"""
A file of secret functions. You weren't able to see this code during the
lab, but you had to figure out what was happening using the debugger.
"""


def a(x, y):
    "Adds two things together."
    return y + x


def b(x):
    "Scrambles up a string."
    parts = x.split()
    return '\n'.join(parts[::-1]) + '\n\n'


def c(x, y):
    "Encrypts or decrypts a message using a password."
    # Pad password to length of message
    while len(y) < len(x):
        y = y * 2

    result = ''

    # Swizzle each character
    for i in range(len(x)):
        c = x[i]
        p = y[i]
        result += crypt(c, p)

    return result


def d(x, y):
    "Decrypts a message using a password."
    # Pad password to length of message
    while len(y) < len(x):
        y = y * 2

    result = ''

    # Un-swizzle each character
    for i in range(len(x)):
        c = x[i]
        p = y[i]
        result += decrypt(c, p)

    return result


def an(x):
    "Returns number from alphabetic value."
    o = ord(x)
    if 0 <= o - ord('a') < 26:  # lowercase letter
        return o - ord('a')
    elif 0 <= o - ord('A') < 26:  # uppercase letter
        return 26 + o - ord('A')
    elif 0 <= o - ord('0') < 10:  # number
        return 52 + o - ord('0')
    elif x == ' ':
        return 62
    elif x == '\n':
        return 63
    else:
        return None


def na(n):
    "Returns letter."
    if n == 63:
        return '\n'
    elif n == 62:
        return ' '
    elif n < 26:
        return chr(ord('a') + n)
    elif n < 52:
        return chr(ord('A') + (n - 26))
    else:
        return chr(ord('0') + (n - 52))


def crypt(a, b):
    "Encrypts letter a using letter b."
    n1 = an(a)
    n2 = an(b)
    if n1 is None or n2 is None:
        return a
    c = (n1 + n2) % 64
    return na(c)


def decrypt(a, b):
    "Decrypts letter a using letter b."
    n1 = an(a)
    n2 = an(b)
    if n1 is None or n2 is None:
        return a
    c = (n1 - n2) % 64
    return na(c)