ldc-volena/app/Traits/Controllers/UpdateModelOrder.php

<?php

namespace App\Traits\Controllers;

use App\Http\Requests\Bo\UpdateOrderRequest;
use Illuminate\Database\Eloquent\Model;
use Illuminate\Http\RedirectResponse;
use Illuminate\Support\Facades\DB;

trait UpdateModelOrder
{
    /**
     * Updates the model order and shifts affected siblings accordingly
     *
     * @param UpdateOrderRequest $request
     * @param Model              $model
     * @return \Illuminate\Http\RedirectResponse
     */
    public function changeCustomOrder(UpdateOrderRequest $request, Model $model): \Illuminate\Http\RedirectResponse
    {
        $newOrder = $request->validated('order');

        return DB::transaction(function () use ($model, $newOrder): RedirectResponse {
            /** @phpstan-ignore-next-line */
            $groupField = $model->getOrderGroupField();

            $query = $model::query()
                ->whereKeyNot($model)
                /** @phpstan-ignore-next-line */
                ->whereBetween('order', [min($model->order, $newOrder), max($model->order, $newOrder)]);

            if ($groupField) {
                $query->where($groupField, $model->{$groupField});
            }

            /** @phpstan-ignore-next-line */
            $model->order < $newOrder ? $query->decrement('order', 1) : $query->increment('order', 1);

            $model->order = $newOrder;
            if (!$model->saveOrFail()) {
                return back()->with('error', trans('crud.messages.order_not_changed'));
            };

            return back()->with('success', trans('crud.messages.order_changed'));
        });
    }
}