<?php
namespace Modules\Commerce\Services;
use Illuminate\Support\Facades\DB;
use Modules\Commerce\Contracts\InventoryProvider;
use Modules\Commerce\Models\InventoryMovement;
use Modules\Commerce\Models\Product;
final class DatabaseInventoryProvider implements InventoryProvider
{
    public function adjust(Product $product, int $quantity, string $reason, ?int $userId = null): void
    {
        DB::transaction(function () use ($product,$quantity,$reason,$userId) { $product->increment('stock_quantity',$quantity); InventoryMovement::create(['product_id'=>$product->id,'quantity'=>$quantity,'reason'=>$reason,'created_by'=>$userId]); });
    }
    public function available(Product $product): int { return max(0,(int)$product->stock_quantity); }
}