<?php

namespace App\Traits\Controllers;

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

trait ManagesOrder
{
    /**
     * Updates the order of a model and reorders all impacted elements.
     *
     * Shifts by +1 or -1 all elements located between the old
     * and new position of the model, then assigns the new position
     * to the target model. The whole operation runs inside a
     * database transaction to ensure data consistency.
     *
     * @param  UpdateOrderRequest       $request The validated request containing the 'priority' field.
     * @param  Model&OrderableInterface $model   The model to reorder (must use the Orderable trait).
     * @return RedirectResponse
     *
     * @throws \Throwable Returns if save fail.
     */
    public function changeOrderPriority(UpdateOrderRequest $request, Model&OrderableInterface $model): RedirectResponse
    {
        $newPriority = (int) $request->validated('priority_order');

        return DB::transaction(function () use ($model, $newPriority): RedirectResponse {

            $query = $model::query()
                ->whereKeyNot($model)
                ->whereBetween('priority_order', [
                    min($model->getPriorityOrder(), $newPriority),
                    max($model->getPriorityOrder(), $newPriority),
                ]);

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

            $model->getPriorityOrder() < $newPriority
                ? $query->decrement('priority_order', 1)
                : $query->increment('priority_order', 1);

            $model->setAttribute('priority_order', $newPriority);
            $model->saveOrFail();

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