"""原图变更后运行此脚本，更新七日活动的透明区域点击数据。需要 Pillow。"""
import json
from pathlib import Path
from PIL import Image

ROOT = Path(__file__).resolve().parents[1]
images = sorted((ROOT / "assets/seven_day_gift/texture").glob("*.png"))
images.append(ROOT / "assets/UI/Cat/cat.png")
masks = {}
for path in images:
    meta = json.loads(path.with_suffix(".png.meta").read_text(encoding="utf-8"))
    alpha = Image.open(path).convert("RGBA").getchannel("A")
    for frame in meta["subMetas"].values():
        x, y, w, h = (frame[k] for k in ("trimX", "trimY", "width", "height"))
        pixels = alpha.crop((x, y, x + w, y + h))
        rows, spans, lookup = [], [], {}
        for row in range(h):
            runs, start = [], None
            for col in range(w + 1):
                solid = col < w and pixels.getpixel((col, row)) >= 16
                if solid and start is None:
                    start = col
                elif not solid and start is not None:
                    runs.extend((start, col))
                    start = None
            key = tuple(runs)
            if key not in lookup:
                lookup[key] = len(spans)
                spans.append(runs)
            rows.append(lookup[key])
        masks[frame["uuid"]] = dict(width=w, height=h, rows=rows, spans=spans)

output = ROOT / "assets/seven_day_gift/SevenDayHitMasks.ts"
output.write_text(
    "// 自动生成的原图 Alpha 命中数据（阈值 16/255），勿手改；更新图片后运行 tools/generate-seven-hit-masks.py。\n"
    "export interface SevenDayHitMask { width: number; height: number; rows: number[]; spans: number[][]; }\n"
    "const masks: { [uuid: string]: SevenDayHitMask } = "
    + json.dumps(masks, separators=(",", ":")) + ";\nexport default masks;\n",
    encoding="utf-8",
)
print(f"Generated {len(masks)} masks, {output.stat().st_size} bytes")