# This code implements a Library application that lets user store and 
# retrieve books from a shelf. 
#
# Tasks: 
#  - Fix storeNewBook, and getBook
#  - Can you add a way to see all books in the library?
#  - Make a way to update a book?
#  - Make sure you cannot add a book with the same title 
#  - Print out the list of book, but in order of number of pages?
#

#from BookModule import Book
import BookModule
import shelve

def bookAlreadyInLibrary(aBook):
    'Determine if the book is in the library'
    listOfTitles = library['listOfTitles']
    if aBook.getTitle() in listOfTitles:
        return True
    else:
        return False

def storeNewBook():
    'Store a new book in the library'
    print 'Store New Book'
    # Ask the user for the input needed to create a book
    title = raw_input('Title is: ')
    author = raw_input('Author is: ')
    numPages = input('Num pages is: ')

    # Create the book
    aBook = BookModule.Book(title, author, numPages)
    print 'The book is', aBook

    if bookAlreadyInLibrary(aBook):
        print 'ERROR: This book is already present! Cannot re-add'
    else:
        # Add the book into the shelf based on the title (make sure to lowercase the title)
        library[title.lower()] = aBook

        # Make sure to keep the list of titles up to date!
        listOfTitles = library['listOfTitles']
        listOfTitles.append(title)



def getBook():
    'Get information about a book from the library'
    print 'Get Book'

    # Get the title we want to see 
    title = raw_input('Title is: ')

    # Look up the book in the library
    myBook = library[title.lower()]

    # Show the book information
    print myBook


def updateBook():
    'Get the book from the library and update pieces of it'
    print 'UpdateBook'

    # Ask the user for the book to update
    title = raw_input('Get title: ')

    # Get the new info
    author = raw_input('Author is: ')
    numPages = input('Num pages is: ')

    # Create the book
    aBook = BookModule.Book(title, author, numPages)

    # Check if the book is present in the library
    if bookAlreadyInLibrary(aBook):
        # Replace the old with the new
        library[aBook.getTitle().lower()] = aBook
    else:
        print "ERROR: The book is not in the library! Cannot update it!"


def main():
    global library

    choice = 'z'

    library = shelve.open('lib', writeback=True) # Opens my library 

    while choice != 'q':
       print '''
           ************************
           MENU
           ------------------------
           (s)tore a new book
           (g)et book info
           (u)pdate book info
           (q)uit
           ************************
       '''

       choice = raw_input('Enter choice:')
       if choice == 's':
           storeNewBook()
       elif choice =='g':
           getBook()
       elif choice =='u':
           updateBook()
       elif choice == 'q':
           None  # Do nothing, but we know this was a valid option
       else:
           print '\n\nSorry, %s is not a valid option \n\n' %(choice)

    print 'The library is closing!'
    library.close() # Close the library

main()