/**
 * Class Link holds a Book object, as well as a count
 * of the number of books in the library, and two links.
 * One of the links points to the next author in alphabetical
 * order, while the second link points to the next book in
 * ISBN order.
 * @author David Thibodeau
 * @version 28-Aug-2002
 */
public class Link
{
   private int numberOfBooks;
   private Book linkBook; // used to hold Book data
   public Link nextAuthor, nextISBN; // used to track next links in lists

   /**
    * Constructor for objects of class Link
    * @param Book linkBook - reference to a Book object
    */
   public Link(Book linkBook)
   {
      this.linkBook = linkBook;
      numberOfBooks = 1;
   }
   
   /**
    * Constructor for objects of class Link
    * @param Book linkBook     - reference to a Book object
    * @param int numberOfBooks - number of books to add to library
    */
   public Link(Book linkBook, int numberOfBooks)
   {
      this.linkBook = linkBook;
      this.numberOfBooks = numberOfBooks;
   }
   
   /**
    * addBooks method - adds the specified number of books
    * to the value of numberOfBooks
    * @param  int numberOfBooks - number of books to add to library
    * @return void - no data returned
    */
   public void addBooks(int numberOfBooks)
   {
      this.numberOfBooks += numberOfBooks;
   } // end addBooks(int numberOfBooks) method
   
   /**
    * getBookTitle method - this method calls the getBookTitle
    * method of the Book object to get the title of the book
    * @param  void   - no data required
    * @return String - title of the book is returned
    */
   public String getBookTitle()
   {
      return linkBook.getBookTitle();
   } // end getBookTitle method
   
   /**
    * getBookPublisher method - this method calls the
    * getBookPublisher method of the Book object to
    * get the publisher of the book
    * @param  void   - no data required
    * @return String - publisher of the book is returned
    */
   public String getBookPublisher()
   {
      return linkBook.getBookPublisher();
   } // end getBookPublisher method
   
   /**
    * getBookISBN method - this method calls the
    * getBookISBN method of the Book object to
    * get the ISBN of the book
    * @param  void   - no data required
    * @return String - ISBN of the book is returned
    */
   public String getBookISBN()
   {
      return linkBook.getBookISBN();
   } // end getBookISBN method
   
   /**
    * getBookSubject method - this method calls the
    * getBookSubject method of the Book object to
    * get the subject of the book
    * @param  void   - no data required
    * @return String - subject of the book is returned
    */
   public String getBookSubject()
   {
      return linkBook.getBookSubject();
   } // end getBookSubject method
   
   /**
    * getBookYear method - this method calls the
    * getBookYear method of the Book object to
    * get the subject of the book
    * @param  void   - no data required
    * @return int - year the book was printed is returned
    */
   public int getBookYear()
   {
      return linkBook.getBookYear();
   } // end getBookYear method
   
   /**
    * getBookEdition method - this method calls the
    * getBookEdition method of the Book object to
    * get the edition of the book
    * @param  void   - no data required
    * @return int - edition of the book is returned
    */
   public int getBookEdition()
   {
      return linkBook.getBookEdition();
   } // end getBookEdition method

   /**
    * checkAuthorLastName method - this method calls the
    * Book method of the same name and returns
    * a boolean value of true if the last name passed to
    * the method matches any of the book authors' last
    * names. Both the check String and the authors' last
    * names are converted to lowercase to prevent false
    * negatives due to differing capitalizations.
    * 
    * @param  String  - the name to be checked
    * @return boolean - true if there is a match
    */
   public boolean checkAuthorLastName(String matchName)
   {
      return linkBook.checkAuthorLastName( matchName );
   } // end checkAuthorLastName(String matchName) method
   
   
   /**
    * getFirstAuthorLastName method - this method returns
    * the last name of the first author, which is used
    * for sorting purposes.
    * @param  void   - no data required
    * @return String - the first author's last name
    */
   public String getFirstAuthorLastName()
   {
      return linkBook.getFirstAuthorLastName();
   } // end getFirstAuthorLastName() method

   /**
    * checkAuthorNationality method - this method calls the
    * Book method of the same name and returns
    * a boolean value of true if the nationality passed to
    * the method matches any of the book authors' 
    * nationalities. Both the check String and the authors'
    * nationalities are converted to lowercase to prevent false
    * negatives due to differing capitalizations.
    * 
    * @param  String  - the nationality to be checked
    * @return boolean - true if there is a match
    */
   public boolean checkAuthorNationality(String matchNationality)
   {
      return linkBook.checkAuthorNationality( matchNationality );
   } // end checkAuthorNationality(String matchNationality) method
   
   /**
    * toString method - this method overrides the default
    * toString method and calls the Book object's
    * toString method
    * @param  void   - no data required
    * @return String - the books author(s) & book information
    */
   public String toString()
   {
      String returnString = linkBook.toString();
      returnString += "Number of Copies in the library = " +
         numberOfBooks + "\n";
      return returnString;
   } // end toString method
} // end Link Class

/////////////////////////////////////////////////////////////////////

/**
 * Class Author holds the author's first & last names,
 * as well as their nationality.
 * 
 * @author David Thibodeau
 * @version 27-Aug-2002
 */

public class Author
{
   // data variables
   private String firstName, lastName, nationality;

   /**
    * Constructor for objects of class Author
    * @param String firstName   - First name of the author
    * @param String lastName    - Last name of the author
    * @param String nationality - Country of author's birth
    */
   public Author(String firstName, String lastName, String nationality)
   {
      // initialise instance variables
      this.firstName   = firstName;
      this.lastName    = lastName;
      this.nationality = nationality;
   } // end Author Constructor

   /**
    * getFirstName method - returns the author's first name
    * 
    * @param  void - no data required
    * @return String - author's first name
    */
   public String getFirstName()
   {
      return firstName;
   }
   
   /**
    * getLastName method - returns the author's last name
    * 
    * @param  void - no data required
    * @return String - author's last name
    */
   public String getLastName()
   {
      return lastName;
   }
   
   /**
    * getNationality method - returns the author's nationality
    * 
    * @param  void - no data required
    * @return String - author's nationality
    */
   public String getNationality()
   {
      return nationality;
   }
   
   /**
    * toString method - this method overrides the inherited
    * toString method in order to give a more useful output
    * for the Author Class than the inherited method allows.
    * 
    * @param  void   - no data required
    * @return String - Returns author data
    */
   public String toString()
   {
      return "AUTHOR FIRST NAME: " + firstName + "\n" +
         "AUTHOR LAST NAME: " + lastName + "\n" +
         "NATIONALITY: " + nationality;
   }

} // end Author Class

///////////////////////////////////////////////////////////

/**
 * Class Book holds data about the book it refers to,
 * title, publisher, year, edition, ISBN, and subject
 * area. Book also has an author array which allows up
 * to 5 separate authors to be listed.
 * 
 * @author David Thibodeau
 * @version 26-Aug-2002
 */
public class Book
{
   // instance variables - replace the example below with your own
   private Author[] authors = new Author[5];
   private int numberOfAuthors; // holds # of authors in the authors array
   private Keyboard getInput; // use the keyboard class to get data
                              // from user
   private String title, publisher, ISBN, subject;
   private int year, edition;

   /**
    * Constructor for objects of class Book
    */
   public Book()
   {
      getBookData();
   }

   /**
    * getBookData method - this private method is used to get all
    * the information on the book, incuding author data
    * 
    * @param  void - no data required
    * @return void - no data returned
    */
   private void getBookData()
   {
      System.out.println( "Enter number of authors who wrote this book: ");
      numberOfAuthors = getInput.readInt();
      
      for(int i = 0; i < numberOfAuthors; i++)
      {
         String firstName, lastName, nationality;
         System.out.println("Enter author #" + (i + 1) +
            "'s first name: ");
         firstName = getInput.readString();
         System.out.println("Enter author #" + (i + 1) +
            "'s last name: ");
         lastName = getInput.readString();
         System.out.println("Enter author #" + (i + 1) +
            "'s nationality: ");
         nationality = getInput.readString();
         
         authors[i] = new Author(firstName, lastName, nationality);
      } // end for loop
      
      System.out.println("Enter the title of this book: ");
      title = getInput.readString();
      
      System.out.println("Enter the publisher of this book: ");
      publisher = getInput.readString();
      
      System.out.println("Enter the ISBN of this book: ");
      ISBN = getInput.readString();
      
      System.out.println("Enter the subject area of this book: ");
      subject = getInput.readString();
      
      System.out.println("Enter the year this book was printed: ");
      year = getInput.readInt();
      
      System.out.println("Enter the this book's edition: ");
      edition = getInput.readInt();
   } // end getBookData method
   
   /**
    * getBookTitle method - this method returns the
    * book's title in a String object
    * 
    * @param  void   - no data required
    * @return String - the book's title
    */
   public String getBookTitle()
   {
      return title;
   }
   
   /**
    * getBookPublisher method - this method returns the
    * book's publisher in a String object
    * 
    * @param  void   - no data required
    * @return String - the book's publisher
    */
   public String getBookPublisher()
   {
      return publisher;
   }

   /**
    * getBookISBN method - this method returns the
    * book's ISBN in a String object
    * 
    * @param  void   - no data required
    * @return String - the book's ISBN
    */
   public String getBookISBN()
   {
      return ISBN;
   }

   /**
    * getBookSubject method - this method returns the
    * book's subject in a String object
    * 
    * @param  void   - no data required
    * @return String - the book's subject
    */
   public String getBookSubject()
   {
      return subject;
   }

   /**
    * getBookYear method - this method returns the
    * book's year in an integer object
    * 
    * @param  void   - no data required
    * @return int - the book's year
    */
   public int getBookYear()
   {
      return year;
   }

   /**
    * getBookEdition method - this method returns the
    * book's edition in an integer object
    * 
    * @param  void   - no data required
    * @return int - the book's edition
    */
   public int getBookEdition()
   {
      return edition;
   }

   /**
    * checkAuthorLastName method - this method returns
    * a boolean value of true if the last name passed to
    * the method matches any of the book authors' last
    * names. Both the check String and the authors' last
    * names are converted to lowercase to prevent false
    * negatives due to differing capitalizations.
    * 
    * @param  String  - the name to be checked
    * @return boolean - true if there is a match
    */
   public boolean checkAuthorLastName(String matchName)
   {
      boolean wasFound = false;
      String temp;
      for(int i = 0; i < numberOfAuthors; i++)
      {
         matchName = matchName.toLowerCase();
         temp = authors[i].getLastName();
         temp = temp.toLowerCase();
         if( temp.equals(matchName) )
         {
            wasFound = true;
            i = numberOfAuthors;
         }
         else
         {
            wasFound = false;
         }
      } // end for
      return wasFound;
   } // end checkAuthorLastName(String matchName) method
   
   /**
    * getFirstAuthorLastName method - returns the first
    * author's last name for sorting purposes.
    * 
    * @param void    - no data required
    * @return String - the first author's last name
    */
   public String getFirstAuthorLastName()
   {
      return authors[0].getLastName(); // gets the last name
   } // end getFirstAuthorLastName method
   
   /**
    * checkAuthorNationality method - this method returns
    * a boolean value of true if the nationality passed to
    * the method matches any of the book authors' 
    * nationalities. Both the check String and the authors'
    * nationalities are converted to lowercase to prevent false
    * negatives due to differing capitalizations.
    * 
    * @param  String  - the nationality to be checked
    * @return boolean - true if there is a match
    */
   public boolean checkAuthorNationality(String matchNationality)
   {
      boolean wasFound = false;
      String temp;
      for(int i = 0; i < numberOfAuthors; i++)
      {
         matchNationality = matchNationality.toLowerCase();
         temp = authors[i].getNationality();
         temp = temp.toLowerCase();
         if( temp.equals(matchNationality) )
         {
            wasFound = true;
            i = numberOfAuthors;
         }
         else
         {
            wasFound = false;
         }
      } // end for
      return wasFound;
   } // end checkAuthorNationality(String matchNationality) method
   
   /**
    * toString method - this method overrides the default
    * toString method and makes it more useful for this
    * object.
    * @param  void   - no data required
    * @return String - the books author(s) & book information
    */
   public String toString()
   {
      String returnString = ""; // used to hold data until complete
                                // String is returned to the caller
      for(int i = 0; i < numberOfAuthors; i++)
      {
         returnString += authors[i].toString();
         returnString += "\n"; // create blank line after every
                               // author data
      } // end for loop
      returnString += "Title: "          + title     + "\n";
      returnString += "Publisher: "      + publisher + "\n";
      returnString += "ISBN: "           + ISBN      + "\n";
      returnString += "Subject: "        + subject   + "\n";
      returnString += "Year Published: " + year      + "\n";
      returnString += "Edition: "        + edition   + "\n";
      
      return returnString;
   } // end toString method
} // end Book Class

/////////////////////////////////////////////////////////////


/**
 * Class SortedList is used to manage a linked list of Link
 * objects. This class insertion, sorting and traversal
 * methods.
 * This class comes from the book "Data Structures & Algorithms
 * in Java" by Robert LaFore
 * @author Robert LaFore, modified by David Thibodeau
 * @version 28-Aug-2002
 */
public class SortedList
{
   // Links used to mark start of lists
   private Link firstAuthor, firstISBN;

   /**
    * Constructor for objects of class LinkList
    */
   public SortedList()
   {
      firstAuthor = null; // lists are empty to start
      firstISBN   = null;
   }

   /**
    * insertLink method - This method inserts links 
    * 
    * @param  Book newBook - Book data to be added to the library
    * @param  int numberOfBooks - the number of books added to the
    *                             library
    * @return void - no data returned
    */
   public void insertLink(Book newBook, int numberOfBooks)
   {
      // create new link to insert (if necessary)
      // the next set of code is for the Author linked list
      Link newLink = new Link(newBook, numberOfBooks);
      Link previous = null;
      Link current = firstAuthor;
      
      if(isEmpty())
      {
         firstAuthor = newLink;
         firstISBN   = newLink;
         return;
      } // creates first links if this is the first insert
      
      while( current != null &&
         (( newLink.getFirstAuthorLastName().compareToIgnoreCase(current.getFirstAuthorLastName() ) > 0) ||
         ( newLink.getFirstAuthorLastName().compareToIgnoreCase(current.getFirstAuthorLastName() ) == 0)))
      {
         if( (newLink.getFirstAuthorLastName().compareToIgnoreCase(
            current.getFirstAuthorLastName() ) == 0) && (
            newLink.getBookTitle().compareToIgnoreCase(
            current.getBookTitle() ) == 0 ))
         {
            current.addBooks( numberOfBooks );
            return;
         } // if the titles match, books are the same; only need to add more books
         
         previous = current;
         current  = current.nextAuthor;
      }
      if(previous == null)
      {
         firstAuthor = newLink;
      }
      else
      {
         previous.nextAuthor = newLink;
      }
      newLink.nextAuthor = current;
      
      // create new link to insert (if necessary)
      // the next set of code is for the ISBN linked list
      previous = null;
      current = firstISBN;
      
      while(current != null &&
         newLink.getBookISBN().compareToIgnoreCase(
         current.getBookISBN() ) > 0)
      {
         previous = current;
         current  = current.nextISBN;
      }
      if(previous == null)
      {
         firstISBN = newLink;
      }
      else
      {
         previous.nextISBN = newLink;
      }
      newLink.nextISBN = current;
   } // end insertLink
   
   /**
    * printSortedList method - this method traverses the book links based
    * on the sort order method selected by the user. The user can choose
    * between sorting by the first author of each book's last names, or
    * ISBN codes.
    * 
    * @param int sortType - 1 if sorting by author, 2 if sorting by ISBN
    * @return void        - no data returned
    */
   public void printSortedList(int sortType)
   {
      Link current;
      // sort by author
      if(sortType == 1)
      {
         current = firstAuthor;
         while(current != null)
         {
            System.out.println( current.toString() );
            current = current.nextAuthor; // advance to next in list
         } // end while
      } // end if
      else if(sortType == 2)
      {
         current = firstISBN;
         while(current != null)
         {
            System.out.println( current.toString() );
            current = current.nextISBN; // advance to next in list
         } // end while
      } // end else if
   } // end printSortedList(int sortType) method
   
   /**
    * searchByAuthor method - this method searches for an author
    * passed to the method and prints out any links that have an
    * author with the same last name
    * @param String lastName - last name to use in search
    * @return void - all results are printed directly to the console
    */
   public void searchByAuthor(String lastName)
   {
      Link current = firstAuthor;
      while(current != null)
      {
         if( current.checkAuthorLastName( lastName ) )
         {
            System.out.println( current.toString() );
         }
         current = current.nextAuthor;
      } // end while
   } // end searchByAuthor(String lastName)
   
   /**
    * searchByNationality method - this method searches for the
    * nationality passed to the method and prints out any links
    * that have an author with the same nationality
    * @param String nationality - nationality to use in search
    * @return void - all results are printed directly to the console
    */
   public void searchByNationality(String nationality)
   {
      Link current = firstAuthor;
      while(current != null)
      {
         if( current.checkAuthorNationality( nationality ) )
         {
            System.out.println( current.toString() );
         }
         current = current.nextAuthor;
      } // end while
   } // end searchByNationality(String nationality)
   
   /**
    * searchByPublisher method - this method searches for the
    * publisher passed to the method and prints out any links
    * that have the same publisher
    * @param String publisher - publisher to use in search
    * @return void - all results are printed directly to the console
    */
   public void searchByPublisher(String publisher)
   {
      Link current = firstAuthor;
      while(current != null)
      {
         if( current.getBookPublisher().compareToIgnoreCase( publisher ) == 0 )
         {
            System.out.println( current.toString() );
         }
         current = current.nextAuthor;
      } // end while
   } // end searchByPublisher(String publisher) method
   
   /**
    * searchBySubject method - this method searches for the
    * subject passed to the method and prints out any links
    * that have the same subject
    * @param String subject - subject to use in search
    * @return void - all results are printed directly to the console
    */
   public void searchBySubject(String subject)
   {
      Link current = firstAuthor;
      while(current != null)
      {
         if( current.getBookSubject().compareToIgnoreCase( subject ) == 0 )
         {
            System.out.println( current.toString() );
         }
         current = current.nextAuthor;
      } // end while
   } // end searchBySubject(String subject)
   
   /**
    * searchByAuthorAndSubject method - this method searches for books
    * with selected subject and authors passed to the method and
    * prints out any links that have the same subject
    * @param String lastName  - last name to use in search
    * @param String subject   - subject to use in search
    * @return void - all results are printed directly to the console
    */
   public void searchByAuthorAndSubject(String lastName, String subject)
   {
      Link current = firstAuthor;
      while(current != null)
      {
         if( ( current.getBookSubject().compareToIgnoreCase( subject ) == 0 ) &&
              current.checkAuthorLastName( lastName ) )
         {
            System.out.println( current.toString() );
         }
         current = current.nextAuthor;
      } // end while
   } // end searchByAuthorAndSubject(String lastName, String subject)
   
   /**
    * addBook method - this method creates a new Book object and
    * inserts it into the linked list.
    * @param int numberOfBooks - number of books to add to the list
    * @return void             - no data returned
    */
   public void addBook(int numberOfBooks)
   {
      Book newBook = new Book();
      this.insertLink( newBook, numberOfBooks );
   } // end addBook(int numberOfBooks) method
   
   /**
    * isEmpty method - returns true if the list is empty
    * 
    * @param void     - no data required
    * @return boolean - true if the list is empty
    */
   public boolean isEmpty()
   {
      return (firstAuthor == null); // if either link != null
                                    // the list isn't empty
   } // end isEmpty method
} // end Class SortedList

//////////////////////////////////////////////////////////////////


/**
 * Class LibraryApp uses the SortedList class to manage a
 * linked list of books and how many of each book 
 * the library owns. This class also interacts with the user
 * through the console using the keyboard class.
 * 
 * @author David Thibodeau
 * @version 28-Aug-2002
 */
public class LibraryApp
{

   /**
    * Constructor for objects of class Library
    */
   public LibraryApp()
   {
   }

   /**
    * main method - this method instantiates a keyboard object
    * and a SortedList object and interacts with the user to
    * add books and display book lists, sorted by author and ISBN
    * 
    * @param  String[] args - these are ignored if passed
    * @return void          - no data returned
    */
   public static void main(String[] args)
   {
      Keyboard getInput = new Keyboard();
      String keyInput = "";
      SortedList libraryList = new SortedList();
      
      while( keyInput.compareToIgnoreCase( "quit" ) != 0 )
      {
         System.out.println( "Welcome to the library program.\n" +
           "Please choose from the following options:" );
         System.out.println( "Type add-book to add a book to the library" );
         System.out.println( "Type list-author to list books by author." );
         System.out.println( "Type list-ISBN to list books by ISBN." );
         System.out.println( "Type search-author to list books by a specific author" );
         System.out.println( "Type search-nationality to list books by authors " +
            "of a specific nationality." );
         System.out.println( "Type search-publisher to list books by a specific " +
            "publisher." );
         System.out.println( "Type search-subject to list books on a specific " +
            "subject." );
         System.out.println( "Type search-subject-author to list books by " +
            "a specific author on a specific subject." );
         System.out.println( "Type quit to end the program." );
      
         keyInput = getInput.readString();

         if( keyInput.compareToIgnoreCase( "add-book" ) == 0)
         {
            System.out.println( "Type in the quantity of this book to add " +
               "to the library." );
            int numberOfBooks = getInput.readInt();
            libraryList.addBook( numberOfBooks );
         } // end add-book
         else if( keyInput.compareToIgnoreCase( "list-author" ) == 0 )
         {
            libraryList.printSortedList( 1 );
         }
         else if( keyInput.compareToIgnoreCase( "list-ISBN" ) == 0 )
         {
            libraryList.printSortedList( 2 );
         }
         else if( keyInput.compareToIgnoreCase( "search-author" ) == 0 )
         {
            System.out.println( "Type in the last name to search on:" );
            String lastName = getInput.readString();
            libraryList.searchByAuthor( lastName );
         }
         else if( keyInput.compareToIgnoreCase( "search-nationality" ) == 0 )
         {
            System.out.println( "Type in the nationality to search on:" );
            String nationality = getInput.readString();
            libraryList.searchByNationality( nationality );
         }
         else if( keyInput.compareToIgnoreCase( "search-publisher" ) == 0 )
         {
            System.out.println( "Type in the publisher to search on:" );
            String publisher = getInput.readString();
            libraryList.searchByPublisher( publisher );
         }
         else if( keyInput.compareToIgnoreCase( "search-subject" ) == 0 )
         {
            System.out.println( "Type in the subject to search on:" );
            String subject = getInput.readString();
            libraryList.searchBySubject( subject );
         }
         else if( keyInput.compareToIgnoreCase( "search-subject-author" ) == 0 )
         {
            System.out.println( "Type in the subject to search on:" );
            String subject = getInput.readString();
            System.out.println( "Type in the author's last name to search on:" );
            String lastName = getInput.readString();
            libraryList.searchByAuthorAndSubject( lastName, subject );
         }
         else if( keyInput.compareToIgnoreCase( "quit" ) == 0 )
         {
            System.out.println( "Program ending." );
         }
         else
         {
            System.out.println( "You have entered an invalid command, " +
               "please try again." );
         }
      } // end while loop
   }
} // end LibraryApp Class