sam-api/app/Models/Tenants/ShipmentItem.php

<?php

namespace App\Models\Tenants;

use App\Traits\BelongsToTenant;
use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\Relations\BelongsTo;
use Illuminate\Database\Eloquent\SoftDeletes;

class ShipmentItem extends Model
{
    use BelongsToTenant, SoftDeletes;

    protected $fillable = [
        'tenant_id',
        'shipment_id',
        'seq',
        'item_code',
        'item_name',
        'floor_unit',
        'specification',
        'quantity',
        'unit',
        'lot_no',
        'stock_lot_id',
        'remarks',
    ];

    protected $casts = [
        'seq' => 'integer',
        'quantity' => 'decimal:2',
        'shipment_id' => 'integer',
        'stock_lot_id' => 'integer',
    ];

    /**
     * 출하 관계
     */
    public function shipment(): BelongsTo
    {
        return $this->belongsTo(Shipment::class);
    }

    /**
     * 재고 LOT 관계
     */
    public function stockLot(): BelongsTo
    {
        return $this->belongsTo(StockLot::class);
    }

    /**
     * 다음 순번 가져오기
     */
    public static function getNextSeq(int $shipmentId): int
    {
        $maxSeq = static::where('shipment_id', $shipmentId)->max('seq');

        return ($maxSeq ?? 0) + 1;
    }
}