"""Compare real MASM lightmap frames; this script is offline QA, not game code."""
import json
import struct
from pathlib import Path

from PIL import Image, ImageChops, ImageStat


def main():
    root = Path(__file__).resolve().parents[2]
    output = root / "build/actions"
    off = Image.open(output / "street-light-off.bmp").convert("RGB")
    on = Image.open(output / "street-light-on.bmp").convert("RGB")
    assert on.size == off.size == (640, 480)
    changed_ground = 0
    warm_ground = 0
    saturated = 0
    for y in range(280, 480):
        for x in range(640):
            before, after = off.getpixel((x, y)), on.getpixel((x, y))
            if before != after:
                changed_ground += 1
                if after[0] - before[0] > after[2] - before[2]:
                    warm_ground += 1
            saturated += min(after) == 255
    assert changed_ground > 2000, "Lamp/window spill is not visible on the ground"
    assert warm_ground > changed_ground * .7, "Light is not warm/localized"
    assert saturated < 1000, "Lighting washed out the pavement"
    assert sum(ImageStat.Stat(on).stddev) > 30, "Texture detail disappeared"
    on.save(output / "street-light-on.png")
    off.save(output / "street-light-off.png")
    ImageChops.difference(on, off).save(output / "street-light-difference.png")
    for name in ("poker-exit", "blackjack-exit"):
        frame = Image.open(output / f"{name}.bmp").convert("RGB")
        assert frame.size == (640, 480)
        assert frame.getpixel((40, 128)) == (213, 199, 158), name
        assert frame.getpixel((64, 300)) == (213, 199, 158), name
        assert frame.getpixel((328, 300)) == (85, 101, 85), name
        frame.save(output / f"{name}.png")
    elapsed = struct.unpack("<2I", (output / "street-light-perf.bin").read_bytes())
    report = {
        "result": "PASS",
        "changed_ground_pixels": changed_ground,
        "warm_ground_pixels": warm_ground,
        "saturated_ground_pixels": saturated,
        "frame_ms_light_off": round(elapsed[0] / 12, 2),
        "frame_ms_light_on": round(elapsed[1] / 12, 2),
        "note": "Headless native render timing, not a whole-game FPS benchmark",
    }
    (output / "city-lighting-report.json").write_text(json.dumps(report, indent=2))
    print(json.dumps(report))


if __name__ == "__main__":
    main()