// Lecture 2 
// CS U213 Fall 2008
// bookstore3.java
/*

  A Book is one of
    -- PrintBook
    -- AudioBook
    -- OnlineBook
  
  A PrintBook is (make-print-book String String Num)
  (define-struct print-book (title author price))

  An AudioBook is (make-audio-book String String Num Num)
  (define-struct audio-book (title author price no-cds))

  An OnlineBook is (make-online-book String String Num String)
  (define-struct online-book (title author price url))

;; Examples of books
(define oms (make-book "Old Man and the Sea" "EH" 10))
(define eos (make-book "Elements of Style" "EBW" 20))
(define htdp (make-book "HtDP" "MF" 60))
*/

/*
                      +-------+
                      | IBook |
                      +-------+
                         / \
                         ---
                          |
         -------------------------------------------
         |                    |                    |
 +---------------+    +---------------+    +---------------+
 | PrintBook     |    | AudioBook     |    | OnlineBook    |
 +---------------+    +---------------+    +---------------+
 | String title  |    | String title  |    | String title  |
 | String author |    | String author |    | String author |
 | int price     |    | int price     |    | int price     |
 +---------------+    | int noCDs     |    | String url    |
                      +---------------+    +---------------+
*/
// to represent various books in a bookstore
interface IBook{}

// to represent a printed book in a bookstore
class PrintBook implements IBook{
  String title;
  String author;
  int price;
  
  PrintBook(String title, String author, int price){
    this.title = title;
    this.author = author;
    this.price = price;  
  }
}

// to represent an audio book in a bookstore
class AudioBook implements IBook{
  String title;
  String author;
  int price;
  int noCDs;
  
  AudioBook(String title, String author, int price, int noCDs){
    this.title = title;
    this.author = author;
    this.price = price;
    this.noCDs = noCDs;    
  }
}

// to represent an online book in a bookstore
class OnlineBook implements IBook{
  String title;
  String author;
  int price;
  String url;
  
  OnlineBook(String title, String author, int price, String url){
    this.title = title;
    this.author = author;
    this.price = price;
    this.url = url;    
  }
}

class Examples{
  Examples(){}
  
  IBook oms = new PrintBook("Old Man and the Sea", "EH", 10);
  IBook eos = new PrintBook("Elements of Style", "EBW", 20);
  IBook htdp = new PrintBook("HtDP", "MF", 60);
  
  IBook omsAudio = new AudioBook("Old Man and the Sea", "EH", 10, 2);
  
  IBook htdpOnline = new OnlineBook("HtDP", "MF", 0, "htdp.org");
}