"""Spine atlas 文本的解析与页名规范化。

.atlas 是文本格式：**第一行是贴图页文件名**，接着 `size:` / `filter:` / `format:` / `scale:`
等页面头，之后才是各区域的 `bounds` / `offsets` / `rotate`。换页就是再来一行页文件名。

两种书写风格都要吃（同一批页面里都存在）：
    size:498,330              ← 紧凑式（nico-tea / zhidong-wonder / kv45）
    size: 256, 256            ← 带空格式（get-memory）

抓取期我们只关心两件事：**这具骨架需要哪些贴图页**，以及**页名能不能原样落盘**
（运行时按第一行去请求贴图页，所以文件名必须与第一行逐字一致）。
"""

from __future__ import annotations

import re
from dataclasses import dataclass, field

__all__ = ["AtlasInfo", "parse", "page_names", "retarget_pages"]

_PAGE_EXT = re.compile(r"\.(png|webp|jpg|jpeg)$", re.IGNORECASE)
_PAGE_HEAD = re.compile(r"^(size|format|filter|repeat|pma|scale)\s*:", re.IGNORECASE)
_REGION_ATTR = re.compile(
    r"^(bounds|offsets|rotate|xy|orig|index|split|pad|width|height)\s*:", re.IGNORECASE
)


@dataclass
class AtlasInfo:
    """一具骨架的 atlas 摘要。"""

    pages: list[str] = field(default_factory=list)
    regions: list[str] = field(default_factory=list)
    region_pages: list[str | None] = field(default_factory=list)

    @property
    def multi_page(self) -> bool:
        return len(self.pages) > 1


def parse(text: str) -> AtlasInfo:
    """解析 atlas 文本。无法识别的行按区域名处理（atlas 里非属性行就是区域名）。"""
    info = AtlasInfo()
    current: str | None = None
    for raw in text.splitlines():
        line = raw.strip()
        if not line:
            current = None
            continue
        if ":" not in line and _PAGE_EXT.search(line):
            current = line
            info.pages.append(line)
            continue
        if _PAGE_HEAD.match(line) or _REGION_ATTR.match(line):
            continue
        info.regions.append(line)
        info.region_pages.append(current)
    return info


def page_names(text: str) -> list[str]:
    """只要贴图页名（顺序即 atlas 里声明的顺序）。"""
    return parse(text).pages


def retarget_pages(text: str, mapping: dict[str, str]) -> str:
    """把 atlas 里的页名按 mapping 改写（只改整行的页名行，不碰区域名）。"""
    out: list[str] = []
    for raw in text.splitlines():
        line = raw.strip()
        if line and ":" not in line and _PAGE_EXT.search(line) and line in mapping:
            out.append(mapping[line])
        else:
            out.append(raw)
    tail = "\n" if text.endswith("\n") else ""
    return "\n".join(out) + tail