"""Inspect snapshots from the real MASM reel renderer, not a Python simulation."""
import hashlib
import struct
from pathlib import Path

from PIL import Image, ImageChops

ROOT = Path(__file__).resolve().parents[2]
OUTPUT = ROOT / "build/actions"
NAMES = ["slots-ready", "slots-600", "slots-1799", "slots-1800",
         "slots-2400", "slots-win", "slots-paytable", "slots-exit"]


def main():
    packs = ROOT / "assets/animations/slots"
    raw = (packs / "cabinet-v1.bin").read_bytes()
    assert struct.unpack_from("<4s4I", raw) == (b"ANM1", 640, 480, 1, 640 * 480 * 4)
    cabinet = Image.frombytes("RGBA", (640, 480), raw[20:], "raw", "BGRA").convert("RGB")
    assert set(raw[23::4]) == {255}, "Fast cabinet copy requires fully opaque pixels"
    symbols = (packs / "symbols-v1.bin").read_bytes()
    assert struct.unpack_from("<4s4I", symbols) == (b"ANM1", 64, 64, 8, 64 * 64 * 4 * 8)
    assert len(symbols) == 20 + 64 * 64 * 4 * 8
    assert set(symbols[23::4]) == {0, 255}
    stride = 64 * 64 * 4
    assert len({hashlib.sha256(symbols[20 + index * stride:20 + (index + 1) * stride]).digest()
                for index in range(8)}) == 8
    frames = {}
    for name in NAMES:
        frame = Image.open(OUTPUT / (name + ".bmp")).convert("RGB")
        assert frame.size == (640, 480)
        assert len(frame.getcolors(640 * 480)) > 2000, name
        frames[name] = frame
        frame.save(OUTPUT / (name + ".png"))
    assert len({hashlib.sha256(frame.tobytes()).digest() for frame in frames.values()}) == len(NAMES)
    # No symbol may cover the reel separators, chrome frame or marquee.
    for name in NAMES:
        if name == "slots-paytable":
            continue
        difference = ImageChops.difference(frames[name], cabinet)
        for y in range(100, 272):
            if 188 <= y < 194:
                continue  # Payline markers and win illumination are intentional.
            for x in range(170, 477):
                in_reel = 124 <= y < 260 and any(left <= x < left + 88 for left in (180, 278, 376))
                if not in_reel:
                    assert difference.getpixel((x, y)) == (0, 0, 0), (name, x, y)
    first = (180, 124, 268, 260)
    second = (278, 124, 366, 260)
    third = (376, 124, 464, 260)
    assert frames["slots-1800"].crop(first).tobytes() == frames["slots-2400"].crop(first).tobytes()
    # The gold winning line is the only permitted difference on a stopped drum.
    for rect in (first, second):
        left, top, right, bottom = rect
        for box in ((left, top, right, 188), (left, 194, right, bottom)):
            assert frames["slots-2400"].crop(box).tobytes() == frames["slots-win"].crop(box).tobytes()
    assert frames["slots-2400"].crop(third).tobytes() != frames["slots-win"].crop(third).tobytes()
    contact = Image.new("RGB", (640 * 4, 480 * 2))
    for index, name in enumerate(NAMES):
        contact.paste(frames[name], ((index % 4) * 640, (index // 4) * 480))
    contact.save(OUTPUT / "slots-contact.png")
    print("PASS: 8 distinct native slot frames; pixel-accurate reel clipping; sequential stops; opaque cabinet and 8 real symbol sprites")


if __name__ == "__main__":
    main()