public function successOAuthCallback($client)
{
    // use BaseClient::normalizeUserAttributeMap to provide consistency for user attribute`s names
    $attributes = $client->getUserAttributes();
    $user = User::find()->where([
            'oauth_client'=>$client->getName(),
            'oauth_client_user_id'=>ArrayHelper::getValue($attributes, 'id')
        ])
        ->one();
    if (!$user) {
        $user = new User();
        $user->scenario = 'oauth_create';
        $user->username = ArrayHelper::getValue($attributes, 'first_name');
        $user->email = ArrayHelper::getValue($attributes, 'email');
        $user->oauth_client = $client->getName();
        $user->oauth_client_user_id = ArrayHelper::getValue($attributes, 'id');
        $password = Yii::$app->security->generateRandomString(8);
        $user->setPassword($password);
        if ($user->save()) {
            $profileData = [];
            if ($client->getName() === 'facebook') {
                $profileData['firstname'] = ArrayHelper::getValue($attributes, 'first_name');
                $profileData['lastname'] = ArrayHelper::getValue($attributes, 'last_name');
            }
            $user->afterSignup($profileData);
            $token = UserToken::create(
                $user->id,
                UserToken::TYPE_ACTIVATION,
                Time::SECONDS_IN_A_DAY
            );
            $sentSuccess = Yii::$app->commandBus->handle(new SendEmailCommand([
                'view' => 'activation',
                'params' => [
                    'user'=>$user,
                    'password'=>$password,
                    'url' => Url::to(['/user/sign-in/activation', 'token' => $token->token], true)
                ],
                'subject' => Yii::t('frontend', '{app-name} | Activation link', ['app-name'=>Yii::$app->name]),
                'to' => $user->email
            ]));
            $sentSuccess1 = Yii::$app->commandBus->handle(new SendEmailCommand([
                'view' => 'oauth_welcome',
                'params' => [
                    'user'=>$user,
                    'password'=>$password,
                ],
                'subject' => Yii::t('frontend', '{app-name} | Login information', ['app-name'=>Yii::$app->name]),
                'to' => $user->email
            ]));
            if ($sentSuccess && $sentSuccess1) {
                Yii::$app->session->setFlash(
                    'alert',
                    [
                        'options'=>['class'=>'alert-success'],
                        'body'=>Yii::t('frontend', 'Welcome to {app-name}. Email with activation link and login information was sent to your email.', [
                            'app-name'=>Yii::$app->name
                        ])
                    ]
                );
            }

        } else {
            // We already have a user with this email. Do what you want in such case
            if ($user->email && User::find()->where(['email'=>$user->email])->count()) {
                Yii::$app->session->setFlash(
                    'alert',
                    [
                        'options'=>['class'=>'alert-danger'],
                        'body'=>Yii::t('frontend', 'We already have a user with email {email}', [
                            'email'=>$user->email
                        ])
                    ]
                );
            } else {
                Yii::$app->session->setFlash(
                    'alert',
                    [
                        'options'=>['class'=>'alert-danger'],
                        'body'=>Yii::t('frontend', 'Error while oauth process.')
                    ]
                );
            }

        };
    }
    if (Yii::$app->user->login($user, 3600 * 24 * 30)) {
        return true;
    } else {
        throw new Exception('OAuth error');
    }
}