app.js

const path = require('path');
const express = require('express');
const morgan = require('morgan');
const rateLimit = require('express-rate-limit');
const helmet = require('helmet');
const mongoSanitize = require('express-mongo-sanitize');
const xss = require('xss-clean');
const hpp = require('hpp');
const cookieParser = require('cookie-parser'); // to get access to certain cookie in a request
const cors = require('cors');
const compression = require('compression');

const AppError = require('./utils/appError');
const globalErrorHandler = require('./controllers/errorController');
const tourRouter = require('./routes/tourRoutes');
const userRouter = require('./routes/userRoutes');
const reviewRouter = require('./routes/reviewRoutes');
const viewRouter = require('./routes/viewRoutes');
const bookingRouter = require('./routes/bookingRoutes');

const app = express();

app.enable('trust proxy');

// CORS
app.use(
  cors({
    origin: true,
    credentials: true,
  })
);
app.options('*', cors());

app.set('view engine', 'pug');
app.set('views', path.join(`${__dirname}`, 'views'));
app.use(express.static(path.join(`${__dirname}`, 'public'))); // Serving Static files

// Middleware functions
if (process.env.NODE_ENV !== 'production') {
  app.use(morgan('dev'));
}

// app.use((req, res, next) => {
//   res.setHeader('Access-Control-Allow-Origin', '*');
//   res.setHeader('Access-Control-Allow-Methods', 'POST, GET, PUT');
//   res.setHeader('Access-Control-Allow-Headers', 'Content-Type');
//   next();
// });
// app.all('/*', (req, res, next) => {
//   res.header('Access-Control-Allow-Origin', '*');
//   res.header('Access-Control-Allow-Headers', 'X-Requested-With');
//   next();
// });

// Set security http headers
app.use(helmet());
app.use(
  helmet.contentSecurityPolicy({
    directives: {
      defaultSrc: ["'self'"],
      baseUri: ["'self'"],
      fontSrc: ["'self'", 'https:', 'data:'],
      scriptSrc: [
        "'self'",
        'https://cdnjs.cloudflare.com/ajax/libs/axios/1.2.1/axios.min.js',
        'https://js.stripe.com/v3/',
      ],
      objectSrc: ["'none'"],
      upgradeInsecureRequests: [],
    },
  })
);

app.use(
  hpp({
    whitelist: [
      'duration',
      'ratingsQuantity',
      'ratingsAverage',
      'maxGroupSize',
      'difficulty',
      'price',
    ],
  })
); // Prevent parameter pollution

app.use(compression());

const limiter = rateLimit({
  max: 100,
  window: 60 * 60 * 1000,
  message: 'Too many requests from this ip try again within an hour!',
  // standardHeaders: true, // Return rate limit info in the `RateLimit-*` headers
  // legacyHeaders: false, // Disable the `X-RateLimit-*` headers
});
app.use('/api', limiter);

app.use(express.json({ limit: '10kb' })); // Body Parser ; reading data from the body to req
app.use(express.urlencoded({ extended: true, limit: '10kb' }));
app.use(cookieParser());

app.use(mongoSanitize()); // Prevent noSql injection
app.use(xss()); // Prevent malicious html inject

app.use((req, res, next) => {
  req.requestTime = new Date().toISOString();
  next();
});

// Routers
// Mounting the Router Process

app.use('/', viewRouter);
app.use('/api/v1/tours', tourRouter);
app.use('/api/v1/users', userRouter);
app.use('/api/v1/reviews', reviewRouter);
app.use('/api/v1/bookings', bookingRouter);

// Handling Undefined Routes
app.all('*', (req, res, next) => {
  next(new AppError(`Can't find "${req.originalUrl}" on this server!`, 404));
});

// Central Error Handler
app.use(globalErrorHandler);

module.exports = app;