library.js

// library class, 2 methods
// find book details by ISBN
// find book by title

// can add more metadata later
function Book(title, author, isbn){
  this.title = title;
  this.author = author;
  this.isbn = isbn;
}

var Library = (function(){

  // book data is hardcoded, ideally it should come from an API, like goodreads?
  var b1 = new Book('A Game of Thrones', 'George RR Martin', '0316769487');
  var b2 = new Book('1984', 'George Orwell', '0316769123');
  var b3 = new Book('The Catcher in the Rye', 'J. D. Salinger', '1236769487');
  
  var books = [];
  books.push(b1);
  books.push(b2);
  books.push(b3);
  
  console.log('the books in the library are:');
  console.log(books);
  
  // method 1
  // an O(n) solution, returns -1 if not found
  // should do a check that the isbn passed is proper
  var findByISBN = function(isbn){
    var foundIdx = -1;
    // step through list of books and try to find a match
    for(var i=0; i<books.length; i++){
      if(books[i].isbn == isbn){
        foundIdx = i;
      }
    }
    
    return foundIdx >= 0 ? books[foundIdx] : 'Book not found';
  }; 
  
  // method 2
  // same as method1, but checks for a matching title instead
  // since titles searchers are hit or miss
  // an improvement can be providing recomendations 
  // based on similar titles if not found
  var findByTitle = function(title){
    var foundIdx = -1;
    
    // step through list of books and try to find a match
    for(var i=0; i<books.length; i++){
      if(books[i].title == title){
        foundIdx = i;
      }
    }
    
    return foundIdx >= 0 ? books[foundIdx] : 'Book not found';
  }
  
  // API
  return {
    findByISBN: findByISBN,
    findByTitle: findByTitle
  };
  
  // IIFE, returns the API
}());


console.log("\n\nFinding books by ISBN");
console.log(Library.findByISBN('0316769487'));
console.log(Library.findByISBN('1986198619'));

console.log("\n\nFinding books by title");
console.log(Library.findByTitle('1984'));
console.log(Library.findByTitle('1986'));