Simple Laravel Cart

Cart.php

<?php

namespace App\Models;


use App\Models\Product\Product;
use Illuminate\Support\Facades\Session;

class Cart
{

    protected static $collection = [];


    public static function add($id, $number)
    {
        $payload = [
            'id' => $id,
            'number' => $number
        ];

        if (!self::isItem($id)) {
            self::$collection[] = $payload;
            Session::push('cart', $payload);
        } else {
            $currentNumber = self::find($id)['number'];
            self::change($id, $currentNumber + $number);
        }
    }


    public static function sub($id, $number)
    {
        if (self::isItem($id)) {
            $currentNumber = self::find($id)['number'];
            if ($currentNumber - $number >= 1)
                self::change($id, $currentNumber - $number);
        }
    }


    protected static function isItem($id)
    {
        $cart = Session::get('cart') ? Session::get('cart') : [];
        foreach ($cart as $item) {
            if ($item['id'] == $id)
                return true;
        }

        return false;
    }


    protected static function getKeySession($idProduct)
    {
        $cart = Session::get('cart');
        foreach ($cart as $key => $item) {
            if ($item['id'] == $idProduct)
                return $key;
        };
    }

    public static function change($id, $number)
    {
        $product = self::find($id);
        if ($product) {
            $product['number'] = $number;
            $keyProduct = self::getKeySession($id);
            Session::put("cart.$keyProduct", $product);
        }
    }


    public static function find($id)
    {
        $cart = Session::get('cart') ? Session::get('cart') : [];
        foreach ($cart as $item) {
            if ($item['id'] == $id) return $item;
        }
    }

    public static function delete($idProduct)
    {
        Session::forget('cart.' . self::getKeySession($idProduct));
    }

    /**
     * Количество определенного товара в корзине
     * @return integer
     */
    public static function getItemAmount($idProduct)
    {
        return self::find($idProduct)['number'];
    }


    public static function get()
    {
        if (self::$collection)
            return self::$collection;

        $cart = Session::get('cart');

        $ids = collect($cart)->map(function ($item) {
            return $item['id'];
        });

        $products = Product::whereIn('id', $ids)->get();

        self::$collection = $products;

        return $products;
    }


    public static function totalPrice()
    {
        return Cart::get()->reduce(function ($carry, $item){
            return $carry + $item->price;
        });
    }

    public static function getRawData()
    {
        return Session::get('cart');
    }

}