#!/usr/bin/env python3

import os
import random

ALPHABET = "abcdefghijklmnopqrstuvwxyz"

# checks if something is a pangram (case-insensitively) by checking if it contains all characters in the alphabet
def is_pangram(string):
    string = string.lower()
    return all(char in string for char in ALPHABET)

PANGRAMS_FILE = "pangrams.txt"

def check_pangrams():
    while True:
        string = input("Input a potential pangram (enter e to see examples): ")
        if string == "e":
            example_pangrams()
        else:
            pangram = is_pangram(string)
            print(pangram)
            already_seen = False
            # ensure pangram uniqueness by checking existing pangrams in file
            if os.path.exists(PANGRAMS_FILE):
                with open(PANGRAMS_FILE, "r") as file:
                    already_seen = string in file.read()
            # if the pangram is not already stored, write it to a file
            if not already_seen and pangram:
                with open(PANGRAMS_FILE, "a") as file:
                    file.write(string + "\n")

def example_pangrams():
    with open(PANGRAMS_FILE, "r") as file:
        pangrams = [ line.strip() for line in file.readlines() ]
    random.shuffle(pangrams)
    pangram_count = int(input("How many pangrams? "))
    if pangram_count > len(pangrams):
        print(f"Not enough pangrams available (maximum is {len(pangrams)}).")
    else:
        print("\n".join(pangrams[:pangram_count]))

check_pangrams()