dyceware

#!/usr/bin/env python3

"""
USAGE: dyceware [wordlist file] [OPTIONS]

DESCRIPTION:
    Generate a diceware passphrase. This requires a diceware wordlist.
    You can download one from the EFF[0].

    [0]: https://www.eff.org/files/2016/07/18/eff_large_wordlist.txt

    -n
        Wordcount of diceware passphrase.

    -j
        Join diceware passphrase words together. Default False.
"""

import sys
import random

def main():
    """Generate a diceware passphrase."""
    delimiter = ' '
    wordcount = 10

    try:
        args = iter(sys.argv[1:])
        for arg in args:
            if arg == '-j':
                delimiter = ''
            elif arg == '-n':
                wordcount = int(next(args))
            else:
                raise ValueError
    except (IndexError, ValueError):
        print(__doc__)
        sys.exit(1)

    with open('wordlist.txt') as f:
        wordlist = dict([
            line.split() for line in f.readlines()
        ])

    phrase = []
    for _ in range(wordcount):
        key = ''.join([str(random.randrange(1, 7)) for _ in range(5)])
        phrase.append(wordlist[key])

    print(delimiter.join(phrase), end='')


if __name__ == '__main__':
    main()