<?php
declare(strict_types=1);

namespace Esun\Reward\Model\Config\Backend;

use Magento\Config\Model\Config\Backend\Serialized\ArraySerialized;
use Magento\Config\Model\ResourceModel\Config\Data as ConfigResource;
use Magento\Config\Model\ResourceModel\Config\Data\Collection as ConfigCollection;

class TierItems extends ArraySerialized
{
    protected function _construct(): void
    {
        $this->_setResourceModel(ConfigResource::class, ConfigCollection::class);
    }

    public function beforeSave()
    {
        $items = [];
        $value = $this->getValue();
        if (is_array($value)) {
            unset($value['__empty']);
            foreach ($value as $row) {
                if (!is_array($row)) {
                    continue;
                }
                $label = trim((string)($row['label'] ?? ''));
                $threshold = max(0.0, (float)($row['threshold'] ?? 0));
                $multiplier = (float)($row['multiplier'] ?? 0);
                if ($label === '' || $multiplier <= 0) {
                    continue;
                }
                $items[] = ['label' => $label, 'threshold' => $threshold, 'multiplier' => $multiplier];
            }
        }

        usort($items, static fn(array $left, array $right): int => $left['threshold'] <=> $right['threshold']);
        $this->setValue($items);

        return parent::beforeSave();
    }
}