Solutions for exercise lecture 3

foreksempel/src/main/java/of3/lf/Item.java

+package of3.lf;
+
+public class Item {
+
+    // Felter / Tilstand
+    private String name;
+    private double price;
+    private final String category;
+    private String barcode;
+
+    // Konstruktør
+    public Item(String name, double price, String category, String barcode) {
+        this.name = name;
+        this.price = price;
+        this.category = category;
+        this.barcode = barcode;
+    }
+
+    // Gettere
+    public String getName() {
+        return name;
+    }
+
+    public double getPrice() {
+        return price;
+    }
+
+    public String getCategory() {
+        return category;
+    }
+
+    public String getBarcode() {
+        return barcode;
+    }
+
+}

foreksempel/src/main/java/of3/lf/SelfServiceCheckout.java

+package of3.lf;
+
+import java.util.List;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+
+public class SelfServiceCheckout {
+
+    public static final Collection<String> days = Arrays.asList("mon", "tue", "wed", "thu", "fri", "sat", "sun");
+
+    // Felter / Tilstand - del 1
+    private String day;
+    private boolean adminMode;
+    private String password;
+    private String phoneNumber;
+    private List<Item> shoppingCart;
+
+    public SelfServiceCheckout(String day, String password) {
+        validateDay(day);
+        validatePassword(password);
+        this.day = day;
+        this.password = password;
+        this.adminMode = false;
+        this.shoppingCart = new ArrayList<>();
+    }
+
+    private void validateDay(String day) {
+        if (!days.contains(day)) {
+            throw new IllegalArgumentException("Invalid weekday");
+        }
+    }
+
+    // Del 4 a)
+    public void removeFromCart(int index) {
+        if (!this.adminMode) {
+            throw new IllegalStateException("Illegal operation");
+        }
+        this.shoppingCart.remove(index);
+    }
+
+    // Del 2 a)
+    public void activateAdminMode(String password) {
+        if (this.adminMode) {
+            throw new IllegalStateException("Admin mode is already active!");
+        }
+        if (this.password.equals(password)) {
+            this.adminMode = true;
+        } else {
+            throw new IllegalArgumentException("Wrong password, permission denied");
+        }
+    }
+
+    public void registerPhoneNumber(String phoneNumer) {
+        if (this.phoneNumber != null) {
+            throw new IllegalStateException("Illegal operation");
+        }
+        if (isValidPhoneNumber(phoneNumer)) {
+            this.phoneNumber = phoneNumer;
+        } else {
+            throw new IllegalArgumentException("Not a valid phone number, please re-enter.");
+        }
+    }
+
+    // Del 4 b)
+    public boolean isMember() {
+        return phoneNumber != null;
+    }
+
+    // Del 3
+    public void scanItem(Item item) {
+        this.shoppingCart.add(item);
+        System.out.println(item.getName() + ": " + item.getPrice() + "kr");
+    }
+
+    public void scanItems(List<Item> shoppingCart) {
+        for (Item i : shoppingCart) {
+            scanItem(i);
+        }
+    }
+
+    // Del 5
+    private double getDiscountForItem(Item item) {
+        // Funksjonaliteten her skal vi utvide senere...
+        if (isMember() && item.getCategory().equals("taco")) {
+            if (day == "fri" || day == "sat") {
+                return 0.3;
+            }
+        }
+        return 0.0;
+    }
+
+    private double getPriceForItem(Item item) {
+        return item.getPrice() - (item.getPrice() * this.getDiscountForItem(item));
+    }
+
+    // Del 6
+    private double getMVAForItem(Item item) {
+        return this.getPriceForItem(item) * 0.15;
+    }
+
+    private double getPriceWithoutMVAForItem(Item item) {
+        return this.getPriceForItem(item) - this.getMVAForItem(item);
+    }
+
+    // Del 7
+    private double getTotalPriceForCart() {
+        double sum = 0;
+        for (Item item : shoppingCart) {
+            sum += this.getPriceForItem(item);
+        }
+        return sum;
+    }
+
+    private double getTotalMVAForCart() {
+        double totalMVA = 0;
+        for (Item item : shoppingCart) {
+            totalMVA += this.getMVAForItem(item);
+        }
+        return totalMVA;
+    }
+
+    // Del 2 b)
+    private boolean validatePassword(String password) {
+        // Eventuelt kan man her bare bruke
+        // password.matches("^(?=.*[0-9])(?=.*[a-zA-Z]).{6,10}$");
+        // Dette uttrykket kalles RegEx og kan være noe utfordrende å skrive på egenhånd
+        // Det finnes dog en rekke gode ressurser på nett hvis man søker litt rundt.
+        // Nedenfor har jeg beskrevet en mer "manuell" metode som løses med vanlig
+        // Java-kode.
+        if (password.length() < 6 || password.length() > 10) {
+            return false;
+        }
+        char[] chars = password.toCharArray();
+        boolean containsNumeric = false;
+        boolean containsAlphabetic = false;
+        for (char c : chars) {
+            if (Character.isDigit(c)) {
+                containsNumeric = true;
+            } else if (Character.isAlphabetic(c)) {
+                containsAlphabetic = true;
+            }
+        }
+        return containsAlphabetic && containsNumeric;
+    }
+
+    private boolean isValidPhoneNumber(String phoneNumber) {
+        String cleanedPhoneNumber = phoneNumber.replaceAll("\\s", "");
+        if (cleanedPhoneNumber.startsWith("00479") || cleanedPhoneNumber.startsWith("00474")) {
+            if (cleanedPhoneNumber.length() != 12) {
+                return false;
+            }
+        } else if (cleanedPhoneNumber.startsWith("+479") || cleanedPhoneNumber.startsWith("+474")) {
+            if (cleanedPhoneNumber.length() != 11) {
+                return false;
+            }
+        } else {
+            return false;
+        }
+
+        // Her kunne man også fjernet første tegn i charArrayen og sjekket resten
+        // Dette kan vi gjøre siden vi allerede har validert de første 4-5 tegnene
+        char[] chars = cleanedPhoneNumber.toCharArray();
+        boolean firstIndex = true;
+        for (char c : chars) {
+            if (!Character.isDigit(c)) {
+                if (c != '+' && !firstIndex) {
+                    return false;
+                }
+                firstIndex = false;
+            }
+        }
+
+        return true;
+    }
+
+    // Del 9
+    private int getNumberOfEqualItemsInCart(String barcode) {
+        int equalItems = 0;
+        for (Item item : shoppingCart) {
+            if (item.getBarcode().equals(barcode)) {
+                equalItems++;
+            }
+        }
+        return equalItems;
+    }
+
+    // Del 8 & 9
+    @Override
+    public String toString() {
+        List<String> uniqueBarcodes = new ArrayList<>();
+        String receipt = """
+                --------------------------------------
+                Hva             Pris    MVA     Total
+                """;
+        for (Item item : shoppingCart) {
+            // ArrayList.contains bruker object.equals internt,
+            // Som gjør at vi sammenligner strenger på riktig måte
+            if (!uniqueBarcodes.contains(item.getBarcode())) {
+                int count = this.getNumberOfEqualItemsInCart(item.getBarcode());
+                receipt += String.format(
+                        """
+                                %dx %s\t%.2f\t%.2f\t%.2f
+                                """,
+                        count,
+                        item.getName(),
+                        this.getPriceWithoutMVAForItem(item),
+                        this.getMVAForItem(item),
+                        this.getPriceForItem(item) * count);
+                uniqueBarcodes.add(item.getBarcode());
+            }
+        }
+        receipt += String.format(
+                """
+                        --------------------------------------
+                        Total MVA                       %.2f
+                        Total                           %.2f
+                                Takk for at du handlet
+                                    hos oss i OOP!
+                        --------------------------------------
+                        """,
+                this.getTotalMVAForCart(),
+                this.getTotalPriceForCart());
+        return receipt;
+    }
+
+    // main-metode for å teste koden
+    public static void main(String[] args) {
+
+        SelfServiceCheckout checkout = new SelfServiceCheckout("fri", "passord123");
+
+        Item tomato = new Item("Tomat", 5, "fruit", "|| ||| | |||| |");
+        Item cheese = new Item("Norvegia", 90, "diary", "| | ||||| | |||");
+        Item cheese2 = new Item("Norvegia", 90, "diary", "| | ||||| | |||");
+        Item tortillas = new Item("Lefser", 15, "taco", " | || | || ||||");
+        Item groundMeat = new Item("Kjøttdeig", 29.99, "taco", "|||| || | |||||");
+
+        checkout.scanItem(tomato);
+        checkout.scanItem(cheese);
+        checkout.scanItem(tortillas);
+        checkout.scanItem(groundMeat);
+        checkout.scanItem(cheese2);
+
+        System.out.println(checkout);
+
+        checkout.registerPhoneNumber("004742345678");
+        checkout.activateAdminMode("passord123");
+        checkout.removeFromCart(0);
+
+        System.out.println(checkout);
+
+    }
+
+}