var http = require('http')
var url = require('url');
var querystring = require('querystring');

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("auth failed");
      } else if(!authUrl){
        res.send("auth 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("Auth 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)
}