Untitled

import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;
import java.util.Random;
import java.util.InputMismatchException;
import java.text.DecimalFormat;

class Customer {
    private String customerName;
    private String email;
    private String password;
    private String address;
    private String contactNumber;
    private String customerId;
    
    public Customer(String customerName, String email, String password, String address, String contactNumber) {
        this.customerName = customerName;
        this.email = email;
        this.password = password;
        this.address = address;
        this.contactNumber = contactNumber;
        this.customerId = generateCustomerId();
    }
    
    private String generateCustomerId() {
        Random random = new Random();
        return String.format("%05d", random.nextInt(100000));
    }
    
    // Getters
    public String getCustomerName() { return customerName; }
    public String getEmail() { return email; }
    public String getPassword() { return password; }
    public String getAddress() { return address; }
    public String getContactNumber() { return contactNumber; }
    public String getCustomerId() { return customerId; }
    
    // Setters
    public void setCustomerName(String customerName) { this.customerName = customerName; }
    public void setEmail(String email) { this.email = email; }
    public void setPassword(String password) { this.password = password; }
    public void setAddress(String address) { this.address = address; }
    public void setContactNumber(String contactNumber) { this.contactNumber = contactNumber; }
    
    @Override
    public String toString() {
        return "Customer ID: " + customerId + 
               "\nName: " + customerName + 
               "\nEmail: " + email + 
               "\nAddress: " + address + 
               "\nContact: " + contactNumber;
    }
}

class Product {
    private String productId;
    private String productName;
    private String productDescription;
    private int availableQuantities;
    private double price;
    
    public Product(String productName, String productDescription, int availableQuantities, double price) {
        this.productId = generateProductId();
        this.productName = productName;
        this.productDescription = productDescription;
        this.availableQuantities = availableQuantities;
        this.price = price;
    }
    
    private String generateProductId() {
        Random random = new Random();
        return String.format("(%d-%04d-%04d-%d)", 
            random.nextInt(10), 
            random.nextInt(10000), 
            random.nextInt(10000), 
            random.nextInt(10));
    }
    
    // Getters
    public String getProductId() { return productId; }
    public String getProductName() { return productName; }
    public String getProductDescription() { return productDescription; }
    public int getAvailableQuantities() { return availableQuantities; }
    public double getPrice() { return price; }
    
    // Setters
    public void setProductName(String productName) { this.productName = productName; }
    public void setProductDescription(String productDescription) { this.productDescription = productDescription; }
    public void setAvailableQuantities(int availableQuantities) { this.availableQuantities = availableQuantities; }
    public void setPrice(double price) { this.price = price; }
    
    @Override
    public String toString() {
        DecimalFormat df = new DecimalFormat("#0.00");
        return "Product ID: " + productId + 
               "\nName: " + productName + 
               "\nDescription: " + productDescription + 
               "\nQuantity: " + availableQuantities + 
               "\nPrice: $" + df.format(price);
    }
}

public class CustomerProductManagementSystem {
    private static List<Customer> customers = new ArrayList<>();
    private static List<Product> products = new ArrayList<>();
    private static Scanner scanner = new Scanner(System.in);
    
    public static void main(String[] args) {
        while (true) {
            displayMenu();
            System.out.print("Enter your choice (1-7): ");
            int choice = getValidChoice();
            
            switch (choice) {
                case 1:
                    registerCustomer();
                    break;
                case 2:
                    updateCustomer();
                    break;
                case 3:
                    addOrUpdateProduct();
                    break;
                case 4:
                    findCustomerByEmail();
                    break;
                case 5:
                    findHighestPricedProduct();
                    break;
                case 6:
                    sortProductsByQuantity();
                    break;
                case 7:
                    System.out.println("Thank you for using the Customer Product Management System!");
                    System.exit(0);
                    break;
                default:
                    System.out.println("Invalid choice! Please try again.");
            }
            
            System.out.println("\nPress Enter to continue...");
            scanner.nextLine();
        }
    }
    
    private static void displayMenu() {
        System.out.println("\n" + "=".repeat(50));
        System.out.println("    CUSTOMER PRODUCT MANAGEMENT SYSTEM");
        System.out.println("=".repeat(50));
        System.out.println("1. Register New Customer");
        System.out.println("2. Update Customer Details");
        System.out.println("3. Add/Update Product");
        System.out.println("4. Find Customer by Email");
        System.out.println("5. Find Highest Priced Product");
        System.out.println("6. Sort Products by Quantity");
        System.out.println("7. Exit");
        System.out.println("=".repeat(50));
    }
    
    private static int getValidChoice() {
        try {
            int choice = scanner.nextInt();
            scanner.nextLine(); // consume newline
            return choice;
        } catch (InputMismatchException e) {
            scanner.nextLine(); // consume invalid input
            return -1;
        }
    }
    
    // Task 1: Customer Registration
    private static void registerCustomer() {
        System.out.println("\n--- CUSTOMER REGISTRATION ---");
        
        System.out.print("Enter Customer Name (max 50 characters): ");
        String name = getValidString(50, "Customer Name");
        
        System.out.print("Enter Email: ");
        String email = getValidEmail();
        
        System.out.print("Enter Password (6-12 characters): ");
        String password = getValidPassword();
        
        System.out.print("Enter Address (max 100 characters): ");
        String address = getValidString(100, "Address");
        
        System.out.print("Enter Contact Number (exactly 10 digits): ");
        String contactNumber = getValidContactNumber();
        
        Customer customer = new Customer(name, email, password, address, contactNumber);
        customers.add(customer);
        
        System.out.println("\nCustomer Registration is successful for <" + customer.getCustomerId() + ">");
    }
    
    // Task 2: Update Customer Details
    private static void updateCustomer() {
        System.out.println("\n--- UPDATE CUSTOMER DETAILS ---");
        
        if (customers.isEmpty()) {
            System.out.println("No customers registered yet!");
            return;
        }
        
        System.out.print("Enter Customer Email to update: ");
        String email = scanner.nextLine().trim();
        
        Customer customer = findCustomerByEmailAddress(email);
        if (customer == null) {
            System.out.println("No customer found with email: " + email);
            return;
        }
        
        System.out.println("Current Details:");
        System.out.println(customer);
        
        System.out.print("\nEnter new Customer Name (max 50 characters): ");
        String name = getValidString(50, "Customer Name");
        
        System.out.print("Enter new Email: ");
        String newEmail = getValidEmail();
        
        System.out.print("Enter new Password (6-12 characters): ");
        String password = getValidPassword();
        
        System.out.print("Enter new Address (max 100 characters): ");
        String address = getValidString(100, "Address");
        
        System.out.print("Enter new Contact Number (exactly 10 digits): ");
        String contactNumber = getValidContactNumber();
        
        customer.setCustomerName(name);
        customer.setEmail(newEmail);
        customer.setPassword(password);
        customer.setAddress(address);
        customer.setContactNumber(contactNumber);
        
        System.out.println("\nYour Details updated successfully");
    }
    
    // Task 3: Add/Update Product
    private static void addOrUpdateProduct() {
        System.out.println("\n--- ADD/UPDATE PRODUCT ---");
        
        System.out.print("Enter Product Name (max 50 characters): ");
        String name = getValidString(50, "Product Name");
        
        System.out.print("Enter Product Description (max 100 characters): ");
        String description = getValidString(100, "Product Description");
        
        System.out.print("Enter Available Quantities: ");
        int quantity = getValidQuantity();
        
        System.out.print("Enter Price (up to 2 decimal points): ");
        double price = getValidPrice();
        
        Product product = new Product(name, description, quantity, price);
        products.add(product);
        
        System.out.println("\nProduct added successfully");
    }
    
    // Task 4: Find Customer by Email
    private static void findCustomerByEmail() {
        System.out.println("\n--- FIND CUSTOMER BY EMAIL ---");
        
        if (customers.isEmpty()) {
            System.out.println("No customers registered yet!");
            return;
        }
        
        System.out.print("Enter Customer Email: ");
        String email = scanner.nextLine().trim();
        
        Customer customer = findCustomerByEmailAddress(email);
        if (customer != null) {
            System.out.println("\nCustomer found:");
            System.out.println(customer);
        } else {
            System.out.println("No Such Customer Exist with the Given Email");
        }
    }
    
    // Task 5: Find Highest Priced Product
    private static void findHighestPricedProduct() {
        System.out.println("\n--- HIGHEST PRICED PRODUCT ---");
        
        if (products.isEmpty()) {
            System.out.println("Product List is Empty");
            return;
        }
        
        Product highestPricedProduct = products.get(0);
        for (Product product : products) {
            if (product.getPrice() > highestPricedProduct.getPrice()) {
                highestPricedProduct = product;
            }
        }
        
        System.out.println("Highest Priced Product:");
        System.out.println(highestPricedProduct);
    }
    
    // Task 6: Sort Products by Quantity
    private static void sortProductsByQuantity() {
        System.out.println("\n--- PRODUCTS SORTED BY QUANTITY ---");
        
        if (products.isEmpty()) {
            System.out.println("Product List is Empty");
            return;
        }
        
        List<Product> sortedProducts = new ArrayList<>(products);
        sortedProducts.sort((p1, p2) -> Integer.compare(p2.getAvailableQuantities(), p1.getAvailableQuantities()));
        
        System.out.println("Products sorted by quantity (highest to lowest):");
        for (int i = 0; i < sortedProducts.size(); i++) {
            System.out.println("\n" + (i + 1) + ". " + sortedProducts.get(i));
            if (i < sortedProducts.size() - 1) {
                System.out.println("-".repeat(40));
            }
        }
    }
    
    // Helper methods
    private static Customer findCustomerByEmailAddress(String email) {
        for (Customer customer : customers) {
            if (customer.getEmail().equalsIgnoreCase(email)) {
                return customer;
            }
        }
        return null;
    }
    
    private static String getValidString(int maxLength, String fieldName) {
        while (true) {
            String input = scanner.nextLine().trim();
            if (input.length() > 0 && input.length() <= maxLength) {
                return input;
            }
            System.out.print(fieldName + " must be between 1 and " + maxLength + " characters. Try again: ");
        }
    }
    
    private static String getValidEmail() {
        while (true) {
            String email = scanner.nextLine().trim();
            if (email.contains("@") && email.contains(".") && email.length() > 5) {
                // Check for duplicate email
                boolean isDuplicate = false;
                for (Customer customer : customers) {
                    if (customer.getEmail().equalsIgnoreCase(email)) {
                        isDuplicate = true;
                        break;
                    }
                }
                if (!isDuplicate) {
                    return email;
                } else {
                    System.out.print("Email already exists. Please enter a different email: ");
                }
            } else {
                System.out.print("Please enter a valid email address: ");
            }
        }
    }
    
    private static String getValidPassword() {
        while (true) {
            String password = scanner.nextLine().trim();
            if (password.length() >= 6 && password.length() <= 12) {
                return password;
            }
            System.out.print("Password must be between 6 and 12 characters. Try again: ");
        }
    }
    
    private static String getValidContactNumber() {
        while (true) {
            String contact = scanner.nextLine().trim();
            if (contact.length() == 10 && contact.matches("\\d+")) {
                return contact;
            }
            System.out.print("Contact number must be exactly 10 digits. Try again: ");
        }
    }
    
    private static int getValidQuantity() {
        while (true) {
            try {
                int quantity = scanner.nextInt();
                scanner.nextLine(); // consume newline
                if (quantity >= 0) {
                    return quantity;
                }
                System.out.print("Quantity must be a non-negative number. Try again: ");
            } catch (InputMismatchException e) {
                scanner.nextLine(); // consume invalid input
                System.out.print("Please enter a valid number for quantity: ");
            }
        }
    }
    
    private static double getValidPrice() {
        while (true) {
            try {
                double price = scanner.nextDouble();
                scanner.nextLine(); // consume newline
                if (price >= 0) {
                    return Math.round(price * 100.0) / 100.0; // Round to 2 decimal places
                }
                System.out.print("Price must be a non-negative number. Try again: ");
            } catch (InputMismatchException e) {
                scanner.nextLine(); // consume invalid input
                System.out.print("Please enter a valid price (up to 2 decimal points): ");
            }
        }
    }
}