Book.java

import java.util.Date;
import java.text.SimpleDateFormat;

/**
 * Book Class for Library Management System
 * Author: GitHub Copilot
 * Description: Represents a book with all its properties and borrowing status
 */
public class Book {
 
 // Private fields to store book information
 private int id;
 private String title;
 private String author;
 private String genre;
 private int publicationYear;
 private boolean borrowed;
 private String borrowerName;
 private Date borrowDate;
 private Date addedDate;
 
 // Static formatter for dates
 private static SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
 
 /**
 * Constructor to create a new book
 * @param id The unique ID for the book
 * @param title The book title
 * @param author The author name
 * @param genre The book genre/category
 * @param publicationYear The year the book was published
 */
 public Book(int id, String title, String author, String genre, int publicationYear) {
 this.id = id;
 this.title = title;
 this.author = author;
 this.genre = genre;
 this.publicationYear = publicationYear;
 this.borrowed = false;
 this.borrowerName = null;
 this.borrowDate = null;
 this.addedDate = new Date();
 }
 
 /**
 * Gets the book ID
 * @return The book ID
 */
 public int getId() {
 return id;
 }
 
 /**
 * Gets the book title
 * @return The book title
 */
 public String getTitle() {
 return title;
 }
 
 /**
 * Sets the book title
 * @param title The new title
 */
 public void setTitle(String title) {
 this.title = title;
 }
 
 /**
 * Gets the author name
 * @return The author name
 */
 public String getAuthor() {
 return author;
 }
 
 /**
 * Sets the author name
 * @param author The new author name
 */
 public void setAuthor(String author) {
 this.author = author;
 }
 
 /**
 * Gets the book genre
 * @return The book genre
 */
 public String getGenre() {
 return genre;
 }
 
 /**
 * Sets the book genre
 * @param genre The new genre
 */
 public void setGenre(String genre) {
 this.genre = genre;
 }
 
 /**
 * Gets the publication year
 * @return The publication year
 */
 public int getPublicationYear() {
 return publicationYear;
 }
 
 /**
 * Sets the publication year
 * @param publicationYear The new publication year
 */
 public void setPublicationYear(int publicationYear) {
 this.publicationYear = publicationYear;
 }
 
 /**
 * Checks if the book is currently borrowed
 * @return true if borrowed, false if available
 */
 public boolean isBorrowed() {
 return borrowed;
 }
 
 /**
 * Sets the borrowing status of the book
 * @param borrowed The borrowing status
 * @param borrowerName The name of the borrower (null if returning)
 */
 public void setBorrowed(boolean borrowed, String borrowerName) {
 this.borrowed = borrowed;
 this.borrowerName = borrowerName;
 
 if (borrowed) {
 this.borrowDate = new Date();
 } else {
 // When returning, keep the borrower name and date for history
 // In a real system, you might want to keep a borrowing history
 this.borrowDate = null;
 }
 }
 
 /**
 * Gets the name of the current borrower
 * @return The borrower name, or null if not borrowed
 */
 public String getBorrowerName() {
 return borrowerName;
 }
 
 /**
 * Gets the borrow date as formatted string
 * @return The borrow date, or "Not borrowed" if available
 */
 public String getBorrowDate() {
 if (borrowDate == null) {
 return "Not borrowed";
 }
 return dateFormat.format(borrowDate);
 }
 
 /**
 * Gets the date when the book was added to the library
 * @return The formatted added date
 */
 public String getAddedDate() {
 return dateFormat.format(addedDate);
 }
 
 /**
 * Gets the raw borrow date object
 * @return The borrow Date object, or null if not borrowed
 */
 public Date getBorrowDateObject() {
 if (borrowDate == null) {
 return null;
 }
 return new Date(borrowDate.getTime()); // Return copy for security
 }
 
 /**
 * Gets the raw added date object
 * @return The added Date object
 */
 public Date getAddedDateObject() {
 return new Date(addedDate.getTime()); // Return copy for security
 }
 
 /**
 * Calculates how many days the book has been borrowed
 * @return Number of days borrowed, or 0 if not borrowed
 */
 public long getDaysBorrowed() {
 if (!borrowed || borrowDate == null) {
 return 0;
 }
 
 Date now = new Date();
 long diffInMillis = now.getTime() - borrowDate.getTime();
 return diffInMillis / (1000 * 60 * 60 * 24); // Convert to days
 }
 
 /**
 * Checks if the book is overdue (borrowed for more than specified days)
 * @param maxDays Maximum allowed borrowing days
 * @return true if overdue, false otherwise
 */
 public boolean isOverdue(int maxDays) {
 return borrowed && getDaysBorrowed() > maxDays;
 }
 
 /**
 * Gets the age of the book in years
 * @return Age in years from publication to current year
 */
 public int getBookAge() {
 int currentYear = java.util.Calendar.getInstance().get(java.util.Calendar.YEAR);
 return currentYear - publicationYear;
 }
 
 /**
 * Checks if the book matches a search term in title, author, or genre
 * @param searchTerm The term to search for
 * @return true if any field contains the search term
 */
 public boolean matches(String searchTerm) {
 if (searchTerm == null || searchTerm.trim().isEmpty()) {
 return false;
 }
 
 String term = searchTerm.toLowerCase();
 return title.toLowerCase().contains(term) ||
 author.toLowerCase().contains(term) ||
 genre.toLowerCase().contains(term);
 }
 
 /**
 * Gets the availability status as a formatted string
 * @return Status string with icon
 */
 public String getAvailabilityStatus() {
 if (borrowed) {
 return "🔴 Borrowed by " + borrowerName;
 } else {
 return "🟢 Available";
 }
 }
 
 /**
 * Gets a short status icon
 * @return Status icon
 */
 public String getStatusIcon() {
 return borrowed ? "🔴" : "🟢";
 }
 
 /**
 * Creates a formatted summary of the book
 * @return Formatted book summary
 */
 public String getSummary() {
 String status = borrowed ? "🔴 Borrowed" : "🟢 Available";
 return String.format("[%d] %s - \"%s\" by %s (%s, %d)", 
 id, status, title, author, genre, publicationYear);
 }
 
 /**
 * Creates a detailed description of the book
 * @return Detailed book information
 */
 public String getDetailedInfo() {
 StringBuilder info = new StringBuilder();
 info.append("Book ID: ").append(id).append("\n");
 info.append("Title: ").append(title).append("\n");
 info.append("Author: ").append(author).append("\n");
 info.append("Genre: ").append(genre).append("\n");
 info.append("Publication Year: ").append(publicationYear).append("\n");
 info.append("Age: ").append(getBookAge()).append(" years\n");
 info.append("Status: ").append(getAvailabilityStatus()).append("\n");
 info.append("Added to Library: ").append(getAddedDate()).append("\n");
 
 if (borrowed) {
 info.append("Borrowed Date: ").append(getBorrowDate()).append("\n");
 info.append("Days Borrowed: ").append(getDaysBorrowed()).append("\n");
 }
 
 return info.toString();
 }
 
 /**
 * Returns a string representation of the book
 * @return String containing book information
 */
 @Override
 public String toString() {
 return String.format("Book{id=%d, title='%s', author='%s', genre='%s', year=%d, borrowed=%s}", 
 id, title, author, genre, publicationYear, borrowed);
 }
 
 /**
 * Checks if two books are equal based on their ID
 * @param obj The object to compare with
 * @return true if books have the same ID, false otherwise
 */
 @Override
 public boolean equals(Object obj) {
 if (this == obj) return true;
 if (obj == null || getClass() != obj.getClass()) return false;
 
 Book book = (Book) obj;
 return id == book.id;
 }
 
 /**
 * Generates hash code based on book ID
 * @return Hash code
 */
 @Override
 public int hashCode() {
 return Integer.hashCode(id);
 }
}