restaurant

first/Address.java

@@ -0,0 +1,17 @@
+public class Address {
+    private double latitude;
+    private double longitude;
+    private String written_address;
+
+    public Address(double latitude, double longitude, String written_address) {
+        this.latitude = latitude;
+        this.longitude = longitude;
+        this.written_address = written_address;
+    }
+
+    public double distance_from(Address other) {
+        double distance = Math.sqrt(Math.pow(other.latitude - this.latitude, 2) +
+                                    Math.pow(other.longitude - this.longitude, 2));
+        return distance;
+    }
+}

first/Customer.java

@@ -0,0 +1,32 @@
+public class Customer {
+    private static int nextCustomerNumber = 1;
+    private final int customerNumber;
+    private String name;
+    private Address address;
+
+    public Customer(String name, Address address) {
+        this.customerNumber = nextCustomerNumber++;
+        this.name = name;
+        this.address = address;
+    }
+
+    public int getCustomerNumber() {
+        return customerNumber;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public Address getAddress() {
+        return address;
+    }
+
+    public void setAddress(Address address) {
+        this.address = address;
+    }
+}

first/Food.java

@@ -0,0 +1,21 @@
+import java.util.Vector;
+
+public class Food {
+    private static Vector<Food> menu = new Vector<>();
+    private final String name;
+    private final int price;
+
+    public Food(String name, int price) {
+        this.name = name;
+        this.price = price;
+        menu.add(this);
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public int getPrice() {
+        return price;
+    }
+}

first/Invoice.java

@@ -0,0 +1,58 @@
+import java.util.ArrayList;
+
+public class Invoice {
+    private static final float tax_rate = 9.4f;
+    private static final int ORDER_REGISTERED = -1;
+    private static final int ORDER_PREPARING = 0;
+    private static final int ORDER_DISPATCHED = 1;
+    private static final int ORDER_DELIVERED = 2;
+
+    private final Customer customer;
+    private final ArrayList<Item> items;
+    private int state;
+
+    public Invoice(Customer customer) {
+        this.customer = customer;
+        this.items = new ArrayList<>();
+        this.state = ORDER_REGISTERED;
+    }
+
+    public boolean addItem(Item item) {
+        if (state != ORDER_REGISTERED || !items.contains(item)) {
+            return false;
+        }
+        items.add(item);
+        return true;
+    }
+
+    public boolean removeItem(Item item) {
+        if (items.contains(item)) {
+            items.remove(item);
+            return true;
+        }
+        return false;
+    }
+
+    public void nextStage() {
+        if (state < ORDER_DELIVERED) {
+            state++;
+        }
+    }
+
+    public int getState() {
+        return state;
+    }
+
+    public Customer getCustomer() {
+        return customer;
+    }
+
+    public int getTotalPrice() {
+        int totalPrice = 0;
+        for (Item item : items) {
+            totalPrice += item.getFood().getPrice() * item.getCount();
+        }
+        float taxAmount = (totalPrice * tax_rate) / 100;
+        return (int) Math.ceil(totalPrice + taxAmount);
+    }
+}

first/Item.java

@@ -0,0 +1,23 @@
+public class Item {
+    private final Food food;
+    private final int count;
+    private final String description;
+
+    public Item(Food food, int count, String description) {
+        this.food = food;
+        this.count = count;
+        this.description = description;
+    }
+
+    public Food getFood() {
+        return food;
+    }
+
+    public int getCount() {
+        return count;
+    }
+
+    public String getDescription() {
+        return description;
+    }
+}