text: // Load modules.
  var OAuthStrategy = require('passport-oauth1')
    , util = require('util')
    , Profile = require('./profile')
    , InternalOAuthError = require('passport-oauth1').InternalOAuthError;
  
  
  /**
   * `Strategy` constructor.
   *
   * The Google authentication strategy authenticates requests by delegating to
   * Google using the OAuth protocol.
   *
   * Applications must supply a `verify` callback which accepts a `token`,
   * `tokenSecret` and service-specific `profile`, and then calls the `cb`
   * callback supplying a `user`, which should be set to `false` if the
   * credentials are not valid.  If an exception occured, `err` should be set.
   *
   * Options:
   *   - `consumerKey`     identifies client to Google
   *   - `consumerSecret`  secret used to establish ownership of the consumer key
   *   - `callbackURL`     URL to which Google will redirect the user after obtaining authorization
   *
   * Examples:
   *
   *     passport.use(new GoogleStrategy({
   *         consumerKey: '123-456-789',
   *         consumerSecret: 'shhh-its-a-secret'
   *         callbackURL: 'https://www.example.net/auth/google/callback'
   *       },
   *       function(token, tokenSecret, profile, cb) {
   *         User.findOrCreate(..., function (err, user) {
   *           cb(err, user);
   *         });
   *       }
   *     ));
   *
   * @constructor
   * @param {Object} options
   * @param {Function} verify
   * @access public
   */
  function Strategy(options, verify) {
    options = options || {};
    options.requestTokenURL = options.requestTokenURL || 'https://www.google.com/accounts/OAuthGetRequestToken';
    options.accessTokenURL = options.accessTokenURL || 'https://www.google.com/accounts/OAuthGetAccessToken';
    options.userAuthorizationURL = options.userAuthorizationURL || 'https://www.google.com/accounts/OAuthAuthorizeToken';
    options.sessionKey = options.sessionKey || 'oauth:google';
  
    OAuthStrategy.call(this, options, verify);
    this.name = 'google';
  }
  
  // Inherit from `OAuthStrategy`.
  util.inherits(Strategy, OAuthStrategy);
  
  /**
   * Retrieve user profile from Google.
   *
   * This function constructs a normalized profile, with the following properties:
   *
   *   - `id`
   *   - `displayName`
   *
   * @param {String} token
   * @param {String} tokenSecret
   * @param {Object} params
   * @param {Function} done
   * @access protected
   */
  Strategy.prototype.userProfile = function(token, tokenSecret, params, done) {
    this._oauth.get('https://www.google.com/m8/feeds/contacts/default/full?max-results=1&alt=json', token, tokenSecret, function (err, body, res) {
      if (err) { return done(new InternalOAuthError('Failed to fetch user profile', err)); }
      
      var json;
      try {
        json = JSON.parse(body);
      } catch (ex) {
        return done(new Error('Failed to parse user profile'));
      }
      
      var profile = Profile.parse(json);
      profile.provider = 'google';
      profile._raw = body;
      profile._json = json;
      
      done(null, profile);
    });
  }
  
  /**
   * Return extra Google-specific parameters to be included in the request token
   * request.
   *
   * @param {Object} options
   * @return {Object}
   * @access protected
   */
  Strategy.prototype.requestTokenParams = function(options) {
    var params = options || {};
    
    var scope = options.scope;
    if (scope) {
      if (Array.isArray(scope)) { scope = scope.join(' '); }
      params['scope'] = scope;
    }
    return params;
  }
  
  
  // Expose constructor.
  module.exports = Strategy;
  