import argparse
import pickle

from Crypto.PublicKey import RSA
from datetime import datetime, timedelta

def encrypt(message, output_filename):
  private_key_file = 'conf/stack/license_key'
  with open(private_key_file, 'r') as private_key:
    encryptor = RSA.importKey(private_key)

  encrypted_data = encryptor.decrypt(message)

  with open(output_filename, 'wb') as encrypted_file:
    encrypted_file.write(encrypted_data)

parser = argparse.ArgumentParser(description='Create a license file.')
parser.add_argument('--users', type=int, default=20,
                    help='Number of users allowed by the license')
parser.add_argument('--days', type=int, default=30,
                    help='Number of days for which the license is valid')
parser.add_argument('--warn', type=int, default=7,
                    help='Number of days prior to expiration to warn users')
parser.add_argument('--output', type=str, required=True,
                    help='File in which to store the license')

if __name__ == "__main__":
  args = parser.parse_args()
  print ('Creating license for %s users for %s days in file: %s' %
         (args.users, args.days, args.output))

  license_data = {
    'LICENSE_EXPIRATION': datetime.utcnow() + timedelta(days=args.days),
    'LICENSE_USER_LIMIT': args.users,
    'LICENSE_EXPIRATION_WARNING': datetime.utcnow() + timedelta(days=(args.days - args.warn)),
  }

  encrypt(pickle.dumps(license_data, 2), args.output)