<?php

declare(strict_types=1);

namespace Mironsoft\Loyalty\Model\Customer\Attribute\Backend;

use Magento\Eav\Model\Entity\Attribute\Backend\AbstractBackend;
use Mironsoft\Loyalty\Model\Config\LoyaltyConfig;
use Mironsoft\Loyalty\Model\Service\PointsCalculator;

/**
 * Backend model for the loyalty_tier customer attribute. Recalculates the tier
 * from loyalty_points_balance on every entity save, so the two denormalized
 * fields introduced in chapter 21 can never silently drift apart.
 */
class LoyaltyTierBackend extends AbstractBackend
{
    /**
     * @param PointsCalculator $pointsCalculator Pure business rule for determining a tier from a point total.
     * @param LoyaltyConfig $loyaltyConfig Typed reader for the tier_thresholds configuration value.
     */
    public function __construct(
        private readonly PointsCalculator $pointsCalculator,
        private readonly LoyaltyConfig $loyaltyConfig
    ) {
    }

    /**
     * Overwrites loyalty_tier with a freshly calculated value based on the
     * entity's current loyalty_points_balance, immediately before it is saved.
     * $object deliberately carries no native type hint - see the warning below
     * this listing for why.
     *
     * @param \Magento\Framework\DataObject $object The entity currently being saved (a Customer model here).
     * @return $this
     */
    public function beforeSave($object)
    {
        $pointsBalance = (int) $object->getData('loyalty_points_balance');

        $tier = $this->pointsCalculator->determineTier(
            $pointsBalance,
            $this->loyaltyConfig->getTierThresholdsJson()
        );

        $object->setData($this->getAttribute()->getAttributeCode(), $tier);

        return parent::beforeSave($object);
    }
}

<?php

declare(strict_types=1);

namespace Mironsoft\Loyalty\Setup\Patch\Data;

use Magento\Customer\Model\Customer;
use Magento\Eav\Setup\EavSetupFactory;
use Magento\Framework\Setup\ModuleDataSetupInterface;
use Magento\Framework\Setup\Patch\DataPatchInterface;
use Mironsoft\Loyalty\Model\Customer\Attribute\Backend\LoyaltyTierBackend;

/**
 * Attaches LoyaltyTierBackend to the existing loyalty_tier customer attribute, so
 * the tier is recalculated automatically from loyalty_points_balance on every save.
 */
class UpdateCustomerLoyaltyTierBackend implements DataPatchInterface
{
    /**
     * @param ModuleDataSetupInterface $moduleDataSetup Provides the setup connection for the patch.
     * @param EavSetupFactory $eavSetupFactory Creates the EavSetup helper used to update the attribute.
     */
    public function __construct(
        private readonly ModuleDataSetupInterface $moduleDataSetup,
        private readonly EavSetupFactory $eavSetupFactory
    ) {
    }

    /**
     * Sets backend_model on loyalty_tier to LoyaltyTierBackend::class.
     *
     * @return void
     */
    public function apply(): void
    {
        $this->moduleDataSetup->getConnection()->startSetup();

        /** @var \Magento\Eav\Setup\EavSetup $eavSetup */
        $eavSetup = $this->eavSetupFactory->create(['setup' => $this->moduleDataSetup]);
        $eavSetup->updateAttribute(
            Customer::ENTITY,
            'loyalty_tier',
            'backend_model',
            LoyaltyTierBackend::class
        );

        $this->moduleDataSetup->getConnection()->endSetup();
    }

    /**
     * @return array<int, string>
     */
    public static function getDependencies(): array
    {
        return [\Mironsoft\Loyalty\Setup\Patch\Data\InstallCustomerLoyaltyAttributes::class];
    }

    /**
     * @return array<int, string>
     */
    public function getAliases(): array
    {
        return [];
    }
}