accounts/api/models/profile/ChangeUsernameForm.php

<?php
namespace api\models\profile;

use api\models\AccountIdentity;
use api\models\base\ApiForm;
use api\validators\PasswordRequiredValidator;
use common\helpers\Error;
use common\helpers\Amqp;
use common\models\Account;
use common\models\amqp\UsernameChanged;
use common\models\UsernameHistory;
use Exception;
use PhpAmqpLib\Message\AMQPMessage;
use Yii;
use yii\base\ErrorException;

class ChangeUsernameForm extends ApiForm {

    public $username;

    public $password;

    public function rules() {
        return [
            ['username', 'required', 'message' => Error::USERNAME_REQUIRED],
            ['username', 'validateUsername'],
            ['password', PasswordRequiredValidator::class],
        ];
    }

    public function validateUsername($attribute) {
        $account = new Account();
        $account->id = $this->getAccount()->id;
        $account->username = $this->$attribute;
        // Это чтобы unique validator учёл, что ник может быть забит на текущий аккаунт
        $account->setIsNewRecord(false);
        if (!$account->validate(['username'])) {
            $this->addErrors($account->getErrors());
        }
    }

    public function change() {
        if (!$this->validate()) {
            return false;
        }

        $transaction = Yii::$app->db->beginTransaction();
        $account = $this->getAccount();
        $oldNickname = $account->username;
        try {
            $account->username = $this->username;
            if (!$account->save(false)) {
                throw new ErrorException('Cannot save account model with new username');
            }

            $usernamesHistory = new UsernameHistory();
            $usernamesHistory->account_id = $account->id;
            $usernamesHistory->username = $account->username;
            if (!$usernamesHistory->save()) {
                throw new ErrorException('Cannot save username history record');
            }

            $this->createEventTask($account->id, $account->username, $oldNickname);

            $transaction->commit();
        } catch (Exception $e) {
            $transaction->rollBack();
            throw $e;
        }

        return true;
    }

    /**
     * TODO: вынести это в отдельную сущность, т.к. эта команда используется внутри формы регистрации
     *
     * @param integer $accountId
     * @param string  $newNickname
     * @param string  $oldNickname
     * @throws \PhpAmqpLib\Exception\AMQPExceptionInterface
     */
    public function createEventTask($accountId, $newNickname, $oldNickname) {
        $model = new UsernameChanged;
        $model->accountId = $accountId;
        $model->oldUsername = $oldNickname;
        $model->newUsername = $newNickname;

        $message = Amqp::getInstance()->prepareMessage($model, [
            'delivery_mode' => AMQPMessage::DELIVERY_MODE_PERSISTENT,
        ]);

        Amqp::sendToEventsExchange('accounts.username-changed', $message);
    }

    protected function getAccount() : AccountIdentity {
        return Yii::$app->user->identity;
    }

}