Main.java

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Library library = new Library();
        Scanner scanner = new Scanner(System.in);

        // Add some default books
        library.addBook(new Book("The Alchemist", "Paulo Coelho"));
        library.addBook(new Book("1984", "George Orwell"));
        library.addBook(new Book("To Kill a Mockingbird", "Harper Lee"));

        System.out.print("Enter your name: ");
        User user = new User(scanner.nextLine());

        while (true) {
            System.out.println("\n=== Library Menu ===");
            System.out.println("1. View available books");
            System.out.println("2. Issue a book");
            System.out.println("3. Return a book");
            System.out.println("4. Show issued books");
            System.out.println("5. Exit");
            System.out.print("Enter choice: ");

            int choice = scanner.nextInt();
            scanner.nextLine(); // consume newline

            switch (choice) {
                case 1:
                    System.out.println("Available Books:");
                    for (Book book : library.getAvailableBooks()) {
                        System.out.println(book.getTitle() + " by " + book.getAuthor());
                    }
                    break;

                case 2:
                    System.out.print("Enter book title to issue: ");
                    String issueTitle = scanner.nextLine();
                    Book bookToIssue = findBookByTitle(library, issueTitle);
                    if (bookToIssue != null && library.issueBook(bookToIssue, user)) {
                        System.out.println("Book issued successfully.");
                    } else {
                        System.out.println("Book not available or already issued.");
                    }
                    break;

                case 3:
                    System.out.print("Enter book title to return: ");
                    String returnTitle = scanner.nextLine();
                    Book bookToReturn = findBookByTitle(library, returnTitle);
                    if (bookToReturn != null && library.returnBook(bookToReturn)) {
                        System.out.println("Book returned successfully.");
                    } else {
                        System.out.println("Book not found or not issued.");
                    }
                    break;

                case 4:
                    library.showIssuedBooks();
                    break;

                case 5:
                    System.out.println("Thank you. Exiting.");
                    scanner.close();
                    return;

                default:
                    System.out.println("Invalid choice. Try again.");
            }
        }
    }

    private static Book findBookByTitle(Library library, String title) {
        for (Book book : library.getAvailableBooks()) {
            if (book.getTitle().equalsIgnoreCase(title)) {
                return book;
            }
        }
        // Search also in issued books (for returning)
        return new Book(title, ""); // fallback (but may fail due to equals() logic)
    }
}