#!/usr/bin/env python3
import sys
from argparse import ArgumentParser

import numpy as n
from PIL import Image

UNIMAP = {
    " ": [0, 0, 0, 0],
    "█": [255, 255, 255, 255],
    "▄": [0, 0, 255, 255],
    "▀": [255, 255, 0, 0],
    "▌": [255, 0, 255, 0],
    "▐": [0, 255, 0, 255],
    "▖": [0, 0, 255, 0],
    "▗": [0, 0, 0, 255],
    "▘": [255, 0, 0, 0],
    "▝": [0, 255, 0, 0],
    "▚": [255, 0, 0, 255],
    "▞": [0, 255, 255, 0],
    "▙": [255, 0, 255, 255],
    "▛": [255, 255, 255, 0],
    "▜": [255, 255, 0, 255],
    "▟": [0, 255, 255, 255],
}
for key in UNIMAP:
    UNIMAP[key] = n.array(UNIMAP[key])


def get_ascii(c):
    if c > 127:
        return "X"
    if c == 0:
        return " "
    return "."


def get_unicode(c):
    minerr = 8192
    minchar = " "
    for key in UNIMAP:
        err = n.sum(n.abs(UNIMAP[key] - 4*n.clip(c,0,63)))
        if err < minerr:
            minerr = err
            minchar = key

    return minchar


def png2uni(inFile):
    im = Image.open(inFile).convert("L")
    # ~ im = im.resize((im.size[0], int(im.size[1]/2)), Image.BICUBIC)
    # ~ im = im.resize((2 * im.size[0], int(im.size[1])), Image.NEAREST)
    pixels = im.load()
    chars = [["." for c in range(0, int(im.size[0] / 2))] for r in range(0, int(im.size[1] / 2))]
    for r in range(0, im.size[1], 2):
        for c in range(0, im.size[0], 2):
            try:
                char = get_unicode(
                    n.array([pixels[c + 0, r + 0], pixels[c + 1, r + 0], pixels[c + 0, r + 1], pixels[c + 1, r + 1]])
                )
                c_r = int(r / 2)
                c_c = int(c / 2)
                chars[c_r][c_c] = char
            except IndexError:
                pass
    for row in chars:
        print("".join(row))


def png2asc(inFile):
    im = Image.open(inFile).convert("L")
    pixels = im.load()
    for r in range(im.size[1]):
        for c in range(im.size[0]):
            char = get_ascii(pixels[c, r])
            sys.stdout.write(char)
        sys.stdout.write("\n")


def asc2png(inFile, outFile):
    reader = open(inFile, "r")
    coords = []
    max_c = 0
    for r, row in enumerate(reader):
        for c, col in enumerate(row):
            if col not in (" ", "\n"):
                if col == ".":
                    coords.append((r, c, 127))
                else:
                    coords.append((r, c, 255))
            max_c = max(max_c, c)
    im = n.zeros((r + 1, max_c), dtype=n.uint8)
    for c in coords:
        im[c[0], c[1]] = c[2]

    data = Image.fromarray(im)
    data.save(outFile)


if __name__ == "__main__":

    parser = ArgumentParser(
        description="Convert image to ascii, or ascii to image. If only input is defined, it is assumed as image (PNG)."
    )
    parser.add_argument("--unicode", "-u", default=False, action="store_true", help="Unicode characters")
    parser.add_argument("input", action="store")
    parser.add_argument("output", action="store", nargs="?")
    opts = parser.parse_args()

    if opts.output == None:
        if opts.unicode:
            png2uni(opts.input)
        else:
            png2asc(opts.input)
    else:
        asc2png(opts.input, opts.output)