AddBookPanel.java

package ui;

import dao.BookDAO;
import models.Book;

import javax.swing.*;
import java.awt.*;
import java.sql.SQLException;
import java.util.logging.Logger;

/**
 * AddBookPanel.java - Panel for adding new books
 * 
 * Features:
 * - Text fields for book details
 * - Input validation
 * - Database persistence via DAO
 * - User feedback messages
 * 
 * OOP: Demonstrates encapsulation and component reusability
 */
public class AddBookPanel extends JPanel {

    private static final Logger logger = Logger.getLogger(AddBookPanel.class.getName());
    private static final long serialVersionUID = 1L;

    // UI Components
    private JTextField titleField, authorField, isbnField, publisherField;
    private JTextField yearField, totalCopiesField, categoryField, priceField;
    private JButton addButton, clearButton;
    private JLabel messageLabel;
    private JButton[] genreButtons;

    private final String[] genreOptions = {
        "Historical", "Romance", "Fantasy", "Science Fiction",
        "Mystery", "Biography", "Self-Help", "Technology",
        "Thriller", "Adventure", "Poetry", "Cooking"
    };

    // Data Access
    private BookDAO bookDAO;

    /**
     * Constructor
     * 
     * @param bookDAO BookDAO instance for database operations
     */
    public AddBookPanel(BookDAO bookDAO) {
        this.bookDAO = bookDAO;
        setLayout(new BorderLayout(10, 10));
        setBorder(BorderFactory.createEmptyBorder(20, 20, 20, 20));

        // Create form panel
        JPanel formPanel = createFormPanel();
        add(formPanel, BorderLayout.CENTER);

        // Add spacing
        add(Box.createVerticalStrut(20), BorderLayout.SOUTH);
    }

    /**
     * Creates the form panel with all input fields
     */
    private JPanel createFormPanel() {
        JPanel panel = new JPanel(new GridBagLayout());
        panel.setBorder(BorderFactory.createTitledBorder("Book Details"));
        GridBagConstraints gbc = new GridBagConstraints();
        gbc.insets = new Insets(5, 5, 5, 5);
        gbc.fill = GridBagConstraints.HORIZONTAL;

        int row = 0;

        // Title
        gbc.gridx = 0;
        gbc.gridy = row;
        panel.add(new JLabel("Title *"), gbc);
        gbc.gridx = 1;
        titleField = createField(20);
        panel.add(titleField, gbc);
        row++;

        // Author
        gbc.gridx = 0;
        gbc.gridy = row;
        panel.add(new JLabel("Author *"), gbc);
        gbc.gridx = 1;
        authorField = createField(20);
        panel.add(authorField, gbc);
        row++;

        // ISBN
        gbc.gridx = 0;
        gbc.gridy = row;
        panel.add(new JLabel("ISBN *"), gbc);
        gbc.gridx = 1;
        isbnField = createField(20);
        panel.add(isbnField, gbc);
        row++;

        // Publisher
        gbc.gridx = 0;
        gbc.gridy = row;
        panel.add(new JLabel("Publisher"), gbc);
        gbc.gridx = 1;
        publisherField = createField(20);
        panel.add(publisherField, gbc);
        row++;

        // Publication Year
        gbc.gridx = 0;
        gbc.gridy = row;
        panel.add(new JLabel("Publication Year *"), gbc);
        gbc.gridx = 1;
        yearField = createField(20);
        panel.add(yearField, gbc);
        row++;

        // Total Copies
        gbc.gridx = 0;
        gbc.gridy = row;
        panel.add(new JLabel("Total Copies *"), gbc);
        gbc.gridx = 1;
        totalCopiesField = createField(20);
        panel.add(totalCopiesField, gbc);
        row++;

        // Category
        gbc.gridx = 0;
        gbc.gridy = row;
        panel.add(new JLabel("Category"), gbc);
        gbc.gridx = 1;
        categoryField = createField(20);
        panel.add(categoryField, gbc);
        row++;

        // Genre quick select with horizontal scrolling
        gbc.gridx = 0;
        gbc.gridy = row;
        panel.add(new JLabel("Genre Suggestions"), gbc);
        gbc.gridx = 1;
        JScrollPane genreScrollPane = createGenreScrollPane();
        panel.add(genreScrollPane, gbc);
        row++;

        // Price
        gbc.gridx = 0;
        gbc.gridy = row;
        panel.add(new JLabel("Price (₹)"), gbc);
        gbc.gridx = 1;
        priceField = createField(20);
        panel.add(priceField, gbc);
        row++;

        // Buttons
        gbc.gridx = 0;
        gbc.gridy = row;
        gbc.gridwidth = 2;
        JPanel buttonPanel = createButtonPanel();
        panel.add(buttonPanel, gbc);
        row++;

        // Message Label
        gbc.gridx = 0;
        gbc.gridy = row;
        gbc.gridwidth = 2;
        messageLabel = new JLabel(" ");
        messageLabel.setFont(new Font("Arial", Font.BOLD, 12));
        messageLabel.setForeground(new Color(20, 28, 40));
        panel.add(messageLabel, gbc);

        return panel;
    }

    private JTextField createField(int columns) {
        JTextField field = new JTextField(columns);
        field.setFont(new Font("Arial", Font.BOLD, 14));
        field.setForeground(new Color(20, 28, 40));
        field.setCaretColor(new Color(20, 28, 40));
        return field;
    }

    /**
     * Creates the button panel
     */
    private JPanel createButtonPanel() {
        JPanel panel = new JPanel(new FlowLayout(FlowLayout.CENTER, 10, 0));

        addButton = new JButton("➕ Add Book");
        addButton.setFont(new Font("Arial", Font.BOLD, 12));
        addButton.addActionListener(e -> handleAddBook());

        clearButton = new JButton("🔄 Clear");
        clearButton.addActionListener(e -> clearFields());

        panel.add(addButton);
        panel.add(clearButton);

        return panel;
    }

    private JScrollPane createGenreScrollPane() {
        JPanel genrePanel = new JPanel();
        genrePanel.setLayout(new BoxLayout(genrePanel, BoxLayout.X_AXIS));
        genrePanel.setOpaque(false);

        genreButtons = new JButton[genreOptions.length];
        for (int i = 0; i < genreOptions.length; i++) {
            String genre = genreOptions[i];
            JButton btn = new JButton(genre);
            btn.setFont(new Font("Arial", Font.PLAIN, 12));
            btn.setForeground(new Color(20, 28, 40));
            btn.setBackground(new Color(235, 244, 255));
            btn.setOpaque(true);
            btn.setFocusPainted(false);
            btn.setBorder(BorderFactory.createCompoundBorder(
                    BorderFactory.createLineBorder(new Color(180, 190, 205)),
                    BorderFactory.createEmptyBorder(6, 12, 6, 12)));
            btn.addActionListener(e -> {
                categoryField.setText(genre);
                updateGenreSelection(genre);
            });
            genreButtons[i] = btn;
            genrePanel.add(btn);
            if (i < genreOptions.length - 1) {
                genrePanel.add(Box.createRigidArea(new Dimension(8, 0)));
            }
        }

        JScrollPane scrollPane = new JScrollPane(genrePanel,
                JScrollPane.VERTICAL_SCROLLBAR_NEVER,
                JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED);
        scrollPane.setBorder(BorderFactory.createLineBorder(new Color(180, 190, 205)));
        scrollPane.setPreferredSize(new Dimension(0, 48));
        scrollPane.getViewport().setBackground(getBackground());
        return scrollPane;
    }

    private void updateGenreSelection(String selectedGenre) {
        if (genreButtons == null) {
            return;
        }
        for (JButton btn : genreButtons) {
            if (btn.getText().equals(selectedGenre)) {
                btn.setBackground(new Color(59, 130, 246));
                btn.setForeground(Color.WHITE);
            } else {
                btn.setBackground(new Color(235, 244, 255));
                btn.setForeground(new Color(20, 28, 40));
            }
        }
    }

    /**
     * Handles add book button click
     */
    private void handleAddBook() {
        try {
            // Validate and get input
            String title = titleField.getText().trim();
            String author = authorField.getText().trim();
            String isbn = isbnField.getText().trim();
            String publisher = publisherField.getText().trim();
            String yearStr = yearField.getText().trim();
            String copiesStr = totalCopiesField.getText().trim();
            String category = categoryField.getText().trim();
            String priceStr = priceField.getText().trim();

            // Validate required fields
            if (title.isEmpty() || author.isEmpty() || isbn.isEmpty() ||
                    yearStr.isEmpty() || copiesStr.isEmpty()) {
                showError("Please fill all required fields (marked with *)");
                return;
            }

            // Validate and parse numeric fields
            int year = Integer.parseInt(yearStr);
            int totalCopies = Integer.parseInt(copiesStr);
            double price = priceStr.isEmpty() ? 0 : Double.parseDouble(priceStr);

            // Additional validation
            if (year < 1000 || year > java.time.Year.now().getValue()) {
                showError("Invalid publication year");
                return;
            }
            if (totalCopies <= 0) {
                showError("Total copies must be positive");
                return;
            }
            if (price < 0) {
                showError("Price cannot be negative");
                return;
            }

            // Create Book object
            Book book = new Book(title, author, isbn, publisher, year,
                    totalCopies, category, price);

            // Add to database
            if (bookDAO.addBook(book)) {
                showSuccess("✓ Book added successfully!");
                JOptionPane.showMessageDialog(this,
                        "Book added successfully!",
                        "Success", JOptionPane.INFORMATION_MESSAGE);
                clearFields();
                logger.info("Book added: " + title + " by " + author);
            } else {
                showError("Failed to add book");
            }

        } catch (NumberFormatException e) {
            showError("Invalid number format. Please check your input.");
        } catch (SQLException e) {
            // Handle duplicate ISBN
            if (e.getMessage().contains("already exists")) {
                showError("✗ A book with this ISBN already exists");
            } else {
                showError("Database error: " + e.getMessage());
            }
        } catch (Exception e) {
            showError("Error: " + e.getMessage());
            logger.severe("Add book error: " + e.getMessage());
        }
    }

    /**
     * Clears all input fields
     */
    private void clearFields() {
        titleField.setText("");
        authorField.setText("");
        isbnField.setText("");
        publisherField.setText("");
        yearField.setText("");
        totalCopiesField.setText("");
        categoryField.setText("");
        priceField.setText("");
        messageLabel.setText(" ");
        titleField.requestFocus();
    }

    /**
     * Shows error message
     */
    private void showError(String message) {
        messageLabel.setForeground(Color.RED);
        messageLabel.setText(message);
    }

    /**
     * Shows success message
     */
    private void showSuccess(String message) {
        messageLabel.setForeground(new Color(0, 150, 0));
        messageLabel.setText(message);
    }

    /**
     * Refreshes the panel (called when tab is switched)
     */
    public void refresh() {
        clearFields();
    }
}