from p1_bimport import import_books

# In the second exercise, we will take the database created in the
# previous exercise (‹books.dat›) and generate the original JSON.
# You may want to use a join or two.

# First write a function which will produce a ‹list› of ‹dict›'s
# that represent the books, starting from an open ‹sqlite›
# connection.

import sqlite3
import json

def read_books( conn ):
    pass

# Now write a driver that takes two filenames. It should open the
# database (do you need the foreign keys pragma this time? why yes
# or why not? what are the cons of leaving it out?), read the books,
# convert the list to JSON and store it in the output file.

def export_books( file_in, file_out ):
    pass


def test_main() -> None:
    import os
    try: os.unlink( 'zt.books.json' )
    except FileNotFoundError: pass

    conn = sqlite3.connect( 'zt.books.dat' )
    import_books( 'zz.books.json', 'zt.books.dat' )
    export_books( 'zt.books.dat', 'zt.books.json' )

    with open( 'zz.books.json', 'r' ) as f1:
        js1 = json.load( f1 )
    with open( 'zt.books.json', 'r' ) as f2:
        js2 = json.load( f2 )
    assert js1 == js2

if __name__ == "__main__":
    test_main()