public static CalendarUser createCalendarUserFromProvider(Connection<?> connection){
    // TODO: FIXME: Need to put this into a Utility:
    UserProfile profile = connection.fetchUserProfile();

    CalendarUser user = new CalendarUser();

    if(profile.getEmail() != null){
        user.setEmail(profile.getEmail());
    }
    else if(profile.getUsername() != null){
        user.setEmail(profile.getUsername());
    }
    else {
        user.setEmail(connection.getDisplayName());
    }

    user.setFirstName(profile.getFirstName());
    user.setLastName(profile.getLastName());

    user.setPassword(randomAlphabetic(32));

    return user;

}
 

@RequestMapping(value="/signup", method = RequestMethod.GET)
public String getForm(NativeWebRequest request,  @ModelAttribute User user) {
	String view = successView;

	// check if this is a new user signing in via Spring Social
    Connection<?> connection = providerSignInUtils.getConnectionFromSession(request);
    if (connection != null) {
        // populate new User from social connection user profile
        UserProfile userProfile = connection.fetchUserProfile();
        user.setId(userProfile.getUsername());

        // finish social signup/login
        providerSignInUtils.doPostSignUp(user.getUsername(), request);

        // sign the user in and send them to the user home page
        signInAdapter.signIn(user.getUsername(), connection, request);
		view += "?spi="+ user.getUsername();
    }
    
    return view;
}
 

@Override
public UserAccount createUserAccount(ConnectionData data, UserProfile profile) {
    long userIdSequence = this.counterService.getNextUserIdSequence();
    
    UserRoleType[] roles = (userIdSequence == 1l) ? 
            new UserRoleType[] { UserRoleType.ROLE_USER, UserRoleType.ROLE_AUTHOR, UserRoleType.ROLE_ADMIN } :
            new UserRoleType[] { UserRoleType.ROLE_USER };
    UserAccount account = new UserAccount(USER_ID_PREFIX + userIdSequence, roles);
    account.setEmail(profile.getEmail());
    account.setDisplayName(data.getDisplayName());
    account.setImageUrl(data.getImageUrl());
    if (userIdSequence == 1l) {
        account.setTrustedAccount(true);
    }
    LOGGER.info(String.format("A new user is created (userId='%s') for '%s' with email '%s'.", account.getUserId(),
            account.getDisplayName(), account.getEmail()));
    return this.accountRepository.save(account);
}
 

@Override
public OAuth2Authentication loadAuthentication(String accessToken)
		throws AuthenticationException, InvalidTokenException {
	AccessGrant accessGrant = new AccessGrant(accessToken);
	Connection<?> connection = this.connectionFactory.createConnection(accessGrant);
	UserProfile user = connection.fetchUserProfile();
	return extractAuthentication(user);
}
 

private OAuth2Authentication extractAuthentication(UserProfile user) {
	String principal = user.getUsername();
	List<GrantedAuthority> authorities = AuthorityUtils.commaSeparatedStringToAuthorityList("ROLE_USER");
	OAuth2Request request = new OAuth2Request(null, this.clientId, null, true, null, null, null, null, null);
	return new OAuth2Authentication(request,
			new UsernamePasswordAuthenticationToken(principal, "N/A", authorities));
}
 

public static CalendarUser createCalendarUserFromProvider(Connection<?> connection){

        // TODO: There is a defect with Facebook:
        // org.springframework.social.UncategorizedApiException: (#12) bio field is
        // deprecated for versions v2.8 and higher:
//
//        Connection<Facebook> connection = facebookConnectionFactory.createConnection(accessGrant);
//        Facebook facebook = connection.getApi();
//        String [] fields = { "id", "email",  "first_name", "last_name" };
//        User userProfile = facebook.fetchObject("me", User.class, fields);
//
//        Object api = connection.getApi();
//        if(api instanceof FacebookTemplate){
//            System.out.println("Facebook");
//        }


        // Does not work with spring-social-facebook:2.0.3.RELEASE
        UserProfile profile = connection.fetchUserProfile();

        CalendarUser user = new CalendarUser();

        if(profile.getEmail() != null){
            user.setEmail(profile.getEmail());
        }
        else if(profile.getUsername() != null){
            user.setEmail(profile.getUsername());
        }
        else {
            user.setEmail(connection.getDisplayName());
        }

        user.setFirstName(profile.getFirstName());
        user.setLastName(profile.getLastName());

        user.setPassword(randomAlphabetic(32));

        return user;

    }
 

public void createSocialUser(Connection<?> connection, String langKey) {
    if (connection == null) {
        log.error("Cannot create social user because connection is null");
        throw new IllegalArgumentException("Connection cannot be null");
    }
    UserProfile userProfile = connection.fetchUserProfile();
    String providerId = connection.getKey().getProviderId();
    User user = createUserIfNotExist(userProfile, langKey, providerId);
    createSocialConnection(user.getLogin(), connection);
    mailService.sendSocialRegistrationValidationEmail(user, providerId);
}
 

private User createUserIfNotExist(UserProfile userProfile, String langKey, String providerId) {
    String email = userProfile.getEmail();
    String userName = userProfile.getUsername();
    if (StringUtils.isBlank(email) && StringUtils.isBlank(userName)) {
        log.error("Cannot create social user because email and login are null");
        throw new IllegalArgumentException("Email and login cannot be null");
    }
    if (StringUtils.isBlank(email) && userRepository.findOneByLogin(userName).isPresent()) {
        log.error("Cannot create social user because email is null and login already exist, login -> {}", userName);
        throw new IllegalArgumentException("Email cannot be null with an existing login");
    }
    Optional<User> user = userRepository.findOneByEmail(email);
    if (user.isPresent()) {
        log.info("User already exist associate the connection to this account");
        return user.get();
    }

    String login = getLoginDependingOnProviderId(userProfile, providerId);
    String encryptedPassword = passwordEncoder.encode(RandomStringUtils.random(10));
    Set<Authority> authorities = new HashSet<>(1);
    authorities.add(authorityRepository.findOne("ROLE_USER"));

    User newUser = new User();
    newUser.setLogin(login);
    newUser.setPassword(encryptedPassword);
    newUser.setFirstName(userProfile.getFirstName());
    newUser.setLastName(userProfile.getLastName());
    newUser.setEmail(email);
    newUser.setActivated(true);
    newUser.setAuthorities(authorities);
    newUser.setLangKey(langKey);

    return userRepository.save(newUser);
}
 

/**
 * @return login if provider manage a login like Twitter or Github otherwise email address.
 *         Because provider like Google or Facebook didn't provide login or login like "12099388847393"
 */
private String getLoginDependingOnProviderId(UserProfile userProfile, String providerId) {
    switch (providerId) {
        case "twitter":
            return userProfile.getUsername().toLowerCase();
        default:
            return userProfile.getEmail();
    }
}
 

@Override
public String execute(Connection<?> connection) {
    UserProfile profile = connection.fetchUserProfile();
    String username = profile.getUsername();

    logger.info("Creating user with id: {}", username);
    User user = new User(username, "", Collections.emptyList());

    userDetailsManager.createUser(user);
    return username;
}
 

@Override
public UserProfile fetchUserProfile(Yahoo2 yahoo) {
	TinyUsercard tinyUserCard = yahoo.profilesOperations().getTinyUsercard();
	return new YahooUserProfile(
			tinyUserCard.getProfile().getNickname(), 
			tinyUserCard.getProfile().getGivenName(), 
			tinyUserCard.getProfile().getFamilyName(), 
			null, 
			tinyUserCard.getProfile().getGuid());
}
 

public UserProfile fetchUserProfile(Plus api) {
    Person person = api.getPeopleOperations().get("me");
    UserProfileBuilder builder = new UserProfileBuilder().setFirstName(person.getName().getGivenName()).setLastName(person.getName().getFamilyName());
    builder.setEmail(person.getGoogleAccountEmail());
    builder.setName(person.getName().getFormatted());
    return builder.build();
}
 

@Override
public UserProfile fetchUserProfile(Wechat api) {
    return null;
}
 

@Override
public UserProfile fetchUserProfile(QQ api) {
	return null;
}
 

@Override
public UserProfile fetchUserProfile(WechatMp api) {
    return null;
}
 

@Override
public UserProfile fetchUserProfile(Alipay api) {
	return null;
}
 

@Override
public UserProfile fetchUserProfile(GitHub api) {
    return null;
}
 

@Override
public UserProfile fetchUserProfile(Gitee api) {
    return null;
}
 

@Override
public UserProfile fetchUserProfile(Weixin api) {
    return null;
}
 

@Override
public UserProfile fetchUserProfile(QQ api) {
    return null;
}
 

@Override
public UserProfile fetchUserProfile(WeiXin api) {
    return null;
}
 

public static CalendarUser createCalendarUserFromProvider(Connection<?> connection){

        // TODO: There is a defect with Facebook:
//        Connection<Facebook> connection = facebookConnectionFactory.createConnection(accessGrant);
//        Facebook facebook = connection.getApi();
//        String [] fields = { "id", "email",  "first_name", "last_name" };
//        User userProfile = facebook.fetchObject("me", User.class, fields);

//        Object api = connection.getApi();
//        if(connection instanceof FacebookTemplate){
//            System.out.println("HERE");
//        }
        /*
            <form name='facebookSocialloginForm'
                  action="<c:url value='/auth/facebook' />" method='POST'>
                <input type="hidden" name="scope"
                    value="public_profile,email,user_about_me,user_birthday,user_likes"/>
                ...
            </form>
         */

        // FIXME: Does not work with Facebook:
        UserProfile profile = connection.fetchUserProfile();

        CalendarUser user = new CalendarUser();

        if(profile.getEmail() != null){
            user.setEmail(profile.getEmail());
        }
        else if(profile.getUsername() != null){
            user.setEmail(profile.getUsername());
        }
        else {
            user.setEmail(connection.getDisplayName());
        }

        user.setFirstName(profile.getFirstName());
        user.setLastName(profile.getLastName());

        user.setPassword(randomAlphabetic(32));

        return user;

    }
 

/**
 * 和上面的方法类似
 * @param qq
 * @return
 */
@Override
public UserProfile fetchUserProfile(QQ qq) {
    return null;
}
 

/**
 * Fetch user profile user profile.
 *
 * @param api the api
 *
 * @return the user profile
 */
@Override
public UserProfile fetchUserProfile(QQ api) {
	return null;
}
 

/**
 * Fetch user profile user profile.
 *
 * @param api the api
 *
 * @return user profile
 */
@Override
public UserProfile fetchUserProfile(Weixin api) {
	return null;
}
 

/**
 * Creates a new UserAccount with user social network account Connection Data and UserProfile.
 * Default has ROLE_USER role.
 * 
 * @param data
 * @param profile
 * @return
 */
UserAccount createUserAccount(ConnectionData data, UserProfile profile);