passport.connect = function()

in api/services/passport.js [67:179]

• 67 lines of code
• 20 McCabe index (conditional complexity)

passport.connect = function (req, query, profile, next) {
  var user = {}
    , provider;

  // Get the authentication provider from the query.
  query.provider = req.param('provider');

  // Use profile.provider or fallback to the query.provider if it is undefined
  // as is the case for OpenID, for example
  provider = profile.provider || query.provider;

  // If the provider cannot be identified we cannot match it to a passport so
  // throw an error and let whoever's next in line take care of it.
  if (!provider){
    return next(new Error('No authentication provider was identified.'));
  }

  // If the profile object contains a list of emails, grab the first one and
  // add it to the user.
  if (profile.hasOwnProperty('emails')) {
    user.email = profile.emails[0].value;
  }
  // If the profile object contains a username, add it to the user.
  if (profile.hasOwnProperty('username')) {
    user.username = profile.username;
  }

  // If neither an email or a username was available in the profile, we don't
  // have a way of identifying the user in the future. Throw an error and let
  // whoever's next in the line take care of it.
  if (!user.username && !user.email) {
    return next(new Error('Neither a username nor email was available'));
  }

  Passport.findOne({
    provider   : provider
  , identifier : query.identifier.toString()
  }, function (err, passport) {
    if (err) {
      return next(err);
    }

    if (!req.user) {
      // Scenario: A new user is attempting to sign up using a third-party
      //           authentication provider.
      // Action:   Create a new user and assign them a passport.
      if (!passport) {

        // Validate user should have access
        GitHub.validateUser(query.tokens.accessToken, function(err) {
          if (err) return next(err);

          User.findOrCreate({ username: user.username }, user, function (err, user) {
            if (err) return next(err);

            query.user = user.id;

            Passport.create(query, function (err, passport) {
              // If a passport wasn't created, bail out
              if (err) return next(err);

              next(err, user);
            });
          });
        });

      }
      // Scenario: An existing user is trying to log in using an already
      //           connected passport.
      // Action:   Get the user associated with the passport.
      else {
        // If the tokens have changed since the last session, update them
        if (query.hasOwnProperty('tokens') && query.tokens !== passport.tokens) {
          passport.tokens = query.tokens;
        }

        GitHub.validateUser(query.tokens.accessToken, function(err) {
          if (err) return next(err);

          // Save any updates to the Passport before moving on
          passport.save(function (err, passport) {
            if (err) return next(err);

            // Fetch the user associated with the Passport
            User.findOne(passport.user.id, next);
          });
        });
      }
    } else {
      // Scenario: A user is currently logged in and trying to connect a new
      //           passport.
      // Action:   Create and assign a new passport to the user.
      if (!passport) {
        query.user = req.user.id;

        GitHub.validateUser(query.tokens.accessToken, function(err) {
          if (err) return next(err);

          Passport.create(query, function (err, passport) {
            // If a passport wasn't created, bail out
            if (err) return next(err);
            next(err, req.user);
          });
        });
      }
      // Scenario: The user is already logged in or pushed the back-button.
      // Action:   Simply pass along the already established session.
      else {
        next(null, req.user);
      }
    }
  });
};