"""名称拼音首字母缩写：库内存小写，检索时大小写不敏感。"""
from __future__ import annotations

import re
from typing import Optional

from pypinyin import Style, lazy_pinyin

_MAX_LEN = 100
_ALNUM = re.compile(r"[a-zA-Z0-9]")


def normalize_name_pinyin_abbr(value: Optional[str]) -> str:
    raw = (value or "").strip().lower()
    if not raw:
        return ""
    return raw[:_MAX_LEN]


def build_name_pinyin_abbr(name: Optional[str]) -> str:
    text = (name or "").strip()
    if not text:
        return ""
    parts: list[str] = []
    for ch in text:
        if "\u4e00" <= ch <= "\u9fff":
            pys = lazy_pinyin(ch, style=Style.FIRST_LETTER)
            if pys and pys[0]:
                parts.append(str(pys[0]).lower()[0])
        elif _ALNUM.match(ch):
            parts.append(ch.lower())
        # else: drop punctuation / spaces / % / brackets
    return "".join(parts)[:_MAX_LEN]


def resolve_name_pinyin_abbr(
    *,
    name: Optional[str],
    submitted: Optional[str] = None,
    existing: Optional[str] = None,
    submitted_provided: bool = False,
) -> Optional[str]:
    """保存时解析拼音字段。

    - submitted_provided=True：用提交值（空则按 name 生成）
    - 否则：已有非空 existing 则保留；existing 空则按 name 生成
    """
    if submitted_provided:
        normalized = normalize_name_pinyin_abbr(submitted)
        if normalized:
            return normalized
        generated = build_name_pinyin_abbr(name)
        return generated or None
    existing_norm = normalize_name_pinyin_abbr(existing)
    if existing_norm:
        return existing_norm
    generated = build_name_pinyin_abbr(name)
    return generated or None