"""Offline sprite-sheet compiler; runtime animation stays in MASM."""
from pathlib import Path
import json
import struct
from PIL import Image

ROOT = Path(__file__).resolve().parents[2]
ART = ROOT / "assets/sprites/fortune"
OUT = ROOT / "assets/animations/fortune"


def grid(name, columns, rows, size):
    source = Image.open(ART / name).convert("RGBA")
    return [source.crop((round(x*source.width/columns), round(y*source.height/rows),
                         round((x+1)*source.width/columns), round((y+1)*source.height/rows)))
            .resize(size, Image.Resampling.LANCZOS)
            for y in range(rows) for x in range(columns)]


def tween(frames, loop=False):
    # One shared canvas/scale, never fit moving hands independently per frame.
    output = []
    for i, frame in enumerate(frames):
        following = frames[(i+1) % len(frames)] if loop or i+1 < len(frames) else frame
        output.extend(Image.blend(frame, following, step/4) for step in range(4))
    return output


def pack(name, frames):
    width, height = frames[0].size
    assert len(frames) <= 64
    assert all(frame.size == (width, height) for frame in frames)
    payload = b"".join(frame.tobytes("raw", "BGRA") for frame in frames)
    (OUT / (name + ".bin")).write_bytes(
        struct.pack("<4s4I", b"ANM1", width, height, len(frames), len(payload)) + payload)
    return {"file": name + ".bin", "width": width, "height": height, "frames": len(frames)}


def main():
    OUT.mkdir(parents=True, exist_ok=True)
    body = grid("teller-actions-v1.png", 8, 5, (256, 256))
    cards = grid("tarot-symbols-v1.png", 6, 4, (96, 128))
    # Orientations are real upside-down artwork, not merely a different label.
    faces = cards[:22] + [c.transpose(Image.Transpose.ROTATE_180) for c in cards[:22]] + [cards[22]]
    room = Image.open(ART / "seated-room-v1.png").convert("RGBA").resize((640, 480), Image.Resampling.LANCZOS)
    manifest = [pack("room-v1", [room]),
                pack("shuffle-v1", tween(body[:16], loop=True)),
                pack("deal-v1", tween(body[16:24])),
                pack("gesture-v1", tween(body[24:32], loop=True)),
                pack("orb-hands-v1", tween(body[32:40], loop=True)),
                pack("orb-mist-v1", grid("crystal-mist-v1.png", 4, 4, (192, 192))),
                pack("cards-v1", faces)]
    (ART / "packed-v1.json").write_text(json.dumps(manifest, indent=2) + "\n", encoding="ascii")
    preview = room.copy()
    preview.alpha_composite(body[0].resize((280, 250)), (134, 32))
    for index in range(3):
        preview.alpha_composite(cards[22].resize((72, 96)), (198+index*100, 302))
    preview.save(ROOT / "build/hall-expansion/fortune-session-art.png")
    print("Packed 160 hand poses, 16 mist frames, 44 oriented faces, back and seated room.")


if __name__ == "__main__":
    main()