import unittest
from library import Library, one_book, at_most_books
import datetime


class TestLibraryAddUsers(unittest.TestCase):
    def setUp(self):  #this is executed before each test case in this class
        self.lib=Library()
        self.lib.add_user("Jano")
        self.lib.add_user("Fero")
        self.lib.add_book("Book")

    def test_if_user_does_exist_adduser_returns_false(self):
        self.assertFalse(self.lib.add_user("Jano"))

    def test_if_user_does_exist_adduser_returns_false(self):
        self.assertTrue(self.lib.add_user("Juro"))


class TestLibraryBooksAndReservations(unittest.TestCase):
    def setUp(self):  
        self.lib=Library()
        self.lib.add_user("Jano")
        self.lib.add_book("Book1")
        self.lib.add_book("Book1")
        self.lib.add_book("Book2")
        self.lib.reserve_book("Jano", "Book1", datetime.date(2018,1,3), datetime.date(2018,1,7))
        self.lib.reserve_book("Jano", "Book1", datetime.date(2018,1,1), datetime.date(2018,1,5))
        self.lib.reserve_book("Jano", "Book2", datetime.date(2018,2,1), datetime.date(2018,2,5))

    def test_existing_users_can_make_reservation_if_book_is_unbooked(self):
        self.assertTrue(self.lib.reserve_book("Jano", "Book2", datetime.date(2018,1,1), datetime.date(2018,1,5)) )

    def test_if_the_book_is_booked_for_the_dates_returns_false_and_no_booking_is_made(self):
        self.assertFalse(self.lib.reserve_book("Jano", "Book2", datetime.date(2018,2,5), datetime.date(2018,2,8)) )
        self.assertTrue(self.lib.reserve_book("Jano", "Book2", datetime.date(2018,2,6), datetime.date(2018,2,8)) )

    def test_if_there_are_k_books_with_the_same_title_you_can_book_it_that_k_times(self):
        self.assertTrue(self.lib.reserve_book("Jano", "Book1", datetime.date(2018,1,1), datetime.date(2018,1,1)) )

    def test_if_there_are_k_books_with_the_same_title_you_can_not_book_it_k_plus_one_times(self):
        self.assertFalse(self.lib.reserve_book("Jano", "Book1", datetime.date(2018,1,1), datetime.date(2018,1,3)) )
        self.assertTrue(self.lib.reserve_book("Jano", "Book1", datetime.date(2017,12,31), datetime.date(2018,1,1)) )

    def test_if_user_does_not_exists_return_false_and_reservation_is_not_created(self):
        self.assertFalse(self.lib.reserve_book("Juro", "Book2", datetime.date(2018,1,5), datetime.date(2018,1,6)) )
        self.assertTrue(self.lib.reserve_book("Jano", "Book2", datetime.date(2018,1,5), datetime.date(2018,1,6)) )

    def test_if_book_does_not_exists_return_false(self):
        self.assertFalse(self.lib.reserve_book("Jano", "Non-existing book", datetime.date(2018,1,5), datetime.date(2018,1,6)) )

    def test_if_the_books_are_in_wrong_order_return_false(self):
        self.assertFalse(self.lib.reserve_book("Jano", "Book2", datetime.date(2018,1,6), datetime.date(2018,1,5)) )

    def test_you_can_iterate_books(self):
        books={"Book1":0, "Book2":0} 
        for b in self.lib.books():
             books[b]+=1
        self.assertEqual(len(books), 2)
        self.assertEqual(books["Book1"], 2)
        self.assertEqual(books["Book2"], 1)

    #Ideally, the method books() should be just a lazily initialized iterable
    #A test could follow that takes a huge list of books and iterates first elements many times to test the behaviour
    #Note that such a test is not good for a basic test cuite
    
    def test_you_can_iterate_reservations_sorted_by_start_date(self):
        reservations=[]
        for r in self.lib.reservations():
            reservations.append(r)
        self.assertEqual(reservations, [ 
                (datetime.date(2018,1,1), datetime.date(2018,1,5), "Book1"), 
                (datetime.date(2018,1,3), datetime.date(2018,1,7), "Book1"), 
                (datetime.date(2018,2,1), datetime.date(2018,2,5), "Book2")  ])

    #Ideally, the method reservations() should be just a lazily initialized iterable
    #This might not be easy, Google, Google, Google       


class TestOneBookDecorator(unittest.TestCase):
    #onebook decorator can be used to decorate library and its subclases 
    #(provided that the subclass implementation does not break Library functionality)  
    @one_book
    class OneBookLibrary(Library):
        pass 

    def setUp(self):
        self.lib=TestOneBookDecorator.OneBookLibrary()
        self.lib.add_user("Jano")


    def test_adding_new_book_returns_true(self):
        self.assertTrue(self.lib.add_book("Book1"))

    def test_you_cannot_add_or_reserve_the_same_book_twice(self):
        self.assertTrue(self.lib.add_book("Book1"))
        self.assertFalse(self.lib.add_book("Book1"))
        self.assertTrue(self.lib.add_book("Book2"))
        books={"Book1":0, "Book2":0}         
        for b in self.lib.books():        
            books[b]+=1
        self.assertEqual(len(books), 2)
        self.assertEqual(books["Book1"], 1)
        self.assertEqual(books["Book2"], 1)

        self.lib.reserve_book("Jano", "Book1", datetime.date(2018,1,3), datetime.date(2018,1,7))
        self.assertFalse(self.lib.reserve_book("Jano", "Book1", datetime.date(2018,1,7), datetime.date(2018,1,8)))
        



class TestAtMostBooksDecorator(unittest.TestCase):
    #onebook decorator can be used to decorate library and its subclases 
    #(provided that the subclass implementation does not break Library functionality)  
    @at_most_books(2)
    class TwoBookLibrary(Library):
        pass 

    def setUp(self):
        self.lib=TestAtMostBooksDecorator.TwoBookLibrary()

    def test_adding_new_book_returns_true(self):
        self.assertTrue(self.lib.add_book("Book1"))
        self.assertTrue(self.lib.add_book("Book1"))

    def test_you_cannot_add_or_reserve_the_same_book_more_than_k_times(self):
        self.assertTrue(self.lib.add_book("Book1"))
        self.assertTrue(self.lib.add_book("Book1"))
        self.assertFalse(self.lib.add_book("Book1"))
        self.assertTrue(self.lib.add_book("Book2"))
        books={"Book1":0, "Book2":0}         
        for b in self.lib.books():        
            books[b]+=1
        self.assertEqual(len(books), 2)
        self.assertEqual(books["Book1"], 2)
        self.assertEqual(books["Book2"], 1)


#you can run this file by "python3 test_library.py"
if __name__ == '__main__':
    unittest.main()