server_setup.coffee

express = require 'express'
path = require 'path'
authentication = require 'passport'
useragent = require 'express-useragent'
fs = require 'graceful-fs'
log = require 'winston'
compressible = require 'compressible'
compression = require 'compression'

geoip = require '@basicer/geoip-lite'
crypto = require 'crypto'
database = require './server/commons/database'
perfmon = require './server/commons/perfmon'
baseRoute = require './server/routes/base'
logging = require './server/commons/logging'
config = require './server_config'
auth = require './server/commons/auth'
routes = require './server/routes'
UserHandler = require './server/handlers/user_handler'
slack = require './server/slack'
Mandate = require './server/models/Mandate'
global.tv4 = require 'tv4' # required for TreemaUtils to work
global.jsondiffpatch = require('jsondiffpatch')
global.stripe = require('stripe')(config.stripe.secretKey)
errors = require './server/commons/errors'
request = require 'request'
Promise = require 'bluebird'
Promise.promisifyAll(request, {multiArgs: true})
Promise.promisifyAll(fs)
wrap = require 'co-express'
codePlayTags = require './server/lib/code-play-tags'
morgan = require 'morgan'
domainFilter = require './server/middleware/domain-filter'
timeout = require('connect-timeout')

{countries} = require './app/core/utils'

productionLogging = (tokens, req, res) ->
  status = res.statusCode
  color = 32
  if status >= 500 then color = 31
  else if status >= 400 then color = 33
  else if status >= 300 then color = 36
  elapsed = (new Date()) - req._startTime
  elapsedColor = if elapsed < 500 then 90 else 31
  return null if status is 404 and /\/feedback/.test req.originalUrl  # We know that these usually 404 by design (bad design?)
  if (status isnt 200 and status isnt 201 and status isnt 204 and status isnt 304 and status isnt 302) or elapsed > 500
    return "[#{config.clusterID}] \x1b[90m#{req.method} #{req.originalUrl} \x1b[#{color}m#{res.statusCode} \x1b[#{elapsedColor}m#{elapsed}ms\x1b[0m"
  null

developmentLogging = (tokens, req, res) ->
  status = res.statusCode
  color = 32
  if status >= 500 then color = 31
  else if status >= 400 then color = 33
  else if status >= 300 then color = 36
  elapsed = (new Date()) - req._startTime
  elapsedColor = if elapsed < 500 then 90 else 31
  s = "\x1b[90m#{req.method} #{req.originalUrl} \x1b[#{color}m#{res.statusCode} \x1b[#{elapsedColor}m#{elapsed}ms\x1b[0m"
  s += ' (proxied)' if req.proxied
  return s

setupDomainFilterMiddleware = (app) ->
  if config.isProduction or global.testing
    app.use domainFilter

setupErrorMiddleware = (app) ->
  app.use (err, req, res, next) ->
    if err
      if err.name is 'MongoError' and err.code is 11000
        err = new errors.Conflict('MongoDB conflict error.')
      if err.code is 422 and err.response
        err = new errors.UnprocessableEntity(err.response)
      if err.code is 409 and err.response
        err = new errors.Conflict(err.response)
      if err.name is 'MongoError' and err.message.indexOf('timed out')
        err = new errors.GatewayTimeout('MongoDB timeout error.')
      if req.timedout # set by connect-timeout
        err = new errors.ServiceUnavailable('Request timed out.')

      # TODO: Make all errors use this
      if err instanceof errors.NetworkError
        console.log err.stack if err.stack and config.TRACE_ROUTES
        res.status(err.code).send(err.toJSON())
        if req.timedout
          # noop return self all response-ending functions
          res.send = res.status = res.redirect = res.end = res.json = res.sendFile = res.download = res.sendStatus = -> res
        return
          
      if err.status and 400 <= err.status < 500
        console.log err.stack if err.stack and config.TRACE_ROUTES
        return res.status(err.status).send("Error #{err.status}")
      
      if err.name is 'CastError' and err.kind is 'ObjectId'
        console.log err.stack if err.stack and config.TRACE_ROUTES
        newError = new errors.UnprocessableEntity('Invalid id provided')
        return res.status(422).send(newError.toJSON())

      res.status(err.status ? 500).send(error: "Something went wrong!")
      console.log err.stack if err.stack and config.TRACE_ROUTES
      message = "Express error: \"#{req.method} #{req.path}\": #{err.stack}"
      log.error message
      if global.testing
        console.log message
      unless message.indexOf('card was declined') >= 0
        slack.sendSlackMessage("Express error: \"#{req.method} #{req.path}\": #{err.message}", ['ops'], {papertrail: true})
    else
      next(err)

setupExpressMiddleware = (app) ->
  if config.isProduction
    morgan.format('prod', productionLogging)
    app.use(morgan('prod'))
    app.use compression filter: (req, res) ->
      return false if req.headers.host is 'codecombat.com'  # CloudFlare will gzip it for us on codecombat.com
      compressible res.getHeader('Content-Type')
  else if not global.testing or config.TRACE_ROUTES
    morgan.format('dev', developmentLogging)
    app.use(morgan('dev'))

  app.use (req, res, next) ->
    res.header 'X-Cluster-ID', config.clusterID
    next()

  public_path = path.join(__dirname, 'public')
  
  app.use('/', express.static(path.join(public_path, 'templates', 'static')))

  if config.buildInfo.sha isnt 'dev' and config.isProduction
    app.use("/#{config.buildInfo.sha}", express.static(public_path, maxAge: '1y'))
  else
    app.use('/dev', express.static(public_path, maxAge: 0))  # CloudFlare overrides maxAge, and we don't want local development caching.

  app.use(express.static(public_path, maxAge: 0))

  if config.proxy
    # Don't proxy static files with sha prefixes, redirect them
    regex = /\/[0-9a-f]{40}\/.*/
    app.use (req, res, next) ->
      if regex.test(req.path)
        newPath = req.path.slice(41)
        return res.redirect(newPath)
      next()

  setupProxyMiddleware app # TODO: Flatten setup into one function. This doesn't fit its function name.

  app.use require('serve-favicon') path.join(__dirname, 'public', 'images', 'favicon.ico')
  app.use require('cookie-parser')()
  app.use require('body-parser').json({limit: '25mb', strict: false, verify: (req, res, buf, encoding) ->
    if req.headers['x-hub-signature']
      # this is an intercom webhook request, with signature that needs checking
      try
        digest = crypto.createHmac('sha1', config.intercom.webhookHubSecret).update(buf).digest('hex')
        req.signatureMatches = req.headers['x-hub-signature'] is "sha1=#{digest}"
      catch e
        log.info 'Error checking hub signature on Intercom webhook: ' + e
  })
  app.use require('body-parser').urlencoded extended: true, limit: '25mb'
  app.use require('method-override')()
  app.use require('cookie-session')
    key: 'codecombat.sess'
    secret: config.cookie_secret


setupPassportMiddleware = (app) ->
  app.use(authentication.initialize())
  if config.picoCTF
    app.use authentication.authenticate('local', failureRedirect: config.picoCTF_login_URL)
    require('./server/lib/picoctf').init app
  else
    app.use(authentication.session())
  auth.setup()

setupCountryTaggingMiddleware = (app) ->
  app.use (req, res, next) ->
    return next() if req.country or req.user?.get('country')
    return next() unless ip = req.headers['x-forwarded-for'] or req.ip or req.connection.remoteAddress
    ip = ip.split(/,? /)[0]  # If there are two IP addresses, say because of CloudFlare, we just take the first.
    geo = geoip.lookup(ip)
    if countryInfo = _.find(countries, countryCode: geo?.country)
      req.country = countryInfo.country
    next()

setupCountryRedirectMiddleware = (app, country='china', host='cn.codecombat.com') ->
  hosts = host.split /;/g
  shouldRedirectToCountryServer = (req) ->
    reqHost = (req.hostname ? req.host ? '').toLowerCase()  # Work around express 3.0
    return req.country is country and reqHost not in hosts and reqHost.indexOf(config.unsafeContentHostname) is -1

  app.use (req, res, next) ->
    if shouldRedirectToCountryServer(req) and hosts.length
      res.writeHead 302, "Location": 'http://' + hosts[0] + req.url
      res.end()
    else
      next()

setupOneSecondDelayMiddleware = (app) ->
  if(config.slow_down)
    app.use((req, res, next) -> setTimeout((-> next()), 1000))

setupMiddlewareToSendOldBrowserWarningWhenPlayersViewLevelDirectly = (app) ->
  isOldBrowser = (req) ->
    # https://github.com/biggora/express-useragent/blob/master/lib/express-useragent.js
    return false unless ua = req.useragent
    return true if ua.isiPad or ua.isiPod or ua.isiPhone or ua.isOpera
    return false unless ua and ua.Browser in ['Chrome', 'Safari', 'Firefox', 'IE'] and ua.Version
    b = ua.Browser
    try
      v = parseInt ua.Version.split('.')[0], 10
    catch TypeError
      log.error('ua.Version does not have a split function.', JSON.stringify(ua, null, '  '))
      return false
    return true if b is 'Chrome' and v < 17
    return true if b is 'Safari' and v < 6
    return true if b is 'Firefox' and v < 21
    return true if b is 'IE' and v < 11
    false

  app.use '/play/', useragent.express()
  app.use '/play/', (req, res, next) ->
    return next() if req.path?.indexOf('web-dev-level') >= 0
    return next() if req.query['try-old-browser-anyway'] or not isOldBrowser req
    res.sendfile(path.join(__dirname, 'public', 'index_old_browser.html'))

setupRedirectMiddleware = (app) ->
  app.all '/account/profile/*', (req, res, next) ->
    nameOrID = req.path.split('/')[3]
    res.redirect 301, "/user/#{nameOrID}/profile"

setupFeaturesMiddleware = (app) ->
  app.use (req, res, next) ->
    # TODO: Share these defaults with run-tests.js
    req.features = features = {
      freeOnly: false
    }

    if req.headers.host is 'brainpop.codecombat.com' or req.session.featureMode is 'brain-pop'
      features.freeOnly = true
      features.campaignSlugs = ['dungeon']
      features.playViewsOnly = true
      features.noAuth = true
      features.brainPop = true
      features.noAds = true

    if req.headers.host is 'cp.codecombat.com' or req.session.featureMode is 'code-play'
      features.freeOnly = true
      features.campaignSlugs = ['dungeon', 'forest', 'desert']
      features.playViewsOnly = true
      features.codePlay = true # for one-off changes. If they're shared across different scenarios, refactor

    if /cn\.codecombat\.com/.test(req.get('host')) or /koudashijie/.test(req.get('host')) or req.session.featureMode is 'china'
      features.china = true
      features.freeOnly = true
      features.noAds = true

    if config.picoCTF or req.session.featureMode is 'pico-ctf'
      features.playOnly = true
      features.noAds = true
      features.picoCtf = true
      
    next()

# When config.TRACE_ROUTES is set, this logs a stack trace every time an endpoint sends a response.
# It's great for finding where a mystery endpoint is!
# The same is done for errors in the error-handling middleware.
setupHandlerTraceMiddleware = (app) ->
  app.use (req, res, next) ->
    oldSend = res.send
    res.send = ->
      result = oldSend.apply(@, arguments)
      console.trace()
      return result
    next()

setupSecureMiddleware = (app) ->
  # Cannot use express request `secure` property in production, due to
  # cluster setup.
  isSecure = ->
    return @secure or @headers['x-forwarded-proto'] is 'https'

  app.use (req, res, next) ->
    req.isSecure = isSecure
    next()

setupPerfMonMiddleware = (app) ->
  app.use perfmon.middleware

setupAPIDocs = (app) ->
  # TODO: Move this into routes, so they're consolidated
  YAML = require 'yamljs'
  swaggerDoc = YAML.load('./server/swagger.yaml')
  swaggerUi = require 'swagger-ui-express'
  app.use('/', swaggerUi.serve)
  app.use('/api-docs', swaggerUi.setup(swaggerDoc))

exports.setupMiddleware = (app) ->
  app.use(timeout(config.timeout))
  setupHandlerTraceMiddleware app if config.TRACE_ROUTES
  setupSecureMiddleware app
  setupPerfMonMiddleware app

  setupDomainFilterMiddleware app
  setupQuickBailToMainHTML app

  
  setupCountryTaggingMiddleware app
  
  setupMiddlewareToSendOldBrowserWarningWhenPlayersViewLevelDirectly app
  setupExpressMiddleware app
  setupAPIDocs app # should happen after serving static files, so we serve the right favicon
  setupPassportMiddleware app
  setupFeaturesMiddleware app

  setupUserDataRoute app
  setupCountryRedirectMiddleware app, 'china', config.chinaDomain
  setupCountryRedirectMiddleware app, 'brazil', config.brazilDomain
  
  setupOneSecondDelayMiddleware app
  setupRedirectMiddleware app
  setupAjaxCaching app
  setupJavascript404s app

###Routing function implementations###

setupAjaxCaching = (app) ->
  # IE/Edge are more aggressive about caching than other browsers, so we'll override their caching here.
  # Assumes our CDN will override these with its own caching rules.
  app.get '/db/*', (req, res, next) ->
    return next() unless req.xhr
    # http://stackoverflow.com/questions/19999388/check-if-user-is-using-ie-with-jquery
    userAgent = req.header('User-Agent') or ""
    if userAgent.indexOf('MSIE ') > 0 or !!userAgent.match(/Trident.*rv\:11\.|Edge\/\d+/)
      res.header 'Cache-Control', 'no-cache, no-store, must-revalidate'
      res.header 'Pragma', 'no-cache'
      res.header 'Expires', 0
    next()

setupJavascript404s = (app) ->
  app.get '/javascripts/*', (req, res) ->
    res.status(404).send('Not found')
  app.get(/^\/?[a-f0-9]{40}/, (req, res) ->
    res.status(404).send('Wrong hash')
  )

templates = {}
getStaticTemplate = (file) ->
  # Don't cache templates in devlopment so you can just edit then.
  return templates[file] if templates[file] and config.isProduction
  templates[file] = fs.readFileAsync(path.join(__dirname, 'public', 'templates', 'static', file), 'utf8')

renderMain = wrap (template, req, res) ->
  template = yield getStaticTemplate(template)
  if req.features.codePlay
    template = template.replace '<!-- CodePlay Tags Header -->', codePlayTags.header
    template = template.replace '<!-- CodePlay Tags Footer -->', codePlayTags.footer
   
  res.status(200).send template

setupQuickBailToMainHTML = (app) ->
  
  fast = (template) ->
    (req, res, next) ->
      req.features = features = {}

      if config.isProduction or true
        res.header 'Cache-Control', 'public, max-age=60'
        res.header 'Expires', 60
      else
        res.header 'Cache-Control', 'no-cache, no-store, must-revalidate'
        res.header 'Pragma', 'no-cache'
        res.header 'Expires', 0

      if req.headers.host is 'cp.codecombat.com'
        features.codePlay = true # for one-off changes. If they're shared across different scenarios, refactor
      if /cn\.codecombat\.com/.test(req.get('host'))
        features.china = true

      renderMain(template, req, res)

  app.get '/', fast('home.html')
  app.get '/home', fast('home.html')
  app.get '/about', fast('about.html')
  app.get '/features', fast('premium-features.html')
  app.get '/privacy', fast('privacy.html')
  app.get '/legal', fast('legal.html')
  app.get '/play', fast('overworld.html')
  app.get '/play/level/:slug', fast('main.html')
  app.get '/play/:slug', fast('main.html')

# Mongo-cache doesnt support the .exec() promise, so we manually wrap it.
getMandate = (app) ->
  return new Promise (res, rej) ->
    Mandate.findOne({}).cache(5 * 60 * 1000).exec (err, data) ->
      return rej(err) if err
      res(data)

setupUserDataRoute = (app) ->

  shouldRedirectToCountryServer = (req, country, host) ->
    reqHost = (req.hostname ? req.host).toLowerCase()  # Work around express 3.0
    hosts = host.split /;/g
    if req.country is country and reqHost not in hosts and reqHost.indexOf(config.unsafeContentHostname) is -1
      hosts[0]
    else
      undefined

  app.get '/user-data', wrap (req, res) ->
    res.header 'Cache-Control', 'no-cache, no-store, must-revalidate'
    res.header 'Pragma', 'no-cache'
    res.header 'Expires', 0

    targetDomain = undefined
    targetDomain ?= shouldRedirectToCountryServer(req, 'china', config.chinaDomain)
    targetDomain ?= shouldRedirectToCountryServer(req, 'brazil', config.brazilDomain)

    redirect = "window.location = 'https://#{targetDomain}' + window.location.pathname;" if targetDomain


    # IMPORTANT: If you edit here, make sure app/assets/javascripts/run-tests.js puts in placeholders for
    # running client tests on Travis.


    sst = JSON.stringify(_.pick(req.session ? {}, 'amActually', 'featureMode'))
    formattedUser = if req.user then JSON.stringify(UserHandler.formatEntity(req, req.user)).replace(/\//g, '\\/') else '{}'
    try
      mandate = yield getMandate()
      configData =  _.omit mandate?.toObject() or {}, '_id'
    catch err
      log.error "Error getting mandate config: #{err}"
      configData = {}

    domainRegex = new RegExp("(.*\.)?(#{config.mainHostname}|#{config.unsafeContentHostname})")
    domainPrefix = (req.hostname ? req.host).match(domainRegex)?[1] or ''

    configData.picoCTF = config.picoCTF
    configData.production = config.isProduction
    configData.codeNinjas = (req.hostname ? req.host) is 'coco.code.ninja'
    configData.fullUnsafeContentHostname = domainPrefix + config.unsafeContentHostname
    configData.buildInfo = config.buildInfo

    if not _.isString(formattedUser)
      throw new Error('Error serving user: #{formattedUser}')
    res.header 'Content-Type', 'application/javascript; charset=utf8'
    res.send [
      "window.serverConfig = #{JSON.stringify(configData)};"
      "window.userObject = #{formattedUser};",
      "window.serverSession = #{sst};",
      "window.features = #{JSON.stringify(req.features)};"
      "window.me = {"
      "\tget: function(attribute) { return window.userObject[attribute]; }"
      "};"
      redirect or ''
    ].join "\n"

setupFallbackRouteToIndex = (app) ->
  app.all '*', (req, res) =>
    res.header 'Cache-Control', 'no-cache, no-store, must-revalidate'
    res.header 'Pragma', 'no-cache'
    res.header 'Expires', 0
    renderMain 'main.html', req, res


setupFacebookCrossDomainCommunicationRoute = (app) ->
  app.get '/channel.html', (req, res) ->
    res.sendfile path.join(__dirname, 'public', 'channel.html')

setupUpdateBillingRoute = (app) ->
  app.get '/update-billing', (req, res) ->
    res.sendfile path.join(__dirname, 'public', 'update-billing.html')

exports.setupRoutes = (app) ->
  routes.setup(app)

  baseRoute.setup app
  setupFacebookCrossDomainCommunicationRoute app
  setupUpdateBillingRoute app
  setupFallbackRouteToIndex app
  setupErrorMiddleware app

###Miscellaneous configuration functions###

exports.setupLogging = ->
  logging.setup()

exports.connectToDatabase = ->
  return if config.proxy
  database.connect()

exports.setExpressConfigurationOptions = (app) ->
  app.set('port', config.port)
  app.set('views', __dirname + '/app/views')
  app.set('view engine', 'jade')
  app.set('view options', { layout: false })
  app.set('env', if config.isProduction then 'production' else 'development')
  app.set('json spaces', 0) if config.isProduction

setupProxyMiddleware = (app) ->
  return if config.isProduction
  return unless config.proxy
  httpProxy = require 'http-proxy'
  proxy = httpProxy.createProxyServer({
    target: 'https://very.direct.codecombat.com'
    secure: false
  })
  log.info 'Using dev proxy server'
  app.use (req, res, next) ->
    req.proxied = true
    proxy.web req, res, (e) ->
      console.warn("Failed to proxy: ", e)
      res.status(502).send({message: 'Proxy failed'})