topnotch_website/app/Models/OrderProduct.php

<?php

namespace App\Models;

use Database\Factories\OrderProductFactory;
use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\Relations\BelongsTo;
use Illuminate\Database\Eloquent\Relations\HasMany;
use Illuminate\Database\Eloquent\Relations\HasOne;
use Illuminate\Database\Eloquent\SoftDeletes;

class OrderProduct extends Model
{
    /** @use HasFactory<OrderProductFactory> */
    use HasFactory, SoftDeletes;

    protected $fillable = [
        'order_id',
        'sku',
        'product_name',
        'color',
    ];

    public function totalQuantity(): int
    {
        return array_sum($this->productSizes()->pluck('amount')->toArray());
    }

    /**
     * @return BelongsTo<Order, self>
     */
    public function order(): BelongsTo
    {
        return $this->belongsTo(Order::class);
    }

    /**
     * @return HasOne<ServiceFile>
     */
    //    public function serviceFile(): HasOne
    //    {
    //        return $this->hasOne(ServiceFile::class);
    //    }

    /**
     * @return HasMany<ProductSize>
     */
    public function productSizes(): HasMany
    {
        return $this->hasMany(ProductSize::class);
    }
}