlencoded({ extended: true }));

app.use(express.static('public'));

// Setup security headers
app.use(helmet());

// Setup body parser
app.use(express.json());

// Set cookie parser
app.use(cookieParser());


// Sanitize data
app.use(mongoSanitize());

// Prevent XSS attacks
app.use(xssClean());

// Prevent Parameter Pollution
app.use(hpp({
    whitelist: ['positions']
}));

// Rate Limiting
const limiter = rateLimit({
    windowMs: 10 * 60 * 1000, //10 Mins
    max: 100
});

// Setup CORS - Accessible by other domains
app.use(cors());

app.use(limiter);

// Importing all routes
const prelaunch = require('./routes/prelaunch');
app.use('/api/v1', prelaunch);

// Handle unhandled routes
app.all('*', (req, res, next) => {
    next(new ErrorHandler(`${req.originalUrl} route not found`, 404));
});



const PORT = process.env.PORT;
const server = app.listen(PORT, () => {
    console.log(`Server started on port ${process.env.PORT} in ${process.env.NODE_ENV} mode.`);
});

// Handling Unhandled Promise Rejection
process.on('unhandledRejection', err => {
    console.log(`Error: ${err.message}`);
    console.log('Shutting down the server due to Unhandled promise rejection.')
    server.close(() => {
        process.exit(1);
    })
});