#!/usr/bin/env python
import glob
from os import path

from PIL import Image

def get_1x_name(file_name):
    """returns name for 1x file given image file with @2x suffix"""
    name, ext = path.splitext(file_name)
    assert name.endswith("@2x")

    return name[:-3] + ext

def scale_down(file_name):
    """Scales given image down x2. 
       File name should have suffix @2x
       Result image will be saved by the same name without suffix
    """
    image = Image.open(file_name)
    new_size = (image.size[0] // 2, 
                image.size[1] // 2)
    result = image.resize(new_size, Image.ANTIALIAS)
    result.save(get_1x_name(file_name))

def enumerate2x():
    """walks over all @2x.png and scales them down"""
    for image_name in glob.glob('./*@2x.png'):
        scale_down(image_name)


if __name__ == '__main__':
   enumerate2x() 

