Added Cart Draft Item class with Product as its dependency

app/Cart/CartCollection.php

@@ -2,6 +2,7 @@
 
 namespace App\Cart;
 
+use App\Product;
 use Illuminate\Support\Collection;
 
 /**
@@ -98,28 +99,26 @@ class CartCollection
         $this->session->remove($this->instance);
     }
 
-    public function addProductToDraft($draftKey, $item)
+    public function addItemToDraft($draftKey, Item $item)
     {
         $content = $this->getContent();
-        $content[$draftKey]->addProduct($item);
-        $content[$draftKey] = $this->updateDraft($content[$draftKey]);
+        $content[$draftKey]->addItem($item);
 
         $this->session->put($this->instance, $content);
     }
 
-    public function updateDraftProduct($draftKey, $itemKey, $newProductData)
+    public function updateDraftItem($draftKey, $itemKey, $newItemData)
     {
         $content = $this->getContent();
-        $content[$draftKey]->updateProduct($itemKey, $newProductData);
-        $content[$draftKey] = $this->updateDraft($content[$draftKey]);
+        $content[$draftKey]->updateItem($itemKey, $newItemData);
 
         $this->session->put($this->instance, $content);
     }
 
-    public function removeProductFromDraft($draftKey, $itemKey)
+    public function removeItemFromDraft($draftKey, $itemKey)
     {
         $content = $this->getContent();
-        $content[$draftKey]->removeProduct($itemKey);
+        $content[$draftKey]->removeItem($itemKey);
 
         $this->session->put($this->instance, $content);
     }

app/Cart/Item.php

@@ -0,0 +1,45 @@
+<?php
+
+namespace App\Cart;
+
+use App\Product;
+
+/**
+* Draft Item class
+*/
+class Item
+{
+    public $id;
+    public $product;
+    public $name;
+    public $price;
+    public $qty;
+    public $item_discount = 0;
+    public $item_discount_subtotal = 0;
+    public $subtotal;
+
+    public function __construct(Product $product, $qty)
+    {
+        $this->id       = $product->id;
+        $this->product  = $product;
+        $this->qty      = $qty;
+        $this->price    = $product->getPrice();
+        $this->subtotal = $product->getPrice() * $qty;
+    }
+
+    public function updateAttribute(array $newItemData)
+    {
+        if (isset($newItemData['qty'])) {
+            $this->qty      = $newItemData['qty'];
+            $this->subtotal = $this->price * $this->qty;
+        }
+
+        if (isset($newItemData['item_discount'])) {
+            $this->item_discount          = $newItemData['item_discount'];
+            $this->item_discount_subtotal = $this->item_discount * $this->qty;
+            $this->subtotal               = $this->subtotal - $this->item_discount_subtotal;
+        }
+
+        return $this;
+    }
+}

app/Cart/TransactionDraft.php

@@ -2,11 +2,15 @@
 
 namespace App\Cart;
 
+use App\Product;
+
 /**
 * Transaction Draft Interface
 */
 abstract class TransactionDraft
 {
+    public $items = [];
+
     public function toArray()
     {
         return [
@@ -21,4 +25,38 @@ abstract class TransactionDraft
             'remark'     => '',
         ];
     }
+
+    public function items()
+    {
+        return collect($this->items);
+    }
+
+    public function addItem(Item $item)
+    {
+        $this->items[] = $item;
+
+        return $item->product;
+    }
+
+    public function removeItem($itemKey)
+    {
+        unset($this->items[$itemKey]);
+    }
+
+    public function getTotal()
+    {
+        return $this->items()->sum('subtotal');
+    }
+
+    public function updateItem($itemKey, $newItemData)
+    {
+        if (!isset($this->items[$itemKey]))
+            return null;
+
+        $item = $this->items[$itemKey];
+
+        $this->items[$itemKey] = $item->updateAttribute($newItemData);
+
+        return $item;
+    }
 }

app/Product.php

@@ -0,0 +1,18 @@
+<?php
+
+namespace App;
+
+use Illuminate\Database\Eloquent\Model;
+
+class Product extends Model
+{
+    protected $fillable = ['cash_price','credit_price'];
+
+    public function getPrice($type = 'cash')
+    {
+        if ($type == 'credit')
+            return $this->credit_price;
+
+        return $this->cash_price;
+    }
+}

database/migrations/2017_04_09_013901_create_products_table.php

@@ -0,0 +1,31 @@
+<?php
+
+use Illuminate\Support\Facades\Schema;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Database\Migrations\Migration;
+
+class CreateProductsTable extends Migration
+{
+    /**
+     * Run the migrations.
+     *
+     * @return void
+     */
+    public function up()
+    {
+        Schema::create('products', function (Blueprint $table) {
+            $table->increments('id');
+            $table->timestamps();
+        });
+    }
+
+    /**
+     * Reverse the migrations.
+     *
+     * @return void
+     */
+    public function down()
+    {
+        Schema::dropIfExists('products');
+    }
+}

tests/Unit/CartCollectionTest.php

@@ -5,6 +5,8 @@ namespace Tests\Unit;
 use App\Cart\CartCollection;
 use App\Cart\CashDraft;
 use App\Cart\CreditDraft;
+use App\Cart\Item;
+use App\Product;
 use Tests\TestCase;
 
 class CartCollectionTest extends TestCase
@@ -145,4 +147,54 @@ class CartCollectionTest extends TestCase
         $this->assertArrayHasKey('creator_id', $draft->toArray());
         $this->assertArrayHasKey('remark', $draft->toArray());
     }
+
+    /** @test */
+    public function it_can_add_product_to_draft()
+    {
+        $cart = new CartCollection;
+
+        $draft = $cart->add(new CashDraft);
+        $count = 2;
+        $item = new Item(new Product(['cash_price' => 1000]), $count);
+
+        $cart->addItemToDraft($draft->draftKey, $item);
+        $this->assertEquals(2000, $draft->getTotal());
+    }
+
+    /** @test */
+    public function it_can_remove_item_from_draft()
+    {
+        $cart = new CartCollection;
+
+        $draft = $cart->add(new CashDraft);
+        $item = new Item(new Product(['cash_price' => 1000]), 3);
+
+        $cart->addItemToDraft($draft->draftKey, $item);
+        $this->assertCount(1, $draft->items());
+        $cart->removeItemFromDraft($draft->draftKey, 0);
+        $this->assertCount(0, $draft->items());
+        $this->assertEquals(0, $draft->getTotal());
+    }
+
+    /** @test */
+    public function it_can_update_an_item_of_draft()
+    {
+        $cart = new CartCollection;
+
+        $draft = $cart->add(new CashDraft);
+        $item = new Item(new Product(['cash_price' => 1100]), 3);
+
+        $cart->addItemToDraft($draft->draftKey, $item);
+        $this->assertCount(1, $draft->items());
+        $this->assertEquals(3300, $draft->getTotal());
+
+        $newItemData = [
+            'qty' => 2,
+            'item_discount' => 100,
+        ];
+
+        $cart->updateDraftItem($draft->draftKey, 0, $newItemData);
+        $this->assertEquals(2000, $draft->getTotal());
+    }
+
 }

tests/Unit/Integration/ProductTest.php

@@ -0,0 +1,36 @@
+<?php
+
+namespace Tests\Unit\Integration;
+
+use App\Product;
+use Illuminate\Foundation\Testing\DatabaseMigrations;
+use Illuminate\Foundation\Testing\DatabaseTransactions;
+use Tests\TestCase;
+
+class ProductTest extends TestCase
+{
+    /** @test */
+    public function it_has_get_price_method()
+    {
+        $product = new Product(['cash_price' => 3000]);
+
+        $this->assertEquals(3000, $product->getPrice());
+    }
+
+    /** @test */
+    public function product_get_price_method_default_to_cash_price()
+    {
+        $product = new Product(['cash_price' => 3000]);
+
+        $this->assertEquals($product->cash_price, $product->getPrice());
+    }
+
+    /** @test */
+    public function product_get_price_can_also_returns_credit_price_of_product()
+    {
+        $product = new Product(['cash_price' => 2000, 'credit_price' => 3000]);
+
+        $this->assertEquals($product->credit_price, $product->getPrice('credit'));
+        $this->assertEquals(3000, $product->getPrice('credit'));
+    }
+}