├── .gitignore
├── Cart.php
├── CartItem.php
├── Product.php
└── index.php


/.gitignore:
--------------------------------------------------------------------------------
1 | .idea


--------------------------------------------------------------------------------
/Cart.php:
--------------------------------------------------------------------------------
 1 | <?php
 2 | 
 3 | 
 4 | class Cart
 5 | {
 6 |     /**
 7 |      * @var CartItem[]
 8 |      */
 9 |     private array $items = [];
10 | 
11 |     /**
12 |      * @return \CartItem[]
13 |      */
14 |     public function getItems()
15 |     {
16 |         return $this->items;
17 |     }
18 | 
19 |     /**
20 |      * @param \CartItem[] $items
21 |      */
22 |     public function setItems($items)
23 |     {
24 |         $this->items = $items;
25 |     }
26 | 
27 |     /**
28 |      * Add Product $product into cart. If product already exists inside cart
29 |      * it must update quantity.
30 |      * This must create CartItem and return CartItem from method
31 |      * Bonus: $quantity must not become more than whatever
32 |      * is $availableQuantity of the Product
33 |      *
34 |      * @param Product $product
35 |      * @param int     $quantity
36 |      * @return \CartItem
37 |      * @throws \Exception
38 |      */
39 |     public function addProduct(Product $product, int $quantity)
40 |     {
41 |         // find product in cart
42 |         $cartItem = $this->findCartItem($product->getId());
43 |         if ($cartItem === null){
44 |             $cartItem = new CartItem($product, 0);
45 |             $this->items[$product->getId()] = $cartItem;
46 |         }
47 |         $cartItem->increaseQuantity($quantity);
48 |         return $cartItem;
49 |     }
50 | 
51 |     private function findCartItem(int $productId)
52 |     {
53 |         return $this->items[$productId] ?? null;
54 |     }
55 | 
56 |     /**
57 |      * Remove product from cart
58 |      *
59 |      * @param Product $product
60 |      */
61 |     public function removeProduct(Product $product)
62 |     {
63 |         unset($this->items[$product->getId()]);
64 |     }
65 | 
66 |     /**
67 |      * This returns total number of products added in cart
68 |      *
69 |      * @return int
70 |      */
71 |     public function getTotalQuantity()
72 |     {
73 |         $sum = 0;
74 |         foreach ($this->items as $item) {
75 |             $sum += $item->getQuantity();
76 |         }
77 |         return $sum;
78 |     }
79 | 
80 |     /**
81 |      * This returns total price of products added in cart
82 |      *
83 |      * @return float
84 |      */
85 |     public function getTotalSum()
86 |     {
87 |         $totalSum = 0;
88 |         foreach ($this->items as $item) {
89 |             $totalSum += $item->getQuantity() * $item->getProduct()->getPrice();
90 |         }
91 | 
92 |         return $totalSum;
93 |     }
94 | }


--------------------------------------------------------------------------------
/CartItem.php:
--------------------------------------------------------------------------------
 1 | <?php
 2 | 
 3 | 
 4 | class CartItem
 5 | {
 6 |     private Product $product;
 7 |     private int $quantity;
 8 | 
 9 |     /**
10 |      * CartItem constructor.
11 |      *
12 |      * @param \Product $product
13 |      * @param int      $quantity
14 |      */
15 |     public function __construct(\Product $product, $quantity)
16 |     {
17 |         $this->product = $product;
18 |         $this->quantity = $quantity;
19 |     }
20 | 
21 |     /**
22 |      * @return \Product
23 |      */
24 |     public function getProduct()
25 |     {
26 |         return $this->product;
27 |     }
28 | 
29 |     /**
30 |      * @param \Product $product
31 |      */
32 |     public function setProduct($product)
33 |     {
34 |         $this->product = $product;
35 |     }
36 | 
37 |     /**
38 |      * @return int
39 |      */
40 |     public function getQuantity()
41 |     {
42 |         return $this->quantity;
43 |     }
44 | 
45 |     /**
46 |      * @param int $quantity
47 |      */
48 |     public function setQuantity($quantity)
49 |     {
50 |         $this->quantity = $quantity;
51 |     }
52 | 
53 | 
54 |     public function increaseQuantity($amount = 1)
55 |     {
56 |         if ($this->getQuantity() + $amount > $this->getProduct()->getAvailableQuantity()){
57 |             throw new Exception("Product quantity can not be more than ".$this->getProduct()->getAvailableQuantity());
58 |         }
59 |         $this->quantity += $amount;
60 |     }
61 | 
62 |     public function decreaseQuantity($amount = 1)
63 |     {
64 |         if ($this->getQuantity() - $amount < 1){
65 |             throw new Exception("Product quantity can not be less than 1");
66 |         }
67 |         $this->quantity -= $amount;
68 |     }
69 | }


--------------------------------------------------------------------------------
/Product.php:
--------------------------------------------------------------------------------
  1 | <?php
  2 | 
  3 | 
  4 | class Product
  5 | {
  6 |     private int $id;
  7 |     private string $title;
  8 |     private float $price;
  9 |     private int $availableQuantity;
 10 | 
 11 |     /**
 12 |      * Product constructor.
 13 |      *
 14 |      * @param int    $id
 15 |      * @param string $title
 16 |      * @param float  $price
 17 |      * @param int    $availableQuantity
 18 |      */
 19 |     public function __construct($id, $title, $price, $availableQuantity)
 20 |     {
 21 |         $this->id = $id;
 22 |         $this->title = $title;
 23 |         $this->price = $price;
 24 |         $this->availableQuantity = $availableQuantity;
 25 |     }
 26 | 
 27 |     /**
 28 |      * @return int
 29 |      */
 30 |     public function getId()
 31 |     {
 32 |         return $this->id;
 33 |     }
 34 | 
 35 |     /**
 36 |      * @param int $id
 37 |      */
 38 |     public function setId($id)
 39 |     {
 40 |         $this->id = $id;
 41 |     }
 42 | 
 43 |     /**
 44 |      * @return string
 45 |      */
 46 |     public function getTitle()
 47 |     {
 48 |         return $this->title;
 49 |     }
 50 | 
 51 |     /**
 52 |      * @param string $title
 53 |      */
 54 |     public function setTitle($title)
 55 |     {
 56 |         $this->title = $title;
 57 |     }
 58 | 
 59 |     /**
 60 |      * @return float
 61 |      */
 62 |     public function getPrice()
 63 |     {
 64 |         return $this->price;
 65 |     }
 66 | 
 67 |     /**
 68 |      * @param float $price
 69 |      */
 70 |     public function setPrice($price)
 71 |     {
 72 |         $this->price = $price;
 73 |     }
 74 | 
 75 |     /**
 76 |      * @return int
 77 |      */
 78 |     public function getAvailableQuantity()
 79 |     {
 80 |         return $this->availableQuantity;
 81 |     }
 82 | 
 83 |     /**
 84 |      * @param int $availableQuantity
 85 |      */
 86 |     public function setAvailableQuantity($availableQuantity)
 87 |     {
 88 |         $this->availableQuantity = $availableQuantity;
 89 |     }
 90 | 
 91 |     /**
 92 |      * Add Product $product into cart. If product already exists inside cart
 93 |      * it must update quantity.
 94 |      * This must create CartItem and return CartItem from method
 95 |      * Bonus: $quantity must not become more than whatever
 96 |      * is $availableQuantity of the Product
 97 |      *
 98 |      * @param Cart $cart
 99 |      * @param int  $quantity
100 |      * @return \CartItem
101 |      * @throws \Exception
102 |      */
103 |     public function addToCart(Cart $cart, int $quantity)
104 |     {
105 |         return $cart->addProduct($this, $quantity);
106 |     }
107 | 
108 |     /**
109 |      * Remove product from cart
110 |      *
111 |      * @param Cart $cart
112 |      */
113 |     public function removeFromCart(Cart $cart)
114 |     {
115 |         return $cart->removeProduct($this);
116 |     }
117 | }


--------------------------------------------------------------------------------
/index.php:
--------------------------------------------------------------------------------
 1 | <?php
 2 | 
 3 | require_once "Product.php";
 4 | require_once "Cart.php";
 5 | require_once "CartItem.php";
 6 | 
 7 | $product1 = new Product(1, "iPhone 11", 2500, 10);
 8 | $product2 = new Product(2, "M2 SSD", 400, 10);
 9 | $product3 = new Product(3, "Samsung Galaxy S20", 3200, 10);
10 | $cart = new Cart();
11 | $cartItem1 = $cart->addProduct($product1, 1);
12 | $cartItem2 = $product2->addToCart($cart, 1);
13 | echo "Number of items in cart: ".PHP_EOL;
14 | echo $cart->getTotalQuantity().PHP_EOL; // This must print 2
15 | echo "Total price of items in cart: ".PHP_EOL;
16 | echo $cart->getTotalSum().PHP_EOL; // This must print 2900
17 | 
18 | $cartItem2->increaseQuantity();
19 | $cartItem2->decreaseQuantity();
20 | 
21 | echo "Number of items in cart: ".PHP_EOL;
22 | echo $cart->getTotalQuantity().PHP_EOL; // This must print 4
23 | 
24 | echo "Total price of items in cart: ".PHP_EOL;
25 | echo $cart->getTotalSum().PHP_EOL; // This must print 3700
26 | 
27 | $cart->removeProduct($product1);
28 | 
29 | echo "Number of items in cart: ".PHP_EOL;
30 | echo $cart->getTotalQuantity().PHP_EOL; // This must print 1
31 | 
32 | 
33 | 


--------------------------------------------------------------------------------