#!/usr/bin/env bash
# Part of JoeyLib, Copyright (c) 2026 Scott Duensing, under the MIT License.
# See LICENSE.md for license information.
# SPDX-License-Identifier: MIT
#
# verify-win16-icon.sh - a Win16 program's icon as Windows 3.1 shows it.
#
# make binds every Win16 program's icon into its executable (make/win16.mk:
# tools/iconBake.py ico16, 32x32 in the 16 VGA colours, resource
# HOSTED_ICON_ID), and the backend gives its window class that icon. Here
# Program Manager is Windows' shell and WIN.INI's load= starts DRAW
# (examples/draw) minimised, so Windows draws the class's icon on the
# desktop -- and DRAW runs on, minimised, presenting to a window with no
# room. DOSBox's own screenshot of the 800x600 screen must hold the baked
# icon: every pixel of it the icon's mask leaves opaque, in its colour.
#
# Usage:   scripts/verify-win16-icon.sh
# Env:     WIN16_ICON_KEEP  keep the screenshot as build/win16/win16-icon.png
# Exit:    0 PASS, 1 FAIL, 2 SKIP (Windows or DOSBox not installed, or DRAW
#          not built)
# Requires: DOSBox Staging, Xvfb, xdotool, python3 + PIL + numpy, the win311
#           component; DRAW.EXE and its icon (make win16).
set -euo pipefail

repo=$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)
source "$repo/scripts/lib/joeyEnv.sh"
source "$repo/scripts/lib/win16Gate.sh"

label=verify-win16-icon
win16Need
program=$(joeyExampleProgram draw win16)
icon=$repo/build/win16/icon/DRAW/icon.ico
[ -f "$program" ] && [ -f "$icon" ] || { echo "$label: build DRAW.EXE first (make win16)" >&2; exit 2; }
# Seconds to wait for the icon (Windows' boot is most of it), and between
# screenshots.
startSeconds=120
shotSeconds=10

# iconShown PNG: true when PNG holds the icon; says where, or that it does
# not.
iconShown() {
    python3 - "$1" "$icon" "$label" <<'PY'
import sys

import numpy
from PIL import Image

png, ico, label = sys.argv[1], sys.argv[2], sys.argv[3]
# The 6-bit DAC behind DOSBox's capture moves a colour by a few levels.
TOLERANCE = 8
screen = numpy.asarray(Image.open(png).convert("RGB"), dtype=numpy.int16)
icon = numpy.asarray(Image.open(ico).convert("RGBA"), dtype=numpy.int16)
opaque = numpy.argwhere(icon[:, :, 3] >= 128)
if len(opaque) == 0:
    print(f"{label}: FAIL - the icon file has no opaque pixel")
    sys.exit(1)
colours = icon[opaque[:, 0], opaque[:, 1], :3]
ih, iw = icon.shape[:2]
sh, sw = screen.shape[:2]


def matches(colour):
    return numpy.all(numpy.abs(screen - colour) <= TOLERANCE, axis=2)


# Anchor on the opaque pixel whose colour the screen holds least, then try
# the icon at every place that pixel's colour is.
counts = [int(matches(c).sum()) for c in colours]
anchor = min(range(len(opaque)), key=lambda i: counts[i])
ay, ax = opaque[anchor]
found = None
for y, x in numpy.argwhere(matches(colours[anchor])):
    top, left = y - ay, x - ax
    if top < 0 or left < 0 or top + ih > sh or left + iw > sw:
        continue
    shown = screen[top + opaque[:, 0], left + opaque[:, 1]]
    if numpy.all(numpy.abs(shown - colours) <= TOLERANCE):
        found = (left, top)
        break
if found is None:
    print(f"{label}: FAIL - the program's icon is not on the screen ({len(opaque)} opaque pixels looked for)")
    sys.exit(1)
print(f"{label}: PASS (DRAW minimised shows its bound icon at {found[0]},{found[1]}: all {len(opaque)} opaque pixels of the baked 32x32 in place)")
PY
}

work=$(mktemp -d -t joeylib-win16-icon.XXXXXX)
cleanup() {
    win16Stop
    rm -rf "$work"
}
trap cleanup EXIT

mkdir -p "$work/program" "$work/shots"
cp "$program" "$work/program/DRAW.EXE"
win16Stage "$work" "$work/program" DRAW.EXE
python3 "$repo/tools/winIni.py" "$work/c/WINDOWS/SYSTEM.INI" set boot shell progman.exe
python3 "$repo/tools/winIni.py" "$work/c/WINDOWS/WIN.INI" set windows load 'D:\DRAW.EXE'
WIN16_DOSBOX_ARGS=(--set "capture_dir=$work/shots" --set "default_image_capture_formats=raw")
win16Start "$work"
win=""
for ((waited = 0; waited < startSeconds; waited += shotSeconds)); do
    sleep "$shotSeconds"
    [ -n "$win" ] || win=$(win16Window) || win=""
    [ -n "$win" ] || continue
    # Ctrl+F5: DOSBox's screenshot hotkey (the Ctrl reaches Program Manager,
    # which ignores it).
    rm -f "$work/shots/"*.png
    DISPLAY="$WIN16_DISPLAY" xdotool key --window "$win" ctrl+F5
    sleep 2
    png=$(find "$work/shots" -name '*.png' -print -quit)
    [ -n "$png" ] || continue
    [ -n "${WIN16_ICON_KEEP:-}" ] && cp "$png" "$repo/build/win16/win16-icon.png"
    if iconShown "$png" > "$work/verdict"; then
        cat "$work/verdict"
        exit 0
    fi
done
cat "$work/verdict" 2> /dev/null || echo "$label: FAIL - no screenshot of Windows within ${startSeconds}s"
exit 1