added Inventory and VendingMachine

src/main/java/products/Inventory.java

@@ -0,0 +1,38 @@
+package main.java.products;
+
+import java.util.HashMap;
+import java.util.Map;
+
+public class Inventory<T> {
+    private Map<T, Integer> inventory = new HashMap<T, Integer>();
+
+    public int getQuantity(T item){
+        Integer value = inventory.get(item);
+        return value == null? 0 : value ;
+    }
+
+    public void add(T item){
+        int count = inventory.get(item);
+        inventory.put(item, count+1);
+    }
+
+    public void deduct(T item) {
+        if (hasItem(item)) {
+            int count = inventory.get(item);
+            inventory.put(item, count - 1);
+        }
+    }
+
+    public boolean hasItem(T item){
+        return getQuantity(item) > 0;
+    }
+
+    public void clear(){
+        inventory.clear();
+    }
+
+    public void put(T item, int quantity) {
+        inventory.put(item, quantity);
+    }
+}
+

src/main/java/products/VendingMachine.java

@@ -0,0 +1,15 @@
+package main.java.products;
+
+import java.util.List;
+
+
+public interface VendingMachine {
+    public long selectProductAndGetPrice(Product product);
+
+    public void insertCoin(Denomination denomination);
+
+    public List<Denomination> refund();
+
+    public void reset();
+}
+

src/main/java/products/VendingMachineFactory.java

@@ -0,0 +1,7 @@
+package main.java.products;
+
+public class VendingMachineFactory {
+    public static VendingMachine createVendingMachine() {
+        return new VendingMachineImpl();
+    }
+}

src/main/java/products/VendingMachineImpl.java

@@ -0,0 +1,48 @@
+package main.java.products;
+
+import java.util.List;
+
+public class VendingMachineImpl implements VendingMachine {
+
+    private Inventory<Object> cashInventory = new Inventory<Object>();
+    private Inventory<Product> productInventory = new Inventory<Product>();
+    private long totalSales;
+    private Product currentItem;
+    private long currentBalance;
+
+    public VendingMachineImpl() {
+        initialize();
+    }
+
+    private void initialize() {
+        //change to better values
+        for (Denomination c : Denomination.values()) {
+            cashInventory.put(c, 5);
+        }
+
+        for () {
+            productInventory.put(i, 5);
+        }
+
+    }
+
+    @Override
+    public long selectProductAndGetPrice(Product product) {
+        return 0;
+    }
+
+    @Override
+    public void insertCoin(Denomination denomination) {
+
+    }
+
+    @Override
+    public List<Denomination> refund() {
+        return null;
+    }
+
+    @Override
+    public void reset() {
+
+    }
+}

src/main/java/products/main.java

@@ -1,5 +1,6 @@
 package main.java.products;
 
+import java.util.Objects;
 import java.util.Scanner;
 
 public class main {
@@ -11,35 +12,52 @@ public class main {
         System.out.println("2. A snack");
         System.out.println("3. A meal");
 
-
-        int opt3 = sc.nextInt();
-        if (opt3 == 1) {
-            orderADrink();
-        } else if (opt3 == 2) {
-            orderASnack();
-        } else if (opt3 == 3){
-            orderAMeal();
+        int selectedType = sc.nextInt();
+        double price = 0;
+        if (selectedType == 1) {
+            price = orderADrink();
+        } else if (selectedType == 2) {
+            price = orderASnack();
+        } else if (selectedType == 3) {
+            price = orderAMeal();
         }
+
+        System.out.println("Choose payment option");
+        System.out.println("1. Cash");
+        System.out.println("2. Credit card");
+
+        int paymentType = sc.nextInt();
+        if (paymentType == 1) {
+            payInCash(price);
+        } else if (paymentType == 2) {
+            payWithCard(price);
+        }
+
+
     }
 
-        private static void orderADrink() {
-            DrinkMenu drinkMenu = new DrinkMenu();
-            drinkMenu.showMenu();
-            int opt;
-            Drink orderedDrink = null;
-            while (orderedDrink == null) {
-                opt = sc.nextInt();
-                if (opt < 1 || opt > 4) {
-                    System.out.println("You have chosen wrong option");
-                } else {
-                    orderedDrink = drinkMenu.get(opt - 1);
-                }
-            }
-            System.out.println("You ordered " + orderedDrink);
-            System.out.println("Price: " + orderedDrink.getPrice());
-        }
 
-    private static void orderASnack() {
+
+
+    private static double orderADrink() {
+        DrinkMenu drinkMenu = new DrinkMenu();
+        drinkMenu.showMenu();
+        int opt;
+        Drink orderedDrink = null;
+        while (orderedDrink == null) {
+            opt = sc.nextInt();
+            if (opt < 1 || opt > 4) {
+                System.out.println("You have chosen wrong option");
+            } else {
+                orderedDrink = drinkMenu.get(opt - 1);
+            }
+        }
+        System.out.println("You ordered " + orderedDrink);
+        System.out.println("Price: " + orderedDrink.getPrice());
+        return orderedDrink.getPrice();
+    }
+
+    private static double orderASnack() {
         SnackMenu snackMenu = new SnackMenu();
         snackMenu.showMenu();
         int opt;
@@ -54,9 +72,11 @@ public class main {
         }
         System.out.println("You ordered " + orderedSnack);
         System.out.println("Price: " + orderedSnack.getPrice());
+        return orderedSnack.getPrice();
+
     }
 
-    private static void orderAMeal() {
+    private static double orderAMeal() {
         MealMenu mealMenu = new MealMenu();
         mealMenu.showMenu();
         int opt;
@@ -71,9 +91,29 @@ public class main {
         }
         System.out.println("You ordered " + orderedMeal);
         System.out.println("Price: " + orderedMeal.getPrice());
+        return orderedMeal.getPrice();
+
+    }
+
+    private static void payWithCard(double price) {
+        System.out.println("Follow the instructions on the pin pad");
+    }
+
+    private static void payInCash(double price) {
+        System.out.println("Insert money");
+        System.out.println("Type inserted denominations, type 'q' when done.");
+        double sum= 0;
+        while (!Objects.equals(sc.nextLine(), "q")){
+            double denomination = sc.nextDouble();
+            sum+=denomination;
+
+        }
+        if (sum > price)
+            giveChange();
+    }
+
+    private static void giveChange() {
     }
 
 
-
-
 }