<?php declare(strict_types=1);


namespace App\Stock;

use App\Products\AbstractProductable;
use App\Products\Product\Product;
use Illuminate\Support\Facades\Log;

/**
 * Class StockService
 *
 * @package App\Stock
 */
class StockService
{
    /**
     * Stock a productable. If the quantity is positive, that quantity will be added to the stock. Else it will be substracted from the stock.
     *
     * @param AbstractProductable $productable
     * @param int $quantity
     * @param bool $dontSave modify the products stock quantity, but dont save it yet when it is true. Otherwise always save it.
     * @return AbstractProductable|void
     */
    public function stockProductable(AbstractProductable $productable, int $quantity = 1, $dontSave = false) {
        switch (get_class($productable)) {
            case Product::class:
                /** @var Product $productable */
                $before = $productable->stock;
                $productable = $this->stockProduct($productable, $quantity, $dontSave);
                break;
            default:
                throw new \InvalidArgumentException('The productable with class "'.get_class($productable).'" is not supported');
        }

        return $productable;
    }

    /**
     * Stock a product. If the quantity is positive, that quantity will be added to the stock. Else it will be substracted from the stock.
     *
     * @param Product $product
     * @param int $quantity
     * @param bool $dontSave modify the products stock quantity, but dont save it yet when it is true. Otherwise always save it.
     * @return Product
     */
    private function stockProduct(Product &$product, int $quantity, $dontSave = false)
    {
        $newQuantity = $product->stock + $quantity;
        if($newQuantity < 0) $this->stockQuantityBelowZeroForProductable($product);
        else if($newQuantity == 0) $this->productableOutOfStock($product);
        $before = $product->stock;
        $product->stock = $newQuantity;
        if(!$dontSave) $product->save();

        return $product;
    }

    /**
     * Do something when the productables quantity is below zero
     *
     * @param AbstractProductable $productable
     */
    protected function stockQuantityBelowZeroForProductable(AbstractProductable $productable)
    {
        Log::warning('The stock quantity of "'.get_class($productable).'" with id "'.$productable->id.'" was set to a value below 0. Was: '.$productable->stock);
    }

    /**
     * Do something when the productables quantity is below zero
     *
     * @param AbstractProductable $productable
     */
    protected function productableOutOfStock(AbstractProductable $productable)
    {
        Log::warning('"'.get_class($productable).'" with id "'.$productable->id.'" has ran out of stock');
    }
}