<?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);
    }
}