/**
 * A library member is defined by an ssn. The member can check out only one
 * book.
 * 
 * @author CSC 142
 * 
 */
public class LibraryMember {
	// a library member is defined by
	// an ssn and a book
	// Note: we wrongly assume that an ssn doesn't start with
	// 0 (a String would be better, but an int is convenient)
	private int ssn;

	private Book book;

	/**
	 * Creates a library member given his/her ssn
	 * 
	 * @param theSSN
	 *            the ssn of the library member
	 */
	public LibraryMember(int theSSN) {
		if (checkSSN(theSSN)) {
			ssn = theSSN;
		} else {
			// It would better to throw an exception
			System.out.println("Invalid ssn value = " + theSSN);
		}
	}

	/**
	 * Returns the book (if there is one)
	 * 
	 * @return true if the operation was successfull, or false otherwise
	 */
	public boolean returnBook() {
		if (book != null) { // there is a book to return
			// \" prints a double quote
			System.out.println("The book titled \"" + book.getTitle()
					+ "\" has been returned.");
			book = null;
			return true;
		} else { // there is no book to return
			System.out.println("There is no book to return.");
			return false;
		}
	}

	/**
	 * Borrows a book given its title
	 * 
	 * @param title
	 *            the title of the book
	 * @return true if the book could be borrowed, or false otherwise
	 */
	public boolean borrowBook(String title) {
		if (book == null) { // the book can be borrowed
			book = new Book(title);
			System.out.println("The book titled \"" + title
					+ "\" has been borrowed.");
			return true;
		} else { // can't borrow the book
			System.out
					.println("You can't borrow a book. You already have one (\""
							+ book.getTitle() + "\")!");
			return false;
		}
	}

	/**
	 * Returns true if the given ssn is valid, or false otherwise
	 * 
	 * @param ssn
	 *            the ssn to check
	 * @return true if the given ssn is valid, or false otherwise
	 */
	private boolean checkSSN(int ssn) {
		if (ssn <= 0) {
			return false;
		}
		// the ssn should have nine digits (but doesn't work if
		// the leading digits are 0's)
		if (ssn > 999999999) {
			return false;
		}
		if (ssn < 100000000) {
			return false;
		}
		// Other way to do the same thing:
		// Integer theSSN = new Integer(ssn);
		// if (theSSN.toString().length() != 9) {
		// return false;
		// }
		// if ( (ssn + "").length() != 9) {
		// return false;
		// }
		return true;
	}
}