#!/usr/bin/env python3
# Part of JoeyLib, Copyright (c) 2026 Scott Duensing, under the MIT License.
# See LICENSE.md for license information.
# SPDX-License-Identifier: MIT

"""netWmIcon.py - an X window's icon against the picture it should be.

A window's icon on X is its _NET_WM_ICON property: one or more pictures,
each its width, its height and then its pixels as 32-bit ARGB, row after
row. SDL3 sets it from SDL_SetWindowIcon; Wine from the window class's icon.
xprop prints it as numbers with

    xprop -id WINDOW -f _NET_WM_ICON 32c ' = $0+' _NET_WM_ICON > XPROP

and this compares the picture of the wanted size in that against WANT
(any picture PIL reads; an .ico's 32-bit picture of that size). A pixel
at least half opaque must be so in both, and then of the same colour,
give or take TOLERANCE a gun (a system may round its own way).

    netWmIcon.py XPROP WANT SIZE LABEL

Prints LABEL: PASS or LABEL: FAIL, and exits 0 or 1.
"""

import re
import sys

from PIL import Image

TOLERANCE = 2
ALPHA_OPAQUE_MIN = 128
ICO_BPP = 32


def pictures(text):
    """Every (width, height, pixels) in xprop's numbers."""
    match = re.search(r"=\s*([\d,\s]+)", text)
    if match is None:
        return []
    values = [int(v) for v in match.group(1).replace(",", " ").split()]
    out = []
    at = 0
    while at + 2 <= len(values):
        w, h = values[at], values[at + 1]
        at += 2
        out.append((w, h, values[at:at + w * h]))
        at += w * h
    return out


def wanted(path, size):
    """WANT as RGBA at SIZE x SIZE: an .ico's 32-bit picture of that size."""
    image = Image.open(path)
    if image.format == "ICO":
        image = image.ico.getimage((size, size), ICO_BPP)
    return image.convert("RGBA")


def main(argv):
    if len(argv) != 5:
        sys.stderr.write(__doc__)
        return 2
    xpropPath, wantPath, size, label = argv[1], argv[2], int(argv[3]), argv[4]
    found = pictures(open(xpropPath, encoding="ascii", errors="replace").read())
    sizes = ", ".join("%dx%d" % (w, h) for w, h, _ in found) or "none"
    shown = [pixels for w, h, pixels in found if w == size and h == size]
    if not shown:
        print("%s: FAIL - the window has no %dx%d icon (it has: %s)" % (label, size, size, sizes))
        return 1
    want = wanted(wantPath, size)
    if want.size != (size, size):
        print("%s: FAIL - %s is %dx%d, not %dx%d" % (label, wantPath, want.size[0], want.size[1], size, size))
        return 1
    wrong = 0
    opaqueCount = 0
    for argb, (r, g, b, a) in zip(shown[0], want.getdata()):
        shownOpaque = (argb >> 24) >= ALPHA_OPAQUE_MIN
        if shownOpaque != (a >= ALPHA_OPAQUE_MIN):
            wrong += 1
            continue
        if not shownOpaque:
            continue
        opaqueCount += 1
        rgb = ((argb >> 16) & 0xFF, (argb >> 8) & 0xFF, argb & 0xFF)
        if max(abs(rgb[0] - r), abs(rgb[1] - g), abs(rgb[2] - b)) > TOLERANCE:
            wrong += 1
    if wrong or opaqueCount == 0:
        print("%s: FAIL - %d of the %dx%d icon's pixels differ from %s (%d opaque)" % (label, wrong, size, size, wantPath, opaqueCount))
        return 1
    print("%s: PASS (the window's %dx%d icon is the baked one: %d opaque pixels and the transparency round them; icons on the window: %s)" % (label, size, size, opaqueCount, sizes))
    return 0


if __name__ == "__main__":
    sys.exit(main(sys.argv))