ViewBooksPanel.java

package ui;

import dao.BookDAO;
import models.Book;

import javax.swing.*;
import javax.swing.table.DefaultTableModel;
import java.awt.*;
import java.util.List;
import java.util.logging.Logger;

/**
 * ViewBooksPanel.java - Panel to display all books in library
 * 
 * Features:
 * - Displays all books in table format
 * - Shows book details (ID, Title, Author, ISBN, etc.)
 * - Sortable columns
 * - Row selection for detailed view
 * - Statistics summary
 * 
 * Best Practice: Pagination could be added for large datasets
 */
public class ViewBooksPanel extends JPanel {
    
    private static final Logger logger = Logger.getLogger(ViewBooksPanel.class.getName());
    private static final long serialVersionUID = 1L;
    
    // UI Components
    private JTable booksTable;
    private DefaultTableModel tableModel;
    private JLabel statisticsLabel;
    private JButton refreshButton;
    private JButton deleteButton;
    private JTextArea detailsArea;
    
    // Data Access
    private BookDAO bookDAO;
    
    // Table columns
    private static final String[] COLUMN_NAMES = 
        {"ID", "Title", "Author", "ISBN", "Publisher", "Year", "Category", 
         "Total", "Available", "Price (₹)"};
    
    /**
     * Constructor
     */
    public ViewBooksPanel(BookDAO bookDAO) {
        this.bookDAO = bookDAO;
        setLayout(new BorderLayout(10, 10));
        setBorder(BorderFactory.createEmptyBorder(10, 10, 10, 10));
        
        // Create top panel with buttons and statistics
        JPanel topPanel = createTopPanel();
        add(topPanel, BorderLayout.NORTH);
        
        // Create center panel with table
        JPanel centerPanel = createTablePanel();
        add(centerPanel, BorderLayout.CENTER);
        
        // Create bottom panel with details
        JPanel bottomPanel = createDetailsPanel();
        add(bottomPanel, BorderLayout.SOUTH);
        
        // Load initial data
        loadAllBooks();
    }
    
    /**
     * Creates top panel with refresh button and statistics
     */
    private JPanel createTopPanel() {
        JPanel panel = new JPanel(new BorderLayout());
        
        JPanel buttonPanel = new JPanel(new FlowLayout(FlowLayout.LEFT));
        refreshButton = new JButton("🔄 Refresh List");
        refreshButton.addActionListener(e -> loadAllBooks());
        buttonPanel.add(refreshButton);

        deleteButton = new JButton("🗑 Delete Selected");
        deleteButton.addActionListener(e -> handleDeleteBook());
        deleteButton.setEnabled(false);
        buttonPanel.add(deleteButton);

        statisticsLabel = new JLabel(" ");
        statisticsLabel.setFont(new Font("Arial", Font.BOLD, 12));
        statisticsLabel.setForeground(new Color(0, 102, 204));
        
        panel.add(buttonPanel, BorderLayout.WEST);
        panel.add(statisticsLabel, BorderLayout.EAST);
        
        return panel;
    }
    
    /**
     * Creates the table panel
     */
    private JPanel createTablePanel() {
        JPanel panel = new JPanel(new BorderLayout());
        panel.setBorder(BorderFactory.createTitledBorder("All Books in Library"));
        
        // Create table model
        tableModel = new DefaultTableModel(COLUMN_NAMES, 0) {
            @Override
            public boolean isCellEditable(int row, int column) {
                return false; // Read-only table
            }
        };
        
        // Create table
        booksTable = new JTable(tableModel);
        booksTable.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
        booksTable.setRowHeight(25);
        booksTable.getTableHeader().setFont(new Font("Arial", Font.BOLD, 11));
        booksTable.setFont(new Font("Arial", Font.PLAIN, 11));
        
        // Set column widths
        booksTable.getColumnModel().getColumn(0).setPreferredWidth(40);   // ID
        booksTable.getColumnModel().getColumn(1).setPreferredWidth(150);  // Title
        booksTable.getColumnModel().getColumn(2).setPreferredWidth(100);  // Author
        booksTable.getColumnModel().getColumn(3).setPreferredWidth(80);   // ISBN
        booksTable.getColumnModel().getColumn(4).setPreferredWidth(100);  // Publisher
        booksTable.getColumnModel().getColumn(5).setPreferredWidth(50);   // Year
        booksTable.getColumnModel().getColumn(6).setPreferredWidth(80);   // Category
        booksTable.getColumnModel().getColumn(7).setPreferredWidth(50);   // Total
        booksTable.getColumnModel().getColumn(8).setPreferredWidth(70);   // Available
        booksTable.getColumnModel().getColumn(9).setPreferredWidth(70);   // Price
        
        // Add selection listener to show details
        booksTable.getSelectionModel().addListSelectionListener(e -> {
            if (!e.getValueIsAdjusting()) {
                showSelectedBookDetails();
                updateDeleteButtonState();
            }
        });
        
        // Create scroll pane
        JScrollPane scrollPane = new JScrollPane(booksTable);
        scrollPane.setPreferredSize(new Dimension(900, 350));
        panel.add(scrollPane, BorderLayout.CENTER);
        
        return panel;
    }
    
    /**
     * Creates details panel for selected book
     */
    private JPanel createDetailsPanel() {
        JPanel panel = new JPanel(new BorderLayout());
        panel.setBorder(BorderFactory.createTitledBorder("Selected Book Details"));
        panel.setPreferredSize(new Dimension(900, 100));
        
        detailsArea = new JTextArea(4, 80);
        detailsArea.setEditable(false);
        detailsArea.setLineWrap(true);
        detailsArea.setWrapStyleWord(true);
        detailsArea.setFont(new Font("Arial", Font.PLAIN, 11));
        detailsArea.setText("Select a book from the table to see details");
        
        JScrollPane scrollPane = new JScrollPane(detailsArea);
        panel.add(scrollPane, BorderLayout.CENTER);
        
        return panel;
    }
    
    /**
     * Loads all books from database and displays in table
     */
    private void loadAllBooks() {
        try {
            List<Book> books = bookDAO.getAllBooks();
            tableModel.setRowCount(0); // Clear existing rows
            
            if (books.isEmpty()) {
                statisticsLabel.setText("No books in library");
                deleteButton.setEnabled(false);
            } else {
                // Add each book as a row
                for (Book book : books) {
                    Object[] rowData = {
                        book.getBookId(),
                        book.getTitle(),
                        book.getAuthor(),
                        book.getIsbn(),
                        book.getPublisher(),
                        book.getPublicationYear(),
                        book.getCategory(),
                        book.getTotalCopies(),
                        book.getAvailableCopies(),
                        String.format("%.2f", book.getPrice())
                    };
                    tableModel.addRow(rowData);
                }
                
                // Update statistics
                updateStatistics(books);
                booksTable.clearSelection();
                updateDeleteButtonState();
                logger.info("Loaded " + books.size() + " books");
            }
        } catch (Exception e) {
            logger.severe("Error loading books: " + e.getMessage());
            JOptionPane.showMessageDialog(this, "Error loading books: " + e.getMessage(),
                                        "Error", JOptionPane.ERROR_MESSAGE);
        }
    }
    
    /**
     * Updates statistics label
     */
    private void updateStatistics(List<Book> books) {
        if (books.isEmpty()) {
            statisticsLabel.setText("No books");
            return;
        }
        
        int totalBooks = books.size();
        int availableBooks = (int) books.stream()
                                       .filter(Book::isAvailable)
                                       .count();
        int unavailableBooks = totalBooks - availableBooks;
        
        double totalPrice = books.stream()
                                .mapToDouble(Book::getPrice)
                                .sum();
        
        String stats = String.format(
            "Total Books: %d | Available: %d | Unavailable: %d | Total Value: ₹%.2f",
            totalBooks, availableBooks, unavailableBooks, totalPrice
        );
        statisticsLabel.setText(stats);
    }
    
    /**
     * Shows details of selected book
     */
    private void showSelectedBookDetails() {
        int selectedRow = booksTable.getSelectedRow();
        if (selectedRow < 0) {
            detailsArea.setText("Select a book from the table to see details");
            updateDeleteButtonState();
            return;
        }
        
        try {
            int bookId = (int) tableModel.getValueAt(selectedRow, 0);
            Book book = bookDAO.getBookById(bookId);
            
            if (book != null) {
                String details = String.format(
                    "ID: %d | Title: %s | Author: %s\nISBN: %s | Publisher: %s | Year: %d\n" +
                    "Category: %s | Total Copies: %d | Available: %d | Price: ₹%.2f\n" +
                    "Availability: %s",
                    book.getBookId(), book.getTitle(), book.getAuthor(),
                    book.getIsbn(), book.getPublisher(), book.getPublicationYear(),
                    book.getCategory(), book.getTotalCopies(), book.getAvailableCopies(),
                    book.getPrice(),
                    book.isAvailable() ? "✓ Available" : "✗ Not Available"
                );
                detailsArea.setText(details);
            }
        } catch (Exception e) {
            logger.severe("Error showing details: " + e.getMessage());
        }
    }

    private void handleDeleteBook() {
        int selectedRow = booksTable.getSelectedRow();
        if (selectedRow < 0) {
            JOptionPane.showMessageDialog(this,
                    "Please select a book to delete.",
                    "No Selection", JOptionPane.WARNING_MESSAGE);
            return;
        }

        int bookId = (int) tableModel.getValueAt(selectedRow, 0);
        String title = (String) tableModel.getValueAt(selectedRow, 1);

        int choice = JOptionPane.showConfirmDialog(this,
                "Are you sure you want to delete the selected book?\n" +
                title + "\nThis action cannot be undone.",
                "Confirm Delete", JOptionPane.YES_NO_OPTION, JOptionPane.WARNING_MESSAGE);

        if (choice == JOptionPane.YES_OPTION) {
            if (bookDAO.deleteBook(bookId)) {
                JOptionPane.showMessageDialog(this,
                        "Book deleted successfully.",
                        "Deleted", JOptionPane.INFORMATION_MESSAGE);
                loadAllBooks();
                detailsArea.setText("Book deleted. Select another book for details.");
            } else {
                JOptionPane.showMessageDialog(this,
                        "Could not delete the selected book.",
                        "Delete Failed", JOptionPane.ERROR_MESSAGE);
            }
        }
    }

    private void updateDeleteButtonState() {
        deleteButton.setEnabled(booksTable.getSelectedRow() >= 0);
    }
    
    /**
     * Refreshes the panel
     */
    public void refresh() {
        loadAllBooks();
    }
}