"""Offline normalization of generated door components and distance-driven gait art."""
from pathlib import Path
import struct
from PIL import Image
from pack_guest_cast import isolate

ROOT = Path(__file__).resolve().parents[2]
ART = ROOT / "assets/sprites/hall"
OUT = ROOT / "assets/animations/hall"
PREVIEWS = ROOT / "build/hall-expansion"


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


def guests():
    sheet = Image.open(ART / "guest-walk-v2.png").convert("RGBA")
    # The generated strip has variable row heights; these gutters separate feet/heads.
    rows = (0, 190, 376, 560, 746, 916, sheet.height)
    frames = []
    for appearance in range(6):
        cells = [isolate(sheet.crop((col*sheet.width//8, rows[appearance],
                                    (col+1)*sheet.width//8, rows[appearance+1]))) for col in range(8)]
        scale = min(126/max(cell.width for cell in cells), 204/max(cell.height for cell in cells))
        for cell in cells:
            cell = cell.resize((round(cell.width*scale), round(cell.height*scale)), Image.Resampling.LANCZOS)
            frame = Image.new("RGBA", (128,224))
            frame.alpha_composite(cell, ((128-cell.width)//2, 224-cell.height))
            frames.append(frame)
    pack("guest-walk-v2.bin", frames)
    pack("guest-walk-left-v2.bin", [frame.transpose(Image.Transpose.FLIP_LEFT_RIGHT) for frame in frames])
    preview = Image.new("RGBA", (8*128,6*224), (27,30,29,255))
    for i, frame in enumerate(frames[:48]):
        preview.alpha_composite(frame, ((i%8)*128, (i//8)*224))
    preview.save(PREVIEWS / "guest-walk-v2-preview.png")


def door():
    sheet = Image.open(ART / "basement-door-v2.png").convert("RGBA")
    leaf = isolate(sheet.crop((0,0,640,sheet.height))).resize((256,512), Image.Resampling.LANCZOS)
    source_frame = isolate(sheet.crop((640,0,1420,sheet.height)))
    wheel = isolate(sheet.crop((1420,0,sheet.width,sheet.height))).resize((92,92), Image.Resampling.LANCZOS)
    frames = []
    for phase in range(17):
        texture = leaf.copy()
        rotated = wheel.rotate(-270*phase/16, Image.Resampling.BICUBIC, expand=False)
        # UV texels are not square in world space on the 1.5 by 1.9 metre leaf.
        rotated = rotated.resize((58,92), Image.Resampling.LANCZOS)
        texture.alpha_composite(rotated, (99,244))
        frames.append(texture)
    # Map the rigid jambs around a known rectangular aperture, without a baked leaf.
    w,h = source_frame.size
    left, right, lintel = round(w*.24), round(w*.72), round(h*.14)
    frame = Image.new("RGBA", (256,512))
    frame.alpha_composite(source_frame.crop((0,0,left,h)).resize((64,512)), (0,0))
    frame.alpha_composite(source_frame.crop((right,0,w,h)).resize((64,512)), (192,0))
    frame.alpha_composite(source_frame.crop((left,0,right,lintel)).resize((128,32)), (64,0))
    frames.append(frame)
    pack("basement-door-v2.bin", frames)
    preview = Image.new("RGBA", (3*256,512), (27,30,29,255))
    for i, texture in enumerate((frames[0],frames[8],frame)):
        preview.alpha_composite(texture,(i*256,0))
    preview.save(PREVIEWS / "basement-door-v2-preview.png")


if __name__ == "__main__":
    PREVIEWS.mkdir(parents=True, exist_ok=True)
    guests()
    door()
    print("Packed 96 gait frames and 18 door textures; runtime remains native assembly.")