ReturnBook.java

import javax.swing.*;
import java.awt.*;
import java.sql.*;

public class ReturnBook extends JFrame {
    JComboBox<BookItem> bookDropdown;
    JTextArea info;

    ReturnBook() {
        setTitle("Return Book");
        setSize(560, 360);
        setLocationRelativeTo(null);
        setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);

        JPanel root = LibraryUI.createContentPanel();
        root.setLayout(new BorderLayout(0, 16));
        setContentPane(root);

        JPanel header = new JPanel();
        header.setOpaque(false);
        header.setLayout(new BoxLayout(header, BoxLayout.Y_AXIS));
        header.add(LibraryUI.createTitle("Return Book"));
        header.add(Box.createVerticalStrut(4));
        header.add(LibraryUI.createSubtitle("Choose an issued book from the dropdown and return it without typing."));
        root.add(header, BorderLayout.NORTH);

        JPanel card = LibraryUI.createCardPanel();
        card.setLayout(new BoxLayout(card, BoxLayout.Y_AXIS));
        root.add(card, BorderLayout.CENTER);

        JLabel label = new JLabel("Issued Books");
        label.setFont(LibraryUI.LABEL_FONT);
        label.setForeground(LibraryUI.TEXT);
        card.add(label);
        card.add(Box.createVerticalStrut(8));

        bookDropdown = LibraryUI.createBookDropdown();
        card.add(bookDropdown);
        card.add(Box.createVerticalStrut(16));

        JPanel buttonRow = new JPanel(new FlowLayout(FlowLayout.LEFT, 0, 0));
        buttonRow.setOpaque(false);
        JButton ret = LibraryUI.createPrimaryButton("Return Book");
        JButton refresh = LibraryUI.createSecondaryButton("Refresh List");
        buttonRow.add(ret);
        buttonRow.add(Box.createHorizontalStrut(10));
        buttonRow.add(refresh);
        card.add(buttonRow);
        card.add(Box.createVerticalStrut(16));

        info = LibraryUI.createInfoArea(6, 34);
        info.setText("Only issued books are listed here. Select one and mark it available again.");
        card.add(LibraryUI.wrap(info));

        ret.addActionListener(e -> returnBook());
        refresh.addActionListener(e -> refreshBooks());

        refreshBooks();
        setVisible(true);
    }

    private void returnBook() {
        BookItem selectedBook = (BookItem) bookDropdown.getSelectedItem();
        if (selectedBook == null) {
            JOptionPane.showMessageDialog(this, "No issued book found to return.");
            return;
        }

        Connection con = DBConnection.getConnection();
        if (con == null) {
            return;
        }

        try (PreparedStatement ps = con.prepareStatement("UPDATE books SET issued=false WHERE id=?")) {
            ps.setInt(1, selectedBook.getId());
            int rows = ps.executeUpdate();

            if (rows > 0) {
                info.setText("Book returned successfully.\n\n"
                    + "ID: " + selectedBook.getId()
                    + "\nName: " + selectedBook.getName()
                    + "\nAuthor: " + selectedBook.getAuthor()
                    + "\nStatus: Available");
                JOptionPane.showMessageDialog(this, "Book returned successfully.");
                refreshBooks();
            }
        } catch (Exception ex) {
            JOptionPane.showMessageDialog(this, "Unable to return book.\n" + ex.getMessage());
        }
    }

    private void refreshBooks() {
        BookRepository.loadBooksInto(bookDropdown, false, true);
        if (bookDropdown.getItemCount() == 0) {
            info.setText("No issued books right now. Issue a book first to see it here.");
        }
    }
}