#!/usr/bin/env python3
"""The mode buttons' pictures for the editor's dark scheme (packages/editor/src/assets/modes/*_dunkel.png).

Java's pictures are 50 x 50 buttons: a frame and a vertical grey gradient (light blue and flat when the mode is
on) around the icon. On a dark button that ground would stand as a light tile, so it is freed: the outer ring of
RING pixels goes, and from there every pixel within GROUND of its row's ground colour (the gradient is row by row)
becomes transparent, flooding inwards; a pixel up to EDGE from it (the icon's edge, blended with the grey) keeps its
colour and fades with its likeness. Needs Pillow; run from the repository's root:

    python3 tools/dark-pictures/make.py
"""

from collections import deque
from pathlib import Path

from PIL import Image

MODES = Path(__file__).resolve().parents[2] / 'packages/editor/src/assets/modes'
RING = 3
GROUND = 8
EDGE = 48


def freed(picture: Image.Image) -> Image.Image:
    image = picture.convert('RGBA')
    width, height = image.size
    pixels = image.load()
    ground = [pixels[RING, y] for y in range(height)]
    for y in range(RING):
        ground[y] = ground[RING]
    for y in range(height - RING, height):
        ground[y] = ground[height - RING - 1]
    seen = set()
    queue = deque()
    for x in range(width):
        for y in range(height):
            if x < RING or y < RING or x >= width - RING or y >= height - RING:
                pixels[x, y] = (0, 0, 0, 0)
                seen.add((x, y))
                queue.extend([(x + 1, y), (x - 1, y), (x, y + 1), (x, y - 1)])
    while queue:
        x, y = queue.popleft()
        if (x, y) in seen or not (0 <= x < width and 0 <= y < height):
            continue
        seen.add((x, y))
        colour = pixels[x, y]
        distance = max(abs(colour[index] - ground[y][index]) for index in range(3))
        if distance <= GROUND:
            pixels[x, y] = (*colour[:3], 0)
            queue.extend([(x + 1, y), (x - 1, y), (x, y + 1), (x, y - 1)])
        elif distance <= EDGE:
            pixels[x, y] = (*colour[:3], min(255, int(255 * (distance - GROUND) / (EDGE - GROUND))))
    return image


if __name__ == '__main__':
    for source in sorted(MODES.glob('*.png')):
        if source.stem.endswith('_dunkel'):
            continue
        freed(Image.open(source)).save(source.with_name(f'{source.stem}_dunkel.png'))
        print(source.with_name(f'{source.stem}_dunkel.png').name)