add cart in docs

docs/_sidebar.md

@@ -16,6 +16,7 @@
 - Purchases
 
     - [Payment](payment)
+    - [Cart](cart)
     - [Payment Free](pay-free)
     - [Refund](refund)
 

docs/cart.md

@@ -0,0 +1,94 @@
+## User Model
+
+Add the `CanPay` trait and `Customer` interface to your User model.
+
+```php
+use Bavix\Wallet\Traits\CanPay;
+use Bavix\Wallet\Interfaces\Customer;
+
+class User extends Model implements Customer
+{
+    use CanPay;
+}
+```
+
+## Item Model
+
+Add the `HasWallet` trait and `Product` interface to Item model.
+
+```php
+use Bavix\Wallet\Traits\HasWallet;
+use Bavix\Wallet\Interfaces\Product;
+use Bavix\Wallet\Interfaces\Customer;
+
+class Item extends Model implements Product
+{
+    use HasWallet;
+
+    public function canBuy(Customer $customer, int $quantity = 1, bool $force = null): bool
+    {
+        /**
+         * If the service can be purchased once, then
+         *  return !$customer->paid($this);
+         */
+        return true; 
+    }
+
+    public function getAmountProduct(): int
+    {
+        return round($this->price * 100);
+    }
+
+    public function getMetaProduct(): ?array
+    {
+        return [
+            'title' => $this->title, 
+            'description' => 'Purchase of Product #' . $this->getUniqueId(), 
+            'price' => $this->getAmountProduct(),
+        ];
+    }
+
+    public function getUniqueId(): string
+    {
+        return (string)$this->getKey();
+    }
+}
+```
+
+## Fill the cart
+
+Find the user and check the balance.
+
+```php
+$user = User::first();
+$user->balance; // int(0)
+```
+
+Let's start shopping.
+
+```php
+use Bavix\Wallet\Objects\Cart;
+
+$list = [
+    'potato' => 3,
+    'carrot' => 10,
+];
+
+$products = Item::query()
+    ->whereIn('slug', ['potato', 'carrot'])
+    ->get();
+
+$cart = Cart::make();
+foreach ($products as $product) {
+    // add product's
+    $cart->addItem($product, $list[$product->slug]);
+}
+
+$user->deposit($cart->getTotal());
+$user->balanceFloat; // float(151.27)
+
+(bool)$user->payCart($cart); // true
+$user->balanceFloat; // float(0)
+```
+
+It worked! 

docs/ru/_sidebar.md

@@ -16,6 +16,7 @@
 - Покупки
 
     - [Платеж](payment)
+    - [Корзина](cart)
     - [Купить бесплатно](pay-free)
     - [Возврат](refund)
 

docs/ru/cart.md

@@ -0,0 +1,94 @@
+## Пользователь
+
+Добавим `CanPay` trait и `Customer` interface в модель User.
+
+```php
+use Bavix\Wallet\Traits\CanPay;
+use Bavix\Wallet\Interfaces\Customer;
+
+class User extends Model implements Customer
+{
+    use CanPay;
+}
+```
+
+## Товар
+
+Добавим `HasWallet` trait и `Product` interface в модель Item.
+
+```php
+use Bavix\Wallet\Traits\HasWallet;
+use Bavix\Wallet\Interfaces\Product;
+use Bavix\Wallet\Interfaces\Customer;
+
+class Item extends Model implements Product
+{
+    use HasWallet;
+
+    public function canBuy(Customer $customer, int $quantity = 1, bool $force = null): bool
+    {
+        /**
+         * If the service can be purchased once, then
+         *  return !$customer->paid($this);
+         */
+        return true; 
+    }
+
+    public function getAmountProduct(): int
+    {
+        return round($this->price * 100);
+    }
+
+    public function getMetaProduct(): ?array
+    {
+        return [
+            'title' => $this->title, 
+            'description' => 'Purchase of Product #' . $this->getUniqueId(), 
+            'price' => $this->getAmountProduct(),
+        ];
+    }
+
+    public function getUniqueId(): string
+    {
+        return (string)$this->getKey();
+    }
+}
+```
+
+## Как заполнить корзину
+
+Найдем пользователя и проверим его баланс.
+
+```php
+$user = User::first();
+$user->balance; // int(0)
+```
+
+Приступим к покупкам.
+
+```php
+use Bavix\Wallet\Objects\Cart;
+
+$list = [
+    'potato' => 3,
+    'carrot' => 10,
+];
+
+$products = Item::query()
+    ->whereIn('slug', ['potato', 'carrot'])
+    ->get();
+
+$cart = Cart::make();
+foreach ($products as $product) {
+    // add product's
+    $cart->addItem($product, $list[$product->slug]);
+}
+
+$user->deposit($cart->getTotal());
+$user->balanceFloat; // float(151.27)
+
+(bool)$user->payCart($cart); // true
+$user->balanceFloat; // float(0)
+```
+
+Это работает!