"""一次性迁移：把 `wallpapers/<游戏>/<壁纸>/` 从「按文件类型分组」改成「一具骨架一组」。

旧：
    effects/<名>.json                    ← 骨架数据
    images/<名>.atlas  images/<名>*.webp ← atlas 与页（扁平）
    images/<名>/<名>.atlas + <名>.png    ← 另一档用的「一骨架一目录」
    images/scene/<图>                    ← 场景图
    images/ava.jpg                       ← 背景图
新：
    spines/<名>/<名>.json | <名>.atlas | <页…>
    scene/<图>                           ← 场景图与背景图
    audios/…                             ← 不动

规则（页的判定用 **atlas 自己声明的页名**，与运行时同一份真相，不做名字启发式）：
  1. 每个 `<atlas>` 的 stem 建 `spines/<stem>/`，把该 atlas 与它声明的页搬进去；
  2. `effects/*.json` → `spines/<stem>/<stem>.json`；
  3. `images/` 里剩下的文件（含 `images/scene/*`）→ `scene/`；
  4. 按实际搬动结果重写 `preset.template.json` 里所有 `./…` 路径。

用法：
    python .scratch/migrate-walls.py            # dry-run，只打印
    python .scratch/migrate-walls.py --apply    # 真搬 + 改预设
"""

from __future__ import annotations

import json
import re
import shutil
import sys
from pathlib import Path

ROOT = Path(__file__).resolve().parents[1]
WALLS = ROOT / "wallpapers"
APPLY = "--apply" in sys.argv

PAGE_EXT = re.compile(r"\.(png|webp|jpg|jpeg)$", re.IGNORECASE)


def atlas_pages(text: str) -> list[str]:
    """取 atlas 声明的页名（非属性行、以图片扩展名结尾的行）。"""
    pages = []
    for raw in text.splitlines():
        line = raw.strip()
        if line and ":" not in line and PAGE_EXT.search(line):
            pages.append(line)
    return pages


def migrate(wall: Path) -> dict[str, str]:
    """搬一档壁纸，返回 {旧相对路径: 新相对路径}（相对壁纸目录，不带 ./）。"""
    moves: dict[str, str] = {}

    # 1) atlas 及其声明的页
    atlases = list((wall / "images").rglob("*.atlas")) + list((wall / "spines").rglob("*.atlas"))
    for atlas in atlases:
        stem = atlas.stem
        dest_dir = wall / "spines" / stem
        pages = atlas_pages(atlas.read_text(encoding="utf-8"))
        moves[str(atlas.relative_to(wall))] = f"spines/{stem}/{atlas.name}"
        for page in pages:
            src = atlas.parent / page
            if src.exists():
                moves[str(src.relative_to(wall))] = f"spines/{stem}/{page}"

    # 2) 骨架 json
    for js in (wall / "effects").glob("*.json") if (wall / "effects").is_dir() else []:
        stem = js.stem
        moves[str(js.relative_to(wall))] = f"spines/{stem}/{js.name}"

    # 3) images/ 下剩下的（含 images/scene/*）→ scene/
    if (wall / "images").is_dir():
        for path in sorted((wall / "images").rglob("*")):
            if path.is_dir():
                continue
            rel = str(path.relative_to(wall))
            if rel in moves:
                continue
            moves[rel] = f"scene/{path.name}"

    # 4) 重写预设（按映射精确替换 ./ 路径）
    preset_path = wall / "preset.template.json"
    preset = json.loads(preset_path.read_text(encoding="utf-8"))
    replaced: list[str] = []

    def rewrite(value: object) -> object:
        if isinstance(value, str) and value.startswith("./"):
            old = value[2:]
            new = moves.get(old)
            if new:
                replaced.append(f"{value} → ./{new}")
                return f"./{new}"
        if isinstance(value, dict):
            return {k: rewrite(v) for k, v in value.items()}
        if isinstance(value, list):
            return [rewrite(v) for v in value]
        return value

    new_preset = rewrite(preset)

    print(f"\n== {wall.relative_to(ROOT)}")
    for old, new in sorted(moves.items()):
        print(f"   {old:52} → {new}")
    for line in replaced:
        print(f"   预设: {line}")

    if APPLY:
        for old, new in moves.items():
            src, dst = wall / old, wall / new
            dst.parent.mkdir(parents=True, exist_ok=True)
            shutil.move(str(src), str(dst))
        # 清掉空目录
        for empty in ["effects", "images"]:
            d = wall / empty
            if d.is_dir():
                shutil.rmtree(d, ignore_errors=True)
        preset_path.write_text(json.dumps(new_preset, ensure_ascii=False, indent="\t") + "\n", encoding="utf-8")
    return moves


total = 0
for wall in sorted(p for p in WALLS.rglob("*") if (p / "preset.template.json").is_file()):
    total += len(migrate(wall))
print(f"\n{'已搬动' if APPLY else '将搬动'} {total} 个文件；{'（dry-run，加 --apply 才真搬）' if not APPLY else ''}")