#!/usr/bin/env python3

import math
import random
import os

words_filename = os.environ.get("WORDS", "/usr/share/dict/words")
num_words = 5
max_word_len = 8
min_word_len = 3

words = open(words_filename)
words = [word.strip().lower() for word in words]
words = [word for word in words if word.isalpha() and min_word_len <= len(word) <= max_word_len]
random_words = [random.choice(words) for _ in range(num_words)]
entropy_words = num_words * math.log(len(words)) / math.log(2)

max_number = 100
min_number = 10
random_number = random.randint(min_number, max_number)
entropy_number = math.log(max_number - min_number) / math.log(2)

print("Entropy:", math.floor(entropy_words + entropy_number))
print("Passphrase:", " ".join(random_words + [str(random_number)]))