server.js

// Core dependencies
const fs = require('fs')
const path = require('path')

// NPM dependencies
const browserSync = require('browser-sync')
const dotenv = require('dotenv')
const express = require('express')
const nunjucks = require('nunjucks')
const sessionInMemory = require('express-session')
const bodyParser = require('body-parser')
const sessionOptions = {
  secret: 'govuk-publishing-frontend'
}

// Run before other code to make sure variables from .env are available
dotenv.config()

// Routing
const routes = require('./app/routes')
const autoRoutes = require('./app/routes/auto')

// Local dependencies
const utils = require('./lib/utils.js')

// Port
// const port = process.env.PORT || 3000

// Configuration
const env = process.env.NODE_ENV || 'development'
const useAuth = process.env.USE_AUTH || true
const useHttps = process.env.USE_HTTPS || true
const username = process.env.USERNAME
const password = process.env.PASSWORD
const useBrowserSync = process.env.USE_BROWSER_SYNC || true

// Set up application
const appViews = [
  path.join(__dirname, '/node_modules/govuk-frontend'),
  path.join(__dirname, '/app/views'),
  path.join(__dirname, '/app/views/layouts'),
  path.join(__dirname, '/app/views/partials'),
  path.join(__dirname, '/src')
]

// Application
const app = express()

app.use(bodyParser.urlencoded({ extended: false }))

// Find a free port and start the server
utils.findAvailablePort(app, (port) => {
  console.log('Listening on port ' + port + ' url: http://localhost:' + port)
  if ((env === 'production' || env === 'staging') || useBrowserSync === 'false') {
    app.listen(port)
  } else {
    app.listen(port - 50, () => {
      browserSync({
        proxy: 'localhost:' + (port - 50),
        port: port,
        ui: false,
        files: ['public/**/*.*', 'app/views/**/*.*'],
        ghostmode: false,
        open: false,
        notify: false,
        logLevel: 'error'
      })
    })
  }
})

// Force HTTPS on production. Do this before using basicAuth to avoid
// asking for username/password twice (for `http`, then `https`).
if ((env === 'production' || env === 'staging') && useHttps === 'true') {
  app.use(utils.forceHttps)
  app.set('trust proxy', 1) // needed for secure cookies on heroku
}

// Ask for username and password on production
if ((env === 'production' || env === 'staging') && useAuth === 'true') {
  app.use(utils.basicAuth(username, password))
}

// Search engine indexing
if ((env === 'production' || env === 'staging') && useAuth === 'false') {
  // Allow search engines to index the site
  app.get('/robots.txt', (req, res) => {
    res.type('text/plain')
    res.send('User-agent: *\nAllow: /')
  })
} else {
  // Prevent search indexing
  app.use((req, res, next) => {
    // Setting headers stops pages being indexed even if indexed pages link to them.
    res.setHeader('X-Robots-Tag', 'noindex')
    next()
  })

  app.get('/robots.txt', (req, res) => {
    res.type('text/plain')
    res.send('User-agent: *\nDisallow: /')
  })
}

// Nunjucks configurations
const nunjucksEnvironment = nunjucks.configure(appViews, {
  autoescape: true,
  express: app,
  noCache: true,
  watch: true
})

// Add Nunjucks filters for application
utils.addNunjucksFilters(nunjucksEnvironment)

// Set view engine
app.set('view engine', 'html')

// Middleware to serve static assets
app.use('/public', express.static(path.join(__dirname, '/public')))
app.use('/assets', express.static(path.join(__dirname, '/node_modules/govuk-frontend/govuk/assets')))
app.use('/assets', express.static(path.join(__dirname, 'src', 'govuk-pub', 'assets')))

app.use(sessionInMemory(Object.assign(sessionOptions, {
  name: 'govuk-publishing-frontend',
  resave: false,
  saveUninitialized: false
})))

// Use routes
app.use(routes)
app.use(autoRoutes) // must be the last one

const nodeModulesExists = fs.existsSync(path.join(__dirname, '/node_modules'))
if (!nodeModulesExists) {
  console.error('ERROR: Node module folder missing. Try running `npm install`')
  process.exit(0)
}

// Create template .env file if it doesn't exist
const envExists = fs.existsSync(path.join(__dirname, '/.env'))
if (!envExists) {
  fs.createReadStream(path.join(__dirname, '/lib/template.env'))
    .pipe(fs.createWriteStream(path.join(__dirname, '/.env')))
}

module.exports = app