# -*-coding:utf-8-*-
import sys
from PIL import Image
import hashlib
def get_key():
    global secret
    global password
    if secret is None:
        secret = hashlib.sha256(password).hexdigest()
        return bytearray(secret)
    secret = hashlib.sha256(secret).hexdigest()
    return bytearray(secret)
def get_pix_matrix(image):
    px = image.load()
    m = []
    width, height = image.size
    for row in range(width-1):
        r = []
        for col in range(height-1):
            a = px[row, col]
            r.append(a)
        m.append(r)
    return m
def set_pix_matrix(image, matrix):
    px = image.load()
    for i, row in enumerate(matrix):
        for j, color in enumerate(row):
            px[i, j] = color
def secure(matrix):
    result = []
    for i, row in enumerate(matrix):
        result.append(xor(row))
    return result
def xor(text):
    result = []
    while text:
        key = get_key()
        head, tail = text[:len(key)], text[len(key):]
        result += [x ^ y for x, y in zip(head, key[:len(head)])]
        text = tail
    return result
if __name__ == "__main__":
    in_file = sys.argv[1]
    out_file = sys.argv[2]
    password = sys.argv[3]
    im = Image.open(in_file)
    secret = None
    
    matrix = get_pix_matrix(im)
    new_matrix = secure(matrix)
    set_pix_matrix(im, new_matrix)
    im.save(out_file)