var http = require('http')

var openid = require('openid')
var express = require('express')
var urljoin = require('url-join')

var logger = require('../../util/logger')
var jwtutil = require('../../util/jwtutil')
var urlutil = require('../../util/urlutil')

module.exports = function(options) {
  var extensions = [new openid.SimpleRegistration({
    email: true
  , fullname: true
  })]

  var relyingParty = new openid.RelyingParty(
    urljoin(options.appUrl, '/auth/openid/verify')
  , null  // Realm (optional, specifies realm for OpenID authentication)
  , false // Use stateless verification
  , false // Strict mode
  , extensions)

  var log = logger.createLogger('auth-openid')
  var app = express()

  app.set('strict routing', true)
  app.set('case sensitive routing', true)

  app.get('/', function(req, res) {
    res.redirect('/auth/openid/')
  })

  app.get('/auth/openid/', function(req, res) {
    log.info('openid identifier url: %s', options.openid.identifierUrl)
    relyingParty.authenticate(options.openid.identifierUrl, false, function(err, authUrl) {
      if (err) {
        res.send('Authentication failed')
      }
      else if (!authUrl) {
        res.send('Authentication failed')
      }
      else {
        log.info('redirect to authUrl: %s', options.openid.identifierUrl)
        res.redirect(authUrl)
      }
    })
  })

  app.get('/auth/openid/verify', function(req, res) {
    log.setLocalIdentifier(req.ip)

    relyingParty.verifyAssertion(req, function(err, result) {
      log.info('openid verify assertion')
      if (err || !result.authenticated) {
        res.send('Authentication failed')
        return
      }
      var email = req.query['openid.sreg.email']
      var name = req.query['openid.sreg.fullname']
      log.info('Authenticated "%s:%s"', name, email)
      var token = jwtutil.encode({
        payload: {
          email: email
        , name: name
        }
      , secret: options.secret
      })
      res.redirect(urlutil.addParams(options.appUrl, {jwt: token}))
    })
  })

  http.createServer(app).listen(options.port)
  log.info('Listening on port %d', options.port)
}