"""Update the Kirara sprite rectangles in web/index.html from transparent PNGs.

Usage: .venv/Scripts/python.exe scripts/build_kirara_sprite_catalog.py
"""

from pathlib import Path

from PIL import Image


ROOT = Path(__file__).resolve().parents[1]
ASSETS = ROOT / "web" / "uploads"
PAGE = ROOT / "web" / "index.html"
START = "    // Source rectangles come from the four generated transparent 2×2 walk sheets."
END = "    let kiraraDirection = \"front\";"


def frame_boxes(path: Path) -> list[list[int]]:
    image = Image.open(path).convert("RGBA")
    width, height = image.size
    if width < 100 or height < 100:
        raise ValueError(f"Sprite is unexpectedly small: {path}")
    boxes = []
    for frame in range(4):
        start = round(frame * width / 4)
        stop = round((frame + 1) * width / 4)
        alpha = image.crop((start, 0, stop, height)).getchannel("A")
        content = alpha.point(lambda value: 255 if value >= 16 else 0).getbbox()
        if content is None:
            raise ValueError(f"Empty frame {frame}: {path}")
        left = max(0, content[0] - 3)
        top = max(0, content[1] - 3)
        right = min(stop - start, content[2] + 3)
        bottom = min(height, content[3] + 3)
        boxes.append([start + left, top, right - left, bottom - top])
    return boxes


names = [
    *(f"kirara_walk_{direction}" for direction in ("front", "back", "left", "right")),
    "kirara_eat_rice", "kirara_eat_dango", "kirara_bath_sponge", "kirara_bath_shower",
    *(f"kirara_idle_{name}" for name in (
        "delivery", "reading", "phone", "sleep", "stretch", "groom",
        "butterfly", "tea", "yarn", "humming")),
    "kirara_rest_breathe",
    *(f"kirara_emotion_{name}_{variant}" for name in (
        "plus3", "plus1", "minus1", "minus3") for variant in ("a", "b")),
]

lines = [
    "    // Crops follow each generated sprite's transparent silhouette.",
    "    const kiraraSpriteBoxes = {",
]
for name in names:
    boxes = frame_boxes(ASSETS / f"{name}.png")
    formatted = ", ".join(str(box).replace(" ", "") for box in boxes)
    lines.append(f'        "{name}": [{formatted}],')
lines += [
    "    };",
    "    const kiraraSpriteAsset = name => ({",
    "        src: `/uploads/${name}.png`, boxes: kiraraSpriteBoxes[name]",
    "    });",
    "    const kiraraWalkAssets = Object.fromEntries(",
    "        [\"front\", \"back\", \"left\", \"right\"].map(direction =>",
    "            [direction, kiraraSpriteAsset(`kirara_walk_${direction}`)])",
    "    );",
    "    const kiraraActionAssets = {",
    "        feed: [kiraraSpriteAsset(\"kirara_eat_rice\"), kiraraSpriteAsset(\"kirara_eat_dango\")],",
    "        bath: [kiraraSpriteAsset(\"kirara_bath_sponge\"), kiraraSpriteAsset(\"kirara_bath_shower\")]",
    "    };",
    "    const kiraraIdleAssets = Object.fromEntries(",
    "        [\"delivery\", \"reading\", \"phone\", \"sleep\", \"stretch\",",
    "            \"groom\", \"butterfly\", \"tea\", \"yarn\", \"humming\"].map(type =>",
    "            [type, kiraraSpriteAsset(`kirara_idle_${type}`)])",
    "    );",
    "    const kiraraRestAsset = kiraraSpriteAsset(\"kirara_rest_breathe\");",
    "    const kiraraEmotionAssets = {",
]
for delta, word in ((3, "plus3"), (1, "plus1"), (-1, "minus1"), (-3, "minus3")):
    lines.append(
        f'        "{delta}": [kiraraSpriteAsset("kirara_emotion_{word}_a"), '
        f'kiraraSpriteAsset("kirara_emotion_{word}_b")],'
    )
lines += ["    };", ""]

text = PAGE.read_text(encoding="utf-8")
start = text.find(START)
if start < 0:
    start = text.find("    // Crops follow each generated sprite's transparent silhouette.")
end = text.find(END, start)
if start < 0 or end < 0:
    raise ValueError("Kirara asset block was not found")
PAGE.write_text(text[:start] + "\n".join(lines) + text[end:], encoding="utf-8")
print(f"Updated {len(names)} Kirara sprite sheets in {PAGE}")