Как в Yii2 реализовать мультивалютность?

<?php

namespace app\modules\shop\models;

use Yii;
use yii\db\ActiveRecord;
use yii\helpers\ArrayHelper;

class Currency extends ActiveRecord
{
    const STATUS_ACTIVE = 1;
    const STATUS_INACTIVE = 0;

    public function behaviors()
    {
        return [
            'timestamp' => [
                'class' => \yii\behaviors\TimestampBehavior::class,
            ],
            'blameable' => [
                'class' => \yii\behaviors\BlameableBehavior::class,
            ],
            'ip' => [
                'class' => \yii\behaviors\AttributeBehavior::class,
                'attributes' => [
                    ActiveRecord::EVENT_BEFORE_INSERT => 'created_ip',
                    ActiveRecord::EVENT_BEFORE_UPDATE => 'updated_ip',
                ],
                'value' => function ($event) {
                    return Yii::$app->request->getUserIP();
                },
            ],
        ];
    }

    public static function tableName()
    {
        return 'currency';
    }

    public function rules()
    {
        return [
            [['name', 'code'], 'required'],
            [['is_default', 'sort', 'status'], 'integer'],
            [['decimal_places'], 'integer', 'max' => 9],
            [['rate'], 'number'],
            [['code'], 'string', 'length' => 3],
            [['code'], 'unique'],
            [['code'], 'match', 'pattern' => '/^[A-Z]+$/', 'message' => Yii::t('app', 'Это поле может содержать только строчные буквы, цифры и дефис')],
            [['name', 'symbol'], 'string', 'max' => 32],
        ];
    }

    public function attributeLabels()
    {
        return [
            'id' => Yii::t('app', 'ID'),
            'created_at' => Yii::t('app', 'Дата создания'),
            'updated_at' => Yii::t('app', 'Дата обновления'),
            'created_by' => Yii::t('app', 'Создано пользователем'),
            'updated_by' => Yii::t('app', 'Обновлено пользователем'),
            'created_ip' => Yii::t('app', 'Создано c IP'),
            'updated_ip' => Yii::t('app', 'Обновлено c IP'),
            'code' => Yii::t('app', 'Код'),
            'name' => Yii::t('app', 'Название'),
            'symbol' => Yii::t('app', 'Символ'),
            'rate' => Yii::t('app', 'Курс'),
            'decimal_places' => Yii::t('app', 'Количество знаков после запятой'),
            'is_default' => Yii::t('app', 'По умолчанию'),
            'sort' => Yii::t('app', 'Сортировка'),
            'status' => Yii::t('app', 'Опубликован'),
        ];
    }
   
    public function afterSave($insert, $changedAttributes)
    {
        return Yii::$app->session->remove('currency');
    }
    
    public static function listItems()
    {
        $items = self::find()
            ->select(['code'])
            ->where(['status' => self::STATUS_ACTIVE])
            ->orderBy(['sort' => SORT_ASC])
            ->asArray()
            ->all();
        return ArrayHelper::map($items, 'code', 'code');
    }
    
    public static function statuses()
    {
        return [
            self::STATUS_ACTIVE => Yii::t('app', 'Опубликован'),
            self::STATUS_INACTIVE => Yii::t('app', 'Не опубликован'),
        ];
    }
}

<?php

namespace app\modules\shop\components;

use Yii;
use yii\base\BaseObject;
use app\modules\shop\models\Currency;

class CurrencyManager extends BaseObject
{
    public $currencies;
    public $defaultCurrency;
    public $siteCurrency;
    
    public function init()
    {
        parent::init();
        
        $this->currencies = Currency::find()
            ->where(['status' => Currency::STATUS_ACTIVE])
            ->orderBy(['sort' => SORT_ASC])
            ->asArray()
            ->all();
        foreach ($this->currencies as $item) {
            if ($item['is_default'] == 1) {
                $this->defaultCurrency = $item;
            }
        }
        if (!Yii::$app->session['currency']) {
            Yii::$app->session['currency'] = $this->defaultCurrency;
        }
        $this->siteCurrency = Yii::$app->session['currency'];
    }
    
    public function listCurrencies()
    {
        $result = [];
        foreach ($this->currencies as $item) {
            $result[$item['code']] = $item['code'];
        }
        return $result;
    }
    
    public function showPrice($offer, $symbol = true)
    {
        if ($offer['currency_code'] == $this->siteCurrency['code']) {
            $price = $offer['price'];
        } else {
            foreach ($this->currencies as $item) {
                if ($item['code'] == $offer['currency_code']) {
                    $rate = $item['rate'];
                }
            }
            $price = ($offer['price'] * $rate) / $this->siteCurrency['rate'];
        }
                
        if ($symbol === true) {
            return number_format($price, $this->siteCurrency['decimal_places'], '.', '') . '&nbsp;' . $this->siteCurrency['symbol'];
        } else {
            //return round($price, $this->siteCurrency['decimal_places']);
            return number_format($price, $this->siteCurrency['decimal_places'], '.', '');
        }
    }
    
    public function showOldPrice($offer, $symbol = true)
    {
        if ($offer['currency_code'] == $this->siteCurrency['code']) {
            $price = $offer['old_price'];
        } else {
            foreach ($this->currencies as $item) {
                if ($item['code'] == $offer['currency_code']) {
                    $rate = $item['rate'];
                }
            }
            $price = ($offer['old_price'] * $rate) / $this->siteCurrency['rate'];
        }
                
        if ($symbol === true) {
            return number_format($price, $this->siteCurrency['decimal_places'], '.', '') . '&nbsp;' . $this->siteCurrency['symbol'];
        } else {
            return round($price, $this->siteCurrency['decimal_places']);
        }
    }
}