#!/usr/bin/env/python

"""

by Kris Schnee


"""

__author__ = "Kris Schnee"
__license__ = ""

##### DEPENDENCIES #####

## Standard


## Third-party
import pygame

## Mine



##### CONSTANTS #####



##### CLASSES #####

class Mask:
    def __init__(self):
        self.img = None

    def Load(self,filename):
        ## Create a Pygame Surface object.
        self.img = pygame.image.load(filename)

    def Save(self,filename):
        pygame.image.save(self.img,filename)

    def Write(self,text):
        if not self.img:
            raise "Need to load an image first."

        ## Set up the pixel location we'll be writing to.
        x = 0
        y = 0
        x_max = self.img.get_width()
        y_max = self.img.get_height()

        for c in text:

            ## Get binary value
            bin = self.ToBin(ord(c))

            ## Write each 0 or 1 to the next pixel.
            for char in bin:
                if char == "0":
                    self.img.set_at((x,y),(0,0,0,255))
                else:
                    ## Change the red channel by +- 1.
                    ## (This method only is readable by comparison to the original image.)
                    pixel = self.img.get_at((x,y))
##                    if pixel[0] == 255:
##                        self.img.set_at((x,y),(pixel[0]-1,pixel[1],pixel[2],pixel[3]))
##                    else:
##                        self.img.set_at((x,y),(pixel[0]+1,pixel[1],pixel[2],pixel[3]))

                    ## You know what? Just make it black/grey.
                    self.img.set_at((x,y),(128,128,128,255))

                ## Advance to next pixel if possible.
                x += 1
                if x == x_max:
                    x = 0
                    y += 1
                    if y == y_max:
                        raise "Error: This message was too long for this size image."

    def ToBin(self,n):
        bstr = lambda n, l=16: n<0 and binarystr((2L<<l)+n) or n and bstr(n>>1).lstrip('0')+str(n&1) or '0'
        return bstr(n)

        
        

##### OTHER FUNCTIONS #####



##### AUTORUN #####

if __name__ == "__main__": ## Do the following if this code is run by itself:
    m = Mask()
    m.Load("darwin.png")
    m.Save("before.png") ## Write a placebo image that might be changed by this program's saving method.
    f = open("flag.txt","r")
    text = f.read()
    f.close()
    m.Write(text)
    m.Save("after.png")