#!/usr/bin/env python

from __future__ import division, print_function

import sys
import time
from PIL import Image


rnd = lambda f: int(round(f))

def split(size, tiles):
    scale = size / tiles
    for i in range(tiles):
        yield (rnd(scale * i), rnd(scale * (i + 1)))


def tiles_crop(im, size, tiles):
    tiled = Image.new(im.mode, size)
    scale = (im.size[0] / size[0], im.size[1] / size[1])

    for y0, y1 in split(size[1], tiles[1]):
        for x0, x1 in split(size[0], tiles[0]):
            tile = im.crop((rnd(x0 * scale[0]), rnd(y0 * scale[1]),
                            rnd(x1 * scale[0]), rnd(y1 * scale[1])))
            tile = tile.resize((x1 - x0, y1 - y0), Image.BICUBIC)
            tiled.paste(tile, (x0, y0))

    return tiled


def tiles_box(im, size, tiles):
    tiled = Image.new(im.mode, size)
    scale = (im.size[0] / size[0], im.size[1] / size[1])

    for y0, y1 in split(size[1], tiles[1]):
        for x0, x1 in split(size[0], tiles[0]):
            box = (x0 * scale[0], y0 * scale[1],
                   x1 * scale[0], y1 * scale[1])
            tile = im.resize((x1 - x0, y1 - y0), Image.BICUBIC, box)
            tiled.paste(tile, (x0, y0))

    return tiled


if __name__ == '__main__':
    im = Image.open(sys.argv[1])
    width = 320
    height = int(width / im.width * im.height)

    start = time.time()
    for _ in range(10):
        tiled = im.resize((width, height), Image.BICUBIC)
    print('>>> ref', time.time() - start)
    tiled.save("{}.ref.png".format(sys.argv[1]))

    for tiles in [(i, i) for i in range(4, 30, 3)]:
        start = time.time()
        for _ in range(10):
            tiled = tiles_crop(im, (width, height), tiles)
        print('>>> crop', tiles, time.time() - start)
        tiled.save("{}.crop.{}x{}.png".format(sys.argv[1], *tiles))

        start = time.time()
        for _ in range(10):
            tiled = tiles_box(im, (width, height), tiles)
        print('>>> box', tiles, time.time() - start)
        tiled.save("{}.box.{}x{}.png".format(sys.argv[1], *tiles))

        print()