/**
 * Module dependencies.
 */
var util = require('util')
  , OAuth2Strategy = require('passport-oauth2')
  , InternalOAuthError = require('passport-oauth2').InternalOAuthError;


/**
 * `Strategy` constructor.
 *
 * The Google authentication strategy authenticates requests by delegating to
 * Google using the OAuth 2.0 protocol.
 *
 * Applications must supply a `verify` callback which accepts an `accessToken`,
 * `refreshToken` and service-specific `profile`, and then calls the `done`
 * 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:
 *   - `clientID`      your Google application's client id
 *   - `clientSecret`  your Google application's client secret
 *   - `callbackURL`   URL to which Google will redirect the user after granting authorization
 *
 * Examples:
 *
 *     passport.use(new GoogleStrategy({
 *         clientID: '123-456-789',
 *         clientSecret: 'shhh-its-a-secret'
 *         callbackURL: 'https://www.example.net/auth/google/callback'
 *       },
 *       function(accessToken, refreshToken, profile, done) {
 *         User.findOrCreate(..., function (err, user) {
 *           done(err, user);
 *         });
 *       }
 *     ));
 *
 * @param {Object} options
 * @param {Function} verify
 * @api public
 */
function Strategy(options, verify) {
  options = options || {};
  options.authorizationURL = options.authorizationURL || 'https://accounts.google.com/o/oauth2/v2/auth';
  options.tokenURL = options.tokenURL || 'https://www.googleapis.com/oauth2/v4/token';

  OAuth2Strategy.call(this, options, verify);
  this.name = 'google';
}

/**
 * Inherit from `OAuth2Strategy`.
 */
util.inherits(Strategy, OAuth2Strategy);

Strategy.prototype.authenticate = function(req, options) {
  options || (options = {})

  var oldHint = options.loginHint
  options.loginHint = req.query.login_hint
  OAuth2Strategy.prototype.authenticate.call(this, req, options)
  options.loginHint = oldHint
}


/**
 * Retrieve user profile from Google.
 *
 * This function constructs a normalized profile, with the following properties:
 *
 *   - `provider`         always set to `google`
 *   - `id`
 *   - `name`
 *   - `displayName`
 *   - `birthday`
 *   - `relationship`
 *   - `isPerson`
 *   - `isPlusUser`
 *   - `placesLived`
 *   - `language`
 *   - `emails`
 *   - `gender`
 *   - `picture`
 *
 * @param {String} accessToken
 * @param {Function} done
 * @api protected
 */
Strategy.prototype.userProfile = function(accessToken, done) {
  this._oauth2.get('https://www.googleapis.com/oauth2/v3/userinfo', accessToken, function (err, body, res) {
    if (err) { return done(new InternalOAuthError('failed to fetch user profile', err)); }

    try {
      var json = JSON.parse(body);

      var profile = { provider: 'google' };
      profile.sub          = json.sub;
      profile.id           = json.id || json.sub;
      profile.displayName  = json.name;
      profile.name         = {
        givenName: json.given_name,
        familyName: json.family_name
      };
      profile.given_name = json.given_name;
      profile.family_name = json.family_name;
      if (json.birthday) profile.birthday = json.birthday;
      if (json.relationshipStatus) profile.relationship = json.relationshipStatus;
      if (json.objectType && json.objectType == 'person') {
        profile.isPerson = true;
      }
      if (json.isPlusUser) profile.isPlusUser = json.isPlusUser;
      if (json.email_verified !== undefined) {
        profile.email_verified = json.email_verified;
	 profile.verified = json.email_verified;
      }
      if (json.placesLived) profile.placesLived = json.placesLived;
      if (json.language) profile.language = json.language;
      if (!json.language && json.locale) {
        profile.language = json.locale;
	 profile.locale = json.local;
      }
      if (json.emails) {
        profile.emails = json.emails;

        profile.emails.some(function(email) {
          if (email.type === 'account') {
            profile.email = email.value
            return true
          }
        })
      }
      if (!profile.email && json.email) {
	 profile.email = json.email;
      }
      if (!profile.emails && profile.email) {
        profile.emails = [{
	   value: profile.email,
   	   type: "account"
	}];
      }
      if (json.gender) profile.gender = json.gender;
      if (!json.domain && json.hd) json.domain = json.hd;
      if (json.image && json.image.url) {
        var photo = {
          value: json.image.url
        };
        if (json.image.isDefault) photo.type = 'default';
        profile.photos = [photo];
      }
      if (!json.image && json.picture) {
        var photo = {
          value: json.picture
        };
        photo.type = 'default';
        profile.photos = [photo];
        profile.picture = json.picture;
      } 
      if (json.cover && json.cover.coverPhoto && json.cover.coverPhoto.url)
        profile.coverPhoto = json.cover.coverPhoto.url;

      profile._raw = body;
      profile._json = json;

      done(null, profile);
    } catch(e) {
      done(e);
    }
  });
};

/**
 * Return extra Google-specific parameters to be included in the authorization
 * request.
 *
 * @param {Object} options
 * @return {Object}
 * @api protected
 */
Strategy.prototype.authorizationParams = function(options) {
  var params = {};
  if (options.accessType) {
    params['access_type'] = options.accessType;
  }
  if (options.approvalPrompt) {
    params['approval_prompt'] = options.approvalPrompt;
  }
  if (options.prompt) {
    // This parameter is undocumented in Google's official documentation.
    // However, it was detailed by Breno de Medeiros (who works at Google) in
    // this Stack Overflow answer:
    //  http://stackoverflow.com/questions/14384354/force-google-account-chooser/14393492#14393492
    params['prompt'] = options.prompt;
  }
  if (options.loginHint) {
    // This parameter is derived from OpenID Connect, and supported by Google's
    // OAuth 2.0 endpoint.
    //   https://github.com/jaredhanson/passport-google-oauth/pull/8
    //   https://bitbucket.org/openid/connect/commits/970a95b83add
    params['login_hint'] = options.loginHint;
  }
  if (options.userID) {
    // Undocumented, but supported by Google's OAuth 2.0 endpoint.  Appears to
    // be equivalent to `login_hint`.
    params['user_id'] = options.userID;
  }
  if (options.hostedDomain || options.hd) {
    // This parameter is derived from Google's OAuth 1.0 endpoint, and (although
    // undocumented) is supported by Google's OAuth 2.0 endpoint was well.
    //   https://developers.google.com/accounts/docs/OAuth_ref
    params['hd'] = options.hostedDomain || options.hd;
  }
  return params;
};


/**
 * Expose `Strategy` directly from package.
 */
exports = module.exports = Strategy;

/**
 * Export constructors.
 */
exports.Strategy = Strategy;