# L-24 MCS 260 Mon 22 Oct 2007 class Catalog

class Catalog:
   """
   The class Catalog imports the class Book.
   It represents the library's book collection.
   """
   collection = []

   def add(self):
      "Prompts the user for number and title."
      import classbook
      b = classbook.Book()
      b.create()
      self.collection.append(b)

   def show(self):
      "Shows the catalog."
      import classbook
      for book in self.collection:
         book.show()

   def search_on_key(self,key):
      """
      Returns the book with the key if it in
      the collection, else -1 is returned.
      """
      for book in self.collection:
         if book.key == key:
            return book
      else:
         return -1

   def checkout(self):
      "Checks out the book with key."
      key = input('Give key : ')
      b = self.search_on_key(key)
      if b == -1:
         print 'no book with key = ', key
      else:
         if not b.check():
            b.show()
         else:
            b.change()

   def checkin(self):
      "Checks in the book with key."
      key = input('Give key : ')
      b = self.search_on_key(key)
      if b == -1:
         print 'no book with key = ', key
      else:
         if not b.check(): b.change()

   def delete(self):
      "Deletes the book with key."
      key = input('Give key : ')
      for k in range(0,len(self.collection)):
         b = self.collection[k]
         if b.key == key:
            d = self.collection.pop(k)
            d.show()
            print 'has been deleted'
            break