#Password Strength
#Copyright 2017 nihad ali
def checkPass(password, pre_pass):
    length = int()
    lower = int()
    upper = int()
    special = int()
    number = int()
    like_past = int()
    f_name = int()
    s_name = int()
    password_strength = 0
    if len(password)>=8 :
        length = 1
    for i in lower_alphabet:
        if i in password:
            lower = 1
    for i in upper_alphabet:
        if i in password:
            upper = 1
    for i in special_characters:
        if i in password:
            special = 1
    for i in numbers:
        if i in password:
            number = 1
    if pre_pass.lower() not in password.lower():
        like_past = 1

    if length == 1:
        password_strength += 1
    if lower == 1 :
        password_strength += 1
    if upper== 1 :
        password_strength += 1
    if special == 1:
        password_strength +=2
    if f_name != 1:
        password_strength -=2
    if s_name != 1:
        password_strength -=2
    if like_past != 1:
        password_strength -=1

    password_rank = str()

    if password_strength >= 5:
        password_rank = 'Very Strong'
    elif password_strength == 4:
        password_rank = 'Strong'
    elif password_strength == 3:
        password_rank = 'OK'
    elif password_strength == 2:
        password_rank = 'Not Good'
    elif password_strength ==1:
        password_rank = 'Bad'
    elif password_strength < 1:
        password_rank = 'very bad'
    print('\nI think that your password is ',password_rank)
    issues = [length, lower, upper, special, number, like_past, f_name, s_name, password_rank]
    return issues

lower_alphabet = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z']
upper_alphabet = ['A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z']
numbers = ['1', '2', '3', '4', '5', '6', '7', '8', '9', '0']
special_characters = [' ', '!', '#', '$', '%', '&', '"', '(', ')', '*', '+', ',', '-', '.', '/', ':', ';', '<', '=', '>', '?', '@', '[', '\\', ']', '^', '_', '`', '{', '|', '}', '~',"'"]

choice = None

print("""
Welcome to Nihad's password strength tester
""")

while choice != '0':
    print("""
Menu options:
    1 - Password Generator
    2 - Check Password Strength
    3 - quit



""")
    choice = str(input('Please type the number that is beside your choice and press enter: '))
    if choice == '1':
        password = input('\nPlease enter your password here: ')
        pre_pass = input('\nPlease enter your old password here: ')
        issues = checkPass(password,pre_pass)
        why = input('\nIf you would like to find out why type why? and press enter: ')
        if why.lower() == 'why?':
            if issues[0] != 1:
                print("It's too short")
            if issues[1] != 1:
                print("It doesn't have a lower case character in it")
            if issues[2] != 1:
                print("It doesn't have an upper case character in it")
            if issues[3] != 1:
                print("It doesn't have a special character in it")
            if issues[4] != 1:
                print("It doesn't have a number in it")
            if issues[5] != 1:
                print("It's like your old password")
            if issues[6] != 1:
                print("It's got your first name in it")
            if issues[7] != 1:
                print("It's got your last name in it")
            if issues[8] == 'Very Strong':
                print('There is nothing wrong with it!')
    elif choice == '0':
        print('Check your password strength here')
    else:
        print('Goodbye')
        from sys import exit

def check_upper(input):
    uppers = 0
    upper_list = "A B C D E F G H I J K L M N O P Q R S T U V W X Y Z".split()
    for char in input:
        if char in upper_list:
            uppers += 1
    if uppers > 0:
        return True
    else:
        return False

def check_lower(input):
    lowers = 0
    lower_list = "a b c d e f g h i j k l m n o p q r s t u v w x y z".split()
    for char in input:
        if char in lower_list:
            lowers += 1
    if lowers > 0:
        return True
    else:
        return False

def check_number(input):
    numbers = 0
    number_list = "1 2 3 4 5 6 7 8 9 0".split()
    for char in input:
        if char in number_list:
            numbers += 1
    if numbers > 0:
        return True
    else:
        return False

def check_special(input):
    specials = 0
    special_list = "! @ $ % ^ & * ( ) _ - + = { } [ ] | \ , . > < / ? ~ ` \" ' : ;".split()
    for char in input:
        if char in special_list:
            specials += 1
    if specials > 0:
        return True
    else:
        return False

def check_len(input):
    if len(input) >= 8:
        return True
    else:
        return False


def validate_password(input):
    check_dict = {
        'upper': check_upper(input),
        'lower': check_lower(input),
        'number': check_number(input),
        'special': check_special(input),
        'len' : check_len(input)
    }
    if check_upper(input) & check_lower(input) & check_number(input) & check_special(input) & check_len(input):
        return True
    else:
        print ("Invalid password! Review below and change your password accordingly!")
        print
        if check_dict['upper'] == False:
            print ("Password needs at least one upper-case character.")
        if check_dict['lower'] == False:
            print ("Password needs at least one lower-case character.")
        if check_dict['number'] == False:
            print ("Password needs at least one number.")
        if check_dict['special'] == False:
            print ("Password needs at least one special character.")
        if check_dict['len'] == False:
            print ("Password needs to be at least 8 characters in length.")
        print

while True:
    password = input ("Enter desired password: ")
    print
    if validate_password(password):
        print ("Password meets all requirements and may be used.")
        print
        print ("Exiting program...")
        print
        exit(0)