"""Normalize generated slot art and export ANM1 packs for the MASM runtime."""
import json
import struct
from pathlib import Path

from PIL import Image

ROOT = Path(__file__).resolve().parents[2]
SOURCE = ROOT / "assets/sprites/slots"
OUTPUT = ROOT / "assets/animations/slots"


def pack(name, frames):
    width, height = frames[0].size
    assert all(frame.size == (width, height) for frame in frames)
    pixels = b"".join(frame.tobytes("raw", "BGRA") for frame in frames)
    (OUTPUT / name).write_bytes(struct.pack("<4s4I", b"ANM1", width, height,
                                          len(frames), len(pixels)) + pixels)


def main():
    OUTPUT.mkdir(parents=True, exist_ok=True)
    cabinet = Image.open(SOURCE / "cabinet-v1.png").convert("RGBA")
    cabinet = cabinet.resize((640, 480), Image.Resampling.NEAREST)
    pack("cabinet-v1.bin", [cabinet])
    sheet = Image.open(SOURCE / "symbols-v1.png").convert("RGBA")
    assert 1.8 < sheet.width / sheet.height < 2.2
    symbols = []
    for index in range(8):
        column, row = index % 4, index // 4
        cell = sheet.crop((round(column * sheet.width / 4), round(row * sheet.height / 2),
                           round((column + 1) * sheet.width / 4), round((row + 1) * sheet.height / 2)))
        bounds = cell.getchannel("A").getbbox()
        assert bounds, f"Empty symbol {index}"
        cell = cell.crop(bounds)
        cell.thumbnail((52, 52), Image.Resampling.NEAREST)
        frame = Image.new("RGBA", (64, 64))
        frame.paste(cell, ((64 - cell.width) // 2, (64 - cell.height) // 2))
        # Opaque pixel clusters allow the native clipped reel sampler to stay cheap.
        frame.putalpha(frame.getchannel("A").point(lambda value: 255 if value >= 128 else 0))
        symbols.append(frame)
    pack("symbols-v1.bin", symbols)
    manifest = {"symbols": ["seven", "cherries", "lemon", "bell", "BAR",
                            "grapes", "diamond", "crown"],
                "cabinet": [640, 480], "symbol": [64, 64],
                "pipeline": "offline normalization only; gameplay and reel animation are MASM"}
    (OUTPUT / "manifest.json").write_text(json.dumps(manifest, indent=2) + "\n", encoding="ascii")
    print("Packed native 777 cabinet and 8 alpha-tested 64x64 reel symbols")


if __name__ == "__main__":
    main()